T Cell Lymphomas

NEW ORLEANS – Tweaking experimental gene therapy for X-linked severe combined immunodeficiency may help to restore patient immune function while reducing the risk for subsequent leukemias.

In a small, multinational phase I/II trial, seven of nine children with SCID-X1 showed evidence of T-cell recovery and function, as well as a lower risk for promoting growth of leukemic cells, when a self-inactivating gamma-retroviral vector (SCID-2) was used to promote reconstitution of the child’s immune system without insertional oncogenesis, reported Dr. Sung-Yun Pai at the annual meeting of the American Society of Hematology.

"Outcomes for boys who do not have well-matched donors are suboptimal, and it’s particularly for these boys that we are targeting gene therapy," said Dr. Pai, of Boston Children’s Hospital and the Dana-Farber Cancer Institute, Boston.

In previous gene therapy trials, investigators used the Moloney leukemia virus (MLV)-based gamma-retroviral vector (SCID-1) with strong promoters and enhancers to express an IL-2 receptor that reconstituted the immune system successfully in 18 of 20 boys.

However, 5 of the 20 boys developed T-cell acute lymphoblastic leukemia; 1 of the children died, and the remaining 4 were successfully treated.

The investigators found that in the patients with leukemia, the SCID-1 vector had inserted into a chromosomal region close to proto-oncogenes such as LMO2, and the enhancers were driving expression of the neighboring oncogene, promoting expression of aberrant T cells. The vector was subsequently modified with the goal of improved safety but similar efficacy to the original, said Dr. Pai. The strong viral enhancers were removed to prevent accident enhancement should the inserted genes manage to find their way into oncogenes.

The phase I/II study is being conducted in London, Paris, Boston, Cincinnati, and Los Angeles, and to date has enrolled 9 male children of a planned 20.

Of the 9, one child died from a preexisting adenoviral infection before immune recovery was complete, and one child did not have engraftment of the gene-marked cells and went on to transplant.

"The other patients have 9 months to 36 months of follow-up, they have evidence of T-cell recovery, of T-cell function, have cleared SCID-related infections, and are all out of hospital, healthy at home, [and] leading essentially normal lives."

When the investigators looked at the comparative efficacy of the SCID-1 and SCID-2 vectors, they saw that 6 months after gene therapy, there was no significant difference in the median number of T cells generated.

"It’s far too early to comment on whether this vector will truly be safer in terms of leukemia," Dr. Pai said, noting that in the SCID-1 trial the leukemias developed 3-5 years after gene therapy, and the longest follow-up in the SCID-2 study is only 3 years.

The investigators are, however, conducting molecular surrogate safety analyses looking at gene insertion sites from the blood of patients treated with SCID-1 and are comparing those sites with the vector-insertion sites in cells from patients in SCID-2.

Looking at a global genomewide map of integrations, they found no significant differences between SCID-1 and SCID-2. However, when they focused on 38 genes that are to be proto-oncogenes in lymphoid cancer, they found that significantly more integration of the modified genes occurred in proximity to the oncogenes in SCID-1 than in SCID-2 (P = .003).

"We hope that these data suggest that the modified SCID vector will show less capacity to drive aberrant cell growth and lead to less leukemogenesis," said Dr. Pai.

SCID-X1 is caused by inherited mutations in the gamma subunit of the interleukin (IL)-2 receptor. As a result, males are born without T lymphocytes or natural killer cells. Without a bone marrow or stem cell transplantation, children with the disease die early from opportunistic or community-acquired infections.

"These are really paradigm-changing results for mortally wounded children," said Dr. Laurence James Neil Cooper of the University of Texas M.D. Anderson Cancer Center in Houston, who moderated the briefing but was not involved in the study.

The trial is being sponsored by Children’s Hospital Boston, Cincinnati Children’s Hospital Medical Center, and the University of California, Los Angeles. Dr. Pai and Dr. Cooper reported having no relevant conflicts of interest.

NEW ORLEANS – Tweaking experimental gene therapy for X-linked severe combined immunodeficiency may help to restore patient immune function while reducing the risk for subsequent leukemias.

In a small, multinational phase I/II trial, seven of nine children with SCID-X1 showed evidence of T-cell recovery and function, as well as a lower risk for promoting growth of leukemic cells, when a self-inactivating gamma-retroviral vector (SCID-2) was used to promote reconstitution of the child’s immune system without insertional oncogenesis, reported Dr. Sung-Yun Pai at the annual meeting of the American Society of Hematology.

