Checkpoint blockade treatment sensitises relapsed/refractory non-Hodgkin lymphoma to subsequent therapy.

Patients with relapsed/refractory (R/R) non-Hodgkin lymphoma (NHL) have limited options for salvage, and checkpoint blockade therapy (CBT) has little efficacy. Usage in solid malignancies suggests that CBT sensitises tumours to subsequent chemotherapy. We performed the first analysis of CBT on subsequent NHL treatment. Seventeen North American centres retrospectively queried records. The primary aim was to evaluate the overall response rate (ORR) to post-CBT treatment. Secondary aims included progression-free survival (PFS), duration of response (DOR) and overall survival (OS). Fifty-nine patients (68% aggressive NHL, 69% advanced disease) were included. Patients received a median of three therapies before CBT. Fifty-three (90%) discontinued CBT due to progression. Post-CBT regimens included chemotherapy (49%), targeted therapy (30%), clinical trial (17%), transplant conditioning (2%) and chimeric antigen receptor T cell (CAR-T) therapy (2%). The ORR to post-CBT treatment was 51%, with median PFS of 6·1 months. In patients with at least stable disease (SD) to post-CBT, the median DOR was significantly longer than to pre-CBT (310 vs. 79 days, P = 0·005) suggesting sensitisation. Nineteen patients were transplanted after post-CBT therapy. Median overall survival was not reached, nor affected by regimen. Prospective trials are warranted, as this may offer R/R NHL patients a novel therapeutic approach.