Hematology Times

Fatih Uckun, MD, PhD

Photo courtesy of Dr Uckun

An engineered protein can enhance the effects of radiation and even overcome radiation resistance to treat B-precursor acute lymphoblastic leukemia (ALL), according to research published in EBioMedicine.

The protein, CD19L-sTRAIL, is a fusion of the CD19 ligand protein, which seeks out and binds to leukemia cells, with soluble TRAIL, a protein that can amplify the potency of radiation if it can be anchored on the membrane of leukemia cells.

Researchers found that CD19L-sTRAIL augmented the potency of radiation therapy even against the most aggressive and radiation-resistant forms of leukemia.

“Even very low doses of radiation were highly effective in mice challenged with aggressive human leukemia cells, when it was combined with [CD19L-sTRAIL],” said Fatih M. Uckun, MD, PhD, of The Saban Research Institute of Children’s Hospital Los Angeles in California.

“Due to its ability to selectively anchor to the surface of leukemia cells via its CD19L portion, CD19L-sTRAIL was 100,000-fold more potent than sTRAIL and consistently killed aggressive leukemia cells taken directly from children with ALL—not only in the test tube but also in mice.”

The researchers found that a combination of low-dose total body irradiation (TBI) and CD19L-sTRAIL greatly improved event-free survival (EFS) in mice that had received a typically fatal dose of cells from a patient with relapsed B-precursor ALL.

The median EFS for mice treated with CD19L-sTRAIL plus low-dose TBI was 72 days, which was significantly longer than the EFS for untreated control mice (17 days, P<0.0001), mice that received TBI alone (64 days, P=0.0014), mice that received CD19L-sTRAIL alone (20 days, P=0.0022), and mice that received a combination of vincristine, dexamethasone, and PEG-asparaginase (17 days, P=0.0033).

Dr Uckun and his colleagues noted that none of the mice that received CD19L-sTRAIL and TBI experienced a toxic death or signs of treatment-related toxicity.

The team also found that TBI plus CD19L-sTRAIL improved progression-free survival (PFS) in CD22ΔE12xBCR-ABL double transgenic mice with radiation-resistant, advanced stage, CD19+ murine B-precursor ALL with lymphomatous features.

The mean PFS was 24.0 ± 4.0 days for mice that received CD19L-sTRAIL plus TBI, which was significantly longer than the PFS for control mice (0 ± 0 days, P<0.0001), mice that received CD19L-sTRAIL alone (3.4 ± 0.9 days, P=0.0003), and mice that received TBI alone (9.0 ± 4.6 days, P=0.020).

Based on these results, Dr Uckun and his colleagues believe that incorporating CD19L-sTRAIL into the pre-transplant TBI regimens of patients with very high-risk B-precursor ALL could improve survival after hematopoietic stem cell transplant.

“We are hopeful that the knowledge gained from this study will open a new range of effective treatment opportunities for children with recurrent leukemia,” Dr Uckun said.

Fatih Uckun, MD, PhD

Photo courtesy of Dr Uckun

An engineered protein can enhance the effects of radiation and even overcome radiation resistance to treat B-precursor acute lymphoblastic leukemia (ALL), according to research published in EBioMedicine.

The protein, CD19L-sTRAIL, is a fusion of the CD19 ligand protein, which seeks out and binds to leukemia cells, with soluble TRAIL, a protein that can amplify the potency of radiation if it can be anchored on the membrane of leukemia cells.

Researchers found that CD19L-sTRAIL augmented the potency of radiation therapy even against the most aggressive and radiation-resistant forms of leukemia.

“Even very low doses of radiation were highly effective in mice challenged with aggressive human leukemia cells, when it was combined with [CD19L-sTRAIL],” said Fatih M. Uckun, MD, PhD, of The Saban Research Institute of Children’s Hospital Los Angeles in California.

“Due to its ability to selectively anchor to the surface of leukemia cells via its CD19L portion, CD19L-sTRAIL was 100,000-fold more potent than sTRAIL and consistently killed aggressive leukemia cells taken directly from children with ALL—not only in the test tube but also in mice.”

The researchers found that a combination of low-dose total body irradiation (TBI) and CD19L-sTRAIL greatly improved event-free survival (EFS) in mice that had received a typically fatal dose of cells from a patient with relapsed B-precursor ALL.

The median EFS for mice treated with CD19L-sTRAIL plus low-dose TBI was 72 days, which was significantly longer than the EFS for untreated control mice (17 days, P<0.0001), mice that received TBI alone (64 days, P=0.0014), mice that received CD19L-sTRAIL alone (20 days, P=0.0022), and mice that received a combination of vincristine, dexamethasone, and PEG-asparaginase (17 days, P=0.0033).

Dr Uckun and his colleagues noted that none of the mice that received CD19L-sTRAIL and TBI experienced a toxic death or signs of treatment-related toxicity.

The team also found that TBI plus CD19L-sTRAIL improved progression-free survival (PFS) in CD22ΔE12xBCR-ABL double transgenic mice with radiation-resistant, advanced stage, CD19+ murine B-precursor ALL with lymphomatous features.

The mean PFS was 24.0 ± 4.0 days for mice that received CD19L-sTRAIL plus TBI, which was significantly longer than the PFS for control mice (0 ± 0 days, P<0.0001), mice that received CD19L-sTRAIL alone (3.4 ± 0.9 days, P=0.0003), and mice that received TBI alone (9.0 ± 4.6 days, P=0.020).

Based on these results, Dr Uckun and his colleagues believe that incorporating CD19L-sTRAIL into the pre-transplant TBI regimens of patients with very high-risk B-precursor ALL could improve survival after hematopoietic stem cell transplant.

“We are hopeful that the knowledge gained from this study will open a new range of effective treatment opportunities for children with recurrent leukemia,” Dr Uckun said.

Fatih Uckun, MD, PhD

Photo courtesy of Dr Uckun

An engineered protein can enhance the effects of radiation and even overcome radiation resistance to treat B-precursor acute lymphoblastic leukemia (ALL), according to research published in EBioMedicine.

The protein, CD19L-sTRAIL, is a fusion of the CD19 ligand protein, which seeks out and binds to leukemia cells, with soluble TRAIL, a protein that can amplify the potency of radiation if it can be anchored on the membrane of leukemia cells.

Researchers found that CD19L-sTRAIL augmented the potency of radiation therapy even against the most aggressive and radiation-resistant forms of leukemia.

“Even very low doses of radiation were highly effective in mice challenged with aggressive human leukemia cells, when it was combined with [CD19L-sTRAIL],” said Fatih M. Uckun, MD, PhD, of The Saban Research Institute of Children’s Hospital Los Angeles in California.

“Due to its ability to selectively anchor to the surface of leukemia cells via its CD19L portion, CD19L-sTRAIL was 100,000-fold more potent than sTRAIL and consistently killed aggressive leukemia cells taken directly from children with ALL—not only in the test tube but also in mice.”

The researchers found that a combination of low-dose total body irradiation (TBI) and CD19L-sTRAIL greatly improved event-free survival (EFS) in mice that had received a typically fatal dose of cells from a patient with relapsed B-precursor ALL.

The median EFS for mice treated with CD19L-sTRAIL plus low-dose TBI was 72 days, which was significantly longer than the EFS for untreated control mice (17 days, P<0.0001), mice that received TBI alone (64 days, P=0.0014), mice that received CD19L-sTRAIL alone (20 days, P=0.0022), and mice that received a combination of vincristine, dexamethasone, and PEG-asparaginase (17 days, P=0.0033).

Dr Uckun and his colleagues noted that none of the mice that received CD19L-sTRAIL and TBI experienced a toxic death or signs of treatment-related toxicity.

The team also found that TBI plus CD19L-sTRAIL improved progression-free survival (PFS) in CD22ΔE12xBCR-ABL double transgenic mice with radiation-resistant, advanced stage, CD19+ murine B-precursor ALL with lymphomatous features.

The mean PFS was 24.0 ± 4.0 days for mice that received CD19L-sTRAIL plus TBI, which was significantly longer than the PFS for control mice (0 ± 0 days, P<0.0001), mice that received CD19L-sTRAIL alone (3.4 ± 0.9 days, P=0.0003), and mice that received TBI alone (9.0 ± 4.6 days, P=0.020).

Based on these results, Dr Uckun and his colleagues believe that incorporating CD19L-sTRAIL into the pre-transplant TBI regimens of patients with very high-risk B-precursor ALL could improve survival after hematopoietic stem cell transplant.

“We are hopeful that the knowledge gained from this study will open a new range of effective treatment opportunities for children with recurrent leukemia,” Dr Uckun said.

Lab mice

Photo by Aaron Logan

Increasing B-cell antigen receptor (BCR) signaling beyond “a point of no return” can lead to the selective elimination of leukemic cells, according to a group of researchers.

The team knew that proximal pre-BCR signaling is toxic to Philadelphia-chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) cells, and their experiments revealed that SYK tyrosine kinase activity mimicked constitutively active pre-BCR signaling.

So it was no surprise that pharmacologic hyperactivation of SYK prompted the removal of self-reactive B cells and selective killing of Ph+ ALL cells in vivo.

Markus Müschen, MD, PhD, of the University of California, San Francisco, and his colleagues described these findings in Nature.

When the researchers tested proximal pre-BCR signaling in mouse BCR-ABL1 cells, they found that an incremental increase of SYK activity could induce cell death.

Additional experiments showed that patient-derived Ph+ ALL cells have high levels of the inhibitory receptors PECAM1, CD300A, and LAIR1. And these receptors are needed to calibrate oncogenic signaling strength via recruitment of the inhibitory phosphatases PTPN6 and INPP5D.

So the researchers wondered if a small-molecule inhibitor of INPP5D, known as 3-a-aminocholestane (3AC), could induce SYK hyperactivation and target Ph+ ALL cells in mice.

They found that 3AC eliminated imatinib-resistant Ph+ ALL cells via rapid and massive cell death, and this significantly prolonged survival in the mice.

Dr Müschen and his colleagues noted that only Ph+ ALL cells were marked for destruction, which suggests a BCR-targeted drug could overcome imatinib resistance without affecting normal B cells.

The team also pointed out that a short exposure to 3AC was sufficient to commit the leukemia cells to death and to clear most of the disease burden from mice.

