The ASCO Post obtained comments on the Smart Stop study from Dipenkumar Modi, MD, a medical oncologist and hematologist at the Barbara Ann Karmanos Cancer Institute and Assistant Professor of Oncology at Wayne State University School of Medicine, Detroit. Dr. Modi applauded the investigators for evaluating an innovative response-adapted approach aimed at reducing chemotherapy in diffuse large B-cell lymphoma (DLBCL). “Kudos to MD Anderson for performing this trial, whose intention was to incorporate novel therapeutics and use a truly individualized approach to reduce the need for chemotherapy,” he said.
However, Dr. Modi cautioned, before the findings can be applied in the clinic, longer follow-up will be important to show the durability of response, as eight patients remain on treatment. Ideally, the results would be replicated in a phase III randomized trial comparing this approach with the current standard of care. Dr. Modi also expressed a few concerns about the study population.
Smart Stop enrolled 30 newly diagnosed patients with DLBCL; however, there were patients of all stages and IPI (International Prognostic Index) levels. “Here, 80% of patients had stage III to IV disease, which means 20% had limited-stage disease. And the IPI score was between 3 and 5 in 67% of patients, which means one-third had low- to intermediate-risk IPIs,” he noted.
Similarly, 83% had the non-GCB (germinal center B-cell) subtype, so the benefit of this approach is unclear for the GCB subtype, which accounts for 40% of those with DLBCL in the general population. “We know that non-GCB patients respond favorably to a rituximab and lenalidomide–based combination. If half the patients had been the GCB subtype, would the data look as good?” he questioned. “It’s also important to know the outcome in double-expressor lymphoma, double-hit lymphoma, and high-grade B-cell lymphoma subtypes.”
“Aside from these issues and the short follow-up, with the Smart Stop data showing a complete remission rate of 100% among 22 patients and a 1-year progression-free survival rate of 100%, this response-adapted approach looks promising,” Dr. Modi concluded. “If we see good outcomes in the next year or so, the study may provide a good signal that we can rely on novel therapeutic approaches in DLBCL to improve outcomes and perhaps minimize the use of chemotherapy and associated side effects.”
DISCLOSURE: Dr. Modi reported no conflicts of interest.