"Outcomes for boys who do not have well-matched donors are suboptimal, and it’s particularly for these boys that we are targeting gene therapy," said Dr. Pai, of Boston Children’s Hospital and the Dana-Farber Cancer Institute, Boston.

In previous gene therapy trials, investigators used the Moloney leukemia virus (MLV)-based gamma-retroviral vector (SCID-1) with strong promoters and enhancers to express an IL-2 receptor that reconstituted the immune system successfully in 18 of 20 boys.

However, 5 of the 20 boys developed T-cell acute lymphoblastic leukemia; 1 of the children died, and the remaining 4 were successfully treated.

The investigators found that in the patients with leukemia, the SCID-1 vector had inserted into a chromosomal region close to proto-oncogenes such as LMO2, and the enhancers were driving expression of the neighboring oncogene, promoting expression of aberrant T cells. The vector was subsequently modified with the goal of improved safety but similar efficacy to the original, said Dr. Pai. The strong viral enhancers were removed to prevent accident enhancement should the inserted genes manage to find their way into oncogenes.

The phase I/II study is being conducted in London, Paris, Boston, Cincinnati, and Los Angeles, and to date has enrolled 9 male children of a planned 20.

Of the 9, one child died from a preexisting adenoviral infection before immune recovery was complete, and one child did not have engraftment of the gene-marked cells and went on to transplant.

"The other patients have 9 months to 36 months of follow-up, they have evidence of T-cell recovery, of T-cell function, have cleared SCID-related infections, and are all out of hospital, healthy at home, [and] leading essentially normal lives."

When the investigators looked at the comparative efficacy of the SCID-1 and SCID-2 vectors, they saw that 6 months after gene therapy, there was no significant difference in the median number of T cells generated.

"It’s far too early to comment on whether this vector will truly be safer in terms of leukemia," Dr. Pai said, noting that in the SCID-1 trial the leukemias developed 3-5 years after gene therapy, and the longest follow-up in the SCID-2 study is only 3 years.

The investigators are, however, conducting molecular surrogate safety analyses looking at gene insertion sites from the blood of patients treated with SCID-1 and are comparing those sites with the vector-insertion sites in cells from patients in SCID-2.

Looking at a global genomewide map of integrations, they found no significant differences between SCID-1 and SCID-2. However, when they focused on 38 genes that are to be proto-oncogenes in lymphoid cancer, they found that significantly more integration of the modified genes occurred in proximity to the oncogenes in SCID-1 than in SCID-2 (P = .003).

"We hope that these data suggest that the modified SCID vector will show less capacity to drive aberrant cell growth and lead to less leukemogenesis," said Dr. Pai.

SCID-X1 is caused by inherited mutations in the gamma subunit of the interleukin (IL)-2 receptor. As a result, males are born without T lymphocytes or natural killer cells. Without a bone marrow or stem cell transplantation, children with the disease die early from opportunistic or community-acquired infections.

"These are really paradigm-changing results for mortally wounded children," said Dr. Laurence James Neil Cooper of the University of Texas M.D. Anderson Cancer Center in Houston, who moderated the briefing but was not involved in the study.

The trial is being sponsored by Children’s Hospital Boston, Cincinnati Children’s Hospital Medical Center, and the University of California, Los Angeles. Dr. Pai and Dr. Cooper reported having no relevant conflicts of interest.

NEW ORLEANS – Tweaking experimental gene therapy for X-linked severe combined immunodeficiency may help to restore patient immune function while reducing the risk for subsequent leukemias.

In a small, multinational phase I/II trial, seven of nine children with SCID-X1 showed evidence of T-cell recovery and function, as well as a lower risk for promoting growth of leukemic cells, when a self-inactivating gamma-retroviral vector (SCID-2) was used to promote reconstitution of the child’s immune system without insertional oncogenesis, reported Dr. Sung-Yun Pai at the annual meeting of the American Society of Hematology.

"Outcomes for boys who do not have well-matched donors are suboptimal, and it’s particularly for these boys that we are targeting gene therapy," said Dr. Pai, of Boston Children’s Hospital and the Dana-Farber Cancer Institute, Boston.

In previous gene therapy trials, investigators used the Moloney leukemia virus (MLV)-based gamma-retroviral vector (SCID-1) with strong promoters and enhancers to express an IL-2 receptor that reconstituted the immune system successfully in 18 of 20 boys.

However, 5 of the 20 boys developed T-cell acute lymphoblastic leukemia; 1 of the children died, and the remaining 4 were successfully treated.