Dr Müschen said 3AC’s fast action was encouraging, because it remains unknown whether prolonged BCR hyperactivation is safe. That is why he and his colleagues are now focusing on formulating hyperactivating drugs that could be administered for only a few hours.

“These experiments show that we can engage signaling checkpoints in a very short period of time and that, once these checkpoints are engaged, the cell is irreversibly slated for death; it’s a point of no return,” Dr Müschen said.

“The next step is to work with medicinal chemists to make better ALL drugs that will overstimulate the B-cell receptor pathway and . . . could be used on a treatment schedule to elicit a very strong, but time-limited, spike in signaling to engage negative B-cell selection.”

Lab mice

Photo by Aaron Logan

Increasing B-cell antigen receptor (BCR) signaling beyond “a point of no return” can lead to the selective elimination of leukemic cells, according to a group of researchers.

The team knew that proximal pre-BCR signaling is toxic to Philadelphia-chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) cells, and their experiments revealed that SYK tyrosine kinase activity mimicked constitutively active pre-BCR signaling.

So it was no surprise that pharmacologic hyperactivation of SYK prompted the removal of self-reactive B cells and selective killing of Ph+ ALL cells in vivo.

Markus Müschen, MD, PhD, of the University of California, San Francisco, and his colleagues described these findings in Nature.

When the researchers tested proximal pre-BCR signaling in mouse BCR-ABL1 cells, they found that an incremental increase of SYK activity could induce cell death.

Additional experiments showed that patient-derived Ph+ ALL cells have high levels of the inhibitory receptors PECAM1, CD300A, and LAIR1. And these receptors are needed to calibrate oncogenic signaling strength via recruitment of the inhibitory phosphatases PTPN6 and INPP5D.

So the researchers wondered if a small-molecule inhibitor of INPP5D, known as 3-a-aminocholestane (3AC), could induce SYK hyperactivation and target Ph+ ALL cells in mice.

They found that 3AC eliminated imatinib-resistant Ph+ ALL cells via rapid and massive cell death, and this significantly prolonged survival in the mice.

Dr Müschen and his colleagues noted that only Ph+ ALL cells were marked for destruction, which suggests a BCR-targeted drug could overcome imatinib resistance without affecting normal B cells.

The team also pointed out that a short exposure to 3AC was sufficient to commit the leukemia cells to death and to clear most of the disease burden from mice.

Dr Müschen said 3AC’s fast action was encouraging, because it remains unknown whether prolonged BCR hyperactivation is safe. That is why he and his colleagues are now focusing on formulating hyperactivating drugs that could be administered for only a few hours.

“These experiments show that we can engage signaling checkpoints in a very short period of time and that, once these checkpoints are engaged, the cell is irreversibly slated for death; it’s a point of no return,” Dr Müschen said.

“The next step is to work with medicinal chemists to make better ALL drugs that will overstimulate the B-cell receptor pathway and . . . could be used on a treatment schedule to elicit a very strong, but time-limited, spike in signaling to engage negative B-cell selection.”

Lab mice

Photo by Aaron Logan

Increasing B-cell antigen receptor (BCR) signaling beyond “a point of no return” can lead to the selective elimination of leukemic cells, according to a group of researchers.

The team knew that proximal pre-BCR signaling is toxic to Philadelphia-chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) cells, and their experiments revealed that SYK tyrosine kinase activity mimicked constitutively active pre-BCR signaling.

So it was no surprise that pharmacologic hyperactivation of SYK prompted the removal of self-reactive B cells and selective killing of Ph+ ALL cells in vivo.

Markus Müschen, MD, PhD, of the University of California, San Francisco, and his colleagues described these findings in Nature.

When the researchers tested proximal pre-BCR signaling in mouse BCR-ABL1 cells, they found that an incremental increase of SYK activity could induce cell death.

Additional experiments showed that patient-derived Ph+ ALL cells have high levels of the inhibitory receptors PECAM1, CD300A, and LAIR1. And these receptors are needed to calibrate oncogenic signaling strength via recruitment of the inhibitory phosphatases PTPN6 and INPP5D.

So the researchers wondered if a small-molecule inhibitor of INPP5D, known as 3-a-aminocholestane (3AC), could induce SYK hyperactivation and target Ph+ ALL cells in mice.

They found that 3AC eliminated imatinib-resistant Ph+ ALL cells via rapid and massive cell death, and this significantly prolonged survival in the mice.

Dr Müschen and his colleagues noted that only Ph+ ALL cells were marked for destruction, which suggests a BCR-targeted drug could overcome imatinib resistance without affecting normal B cells.

The team also pointed out that a short exposure to 3AC was sufficient to commit the leukemia cells to death and to clear most of the disease burden from mice.

Dr Müschen said 3AC’s fast action was encouraging, because it remains unknown whether prolonged BCR hyperactivation is safe. That is why he and his colleagues are now focusing on formulating hyperactivating drugs that could be administered for only a few hours.

“These experiments show that we can engage signaling checkpoints in a very short period of time and that, once these checkpoints are engaged, the cell is irreversibly slated for death; it’s a point of no return,” Dr Müschen said.

“The next step is to work with medicinal chemists to make better ALL drugs that will overstimulate the B-cell receptor pathway and . . . could be used on a treatment schedule to elicit a very strong, but time-limited, spike in signaling to engage negative B-cell selection.”

Thrombus

Image by Andre E.X. Brown

A new approach for treating thrombotic thrombocytopenic purpura (TTP) has proven effective in mice, according to a paper published in Blood.

Researchers showed they could “hide” functional recombinant human ADAMTS13 (rADAMTS13) inside mouse platelets to prevent antibodies from impairing ADAMTS13 activity.

These rADAMTS13-expressing platelets were able to inhibit thrombosis and prevent the development of hereditary and acquired TTP in mice.

If a similar technique were to prove effective in humans, it could reduce the amount of plasma transfusions TTP patients require, the researchers said.

They also believe such a method could be used in emergency situations to treat strokes, heart attacks, malignant malaria, and pre-eclampsia, as all of these conditions are associated with relative deficiency of plasma ADAMTS13 activity.

This research began when X. Long Zheng, MD, PhD, of the University of Alabama at Birmingham, had the idea that he could treat TTP by hiding ADAMTS13 inside platelets where autoantibodies can’t see it.

He reasoned that, if he could fill platelets with ADAMTS13, the platelets would then carry the enzyme right to the place it was most needed to dissolve thrombi.

So he and his colleagues developed transgenic mice that expressed rADAMTS13 in their platelets.

The platelets had normal agglutination and aggregation. And they released rADAMTS13 upon stimulation with thrombin and collagen, although they released less when stimulated with 2MesADP.

Mice with rADAMTS13-expressing platelets were significantly protected in a vascular injury model of thrombus formation.

In mice that lacked plasma ADAMTS13 activity due to ADAMTS13 gene deletion and those that had antibody-mediated inhibition of plasma ADAMTS13 activity, rADAMTS13-expressing platelets protected the animals against TTP induced by bacterial toxin or recombinant von Willebrand factor.

These results, the researchers said, “suggest that platelets may be ideal carriers for antithrombic ADAMTS13, allowing its release at high concentrations at the site of thrombus formation without being inactivated by the potential circulating anti-ADAMTS13 inhibitors.”

To employ this treatment method in humans, Dr Zheng said researchers could investigate how to load ADAMTS13 inside donated platelets. They could then test these platelets to learn how many ADAMTS13-loaded platelets need to be transfused to produce antithrombotic and anti-TTP effects in patients with TTP.

Thrombus

Image by Andre E.X. Brown

A new approach for treating thrombotic thrombocytopenic purpura (TTP) has proven effective in mice, according to a paper published in Blood.

Researchers showed they could “hide” functional recombinant human ADAMTS13 (rADAMTS13) inside mouse platelets to prevent antibodies from impairing ADAMTS13 activity.

These rADAMTS13-expressing platelets were able to inhibit thrombosis and prevent the development of hereditary and acquired TTP in mice.

If a similar technique were to prove effective in humans, it could reduce the amount of plasma transfusions TTP patients require, the researchers said.

They also believe such a method could be used in emergency situations to treat strokes, heart attacks, malignant malaria, and pre-eclampsia, as all of these conditions are associated with relative deficiency of plasma ADAMTS13 activity.

This research began when X. Long Zheng, MD, PhD, of the University of Alabama at Birmingham, had the idea that he could treat TTP by hiding ADAMTS13 inside platelets where autoantibodies can’t see it.

He reasoned that, if he could fill platelets with ADAMTS13, the platelets would then carry the enzyme right to the place it was most needed to dissolve thrombi.

So he and his colleagues developed transgenic mice that expressed rADAMTS13 in their platelets.

The platelets had normal agglutination and aggregation. And they released rADAMTS13 upon stimulation with thrombin and collagen, although they released less when stimulated with 2MesADP.

Mice with rADAMTS13-expressing platelets were significantly protected in a vascular injury model of thrombus formation.

In mice that lacked plasma ADAMTS13 activity due to ADAMTS13 gene deletion and those that had antibody-mediated inhibition of plasma ADAMTS13 activity, rADAMTS13-expressing platelets protected the animals against TTP induced by bacterial toxin or recombinant von Willebrand factor.

These results, the researchers said, “suggest that platelets may be ideal carriers for antithrombic ADAMTS13, allowing its release at high concentrations at the site of thrombus formation without being inactivated by the potential circulating anti-ADAMTS13 inhibitors.”

To employ this treatment method in humans, Dr Zheng said researchers could investigate how to load ADAMTS13 inside donated platelets. They could then test these platelets to learn how many ADAMTS13-loaded platelets need to be transfused to produce antithrombotic and anti-TTP effects in patients with TTP.

Thrombus

Image by Andre E.X. Brown

A new approach for treating thrombotic thrombocytopenic purpura (TTP) has proven effective in mice, according to a paper published in Blood.

Researchers showed they could “hide” functional recombinant human ADAMTS13 (rADAMTS13) inside mouse platelets to prevent antibodies from impairing ADAMTS13 activity.

These rADAMTS13-expressing platelets were able to inhibit thrombosis and prevent the development of hereditary and acquired TTP in mice.

