P1090: CAMRELIZUMAB (CAM) COMBINED WITH GEMOX CHEMOTHERAPY RESULTS IN HIGH COMPLETE METABOLIC RESPONSE RATES IN RELAPSED/REFRACTORY CLASSIC HODGKIN LYMPHOMA (CHL): A PHASE II TRIAL

Abstract

Background: Approximately 30-35% of patients with classic Hodgkin Lymphoma will prove refractory to frontline therapy or relapse subsequently. Traditional second-line chemotherapy regimens result in complete response rates about 20-40%. Achievement of complete metabolic response (CMR) assessed by PET/CT imaging prior to hematopoietic stem cell transplant (HSCT) predicts favorable progression free survival (PFS) and overall survival (OS). PD‐1 antibody has shown remarkable efficacy in relapsed or refractory hodgkin lymphoma (R/R HL). Aims: we designed a clinical trial to evaluate the efficacy and safety of PD‐1 antibody camrelizumab combined with GEMOX chemotherapy in R/R HL patients. The preliminary results had been obtained. Methods: This is an open‐label, single‐center, non‐randomized, phase 2 study (NCT04239170). The main inclusion criteria included age ≥ 18, ECOG < 2, histopathology confirmed classical HL, no more than 3 lines of previous chemotherapy treatment, having measurable lesion(s) assessed by Lugano 2014 criteria and preparing to receive autologous stem cell transplantation (ASCT). Patients were treated with 2 cycles of camrelizumab (CAM, 200 mg IV, q2w) followed by 2 cycles (28-day cycle) of CAM (IV, day 1 and day 15) combined with standard GEMOX (gemcitabine 1000 mg/m2 and oxaliplatin 100mg/m2, IV, day 1 and day 15). Patients achieved CR were transferred to stem cell mobilization/collection stage; patients achieved PR/SD could have another cycle of CAM plus GEMOX, patients who achieved PR/CR underwent stem cell mobilization/collection. For patients waiting more than 4 weeks for ASCT, 1-2 cycles of CAM monotherapy were allowed. The primary endpoint is the proportion of patients who achieved PET‐CT‐confirmed complete response (CR) according to Lugano 2014 criteria. Results: From March 2020 to December 2021, 30 patients were enrolled. One patient withdrew informed consent. The median age of remaining 29 patients was 34 years old (ranged from 22 to 63), with a male‐to‐female ratio of 16:13. At the first tumor response evaluation, 69% (20/29) patients achieved CR and 17% (5/29) patients achieved partial response (PR), resulting an overall response rate (ORR) of 86%. Only one patient had progression disease (PD). The patients who achieved PR or stable disease (SD) received an additional cycle of CAM plus GEMOX treatment, and one patient who had PR in the first evaluation was found to achieve CR. Up to now, collection of the autologous hematopoietic stem cells was completed in thirteen patients. With a cutoff date of February 10, 2022, the 1-year (progression-free survival) PFS rate was 74% and the 1-year (overall survival) OS rate was 100%, median PFS and OS were not reached with too few events (Figure). Most adverse events (AEs) were of grade 1 to 2. Common AEs included reactive capillary endothelial proliferation (RCEP), alanine aminotransferase (ALT)/ aspartate aminotransferase (AST) elevation, vomiting, nausea, hyperuricemia (all > 30%). Hematologic AEs included neutropenia (> 34%). No grade 4 or above AEs occurred. Grade 3 AE occurred in 6 patients, including 1 pulmonary infection, 1 nausea, 1 fever, 1 hypertriglyceridemia, 1 ALT elevation, and 1 neutropenia. Serious adverse events included 1 case of interstitial pneumonia (grade 2) and 1 case of fever (grade 3) resulting in hospitalization. Image:Summary/Conclusion: Camrelizumab combined with GEMOX chemotherapy showed encouraging clinical efficacy and tolerable toxicity in R/R HL patients and merited further study.