The investigators found that in the patients with leukemia, the SCID-1 vector had inserted into a chromosomal region close to proto-oncogenes such as LMO2, and the enhancers were driving expression of the neighboring oncogene, promoting expression of aberrant T cells. The vector was subsequently modified with the goal of improved safety but similar efficacy to the original, said Dr. Pai. The strong viral enhancers were removed to prevent accident enhancement should the inserted genes manage to find their way into oncogenes.

The phase I/II study is being conducted in London, Paris, Boston, Cincinnati, and Los Angeles, and to date has enrolled 9 male children of a planned 20.

Of the 9, one child died from a preexisting adenoviral infection before immune recovery was complete, and one child did not have engraftment of the gene-marked cells and went on to transplant.

"The other patients have 9 months to 36 months of follow-up, they have evidence of T-cell recovery, of T-cell function, have cleared SCID-related infections, and are all out of hospital, healthy at home, [and] leading essentially normal lives."

When the investigators looked at the comparative efficacy of the SCID-1 and SCID-2 vectors, they saw that 6 months after gene therapy, there was no significant difference in the median number of T cells generated.

"It’s far too early to comment on whether this vector will truly be safer in terms of leukemia," Dr. Pai said, noting that in the SCID-1 trial the leukemias developed 3-5 years after gene therapy, and the longest follow-up in the SCID-2 study is only 3 years.

The investigators are, however, conducting molecular surrogate safety analyses looking at gene insertion sites from the blood of patients treated with SCID-1 and are comparing those sites with the vector-insertion sites in cells from patients in SCID-2.

Looking at a global genomewide map of integrations, they found no significant differences between SCID-1 and SCID-2. However, when they focused on 38 genes that are to be proto-oncogenes in lymphoid cancer, they found that significantly more integration of the modified genes occurred in proximity to the oncogenes in SCID-1 than in SCID-2 (P = .003).

"We hope that these data suggest that the modified SCID vector will show less capacity to drive aberrant cell growth and lead to less leukemogenesis," said Dr. Pai.

SCID-X1 is caused by inherited mutations in the gamma subunit of the interleukin (IL)-2 receptor. As a result, males are born without T lymphocytes or natural killer cells. Without a bone marrow or stem cell transplantation, children with the disease die early from opportunistic or community-acquired infections.

"These are really paradigm-changing results for mortally wounded children," said Dr. Laurence James Neil Cooper of the University of Texas M.D. Anderson Cancer Center in Houston, who moderated the briefing but was not involved in the study.

The trial is being sponsored by Children’s Hospital Boston, Cincinnati Children’s Hospital Medical Center, and the University of California, Los Angeles. Dr. Pai and Dr. Cooper reported having no relevant conflicts of interest.

ATLANTA – The antilymphoma drug vorinostat may help to reduce the incidence of serious acute graft-versus-host disease in patients who have undergone blood and bone marrow transplants, said researchers at the annual meeting of the American Society of Hematology.

In a first-in-humans phase I/II trial, adults with hematologic malignancies who underwent hematopoietic stem-cell transplants (HSCTs) with reduced-intensity conditioning and also received vorinostat (Zolinza) before, during, and after transplant had significantly fewer episodes of graft-versus-host disease (GvHD) than did historical controls who received standard GvHD prophylaxis but not vorinostat, reported Dr. Pavan Reddy of the University of Michigan, Ann Arbor.

"From a biological standpoint, we found that using this drug, just as we did in our experimental mouse models, we were able to reduce inflammation." The results were based on measurement of different cytokines, as well as increased acetylation of certain proteins, said Dr. Reddy at a media briefing.

Vorinostat treatment also increased the population of regulatory T cells, "which really have salutary effects on graft-versus-host disease outcomes," he added.

Vorinostat is a histone deacetylase (HDAC) inhibitor approved as a third-line therapy for the treatment of progressive, persistent, or recurrent cutaneous T-cell lymphoma.

In animal studies, Dr. Reddy and his colleague Dr. Sung W. Choi, as well as other groups, have shown that HDAC inhibitors are effective against experimental GvHD, suppress the production of proinflammatory cytokines, and alter the immune response by modulating antigen-presenting cells and by enhancing the production and function of regulatory T cells.

With investigators at Washington University in St. Louis, the Michigan researchers enrolled adult patients scheduled to undergo allogeneic HSCT from donors matched by at least 7 of 8 HLA factors. The patients could be in either complete or partial remission or have progressive disease.

A total of 47 patients were available for the analysis presented at the meeting. In phase I, 10 patients received 100 mg of vorinostat twice daily, and nine additional patients underwent dose escalation to 200 mg twice daily. The remaining 28 patients were treated in phase II at the 100-mg b.i.d. dose. All patients also received standard GvHD prophylaxis with tacrolimus and mycophenolate mofetil. Patients received vorinostat beginning 10 days before transplant and continuing through day 100, when the incidence of grade 2-4 GvHD, the primary endpoint, was assessed.