If a similar technique were to prove effective in humans, it could reduce the amount of plasma transfusions TTP patients require, the researchers said.

They also believe such a method could be used in emergency situations to treat strokes, heart attacks, malignant malaria, and pre-eclampsia, as all of these conditions are associated with relative deficiency of plasma ADAMTS13 activity.

This research began when X. Long Zheng, MD, PhD, of the University of Alabama at Birmingham, had the idea that he could treat TTP by hiding ADAMTS13 inside platelets where autoantibodies can’t see it.

He reasoned that, if he could fill platelets with ADAMTS13, the platelets would then carry the enzyme right to the place it was most needed to dissolve thrombi.

So he and his colleagues developed transgenic mice that expressed rADAMTS13 in their platelets.

The platelets had normal agglutination and aggregation. And they released rADAMTS13 upon stimulation with thrombin and collagen, although they released less when stimulated with 2MesADP.

Mice with rADAMTS13-expressing platelets were significantly protected in a vascular injury model of thrombus formation.

In mice that lacked plasma ADAMTS13 activity due to ADAMTS13 gene deletion and those that had antibody-mediated inhibition of plasma ADAMTS13 activity, rADAMTS13-expressing platelets protected the animals against TTP induced by bacterial toxin or recombinant von Willebrand factor.

These results, the researchers said, “suggest that platelets may be ideal carriers for antithrombic ADAMTS13, allowing its release at high concentrations at the site of thrombus formation without being inactivated by the potential circulating anti-ADAMTS13 inhibitors.”

To employ this treatment method in humans, Dr Zheng said researchers could investigate how to load ADAMTS13 inside donated platelets. They could then test these platelets to learn how many ADAMTS13-loaded platelets need to be transfused to produce antithrombotic and anti-TTP effects in patients with TTP.

Red blood cells

Image courtesy of NHLBI

The US Food and Drug Administration (FDA) has granted orphan drug designation to AG-348 for the treatment of pyruvate kinase deficiency (PKD), a rare form of hemolytic anemia.

AG-348 is a small molecule allosteric activator of pyruvate kinase-R enzymes that directly targets the underlying metabolic defect in PKD.

The orphan designation will provide Agios Pharmaceuticals, the company developing AG-348, with certain benefits. These include market exclusivity upon regulatory approval and exemption from FDA application fees and tax credits for qualified clinical trials.

According to Agios, AG-348 exhibited favorable safety and pharmacokinetic profiles in a pair of phase 1 studies conducted in healthy volunteers.

Study investigators also observed dose-dependent changes in adenosine triphosphate (ATP) and 2,3-DPG blood levels, which are consistent with increased activity of the glycolytic pathway, the expected pharmacodynamic effect of AG-348.

Results from both studies were presented in a poster at the 2014 ASH Annual Meeting (abstract 4007*). One of the studies was a single ascending dose (SAD) study, and the other was a multiple ascending dose (MAD) study.

SAD study

In this study, healthy volunteers were randomized to receive AG-348 (n=36) or placebo (n=12). Patients were divided into 6 dosing cohorts: 30 mg, 120 mg, 360 mg, 700 mg, 1400 mg, and 2500 mg.

The maximum-tolerated dose of AG-348 was not reached, and there were no serious adverse events (AEs) or early withdrawals among AG-348-treated subjects. Overall, the rate of AEs was 33.3% in the placebo arm and 44.4% in the AG-348 arm.

The rate of AEs that were considered possibly treatment-related was 16.7% in the placebo arm and 30.6% in the AG-348 arm. The most common treatment-related AEs were headache (occurring in 16.7% and 11.1% of patients, respectively), nausea (0% and 13.9%, respectively), and vomiting (0% and 5.6%, respectively).

Exposure to AG-348, as measured by area under the concentration × time curve (AUC), increased in a dose-proportional manner after a single dose. And absorption was rapid (median T_max ranged from 0.77 to 4.07 hours), although T_max increased and there was a less-than-proportional increase in C_max at higher doses.

When AG-348 was administered from 30 mg to 360 mg, there was a dose-dependent decrease in blood 2,3-DPG levels over 24 hours—up to a 49% mean decrease. Increasing the dose beyond 360 mg did not result in additional decreases in 2,3-DPG levels. And levels returned to placebo levels after about 72 hours.

There were minimal increases in blood ATP levels after AG-348 treatment at any dose.

MAD study

At the time of the presentation, 2 cohorts of 8 subjects each (6 receiving AG-348 and 2 receiving placebo) had completed treatment in the MAD study. One cohort received drug or placebo at 120 mg BID, and the other received 360 mg BID.

The pharmacokinetic results for day 1 of this study were consistent with those of the SAD study. However, the C_max and AUC_0-Ʈ were lower on day 14 than day 1. Investigators said this suggests that multiple doses of AG-348 increase the rate of its own metabolism.

They also said the decrease in exposure observed on day 14 is consistent with preclinical data that suggest AG-348 is a moderate inducer of CYP3A4, which is the major route of the oxidative metabolism of AG-348.

As in the SAD study, the investigators observed decreases in 2,3-DPG blood levels after the first dose in cohorts 1 and 2—up to a 48% mean decrease from baseline for both doses. Concentrations returned to placebo levels between 48 and 72 hours after the last dose.

Unlike in the SAD study, patients in this study had increases in ATP—up to a 52% mean increase from baseline in both dosing cohorts. ATP levels remained elevated through 72 hours after the last dose.

The investigators said the results of these 2 studies have informed dose selection for the planned phase 2 study of AG-348 in PKD patients, which is expected to begin soon.

*Information in the abstract differs from that presented at the meeting.

Red blood cells

Image courtesy of NHLBI

The US Food and Drug Administration (FDA) has granted orphan drug designation to AG-348 for the treatment of pyruvate kinase deficiency (PKD), a rare form of hemolytic anemia.

AG-348 is a small molecule allosteric activator of pyruvate kinase-R enzymes that directly targets the underlying metabolic defect in PKD.

The orphan designation will provide Agios Pharmaceuticals, the company developing AG-348, with certain benefits. These include market exclusivity upon regulatory approval and exemption from FDA application fees and tax credits for qualified clinical trials.

According to Agios, AG-348 exhibited favorable safety and pharmacokinetic profiles in a pair of phase 1 studies conducted in healthy volunteers.

Study investigators also observed dose-dependent changes in adenosine triphosphate (ATP) and 2,3-DPG blood levels, which are consistent with increased activity of the glycolytic pathway, the expected pharmacodynamic effect of AG-348.

Results from both studies were presented in a poster at the 2014 ASH Annual Meeting (abstract 4007*). One of the studies was a single ascending dose (SAD) study, and the other was a multiple ascending dose (MAD) study.

SAD study

In this study, healthy volunteers were randomized to receive AG-348 (n=36) or placebo (n=12). Patients were divided into 6 dosing cohorts: 30 mg, 120 mg, 360 mg, 700 mg, 1400 mg, and 2500 mg.

The maximum-tolerated dose of AG-348 was not reached, and there were no serious adverse events (AEs) or early withdrawals among AG-348-treated subjects. Overall, the rate of AEs was 33.3% in the placebo arm and 44.4% in the AG-348 arm.

The rate of AEs that were considered possibly treatment-related was 16.7% in the placebo arm and 30.6% in the AG-348 arm. The most common treatment-related AEs were headache (occurring in 16.7% and 11.1% of patients, respectively), nausea (0% and 13.9%, respectively), and vomiting (0% and 5.6%, respectively).

Exposure to AG-348, as measured by area under the concentration × time curve (AUC), increased in a dose-proportional manner after a single dose. And absorption was rapid (median T_max ranged from 0.77 to 4.07 hours), although T_max increased and there was a less-than-proportional increase in C_max at higher doses.

When AG-348 was administered from 30 mg to 360 mg, there was a dose-dependent decrease in blood 2,3-DPG levels over 24 hours—up to a 49% mean decrease. Increasing the dose beyond 360 mg did not result in additional decreases in 2,3-DPG levels. And levels returned to placebo levels after about 72 hours.

There were minimal increases in blood ATP levels after AG-348 treatment at any dose.

MAD study

At the time of the presentation, 2 cohorts of 8 subjects each (6 receiving AG-348 and 2 receiving placebo) had completed treatment in the MAD study. One cohort received drug or placebo at 120 mg BID, and the other received 360 mg BID.

The pharmacokinetic results for day 1 of this study were consistent with those of the SAD study. However, the C_max and AUC_0-Ʈ were lower on day 14 than day 1. Investigators said this suggests that multiple doses of AG-348 increase the rate of its own metabolism.

They also said the decrease in exposure observed on day 14 is consistent with preclinical data that suggest AG-348 is a moderate inducer of CYP3A4, which is the major route of the oxidative metabolism of AG-348.

As in the SAD study, the investigators observed decreases in 2,3-DPG blood levels after the first dose in cohorts 1 and 2—up to a 48% mean decrease from baseline for both doses. Concentrations returned to placebo levels between 48 and 72 hours after the last dose.

Unlike in the SAD study, patients in this study had increases in ATP—up to a 52% mean increase from baseline in both dosing cohorts. ATP levels remained elevated through 72 hours after the last dose.

The investigators said the results of these 2 studies have informed dose selection for the planned phase 2 study of AG-348 in PKD patients, which is expected to begin soon.

*Information in the abstract differs from that presented at the meeting.

Red blood cells

Image courtesy of NHLBI

The US Food and Drug Administration (FDA) has granted orphan drug designation to AG-348 for the treatment of pyruvate kinase deficiency (PKD), a rare form of hemolytic anemia.

AG-348 is a small molecule allosteric activator of pyruvate kinase-R enzymes that directly targets the underlying metabolic defect in PKD.

The orphan designation will provide Agios Pharmaceuticals, the company developing AG-348, with certain benefits. These include market exclusivity upon regulatory approval and exemption from FDA application fees and tax credits for qualified clinical trials.

According to Agios, AG-348 exhibited favorable safety and pharmacokinetic profiles in a pair of phase 1 studies conducted in healthy volunteers.

Study investigators also observed dose-dependent changes in adenosine triphosphate (ATP) and 2,3-DPG blood levels, which are consistent with increased activity of the glycolytic pathway, the expected pharmacodynamic effect of AG-348.

