CBT May Improve Response to Subsequent Treatment in Heavily Pretreated Patients With HL
Patients with relapsed or refractory Hodgkin lymphoma (HL) after checkpoint blockade therapy (CBT) have limited options. However, researchers found that CBT may impact response to subsequent therapies. Nicole A. Carreau, MD, of New York University Langone Health in New York City, discussed the findings at the ASH Annual Meeting (https://ash.confex.com/ash/2018/webprogram/Paper117672.html) on December 1, 2018.
Researchers assessed medical records from 17 U.S. and Canadian centers to identify 71 patients with HL who received CBT followed by an additional line of therapy (median age = 37 years; range = 23–74 years; 39 female). They excluded patients who discontinued CBT because of complete response (CR) or whose best response could not be determined because death from another cause.
The final cohort included 50 patients. Fifteen patients had stage 1 or 2 disease, and all patients were heavily pretreated, having received a median of four prior therapies before CBT (range = 1–10 therapies), including 31 patients who received brentuximab vedotin. Twenty-eight patients had undergone allogeneic (n = 3) or autologous (n = 25) hematopoietic cell transplantation (HCT). Prior to CBT, the median duration of response to therapy was 3.5 months: 18 patients (36%) had relapsed disease and 32 (64%) had refractory disease.
Best response to CBT included 2 CRs (4%), 21 partial responses ([PRs]; 42%), 13 with stable disease ([SD]; 26%), and 14 with progressive disease (PD; 28%). Patients discontinued CBT because of PD (72%), preparation for transplant (16%), toxicity (8%), CR after the addition of chemotherapy (2%), or infectious complication (2%).
Post-CBT, patients received standard chemotherapy (46%), targeted therapy (22%), conditioning regimens for HCT (16%), other immunotherapy (4%), or investigational drugs (12%). Following CBT, the objective response rate (ORR) was 52%, including 17 CRs (34%) and 9 PRs (18%). Eight patients (16%) achieved SD, whereas 16 (32%) progressed. Response to subsequent treatment was associated with response to CBT: among patients who experienced CR or PR with CBT, the post-CBT ORR was 70% compared to 37% for those who did not respond to CBT.
At a median 14 months of follow-up, the median progression-free survival for the 34 patients who achieved CR, PR, or SD after CBT was 10.7 months. Twenty patients (58.8%) had not progressed at the time of reporting, and overall survival was not reached. Many patients (85%) remain alive.
The researchers observed no statistical difference in survival based on post-CBT treatment; however, 21 patients received subsequent HCT and all remain alive, although nine (75%) have progressed.
“A response to CBT appears to correlate with response to post-CBT treatment, but PD following CBT did not preclude a response to subsequent therapy,” the researchers concluded.