SAN DIEGO — Children and young adults with low-risk relapsed or refractory classic Hodgkin lymphoma may be able to skip autologous stem cell transplant.
Patients who received second-line chemoimmunotherapy with nivolumab-brentuximab vedotin, with or without bendamustine, and proceeded to involved-site radiation appeared to have similar survival outcomes to those who received the chemoimmunotherapy combination plus the current second-line standard of care, which includes high-dose therapy and autologous stem cell transplant.
Among 28 patients with low-risk relapsed/refractory Hodgkin lymphoma followed for a median of 32 months, 3-year event-free survival without autologous stem cell transplant was 86.9% and 3-year progression-free survival was 95%, reported Brad Hoppe, MD, MPH, from the Mayo Clinic in Jacksonville, Florida. In contrast, 1-year progression-free survival was 91% among the 44 standard-risk patients who received high-dose therapy and autologous stem cell transplant, published separately earlier this year.
The latest results from the phase 2 CheckMate 744 trial were reported this week at the American Society of Radiation Oncology (ASTRO) annual meeting.
"The findings suggest that children, adolescents, and young adults with low-risk relapsed classic Hodgkin lymphoma can be salvaged with low-toxicity chemoimmunotherapy and may not require high-dose therapy and transplant for a cure," Hoppe said in an oral abstract session.
Andrea Ng, MD, MPH, a radiation oncologist who specializes in treating patients with Hodgkin lymphoma and other hematologic malignancies, said that while the number of patients in the study was small and the follow-up too short, this option is "certainly something that's very promising for the future."
"The use of transplant in relapsed patients, which we have been doing for decades, is based on two very old, small, randomized studies," said Ng, from the Dana-Farber Cancer Institute in Boston, who moderated the session.
"So, do we really need to transplant everybody? In the back of our minds, we think that we may be overtreating some patients," she said.
Several small, retrospective studies exploring treatment with conventional chemotherapy with or without radiation therapy and without transplant in patients with relapsed or refractory Hodgkin lymphoma have demonstrated only modest results.
The CheckMate 744 trial, however, was designed to examine a risk-adapted and response-adapted approach to treating children, adolescents, and young adults with relapsed or refractory classic Hodgkin lymphoma within the setting of modern immunotherapy and targeted therapy. This approach was developed jointly by investigators with the Children's Oncology Group and Euronet.
In the nonrandomized trial, patients were stratified into low-risk or standard-risk disease categories based on an algorithm that included factors at the time of initial diagnosis and relapse.
Patients were considered low-risk for relapse in three scenarios: (1) if they had initial stage IA or IIA disease that relapsed at least 1 year after the end of therapy; (2) if they had initial stage IA or IIA disease that relapsed between 3 and 12 months from the end of therapy but had received no more than 3 cycles of chemotherapy and no radiation therapy; or (3) if they had initial stage IB, IIB, or IIIA disease that relapsed more than 12 months after the end of first-line therapy.
To be included in the low-risk category, patients also had to be free of B symptoms or extranodal disease, free of relapse in prior radiation therapy fields, and have no more than four sites of lymphoma.
Low-risk patients were treated with a combination of nivolumab and brentuximab vedotin, which could be followed by additional brentuximab vedotin and bendamustine for those with a suboptimal response. Patients who achieved complete molecular remission after induction went on to consolidation therapy with involved-site radiation at a total dose of 30 Gy.
Patients considered standard-risk for relapse received the same nivolumab-brentuximab vedotin combination, with or without bendamustine, and then went on to high-dose therapy and autologous stem cell transplant.
The investigators previously reported results for the standard-risk patients earlier this year. In this cohort of 44 patients, the objective response rate was 95% — 86% of patients who achieved complete molecular remissions and 9% who achieved partial molecular remissions. In this group, 1-year progression-free survival was 91% and median progression-free survival was not reached over a minimum follow-up of 15.6 months.
At ASTRO, Hoppe reported results for the 28 patients with low-risk disease. One patient discontinued nivolumab/brentuximab vedotin after two cycles due to skin toxicity and was lost to follow-up. Of the remaining 27 patients, 21 experienced complete molecular remission after four cycles of the combination, and these patients went on to an additional two cycles of the combination, with 19 of 21 receiving involved-site radiation consolidation.
Six patients who had either a partial molecular remission or no response were given two additional cycles of brentuximab vedotin plus bendamustine. Of this group, 3 went on to complete molecular remission and received involved-site radiation consolidation on protocol. The remaining 3 patients who did not experience complete molecular remission received involved-site radiation off protocol.
The rate of complete molecular remission after four cycles of induction was 82.1%, and the rate of partial molecular remission was 14.3%, for an objective response rate of 96.4%. The respective response rates with the addition of two cycles of brentuximab vedotin and bendamustine were 92.9% and 7.1%, for an objective response rate of 100%, Hoppe reported.
Overall, at a median follow-up of 32 months, the 3-year event-free survival rate without transplant was 86.9%, and the 3-year progression-free survival rate was 95%.
Treatment-related adverse events of any grade occurred in 22 patients (78.6%) after induction, with 7 of those events (25%) being grade 3 or 4 in severity. Grade 3 or 4 events consisted of skin and subcutaneous tissue disorders in 3 patients, elevated liver function tests in 3 patients, and blood and lymphatic system disorders in 1 patient.
There were no new toxicities detected within 100 days of treatment.
"The results that Dr Hoppe showed us are really, really good," Ng said. And "the volume of treatment is pretty tiny, so I think we can safely say that long term toxicities are very, very minimal."
The study was supported by Bristol-Myers Squibb in collaboration with Seagen, Euronet-Paediatric Hodgkin Lymphoma, and the Children's Oncology Group. Hoppe reported serving on a scientific advisory committee for Merck. Ng reported having no relevant conflicts of interest.
American Society of Radiation Oncology (ASTRO) 2023 Annual Meeting. Abstract 3. Presented October 1, 2023.
Neil Osterweil, an award-winning medical journalist, is a long-standing and frequent contributor to Medscape.
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Cite this: Salvage Option to Replace Transplant in RR Hodgkin Lymphoma? - Medscape - Oct 03, 2023.