Results from both studies were presented in a poster at the 2014 ASH Annual Meeting (abstract 4007*). One of the studies was a single ascending dose (SAD) study, and the other was a multiple ascending dose (MAD) study.

SAD study

In this study, healthy volunteers were randomized to receive AG-348 (n=36) or placebo (n=12). Patients were divided into 6 dosing cohorts: 30 mg, 120 mg, 360 mg, 700 mg, 1400 mg, and 2500 mg.

The maximum-tolerated dose of AG-348 was not reached, and there were no serious adverse events (AEs) or early withdrawals among AG-348-treated subjects. Overall, the rate of AEs was 33.3% in the placebo arm and 44.4% in the AG-348 arm.

The rate of AEs that were considered possibly treatment-related was 16.7% in the placebo arm and 30.6% in the AG-348 arm. The most common treatment-related AEs were headache (occurring in 16.7% and 11.1% of patients, respectively), nausea (0% and 13.9%, respectively), and vomiting (0% and 5.6%, respectively).

Exposure to AG-348, as measured by area under the concentration × time curve (AUC), increased in a dose-proportional manner after a single dose. And absorption was rapid (median T_max ranged from 0.77 to 4.07 hours), although T_max increased and there was a less-than-proportional increase in C_max at higher doses.

When AG-348 was administered from 30 mg to 360 mg, there was a dose-dependent decrease in blood 2,3-DPG levels over 24 hours—up to a 49% mean decrease. Increasing the dose beyond 360 mg did not result in additional decreases in 2,3-DPG levels. And levels returned to placebo levels after about 72 hours.

There were minimal increases in blood ATP levels after AG-348 treatment at any dose.

MAD study

At the time of the presentation, 2 cohorts of 8 subjects each (6 receiving AG-348 and 2 receiving placebo) had completed treatment in the MAD study. One cohort received drug or placebo at 120 mg BID, and the other received 360 mg BID.

The pharmacokinetic results for day 1 of this study were consistent with those of the SAD study. However, the C_max and AUC_0-Ʈ were lower on day 14 than day 1. Investigators said this suggests that multiple doses of AG-348 increase the rate of its own metabolism.

They also said the decrease in exposure observed on day 14 is consistent with preclinical data that suggest AG-348 is a moderate inducer of CYP3A4, which is the major route of the oxidative metabolism of AG-348.

As in the SAD study, the investigators observed decreases in 2,3-DPG blood levels after the first dose in cohorts 1 and 2—up to a 48% mean decrease from baseline for both doses. Concentrations returned to placebo levels between 48 and 72 hours after the last dose.

Unlike in the SAD study, patients in this study had increases in ATP—up to a 52% mean increase from baseline in both dosing cohorts. ATP levels remained elevated through 72 hours after the last dose.

The investigators said the results of these 2 studies have informed dose selection for the planned phase 2 study of AG-348 in PKD patients, which is expected to begin soon.

*Information in the abstract differs from that presented at the meeting.

Lab mouse

In developing a compound that exhibits activity against a type of acute myeloid leukemia (AML), investigators have shown that transcription factors are, in fact, “druggable.”

The compound, AI-10-49, selectively binds to the mutated transcription factor CBFβ-SMMHC, and this prevents CBFβ-SMMHC from binding to another transcription factor, RUNX1.

In this way, AI-10-49 restores RUNX1 transcriptional activity, which leads to the death of inv(16) AML cells in vitro and in vivo.

“This drug that we’ve developed is . . . targeting a class of proteins that hasn’t been targeted for drug development very much in the past,” said study author John H. Bushweller, PhD, of the University of Virginia Health System in Charlottesville.

“It’s really a new paradigm, a new approach to try to treat these diseases. This class of proteins is very important for determining how much of many other proteins are made, so it’s a unique way of changing the way the cell behaves.”

Dr Bushweller and his colleagues described their work in Science.

The investigators noted that CBFβ-SMMHC is expressed in AML with the chromosome inversion inv(16)(p13q22). And CBFβ-SMMHC outcompetes wild-type CBFβ for binding to RUNX1, thereby deregulating RUNX1 activity in hematopoiesis and inducing AML.

“When you target a mutated protein in a cancer, you would ideally like to inhibit that mutated form of the protein but not affect the normal form of the protein that’s still there,” Dr Bushweller said. “In the case of [AI-10-49], we’ve achieved that.”

He and his colleagues tested AI-10-49 in 11 leukemia cells lines and found that only ME-1 cells were highly sensitive to the treatment. AI-10-49 effectively dissociated RUNX1 from CBFβ-SMMHC in ME-1 cells, with 90% dissociation after 6 hours of treatment.

But the drug had a modest effect on CBFβ-RUNX1 association. It also had negligible activity in normal human bone marrow cells.

The investigators then tested AI-10-49 in a mouse model of inv(16) AML. Control mice (vehicle-treated) succumbed to leukemia in a median of 33.5 days, compared to a median of 61 days for mice that received AI-10-49.

Dr Bushweller and his colleagues did not evaluate toxicity after long-term exposure to AI-10-49, but they found no evidence of toxicity after 7 days of AI-10-49 treatment.

Next, the investigators tested AI-10-49 in 4 primary inv(16) AML cell samples. They saw a reduction in leukemia cell viability when AI-10-49 was administered at 5 μM and 10 μM concentrations. Bivalent AI-10-49 was more potent than monovalent AI-10-47.

The team said these results suggest that direct inhibition of CBFβ-SMMHC may be an effective therapeutic approach for inv(16) AML, and the findings provide support for therapies targeting transcription factors.

Lab mouse

In developing a compound that exhibits activity against a type of acute myeloid leukemia (AML), investigators have shown that transcription factors are, in fact, “druggable.”

The compound, AI-10-49, selectively binds to the mutated transcription factor CBFβ-SMMHC, and this prevents CBFβ-SMMHC from binding to another transcription factor, RUNX1.

In this way, AI-10-49 restores RUNX1 transcriptional activity, which leads to the death of inv(16) AML cells in vitro and in vivo.

“This drug that we’ve developed is . . . targeting a class of proteins that hasn’t been targeted for drug development very much in the past,” said study author John H. Bushweller, PhD, of the University of Virginia Health System in Charlottesville.

“It’s really a new paradigm, a new approach to try to treat these diseases. This class of proteins is very important for determining how much of many other proteins are made, so it’s a unique way of changing the way the cell behaves.”

Dr Bushweller and his colleagues described their work in Science.

The investigators noted that CBFβ-SMMHC is expressed in AML with the chromosome inversion inv(16)(p13q22). And CBFβ-SMMHC outcompetes wild-type CBFβ for binding to RUNX1, thereby deregulating RUNX1 activity in hematopoiesis and inducing AML.

“When you target a mutated protein in a cancer, you would ideally like to inhibit that mutated form of the protein but not affect the normal form of the protein that’s still there,” Dr Bushweller said. “In the case of [AI-10-49], we’ve achieved that.”

He and his colleagues tested AI-10-49 in 11 leukemia cells lines and found that only ME-1 cells were highly sensitive to the treatment. AI-10-49 effectively dissociated RUNX1 from CBFβ-SMMHC in ME-1 cells, with 90% dissociation after 6 hours of treatment.

But the drug had a modest effect on CBFβ-RUNX1 association. It also had negligible activity in normal human bone marrow cells.

The investigators then tested AI-10-49 in a mouse model of inv(16) AML. Control mice (vehicle-treated) succumbed to leukemia in a median of 33.5 days, compared to a median of 61 days for mice that received AI-10-49.

Dr Bushweller and his colleagues did not evaluate toxicity after long-term exposure to AI-10-49, but they found no evidence of toxicity after 7 days of AI-10-49 treatment.

Next, the investigators tested AI-10-49 in 4 primary inv(16) AML cell samples. They saw a reduction in leukemia cell viability when AI-10-49 was administered at 5 μM and 10 μM concentrations. Bivalent AI-10-49 was more potent than monovalent AI-10-47.

The team said these results suggest that direct inhibition of CBFβ-SMMHC may be an effective therapeutic approach for inv(16) AML, and the findings provide support for therapies targeting transcription factors.

Lab mouse

In developing a compound that exhibits activity against a type of acute myeloid leukemia (AML), investigators have shown that transcription factors are, in fact, “druggable.”

The compound, AI-10-49, selectively binds to the mutated transcription factor CBFβ-SMMHC, and this prevents CBFβ-SMMHC from binding to another transcription factor, RUNX1.

In this way, AI-10-49 restores RUNX1 transcriptional activity, which leads to the death of inv(16) AML cells in vitro and in vivo.

“This drug that we’ve developed is . . . targeting a class of proteins that hasn’t been targeted for drug development very much in the past,” said study author John H. Bushweller, PhD, of the University of Virginia Health System in Charlottesville.

“It’s really a new paradigm, a new approach to try to treat these diseases. This class of proteins is very important for determining how much of many other proteins are made, so it’s a unique way of changing the way the cell behaves.”

Dr Bushweller and his colleagues described their work in Science.

The investigators noted that CBFβ-SMMHC is expressed in AML with the chromosome inversion inv(16)(p13q22). And CBFβ-SMMHC outcompetes wild-type CBFβ for binding to RUNX1, thereby deregulating RUNX1 activity in hematopoiesis and inducing AML.

“When you target a mutated protein in a cancer, you would ideally like to inhibit that mutated form of the protein but not affect the normal form of the protein that’s still there,” Dr Bushweller said. “In the case of [AI-10-49], we’ve achieved that.”

He and his colleagues tested AI-10-49 in 11 leukemia cells lines and found that only ME-1 cells were highly sensitive to the treatment. AI-10-49 effectively dissociated RUNX1 from CBFβ-SMMHC in ME-1 cells, with 90% dissociation after 6 hours of treatment.

But the drug had a modest effect on CBFβ-RUNX1 association. It also had negligible activity in normal human bone marrow cells.

The investigators then tested AI-10-49 in a mouse model of inv(16) AML. Control mice (vehicle-treated) succumbed to leukemia in a median of 33.5 days, compared to a median of 61 days for mice that received AI-10-49.