Neil Osterweil/IMNG Medical Media

The results were compared with those of 25 historical controls. Both neutrophil and platelet engraftment occurred at a median of 12 days on study, compared with 11 days each for controls.

The cumulative incidence of grade 2-4 GvHD at day 100 was 22% for patients on vorinostat, compared with 48% for controls (P = .03). There was also a nonsignificant trend favoring vorinostat for prevention of grade 3-4 GvHD, Dr. Reddy noted.

There were nine cases of thrombocytopenia among patients on vorinostat, six among patients on the 200-mg b.i.d. dose, and three at the 100-mg b.i.d. dose. Ten patients on the drug had nausea. There were no significant differences in adverse event profiles, infectious complications, or causes of death between patients in the study and historical controls.

A hematologist who was not involved in the study commented that with vorinostat, investigators seemed to have found a balance between preventing serious GvHD, which significantly increases the risk of death, and mild or moderate GvHD, which is helpful for mounting an immune defense against malignant cells.

"We have seen in some biological studies that this kind of drug – and not only this drug but this group of drugs – can increase some cells in the blood of patients that will in fact decrease the probability of acute graft-versus-host disease and at the same time can also fight against the cancer cells," said Dr. Vanderson Rocha from the University of Oxford (England). Dr. Rocha moderated the briefing where Dr. Reddy presented the data.

The study was supported by the National Institutes of Health. Dr. Reddy, Dr. Choi, and Dr. Rocha all declared having no relevant conflicts of interest to disclose.

ATLANTA – The antilymphoma drug vorinostat may help to reduce the incidence of serious acute graft-versus-host disease in patients who have undergone blood and bone marrow transplants, said researchers at the annual meeting of the American Society of Hematology.

In a first-in-humans phase I/II trial, adults with hematologic malignancies who underwent hematopoietic stem-cell transplants (HSCTs) with reduced-intensity conditioning and also received vorinostat (Zolinza) before, during, and after transplant had significantly fewer episodes of graft-versus-host disease (GvHD) than did historical controls who received standard GvHD prophylaxis but not vorinostat, reported Dr. Pavan Reddy of the University of Michigan, Ann Arbor.

"From a biological standpoint, we found that using this drug, just as we did in our experimental mouse models, we were able to reduce inflammation." The results were based on measurement of different cytokines, as well as increased acetylation of certain proteins, said Dr. Reddy at a media briefing.

Vorinostat treatment also increased the population of regulatory T cells, "which really have salutary effects on graft-versus-host disease outcomes," he added.

Vorinostat is a histone deacetylase (HDAC) inhibitor approved as a third-line therapy for the treatment of progressive, persistent, or recurrent cutaneous T-cell lymphoma.

In animal studies, Dr. Reddy and his colleague Dr. Sung W. Choi, as well as other groups, have shown that HDAC inhibitors are effective against experimental GvHD, suppress the production of proinflammatory cytokines, and alter the immune response by modulating antigen-presenting cells and by enhancing the production and function of regulatory T cells.

With investigators at Washington University in St. Louis, the Michigan researchers enrolled adult patients scheduled to undergo allogeneic HSCT from donors matched by at least 7 of 8 HLA factors. The patients could be in either complete or partial remission or have progressive disease.

A total of 47 patients were available for the analysis presented at the meeting. In phase I, 10 patients received 100 mg of vorinostat twice daily, and nine additional patients underwent dose escalation to 200 mg twice daily. The remaining 28 patients were treated in phase II at the 100-mg b.i.d. dose. All patients also received standard GvHD prophylaxis with tacrolimus and mycophenolate mofetil. Patients received vorinostat beginning 10 days before transplant and continuing through day 100, when the incidence of grade 2-4 GvHD, the primary endpoint, was assessed.

Neil Osterweil/IMNG Medical Media

The results were compared with those of 25 historical controls. Both neutrophil and platelet engraftment occurred at a median of 12 days on study, compared with 11 days each for controls.

The cumulative incidence of grade 2-4 GvHD at day 100 was 22% for patients on vorinostat, compared with 48% for controls (P = .03). There was also a nonsignificant trend favoring vorinostat for prevention of grade 3-4 GvHD, Dr. Reddy noted.

There were nine cases of thrombocytopenia among patients on vorinostat, six among patients on the 200-mg b.i.d. dose, and three at the 100-mg b.i.d. dose. Ten patients on the drug had nausea. There were no significant differences in adverse event profiles, infectious complications, or causes of death between patients in the study and historical controls.

