ORLANDO — There is an urgent need for new therapies to treat relapsed or refractory peripheral T-cell lymphoma, but results of a phase 2 study suggest that monotherapy with the immune checkpoint inhibitor nivolumab (Opdivo) is not the hoped-for salvage treatment.
An interim analysis of data on 12 patients with peripheral T-cell lymphoma (PTCL) treated with nivolumab monotherapy showed an overall response rate of 33%, consisting of 2 complete responses and 2 partial responses. But the responses were short lived, and one patient had hyperprogressive disease — dramatic progression within one cycle of treatment — while two more had progression within two cycles, leading to a trial halt, reported N. Nora Bennani, MD, from the Mayo Clinic in Rochester, Minn.
"These findings likely reflect the distinct biology of PTCL and should be considered when designing future studies using checkpoint inhibitors in these diseases," she said at the annual meeting of the American Society of Hematology.
The rationale for using an immune checkpoint inhibitor directed against the programmed death–1 protein and its ligands (PD and PD-L1/2) is that malignant cells in PTCL induce a profoundly immunosuppressive tumor microenvironment. Checkpoint inhibitors have shown strong activity against relapsed Hodgkin lymphoma, and the Mayo Clinic researchers speculated that an anti-PD-1 agent could have a similar effect in PTCL.
They had originally planned to enroll 29 patients into a phase 2 trial with nivolumab delivered 240 mg every 2 weeks for eight cycles, followed by a dose of 480 mg given every 4 weeks until disease progression or intolerable toxicities.
Patients were eligible if they had biopsy-confirmed relapsed or refractory PTCL, measurable disease on cross-sectional imaging of at least 1.5 cm, and prior systemic chemoimmunotherapy and/or autologous stem cell transplantation.
The interim analysis included 12 patients who received at least one dose of nivolumab. Of the 12 patients, 6 had angioimmunoblastic T-cell lymphoma (AITL), 3 had PTCL not otherwise specified, and 1 each had ALK-negative anaplastic large cell lymphoma (ALK-ALCL), enteropathy-associated T-cell lymphoma (EATL), or hepatosplenic gamma/delta T-cell lymphoma.
All patients had Ann Arbor stage III/IV disease, and 11 had extranodal involvement.
As noted, there were 4 responses among the 12 patients, consisting of 1 complete response in the patient with ALK-ALCL and 1 in a patient with AITL, and 2 partial responses – 1 in a patient with PTCL-NOS, and 1 in the patient with EATL.
The median progression-free survival for all 12 patients was short at 2.7 months, and the median overall survival was estimated at 6.7 months.
"It was staggering to see this: The duration of response was significantly short, less than 2 months," Dr. Bennani said.
Nonhematologic toxicities were seen in 5 of the 12 patients (42%), and hematologic adverse events occurred in 3 (25%). All patients are now off treatment, 10 because of disease progression, 1 because of acute pancreatitis, and the aforementioned patient with hyperprogressive disease.
The patient with hyperprogressive disease had significant progression in tonsillar and cervical lymphadenopathy within 7-10 days of nivolumab infusion, with biopsy-proven AITL in the involved nodes.
"I believe that, in this patient population, combination therapies will be key. I think checkpoint blockers alone are not going to be sufficient to see meaningful outcomes in these patients," Dr. Bennani said in an interview.
"An overall response rate of 33% is significant, because most other agents that were FDA approved in this patient population have response rates around 30%," she said, adding that it's possible that the patients with rapid progression had disease too advanced to be effectively treated with a checkpoint inhibitor.
"Ideally however, if we want to move forward, it will need to be with combinations of checkpoint inhibitors with HDAC [histone deacetylase] inhibitors, hypomethylating agents, or even PI3 kinase inhibitors," she said.
The study was supported by Bristol-Myers Squibb. Dr. Bennani reported research funding and advisory board activities for Bristol-Myers Squibb and others.
Bennani NN et al. ASH 2019. Abstract 467.
This article first appeared on MDEdge.com
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