Dr Bushweller and his colleagues did not evaluate toxicity after long-term exposure to AI-10-49, but they found no evidence of toxicity after 7 days of AI-10-49 treatment.

Next, the investigators tested AI-10-49 in 4 primary inv(16) AML cell samples. They saw a reduction in leukemia cell viability when AI-10-49 was administered at 5 μM and 10 μM concentrations. Bivalent AI-10-49 was more potent than monovalent AI-10-47.

The team said these results suggest that direct inhibition of CBFβ-SMMHC may be an effective therapeutic approach for inv(16) AML, and the findings provide support for therapies targeting transcription factors.

Micrograph showing SCD

Image by Graham Beards

Results of a small study suggest there may be a high prevalence of sleep disordered breathing (SDB) in adults with sickle cell disease (SCD).

Of the 32 patients included in the study, 44% had a clinical diagnosis of SDB.

These patients had significantly increased REM latency, a significantly higher mean score on the Epworth Sleepiness Scale, and a significantly higher oxygen desaturation index (ODI) than patients who did not have SDB.

However, there was no significant difference between SDB and non-SDB patients with regard to insomnia, delayed sleep phase syndrome, nocturia, or SCD complications.

Sunil Sharma, MD, of Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, Pennsylvania, and his colleagues recounted these results in the Journal of Clinical Sleep Medicine.

“Previous research identified pain and sleep disturbance as 2 common symptoms of adult sickle cell disorder,” Dr Sharma said. “We wanted to examine the reasons for the sleep disturbances, as it can have a strong impact on our patients’ quality of life and overall health. We discovered a high incidence of sleep disordered breathing in patients with sickle cell disease who also report trouble with sleep.”

Dr Sharma and his colleagues analyzed 32 consecutive adult SCD patients who had reported symptoms suggesting disordered sleep or had an Epworth Sleepiness Scale score of 10 or greater. The patients underwent a comprehensive sleep evaluation and overnight polysomnography in an accredited sleep center.

SDB was defined as having an apnea-hypopnea index (AHI, events/hour) of 5 or greater. SDB was considered mild if the AHI was 5 to < 15, moderate if the AHI was 15 to < 30, and severe if the AHI was ≥ 30. Once they determined which patients had SDB, the researchers compared these patients to those without the condition.

The team found that 44% of patients (n=14) had SDB. It was mild in 8 patients, moderate in 4, and severe in 2.

Compared to non-SDB patients, those with SDB had a significantly higher mean AHI (1.6 and 17, respectively; P=0.0001), a significantly increased REM latency (98 and 159 minutes, respectively; P=0.014), and a significantly higher mean score on the Epworth Sleepiness Scale (8.6 and 13, respectively; P=0.017).

Patients with SDB also had a significantly higher ODI than non-SDB patients (13 and 1.6, respectively; P=0.0009). Significant oxygen desaturation was defined as oxygen saturation < 89% for 5 cumulative minutes or more. The ODI was the number of recorded oxygen desaturations ≥ 4% per hour of sleep.

There was no significant difference between SDB and non-SDB patients in the incidence of nocturia (2.3 and 1.6, respectively; P=0.063), insomnia (57% and 72%, respectively; P=0.46), or delayed sleep phase syndrome (57% and 50%, respectively; P=0.73).

Delayed sleep phase syndrome was defined as a delay in sleep onset of 2 hours or greater from the desired sleep time and an inability to awaken at the desired time. Insomnia was defined as difficulty initiating sleep (sleep latency greater than 60 minutes) or difficulty maintaining sleep (more than 2 awakenings requiring more than 20 minutes to fall back asleep) on the majority of nights for more than 4 weeks.

There was no significant difference between SDB and non-SDB patients with regard to SCD complications, including crises during sleep (44% and 39%, respectively; P=0.67), average hospital admissions in the last 5 years (9.1 and 6.0, respectively; P=0.15), or average mini-crises per month (2.7 and 3.6, respectively; P=0.69).

Dr Sharma said the diagnosis of SDB could be missed in adults with SCD because they are not generally obese, a common risk factor for SDB, and daytime sleepiness is attributed to the pain medications used to treat the symptoms of SCD. He hopes this study will increase awareness among physicians who can screen patients for SDB.

“Our study suggests that patients with sickle cell disorder should be screened using a questionnaire to identify problems with sleep,” Dr Sharma said. “For further testing, an oxygen desaturation index is another low-cost screening tool that can identify sleep disordered breathing in this population.”

Micrograph showing SCD

Image by Graham Beards

Results of a small study suggest there may be a high prevalence of sleep disordered breathing (SDB) in adults with sickle cell disease (SCD).

Of the 32 patients included in the study, 44% had a clinical diagnosis of SDB.

These patients had significantly increased REM latency, a significantly higher mean score on the Epworth Sleepiness Scale, and a significantly higher oxygen desaturation index (ODI) than patients who did not have SDB.

However, there was no significant difference between SDB and non-SDB patients with regard to insomnia, delayed sleep phase syndrome, nocturia, or SCD complications.

Sunil Sharma, MD, of Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, Pennsylvania, and his colleagues recounted these results in the Journal of Clinical Sleep Medicine.

“Previous research identified pain and sleep disturbance as 2 common symptoms of adult sickle cell disorder,” Dr Sharma said. “We wanted to examine the reasons for the sleep disturbances, as it can have a strong impact on our patients’ quality of life and overall health. We discovered a high incidence of sleep disordered breathing in patients with sickle cell disease who also report trouble with sleep.”

Dr Sharma and his colleagues analyzed 32 consecutive adult SCD patients who had reported symptoms suggesting disordered sleep or had an Epworth Sleepiness Scale score of 10 or greater. The patients underwent a comprehensive sleep evaluation and overnight polysomnography in an accredited sleep center.

SDB was defined as having an apnea-hypopnea index (AHI, events/hour) of 5 or greater. SDB was considered mild if the AHI was 5 to < 15, moderate if the AHI was 15 to < 30, and severe if the AHI was ≥ 30. Once they determined which patients had SDB, the researchers compared these patients to those without the condition.

The team found that 44% of patients (n=14) had SDB. It was mild in 8 patients, moderate in 4, and severe in 2.

Compared to non-SDB patients, those with SDB had a significantly higher mean AHI (1.6 and 17, respectively; P=0.0001), a significantly increased REM latency (98 and 159 minutes, respectively; P=0.014), and a significantly higher mean score on the Epworth Sleepiness Scale (8.6 and 13, respectively; P=0.017).

Patients with SDB also had a significantly higher ODI than non-SDB patients (13 and 1.6, respectively; P=0.0009). Significant oxygen desaturation was defined as oxygen saturation < 89% for 5 cumulative minutes or more. The ODI was the number of recorded oxygen desaturations ≥ 4% per hour of sleep.

There was no significant difference between SDB and non-SDB patients in the incidence of nocturia (2.3 and 1.6, respectively; P=0.063), insomnia (57% and 72%, respectively; P=0.46), or delayed sleep phase syndrome (57% and 50%, respectively; P=0.73).

Delayed sleep phase syndrome was defined as a delay in sleep onset of 2 hours or greater from the desired sleep time and an inability to awaken at the desired time. Insomnia was defined as difficulty initiating sleep (sleep latency greater than 60 minutes) or difficulty maintaining sleep (more than 2 awakenings requiring more than 20 minutes to fall back asleep) on the majority of nights for more than 4 weeks.

There was no significant difference between SDB and non-SDB patients with regard to SCD complications, including crises during sleep (44% and 39%, respectively; P=0.67), average hospital admissions in the last 5 years (9.1 and 6.0, respectively; P=0.15), or average mini-crises per month (2.7 and 3.6, respectively; P=0.69).

Dr Sharma said the diagnosis of SDB could be missed in adults with SCD because they are not generally obese, a common risk factor for SDB, and daytime sleepiness is attributed to the pain medications used to treat the symptoms of SCD. He hopes this study will increase awareness among physicians who can screen patients for SDB.

“Our study suggests that patients with sickle cell disorder should be screened using a questionnaire to identify problems with sleep,” Dr Sharma said. “For further testing, an oxygen desaturation index is another low-cost screening tool that can identify sleep disordered breathing in this population.”

Micrograph showing SCD

Image by Graham Beards

Results of a small study suggest there may be a high prevalence of sleep disordered breathing (SDB) in adults with sickle cell disease (SCD).

Of the 32 patients included in the study, 44% had a clinical diagnosis of SDB.

These patients had significantly increased REM latency, a significantly higher mean score on the Epworth Sleepiness Scale, and a significantly higher oxygen desaturation index (ODI) than patients who did not have SDB.

However, there was no significant difference between SDB and non-SDB patients with regard to insomnia, delayed sleep phase syndrome, nocturia, or SCD complications.

Sunil Sharma, MD, of Sidney Kimmel Medical College at Thomas Jefferson University in Philadelphia, Pennsylvania, and his colleagues recounted these results in the Journal of Clinical Sleep Medicine.

“Previous research identified pain and sleep disturbance as 2 common symptoms of adult sickle cell disorder,” Dr Sharma said. “We wanted to examine the reasons for the sleep disturbances, as it can have a strong impact on our patients’ quality of life and overall health. We discovered a high incidence of sleep disordered breathing in patients with sickle cell disease who also report trouble with sleep.”

Dr Sharma and his colleagues analyzed 32 consecutive adult SCD patients who had reported symptoms suggesting disordered sleep or had an Epworth Sleepiness Scale score of 10 or greater. The patients underwent a comprehensive sleep evaluation and overnight polysomnography in an accredited sleep center.

SDB was defined as having an apnea-hypopnea index (AHI, events/hour) of 5 or greater. SDB was considered mild if the AHI was 5 to < 15, moderate if the AHI was 15 to < 30, and severe if the AHI was ≥ 30. Once they determined which patients had SDB, the researchers compared these patients to those without the condition.

The team found that 44% of patients (n=14) had SDB. It was mild in 8 patients, moderate in 4, and severe in 2.

Compared to non-SDB patients, those with SDB had a significantly higher mean AHI (1.6 and 17, respectively; P=0.0001), a significantly increased REM latency (98 and 159 minutes, respectively; P=0.014), and a significantly higher mean score on the Epworth Sleepiness Scale (8.6 and 13, respectively; P=0.017).

