Nivolumab may provide a benefit for a small group of patients with diffuse large B-cell lymphoma (DLBCL) who have failed a transplant or are ineligible for one, according to researchers.
Nivolumab produced a response in 10 of 121 DLBCL patients studied. Three patients achieved a complete response (CR) lasting 11 months or more.
Why this small group responded to nivolumab isn’t clear, according to Stephen M. Ansell, MD, PhD, of the Mayo Clinic in Rochester, Minn., and his colleagues.
Some responders did have 9p24.1 alterations, but others did not. None of the responders had tumor cells positive for programmed death–ligand 1 (PD-L1), and only one responder had detectable PD-L2 expression in malignant cells.
Dr. Ansell and his colleagues described these findings in the Journal of Clinical Oncology.
The researchers evaluated nivolumab in a phase 2 trial (NCT02038933) of patients with relapsed/refractory DLBCL. Of the 121 patients, 87 had failed autologous hematopoietic stem cell transplant (HSCT) and 34 were ineligible for autologous HSCT. The patients received nivolumab at 3 mg/kg every 2 weeks until disease progression, unacceptable toxicity, or study withdrawal.
HSCT failures
The patients who had failed HSCT had a median age of 62 years (range, 24-75 years). They had received a median of three prior systemic therapies (range, 1-11), and 28% were refractory to their most recent therapy.
About 40% of patients had germinal center B-cell–like (GCB) DLBCL, 32% had non-GCB disease, and data on disease subtype were missing for the rest of the group.
The patients received a median of four nivolumab doses (range, 1-44) and were followed for a median of 9 months (range, 0.1-25 months).
Nine patients (10%) achieved a response, and the median duration of response was 11 months. Responses occurred in patients with GCB and non-GCB DLBCL.
Three patients achieved a CR. Two of them were still on treatment and in CR at the data cutoff. Their responses had lasted 11 months and 14 months, respectively. The third complete responder did not progress on nivolumab but developed myelodysplastic syndrome, which was unrelated to the drug, and died.
Among all patients who had failed HSCT, the median progression-free survival was 1.9 months, and the median overall survival was 12.2 months.
Seven patients in this group were still receiving nivolumab at the data cutoff. Two of them were in CR, two had a partial response, and three had stable disease.
HSCT-ineligible group
The patients who were ineligible for HSCT had a median age of 68 years (range, 28-86 years). They had received a median of three prior systemic therapies (range, 1-7), and 59% were refractory to their most recent therapy.
About 56% of these patients had GCB DLBCL, 18% had non-GCB disease, and data on subtype were missing for the rest of the group.
The patients received a median of three nivolumab doses (range, 1-22) and were followed for a median of 6 months (range, 0.2-24 months). One patient (3%) achieved a partial response, which lasted 8.3 months.
The median progression-free survival in this group was 1.4 months, and the median overall survival was 5.8 months.
None of the patients in this group were still taking nivolumab at the data cutoff.