2019 ASCO: Rituximab, Lenalidomide, and Ibrutinib Prior to Chemotherapy in DLBCL
Results of the phase II Smart Start trial revealed that combination targeted therapy consisting of rituximab, lenalidomide, and ibrutinib had an 84.6% overall response rate (ORR) and 38.5% complete response rate (CRR) when given prior to any chemotherapy for newly diagnosed patients with a specific type of diffuse large B-cell lymphoma (DLBCL). Results of the trial were presented by Westin et al at the 2019 ASCO Annual Meeting (Abstract 7508).
The first-of-its-kind study examined a treatment regimen without chemotherapy for patients with non–germinal center DLBCL. Although confirmatory trials are needed, the findings suggest that patients who respond to targeted therapy initially may not need chemotherapy—currently the standard of care.
“The responses we’ve seen have been remarkable. More than 80% of our patients have responded, and around 40% have had a complete response, showing no evidence of cancer, prior to receiving any chemotherapy,” said principal investigator Jason Westin, MD, Assistant Professor of Lymphoma & Myeloma at The University of Texas MD Anderson Cancer Center, Houston. “All patients have gone on to receive standard chemotherapy in combination with these targeted treatments per the protocol, and, so far, we’ve had a 100% response rate.”
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The clinical trial enrolled 60 patients at MD Anderson with non–germinal center DLBCL and treated those patients with two cycles of rituximab, lenalidomide, and ibrutinib followed by six cycles of rituximab, lenalidomide, and ibrutinib with chemotherapy. Dr. Westin’s team designed the trial to bring new treatment options to these patients based on promising findings in the lab.
“We called the trial ‘Smart Start’ because we thought this was a smarter way to start therapy for these patients,” said Dr. Westin. “Standard treatment for large-cell lymphoma has been largely stagnant for the better part of 40 years, despite many advances in our understanding of the disease and a host of new medications. It’s exciting to see an idea that worked in the lab now beginning to yield results and show this is a potentially new way forward to fight this disease.” More than 90% of patients on this trial remain in remission after 1 year, he added.
One patient on the trial had a fatal fungal infection (central nervous system aspergillosis) attributed to high-dose corticosteroids and rituximab/lenalidomide/ibrutinib, leading to prohibition of corticosteroids during the rituximab/lenalidomide/ibrutinib–only cycles, with no further fungal infections identified.
Going forward, Dr. Westin and colleagues plan to launch clinical trials to investigate whether patients who respond well to rituximab/lenalidomide/ibrutinib treatment upfront can receive little or no chemotherapy and still attain long-term remission.
Disclosure: This study was supported by the Conquer Cancer Foundation, Celgene, and Janssen Pharmaceuticals. For full disclosures of the study authors, visit coi.asco.org.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