Patients with SDB also had a significantly higher ODI than non-SDB patients (13 and 1.6, respectively; P=0.0009). Significant oxygen desaturation was defined as oxygen saturation < 89% for 5 cumulative minutes or more. The ODI was the number of recorded oxygen desaturations ≥ 4% per hour of sleep.

There was no significant difference between SDB and non-SDB patients in the incidence of nocturia (2.3 and 1.6, respectively; P=0.063), insomnia (57% and 72%, respectively; P=0.46), or delayed sleep phase syndrome (57% and 50%, respectively; P=0.73).

Delayed sleep phase syndrome was defined as a delay in sleep onset of 2 hours or greater from the desired sleep time and an inability to awaken at the desired time. Insomnia was defined as difficulty initiating sleep (sleep latency greater than 60 minutes) or difficulty maintaining sleep (more than 2 awakenings requiring more than 20 minutes to fall back asleep) on the majority of nights for more than 4 weeks.

There was no significant difference between SDB and non-SDB patients with regard to SCD complications, including crises during sleep (44% and 39%, respectively; P=0.67), average hospital admissions in the last 5 years (9.1 and 6.0, respectively; P=0.15), or average mini-crises per month (2.7 and 3.6, respectively; P=0.69).

Dr Sharma said the diagnosis of SDB could be missed in adults with SCD because they are not generally obese, a common risk factor for SDB, and daytime sleepiness is attributed to the pain medications used to treat the symptoms of SCD. He hopes this study will increase awareness among physicians who can screen patients for SDB.

“Our study suggests that patients with sickle cell disorder should be screened using a questionnaire to identify problems with sleep,” Dr Sharma said. “For further testing, an oxygen desaturation index is another low-cost screening tool that can identify sleep disordered breathing in this population.”

Drug production

Photo courtesy of the US FDA

The Israeli Ministry of Health has granted regulatory approval for the kinase inhibitor ponatinib (Iclusig) to treat certain adults with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph⁺ ALL).

The drug can now be used to treat adults with any phase of CML who have the T315I mutation or are resistant to/cannot tolerate dasatinib or nilotinib and for whom subsequent treatment with imatinib is not clinically appropriate.

Ponatinib is also approved to treat patients with Ph⁺ ALL who have the T315I mutation or are resistant to/cannot tolerate dasatinib and for whom subsequent treatment with imatinib is not clinically appropriate.

Ariad Pharmaceuticals, Inc., the company developing ponatinib, said the drug should be available in Israel in the second quarter of 2015.

Trial results

The Ministry of Health’s decision to approve ponatinib was based on results from the phase 2 PACE trial, which included patients with CML or Ph⁺ ALL who were resistant to or intolerant of prior tyrosine kinase inhibitor therapy, or who had the T315I mutation.

The median follow-up times were 15.3 months in chronic-phase CML patients, 15.8 months in accelerated-phase CML patients, and 6.2 months in patients with blast-phase CML or Ph⁺ ALL.

In chronic-phase CML, the primary endpoint was major cytogenetic response, and it occurred in 56% of patients. Among chronic-phase patients with the T315I mutation, 70% achieved a major cytogenetic response. Among patients who had failed treatment with dasatinib or nilotinib, 51% achieved a major cytogenetic response.

In accelerated-phase CML, the primary endpoint was major hematologic response. This occurred in 57% of all patients in this group, 50% of patients with the T315I mutation, and 58% of patients who had failed treatment with dasatinib or nilotinib.

The primary endpoint was major hematologic response in blast-phase CML/Ph⁺ ALL as well. Thirty-four percent of all patients in this group met this endpoint, as did 33% of patients with the T315I mutation and 35% of patients who had failed treatment with dasatinib or nilotinib.

Common non-hematologic adverse events included rash (38%), abdominal pain (38%), headache (35%), dry skin (35%), constipation (34%), fatigue (27%), pyrexia (27%), nausea (26%), arthralgia (25%), hypertension (21%), increased lipase (19%), and increased amylase (7%).

Hematologic events of any grade included thrombocytopenia (42%), neutropenia (24%), and anemia (20%). Serious adverse events of arterial thromboembolism, including arterial stenosis, occurred in patients with cardiovascular risk factors.

Safety issues

Extended follow-up data from the PACE trial, collected in 2013, suggested ponatinib can increase the risk of thrombotic events. When these data came to light, officials in the European Union and the US, where ponatinib had already been approved, began to investigate the drug.

Ponatinib was pulled from the US market for a little over 2 months, and trials of the drug were placed on partial hold while the Food and Drug Administration evaluated the drug’s safety. Ponatinib went back on the market in January 2014, with new safety measures in place.

The drug was not pulled from the market in the European Union, but the European Medicine’s Agency released recommendations for safer use of ponatinib. The Committee for Medicinal Products for Human Use reviewed data on ponatinib and decided the drug’s benefits outweigh its risks.

Drug production

Photo courtesy of the US FDA

The Israeli Ministry of Health has granted regulatory approval for the kinase inhibitor ponatinib (Iclusig) to treat certain adults with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph⁺ ALL).

The drug can now be used to treat adults with any phase of CML who have the T315I mutation or are resistant to/cannot tolerate dasatinib or nilotinib and for whom subsequent treatment with imatinib is not clinically appropriate.

Ponatinib is also approved to treat patients with Ph⁺ ALL who have the T315I mutation or are resistant to/cannot tolerate dasatinib and for whom subsequent treatment with imatinib is not clinically appropriate.

Ariad Pharmaceuticals, Inc., the company developing ponatinib, said the drug should be available in Israel in the second quarter of 2015.

Trial results

The Ministry of Health’s decision to approve ponatinib was based on results from the phase 2 PACE trial, which included patients with CML or Ph⁺ ALL who were resistant to or intolerant of prior tyrosine kinase inhibitor therapy, or who had the T315I mutation.

The median follow-up times were 15.3 months in chronic-phase CML patients, 15.8 months in accelerated-phase CML patients, and 6.2 months in patients with blast-phase CML or Ph⁺ ALL.

In chronic-phase CML, the primary endpoint was major cytogenetic response, and it occurred in 56% of patients. Among chronic-phase patients with the T315I mutation, 70% achieved a major cytogenetic response. Among patients who had failed treatment with dasatinib or nilotinib, 51% achieved a major cytogenetic response.

In accelerated-phase CML, the primary endpoint was major hematologic response. This occurred in 57% of all patients in this group, 50% of patients with the T315I mutation, and 58% of patients who had failed treatment with dasatinib or nilotinib.

The primary endpoint was major hematologic response in blast-phase CML/Ph⁺ ALL as well. Thirty-four percent of all patients in this group met this endpoint, as did 33% of patients with the T315I mutation and 35% of patients who had failed treatment with dasatinib or nilotinib.

Common non-hematologic adverse events included rash (38%), abdominal pain (38%), headache (35%), dry skin (35%), constipation (34%), fatigue (27%), pyrexia (27%), nausea (26%), arthralgia (25%), hypertension (21%), increased lipase (19%), and increased amylase (7%).

Hematologic events of any grade included thrombocytopenia (42%), neutropenia (24%), and anemia (20%). Serious adverse events of arterial thromboembolism, including arterial stenosis, occurred in patients with cardiovascular risk factors.

Safety issues

Extended follow-up data from the PACE trial, collected in 2013, suggested ponatinib can increase the risk of thrombotic events. When these data came to light, officials in the European Union and the US, where ponatinib had already been approved, began to investigate the drug.

Ponatinib was pulled from the US market for a little over 2 months, and trials of the drug were placed on partial hold while the Food and Drug Administration evaluated the drug’s safety. Ponatinib went back on the market in January 2014, with new safety measures in place.

The drug was not pulled from the market in the European Union, but the European Medicine’s Agency released recommendations for safer use of ponatinib. The Committee for Medicinal Products for Human Use reviewed data on ponatinib and decided the drug’s benefits outweigh its risks.

Drug production

Photo courtesy of the US FDA

The Israeli Ministry of Health has granted regulatory approval for the kinase inhibitor ponatinib (Iclusig) to treat certain adults with chronic myeloid leukemia (CML) or Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph⁺ ALL).

The drug can now be used to treat adults with any phase of CML who have the T315I mutation or are resistant to/cannot tolerate dasatinib or nilotinib and for whom subsequent treatment with imatinib is not clinically appropriate.

Ponatinib is also approved to treat patients with Ph⁺ ALL who have the T315I mutation or are resistant to/cannot tolerate dasatinib and for whom subsequent treatment with imatinib is not clinically appropriate.

Ariad Pharmaceuticals, Inc., the company developing ponatinib, said the drug should be available in Israel in the second quarter of 2015.

Trial results

The Ministry of Health’s decision to approve ponatinib was based on results from the phase 2 PACE trial, which included patients with CML or Ph⁺ ALL who were resistant to or intolerant of prior tyrosine kinase inhibitor therapy, or who had the T315I mutation.

The median follow-up times were 15.3 months in chronic-phase CML patients, 15.8 months in accelerated-phase CML patients, and 6.2 months in patients with blast-phase CML or Ph⁺ ALL.

In chronic-phase CML, the primary endpoint was major cytogenetic response, and it occurred in 56% of patients. Among chronic-phase patients with the T315I mutation, 70% achieved a major cytogenetic response. Among patients who had failed treatment with dasatinib or nilotinib, 51% achieved a major cytogenetic response.

In accelerated-phase CML, the primary endpoint was major hematologic response. This occurred in 57% of all patients in this group, 50% of patients with the T315I mutation, and 58% of patients who had failed treatment with dasatinib or nilotinib.

The primary endpoint was major hematologic response in blast-phase CML/Ph⁺ ALL as well. Thirty-four percent of all patients in this group met this endpoint, as did 33% of patients with the T315I mutation and 35% of patients who had failed treatment with dasatinib or nilotinib.

Common non-hematologic adverse events included rash (38%), abdominal pain (38%), headache (35%), dry skin (35%), constipation (34%), fatigue (27%), pyrexia (27%), nausea (26%), arthralgia (25%), hypertension (21%), increased lipase (19%), and increased amylase (7%).

