At the recent 2019 American Society of Hematology annual meeting, researchers confirmed a clinical benefit for blinatumomab (Blincyto) in children and young adults with B-cell acute lymphoblastic leukemia (B-ALL) who still had residual disease following induction therapy.
In this exclusive ľֱ video, , director of the Hematologic Malignancies Section of Herbert Irving Comprehensive Cancer Center in New York City, discusses the study.
Following is a transcript of his remarks:
This is an . Blinatumomab is a bispecific T-cell engager that binds to CD19, which is on the surface of malignant B cells as well as CD3, which is on T cells. In this study, they treated patients up until age 30, and they took patients with high- or intermediate-risk relapse disease, gave them an intensive re-induction therapy with mitoxantrone, and then patients were randomized to receive either two blocks of intensive consolidation chemotherapy or two cycles of blinatumomab for 4 weeks each.
What was interesting in the study was that it was positive on many accounts in the blinatumomab arm. First, the 2-year overall survival was improved for the blinatumomab patients. Those patients had a 60% 2-year survival and about 40% for the chemotherapy arm.
Secondly, there was a higher relapse-free survival in these patients -- about 80% versus 60%. The MRD [minimal residual disease] negativity was also higher in the blinatumomab patients, and this confirms what we've seen in other studies, so this is a highly effective therapy for minimal residual disease. After just one cycle of blinatumomab, 80% of the patients achieved an MRD-negative state, whereas with chemotherapy it was only about 20% of patients.
Now eventually with chemotherapy, those numbers did equalize, but of course, multiple cycles of intensive chemotherapy put patients at higher risk for complications, neutropenia, infection, mucositis. More patients in the blinatumomab arm were able to undergo stem cell transplant, which is the only potentially curative therapy for such patients. About 75% of the patients receiving blinatumomab were able to undergo transplant, whereas it was only around 40% or 45% of patients that were receiving chemotherapy only that underwent transplant.
Overall, we can see that blinatumomab was highly effective at eliminating minimal residual disease, as we would have expected. More patients were able to get the transplant, more patients survived longer with less relapse. Interestingly, the toxicity profile was also favorable in the blinatumomab arm. One of the concerns with blinatumomab is it can produce cytokine-release syndrome. It can also produce significant neurologic toxicity, but we know this is disease dependent or disease-volume dependent.
I think this clearly represents an advance for patients. One wonders whether we can take patients with relapsed disease and use blinatumomab earlier on in the relapse course to get them to transplant without subjecting them to the side effects of intensive chemotherapy.
Of course, there are many other options now for patients with relapsed disease. Inotuzumab is another monoclonal antibody targeting CD22, delivering the chemotherapeutic agent calicheamicin. This is also effective in relapsed therapy.
Of course, there are CAR T cells. Interestingly, there's going to be a study coming up looking at CAR T-cell therapy versus either blinatumomab or inotuzumab in the relapsed-refractory setting, and I think that will also be a very interesting study, and we're anxiously awaiting those results.