A hematologist who was not involved in the study commented that with vorinostat, investigators seemed to have found a balance between preventing serious GvHD, which significantly increases the risk of death, and mild or moderate GvHD, which is helpful for mounting an immune defense against malignant cells.

"We have seen in some biological studies that this kind of drug – and not only this drug but this group of drugs – can increase some cells in the blood of patients that will in fact decrease the probability of acute graft-versus-host disease and at the same time can also fight against the cancer cells," said Dr. Vanderson Rocha from the University of Oxford (England). Dr. Rocha moderated the briefing where Dr. Reddy presented the data.

The study was supported by the National Institutes of Health. Dr. Reddy, Dr. Choi, and Dr. Rocha all declared having no relevant conflicts of interest to disclose.

ATLANTA – The antilymphoma drug vorinostat may help to reduce the incidence of serious acute graft-versus-host disease in patients who have undergone blood and bone marrow transplants, said researchers at the annual meeting of the American Society of Hematology.

In a first-in-humans phase I/II trial, adults with hematologic malignancies who underwent hematopoietic stem-cell transplants (HSCTs) with reduced-intensity conditioning and also received vorinostat (Zolinza) before, during, and after transplant had significantly fewer episodes of graft-versus-host disease (GvHD) than did historical controls who received standard GvHD prophylaxis but not vorinostat, reported Dr. Pavan Reddy of the University of Michigan, Ann Arbor.

"From a biological standpoint, we found that using this drug, just as we did in our experimental mouse models, we were able to reduce inflammation." The results were based on measurement of different cytokines, as well as increased acetylation of certain proteins, said Dr. Reddy at a media briefing.

Vorinostat treatment also increased the population of regulatory T cells, "which really have salutary effects on graft-versus-host disease outcomes," he added.

Vorinostat is a histone deacetylase (HDAC) inhibitor approved as a third-line therapy for the treatment of progressive, persistent, or recurrent cutaneous T-cell lymphoma.

In animal studies, Dr. Reddy and his colleague Dr. Sung W. Choi, as well as other groups, have shown that HDAC inhibitors are effective against experimental GvHD, suppress the production of proinflammatory cytokines, and alter the immune response by modulating antigen-presenting cells and by enhancing the production and function of regulatory T cells.

With investigators at Washington University in St. Louis, the Michigan researchers enrolled adult patients scheduled to undergo allogeneic HSCT from donors matched by at least 7 of 8 HLA factors. The patients could be in either complete or partial remission or have progressive disease.

A total of 47 patients were available for the analysis presented at the meeting. In phase I, 10 patients received 100 mg of vorinostat twice daily, and nine additional patients underwent dose escalation to 200 mg twice daily. The remaining 28 patients were treated in phase II at the 100-mg b.i.d. dose. All patients also received standard GvHD prophylaxis with tacrolimus and mycophenolate mofetil. Patients received vorinostat beginning 10 days before transplant and continuing through day 100, when the incidence of grade 2-4 GvHD, the primary endpoint, was assessed.

Neil Osterweil/IMNG Medical Media

The results were compared with those of 25 historical controls. Both neutrophil and platelet engraftment occurred at a median of 12 days on study, compared with 11 days each for controls.

The cumulative incidence of grade 2-4 GvHD at day 100 was 22% for patients on vorinostat, compared with 48% for controls (P = .03). There was also a nonsignificant trend favoring vorinostat for prevention of grade 3-4 GvHD, Dr. Reddy noted.

There were nine cases of thrombocytopenia among patients on vorinostat, six among patients on the 200-mg b.i.d. dose, and three at the 100-mg b.i.d. dose. Ten patients on the drug had nausea. There were no significant differences in adverse event profiles, infectious complications, or causes of death between patients in the study and historical controls.

A hematologist who was not involved in the study commented that with vorinostat, investigators seemed to have found a balance between preventing serious GvHD, which significantly increases the risk of death, and mild or moderate GvHD, which is helpful for mounting an immune defense against malignant cells.

"We have seen in some biological studies that this kind of drug – and not only this drug but this group of drugs – can increase some cells in the blood of patients that will in fact decrease the probability of acute graft-versus-host disease and at the same time can also fight against the cancer cells," said Dr. Vanderson Rocha from the University of Oxford (England). Dr. Rocha moderated the briefing where Dr. Reddy presented the data.

The study was supported by the National Institutes of Health. Dr. Reddy, Dr. Choi, and Dr. Rocha all declared having no relevant conflicts of interest to disclose.