Hematologic events of any grade included thrombocytopenia (42%), neutropenia (24%), and anemia (20%). Serious adverse events of arterial thromboembolism, including arterial stenosis, occurred in patients with cardiovascular risk factors.

Safety issues

Extended follow-up data from the PACE trial, collected in 2013, suggested ponatinib can increase the risk of thrombotic events. When these data came to light, officials in the European Union and the US, where ponatinib had already been approved, began to investigate the drug.

Ponatinib was pulled from the US market for a little over 2 months, and trials of the drug were placed on partial hold while the Food and Drug Administration evaluated the drug’s safety. Ponatinib went back on the market in January 2014, with new safety measures in place.

The drug was not pulled from the market in the European Union, but the European Medicine’s Agency released recommendations for safer use of ponatinib. The Committee for Medicinal Products for Human Use reviewed data on ponatinib and decided the drug’s benefits outweigh its risks.

Researcher in the lab

Photo by Darren Baker

By agreeing upon—and addressing—the aspects of lymphoma research that need the most improvement, the research community could advance the treatment of these diseases, according to a report published in Blood.

The report’s authors said limitations in research infrastructure, funding, and collaborative approaches across research centers present potential challenges on the road to developing better treatments.

And they outlined several “priority areas” that, they believe, require particular attention.

“[Our report] draws focus to our most pressing needs, which, if unaddressed, will prevent transformative changes to how we study and treat these diseases,” said David M. Weinstock, MD, of the Dana-Farber Cancer Institute in Boston, Massachusetts.

“Directing our collaborative efforts toward the most high-impact areas will enable us to more rapidly bring life-saving treatments to our patients.”

The report lists the following priority areas:

• Infrastructure

  • Develop an adequate number of disease models for each lymphoma subtype
  • Establish a central repository of biospecimens, cell lines, and in vivo models with open access
  • Organize patient advocacy to support research.

• Research

  • Catalogue how lymphoma cells differ across disease subtypes
  • Better define and identify mutations and other abnormalities associated with the disease
  • Develop strategies to identify high-risk patients who may benefit most from clinical trials
  • Enhance efforts to use immune therapies to cure lymphoma
  • Better understand how lymphoma cells communicate with normal cells.

“[W]e invite clinicians, scientists, advocates, and patients to weigh in on this strategic roadmap so that it reflects the input of everyone in the community,” Dr Weinstock said. “We will share these priorities with funding agencies, advocacy groups, and others who can help us address the challenges we have identified, and thereby accelerate the development of new approaches to understand and eradicate lymphoma.”

To weigh in, visit: http://www.hematology.org/lymphoma-roadmap.

This report was developed after a review of the state of the science in lymphoma that took place at a special ASH Meeting on Lymphoma Biology in August 2014. A second ASH Meeting on Lymphoma Biology is planned for the summer of 2016.

Researcher in the lab

Photo by Darren Baker

By agreeing upon—and addressing—the aspects of lymphoma research that need the most improvement, the research community could advance the treatment of these diseases, according to a report published in Blood.

The report’s authors said limitations in research infrastructure, funding, and collaborative approaches across research centers present potential challenges on the road to developing better treatments.

And they outlined several “priority areas” that, they believe, require particular attention.

“[Our report] draws focus to our most pressing needs, which, if unaddressed, will prevent transformative changes to how we study and treat these diseases,” said David M. Weinstock, MD, of the Dana-Farber Cancer Institute in Boston, Massachusetts.

“Directing our collaborative efforts toward the most high-impact areas will enable us to more rapidly bring life-saving treatments to our patients.”

The report lists the following priority areas:

• Infrastructure

  • Develop an adequate number of disease models for each lymphoma subtype
  • Establish a central repository of biospecimens, cell lines, and in vivo models with open access
  • Organize patient advocacy to support research.

• Research

  • Catalogue how lymphoma cells differ across disease subtypes
  • Better define and identify mutations and other abnormalities associated with the disease
  • Develop strategies to identify high-risk patients who may benefit most from clinical trials
  • Enhance efforts to use immune therapies to cure lymphoma
  • Better understand how lymphoma cells communicate with normal cells.

“[W]e invite clinicians, scientists, advocates, and patients to weigh in on this strategic roadmap so that it reflects the input of everyone in the community,” Dr Weinstock said. “We will share these priorities with funding agencies, advocacy groups, and others who can help us address the challenges we have identified, and thereby accelerate the development of new approaches to understand and eradicate lymphoma.”

To weigh in, visit: http://www.hematology.org/lymphoma-roadmap.

This report was developed after a review of the state of the science in lymphoma that took place at a special ASH Meeting on Lymphoma Biology in August 2014. A second ASH Meeting on Lymphoma Biology is planned for the summer of 2016.

Researcher in the lab

Photo by Darren Baker

By agreeing upon—and addressing—the aspects of lymphoma research that need the most improvement, the research community could advance the treatment of these diseases, according to a report published in Blood.

The report’s authors said limitations in research infrastructure, funding, and collaborative approaches across research centers present potential challenges on the road to developing better treatments.

And they outlined several “priority areas” that, they believe, require particular attention.

“[Our report] draws focus to our most pressing needs, which, if unaddressed, will prevent transformative changes to how we study and treat these diseases,” said David M. Weinstock, MD, of the Dana-Farber Cancer Institute in Boston, Massachusetts.

“Directing our collaborative efforts toward the most high-impact areas will enable us to more rapidly bring life-saving treatments to our patients.”

The report lists the following priority areas:

• Infrastructure

  • Develop an adequate number of disease models for each lymphoma subtype
  • Establish a central repository of biospecimens, cell lines, and in vivo models with open access
  • Organize patient advocacy to support research.

• Research

  • Catalogue how lymphoma cells differ across disease subtypes
  • Better define and identify mutations and other abnormalities associated with the disease
  • Develop strategies to identify high-risk patients who may benefit most from clinical trials
  • Enhance efforts to use immune therapies to cure lymphoma
  • Better understand how lymphoma cells communicate with normal cells.

“[W]e invite clinicians, scientists, advocates, and patients to weigh in on this strategic roadmap so that it reflects the input of everyone in the community,” Dr Weinstock said. “We will share these priorities with funding agencies, advocacy groups, and others who can help us address the challenges we have identified, and thereby accelerate the development of new approaches to understand and eradicate lymphoma.”

To weigh in, visit: http://www.hematology.org/lymphoma-roadmap.

This report was developed after a review of the state of the science in lymphoma that took place at a special ASH Meeting on Lymphoma Biology in August 2014. A second ASH Meeting on Lymphoma Biology is planned for the summer of 2016.

Researchers in the lab

Photo by Rhoda Baer

New research suggests that heritable mutations in the gene ETV6 can predispose people to acute lymphoblastic leukemia (ALL).

Somatic mutations in ETV6 have previously been implicated in the development of ALL and other hematologic malignancies.

The new study, published in Nature Genetics, has shown that germline mutations in ETV6 are associated with thrombocytopenia, red blood cell (RBC) macrocytosis, and predisposition to ALL.

The research began with a family (family 1) that had autosomal dominant thrombocytopenia  (67,000-132,000 platelets/μL), high RBC mean corpuscular volume (MCV,  92.5-101.5 fl), and 2 cases of B-cell-precursor ALL.

“All of them had big red blood cells, low platelet counts, and propensity to bleed,” said study author Christopher Porter, MD, of the University of Colorado Denver.

This familial link to abnormal blood dynamics and predisposition to ALL implied a common genetic denominator. To find it, the researchers performed whole-exome sequencing and found a heterozygous single-nucleotide change in ETV6, c.641C>T, encoding a p.Pro214Leu substitution in the central domain.

The researchers then screened 23 other families with similar phenotypes as the first and identified 2 families with ETV6 mutations.

One family (family 2) had members with platelet counts ranging from 44,000 to 115,000 platelets/μL, RBC MCVs ranging from 88 to 97 fl, and a member with ALL. All affected family members had a c.641C>T mutation identical to the one identified in family 1.

Another family (family 3) had members with platelet counts ranging from 99,000 to 101,000 platelets/μL and RBC MCVs ranging from 93 to 98 fl but no malignancies. Members of this family had a c.1252A>G transition producing a p.Arg418Gly substitution in the DNA-binding domain, with alternative splicing and exon skipping.

The researchers said these mutations partially disrupt ETV6 transcriptional repression in vitro and cause aberrant cytoplasmic localization of both mutant and endogenous ETV6, suggesting a dominant-negative effect. The mutations also impair megakaryocyte development and proplatelet formation in culture.

Dr Porter and his colleagues noted that another team of researchers recently discovered germline missense mutations in ETV6 in 3 unrelated families. Dr Porter’s group hopes future work will show the prevalence of germline mutations in ETV6.

“It’s not common in a general population, but we think it might be much more common in people who develop ALL,” Dr Porter said. “[Our] paper highlights this gene in the development of leukemia. By studying this mutation, we should be able to gather a better understanding of how leukemia develops.”

Researchers in the lab

Photo by Rhoda Baer

New research suggests that heritable mutations in the gene ETV6 can predispose people to acute lymphoblastic leukemia (ALL).

Somatic mutations in ETV6 have previously been implicated in the development of ALL and other hematologic malignancies.

The new study, published in Nature Genetics, has shown that germline mutations in ETV6 are associated with thrombocytopenia, red blood cell (RBC) macrocytosis, and predisposition to ALL.

The research began with a family (family 1) that had autosomal dominant thrombocytopenia  (67,000-132,000 platelets/μL), high RBC mean corpuscular volume (MCV,  92.5-101.5 fl), and 2 cases of B-cell-precursor ALL.

“All of them had big red blood cells, low platelet counts, and propensity to bleed,” said study author Christopher Porter, MD, of the University of Colorado Denver.

This familial link to abnormal blood dynamics and predisposition to ALL implied a common genetic denominator. To find it, the researchers performed whole-exome sequencing and found a heterozygous single-nucleotide change in ETV6, c.641C>T, encoding a p.Pro214Leu substitution in the central domain.

The researchers then screened 23 other families with similar phenotypes as the first and identified 2 families with ETV6 mutations.

One family (family 2) had members with platelet counts ranging from 44,000 to 115,000 platelets/μL, RBC MCVs ranging from 88 to 97 fl, and a member with ALL. All affected family members had a c.641C>T mutation identical to the one identified in family 1.

Another family (family 3) had members with platelet counts ranging from 99,000 to 101,000 platelets/μL and RBC MCVs ranging from 93 to 98 fl but no malignancies. Members of this family had a c.1252A>G transition producing a p.Arg418Gly substitution in the DNA-binding domain, with alternative splicing and exon skipping.

The researchers said these mutations partially disrupt ETV6 transcriptional repression in vitro and cause aberrant cytoplasmic localization of both mutant and endogenous ETV6, suggesting a dominant-negative effect. The mutations also impair megakaryocyte development and proplatelet formation in culture.

Dr Porter and his colleagues noted that another team of researchers recently discovered germline missense mutations in ETV6 in 3 unrelated families. Dr Porter’s group hopes future work will show the prevalence of germline mutations in ETV6.

“It’s not common in a general population, but we think it might be much more common in people who develop ALL,” Dr Porter said. “[Our] paper highlights this gene in the development of leukemia. By studying this mutation, we should be able to gather a better understanding of how leukemia develops.”

Researchers in the lab

Photo by Rhoda Baer

New research suggests that heritable mutations in the gene ETV6 can predispose people to acute lymphoblastic leukemia (ALL).

Somatic mutations in ETV6 have previously been implicated in the development of ALL and other hematologic malignancies.

The new study, published in Nature Genetics, has shown that germline mutations in ETV6 are associated with thrombocytopenia, red blood cell (RBC) macrocytosis, and predisposition to ALL.

The research began with a family (family 1) that had autosomal dominant thrombocytopenia  (67,000-132,000 platelets/μL), high RBC mean corpuscular volume (MCV,  92.5-101.5 fl), and 2 cases of B-cell-precursor ALL.

“All of them had big red blood cells, low platelet counts, and propensity to bleed,” said study author Christopher Porter, MD, of the University of Colorado Denver.

This familial link to abnormal blood dynamics and predisposition to ALL implied a common genetic denominator. To find it, the researchers performed whole-exome sequencing and found a heterozygous single-nucleotide change in ETV6, c.641C>T, encoding a p.Pro214Leu substitution in the central domain.

The researchers then screened 23 other families with similar phenotypes as the first and identified 2 families with ETV6 mutations.

One family (family 2) had members with platelet counts ranging from 44,000 to 115,000 platelets/μL, RBC MCVs ranging from 88 to 97 fl, and a member with ALL. All affected family members had a c.641C>T mutation identical to the one identified in family 1.

Another family (family 3) had members with platelet counts ranging from 99,000 to 101,000 platelets/μL and RBC MCVs ranging from 93 to 98 fl but no malignancies. Members of this family had a c.1252A>G transition producing a p.Arg418Gly substitution in the DNA-binding domain, with alternative splicing and exon skipping.

The researchers said these mutations partially disrupt ETV6 transcriptional repression in vitro and cause aberrant cytoplasmic localization of both mutant and endogenous ETV6, suggesting a dominant-negative effect. The mutations also impair megakaryocyte development and proplatelet formation in culture.

Dr Porter and his colleagues noted that another team of researchers recently discovered germline missense mutations in ETV6 in 3 unrelated families. Dr Porter’s group hopes future work will show the prevalence of germline mutations in ETV6.

“It’s not common in a general population, but we think it might be much more common in people who develop ALL,” Dr Porter said. “[Our] paper highlights this gene in the development of leukemia. By studying this mutation, we should be able to gather a better understanding of how leukemia develops.”

Colony of iPSCs

Image by James Thomson

A new study has improved researchers’ understanding of a genetic defect associated with myelodysplastic syndromes (MDS), and the team hopes this will ultimately help us correct the defect in patients.

The researchers used induced pluripotent stem cells (iPSCs) to study del(7q), a chromosomal abnormality found in patients with MDS.

This provided the team with new insight into how the deletion contributes to MDS development.

Steven D. Nimer, MD, of the Sylvester Comprehensive Cancer Center at the University of Miami in Florida, and his colleagues described this work in Nature Biotechnology.

To determine how del(7q) contributes to MDS development, the researchers isolated hematopoietic cells from a patient with del(7q) and reprogrammed them into iPSCs. These iPSCs recapitulated MDS-associated phenotypes, including impaired hematopoietic differentiation.

The researchers also showed that, by engineering heterozygous chromosome 7q loss, they could recapitulate in normal iPSCs the characteristics they observed in the del(7q) iPSCs.

So the team was not surprised to find that disease phenotypes were rescued when del(7q) iPSC lines acquired a duplicate copy of chromosome 7q material.

The researchers also found that hemizygosity of chromosome 7q reduced the expression of many genes in the chromosome7q-deleted region. But gene expression was restored upon chromosome 7q dosage correction.

“[W]e were able to pinpoint a region on chromosome 7 that is critical and were able to identify candidate genes residing there that may cause this disease,” said study author Eirini Papapetrou, MD, PhD, of the Icahn School of Medicine at Mount Sinai in New York, New York.

Focusing on hits residing in this region, 7q32.3–7q36.1, the researchers found 10 genes that were enriched (by >1.5-fold) recurrently.

Further investigation confirmed that 4 of these genes—HIPK2, ATP6V0E2, LUC7L2, and EZH2—could partially rescue the emergence of CD45⁺ hematopoietic progenitors when overexpressed in del(7q) iPSCs.

The researchers conducted additional experiments focusing on EZH2 alone and found that haploinsufficiency of EZH2 decreases cells’ hematopoietic potential.

But it seems the hematopoietic defects caused by chromosome 7q hemizygosity are mediated through the haploinsufficiency of EZH2 in combination with 1 or more additional genes, which might include LUC7L2, HIPK2, ATP6V0E2, and/or other genes.

Colony of iPSCs

Image by James Thomson

A new study has improved researchers’ understanding of a genetic defect associated with myelodysplastic syndromes (MDS), and the team hopes this will ultimately help us correct the defect in patients.

The researchers used induced pluripotent stem cells (iPSCs) to study del(7q), a chromosomal abnormality found in patients with MDS.

This provided the team with new insight into how the deletion contributes to MDS development.

Steven D. Nimer, MD, of the Sylvester Comprehensive Cancer Center at the University of Miami in Florida, and his colleagues described this work in Nature Biotechnology.

To determine how del(7q) contributes to MDS development, the researchers isolated hematopoietic cells from a patient with del(7q) and reprogrammed them into iPSCs. These iPSCs recapitulated MDS-associated phenotypes, including impaired hematopoietic differentiation.

The researchers also showed that, by engineering heterozygous chromosome 7q loss, they could recapitulate in normal iPSCs the characteristics they observed in the del(7q) iPSCs.

So the team was not surprised to find that disease phenotypes were rescued when del(7q) iPSC lines acquired a duplicate copy of chromosome 7q material.

The researchers also found that hemizygosity of chromosome 7q reduced the expression of many genes in the chromosome7q-deleted region. But gene expression was restored upon chromosome 7q dosage correction.

“[W]e were able to pinpoint a region on chromosome 7 that is critical and were able to identify candidate genes residing there that may cause this disease,” said study author Eirini Papapetrou, MD, PhD, of the Icahn School of Medicine at Mount Sinai in New York, New York.

Focusing on hits residing in this region, 7q32.3–7q36.1, the researchers found 10 genes that were enriched (by >1.5-fold) recurrently.

Further investigation confirmed that 4 of these genes—HIPK2, ATP6V0E2, LUC7L2, and EZH2—could partially rescue the emergence of CD45⁺ hematopoietic progenitors when overexpressed in del(7q) iPSCs.

The researchers conducted additional experiments focusing on EZH2 alone and found that haploinsufficiency of EZH2 decreases cells’ hematopoietic potential.

But it seems the hematopoietic defects caused by chromosome 7q hemizygosity are mediated through the haploinsufficiency of EZH2 in combination with 1 or more additional genes, which might include LUC7L2, HIPK2, ATP6V0E2, and/or other genes.

Colony of iPSCs

Image by James Thomson

A new study has improved researchers’ understanding of a genetic defect associated with myelodysplastic syndromes (MDS), and the team hopes this will ultimately help us correct the defect in patients.

The researchers used induced pluripotent stem cells (iPSCs) to study del(7q), a chromosomal abnormality found in patients with MDS.

This provided the team with new insight into how the deletion contributes to MDS development.

Steven D. Nimer, MD, of the Sylvester Comprehensive Cancer Center at the University of Miami in Florida, and his colleagues described this work in Nature Biotechnology.

To determine how del(7q) contributes to MDS development, the researchers isolated hematopoietic cells from a patient with del(7q) and reprogrammed them into iPSCs. These iPSCs recapitulated MDS-associated phenotypes, including impaired hematopoietic differentiation.

The researchers also showed that, by engineering heterozygous chromosome 7q loss, they could recapitulate in normal iPSCs the characteristics they observed in the del(7q) iPSCs.

So the team was not surprised to find that disease phenotypes were rescued when del(7q) iPSC lines acquired a duplicate copy of chromosome 7q material.

The researchers also found that hemizygosity of chromosome 7q reduced the expression of many genes in the chromosome7q-deleted region. But gene expression was restored upon chromosome 7q dosage correction.

“[W]e were able to pinpoint a region on chromosome 7 that is critical and were able to identify candidate genes residing there that may cause this disease,” said study author Eirini Papapetrou, MD, PhD, of the Icahn School of Medicine at Mount Sinai in New York, New York.

Focusing on hits residing in this region, 7q32.3–7q36.1, the researchers found 10 genes that were enriched (by >1.5-fold) recurrently.

Further investigation confirmed that 4 of these genes—HIPK2, ATP6V0E2, LUC7L2, and EZH2—could partially rescue the emergence of CD45⁺ hematopoietic progenitors when overexpressed in del(7q) iPSCs.

The researchers conducted additional experiments focusing on EZH2 alone and found that haploinsufficiency of EZH2 decreases cells’ hematopoietic potential.

But it seems the hematopoietic defects caused by chromosome 7q hemizygosity are mediated through the haploinsufficiency of EZH2 in combination with 1 or more additional genes, which might include LUC7L2, HIPK2, ATP6V0E2, and/or other genes.