Huang, Liping

8016 Background: Patients (pts) with RRMM previously exposed to immunomodulatory agents, proteasome inhibitors (PIs), and CD38 antibodies (mAbs) have poor outcomes with subsequent treatments. Ide-cel, a BCMA-directed CAR T cell therapy, showed frequent, deep, and durable responses in heavily pretreated pts with RRMM in the pivotal KarMMa trial (Munshi NC, et al. J Clin Oncol 2020;38[suppl 15]. Abstract 8503). Here, we present updated data. Methods: Pts with ≥ 3 prior regimens (including immunomodulatory agent, PI, and CD38 mAb) and refractory to their last regimen per IMWG criteria were eligible (NCT03361748). Pts received 150─450 × 106 CAR+ T cells (target dose range) after 3 days of lymphodepletion (cyclophosphamide 300 mg/m2 + fludarabine 30 mg/m2). Endpoints included overall response rate (ORR; primary) and complete response (CR) rate (key secondary). Additional secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Results: KarMMa enrolled 140 pts, and 128 received ide-cel. Pts had a median age of 61 years and a median of 6 (range, 3-16) prior regimens; 84% were triple-class refractory, and 26% were penta-class refractory (lenalidomide, pomalidomide, bortezomib, carfilzomib, and daratumumab). Most pts (88%) had bridging therapy. Median follow-up was 15.4 mo (data cutoff, 7 Apr 2020). ORR was 73% and median PFS was 8.8 mo in all treated pts; both increased with higher dose (Table). At the highest target dose (450 × 106 CAR+ T cells), the ORR was 81%, the CR rate was 39%, and the median PFS increased to 12.2 months with longer follow-up. Responses were observed in all subgroups including difficult-to-treat subsets (eg, extramedullary disease [ORR, 70%], high tumor burden [71%], and R-ISS stage III disease [48%]). OS continues to mature and the median has not been reached; the 15-month event-free rate for OS was 71%. Cytopenias (97%) and cytokine release syndrome (CRS; 84%) were the most common any-grade toxicities. CRS was mostly grade 1/2; 5 pts (4%) had grade 3, 1 had grade 4 (at 300 × 106), and 1 had grade 5 (at 300 × 106). Investigator-identified neurotoxicity was reported in 23 pts (18%); 4 pts (3%) had grade 3 and 0 had grade ≥ 4. Tocilizumab was used in 67 and 3 pts with CRS and neurotoxicity, respectively. Conclusions: Updated results from the KarMMa trial continue to demonstrate deep, durable responses with ide-cel in heavily pretreated pts with RRMM. Efficacy and safety reflect prior reports and support a favorable clinical benefit-risk profile for ide-cel across the target dose range. Clinical trial information: NCT03361748. [Table: see text]

8503 Background: Outcomes are poor in triple-class exposed RRMM patients (pts) who progress on immunomodulatory agents (IMiDs), proteasome inhibitors (PIs), and CD38 antibodies (mAbs). Ide-cel, a BCMA targeted CAR T cell therapy, showed promising tolerability and efficacy in RRMM pts in the phase I CRB-401 study ( NEJM2019;380:1726). We present primary efficacy and safety data from the pivotal phase II KarMMa trial of ide-cel in RRMM (NCT03361748). Methods: Enrolled pts had ≥3 prior regimens (including IMiD, PI, and CD38 mAb) and were refractory to their last regimen per IMWG criteria. After lymphodepletion (cyclophosphamide 300 mg/m2+ fludarabine 30 mg/m2 x 3), pts received 150─450 × 106 CAR+ T cells (target dose range). Endpoints included overall response rate (ORR; primary), complete response (CR) rate, duration of response (DoR), and PFS. Results: Of 140 pts enrolled, 128 received ide-cel. Median age was 61 y; median no. of prior regimens was 6; 84% were triple- and 26% were penta-refractory. Most pts (88%) had bridging therapy. At data cutoff (16 Oct 2019), median follow up was 11.3 mo. ORR was 73% and median PFS was 8.6 mo; both increased with higher dose (Table). All subgroups had an ORR ≥50%, including older and high-risk pts. Most common any-grade (Gr) toxicities were cytopenias (97%) and cytokine release syndrome (CRS; 84%). CRS was mainly Gr 1/2; 5 pts (5%) had Gr 3, 1 had Gr 4, and 1 had Gr 5 (at 300 × 106). Neurotoxicity developed in 23 pts (18%); 4 (3%) Gr 3 and 0 Gr ≥4. Median peak CAR+ T cell expansion occurred at 11 d. Expansion was higher in responders and parameters (AUC0−28d, Cmax) increased with higher dose, with exposure overlap across doses. Persistence was durable, with CAR+ T cells detected in 29/49 (59%) and 4/11 pts (36%) at 6 and 12 mo. Conclusions: Ide-cel demonstrated deep, durable responses in heavily pretreated RRMM pts. Efficacy and safety reflected prior reports and support a favorable ide-cel clinical benefit-risk profile across the target dose range. Clinical trial information: NCT03361748 . [Table: see text]

3551 Background: Cutaneous toxicity is a known adverse effect of multikinase inhibitors and has been associated with clinical outcomes (Granito 2016). In the phase 3 CORRECT trial (NCT01103323), the multikinase inhibitor regorafenib significantly improved overall survival (OS) vs placebo in patients with mCRC (hazard ratio [HR] 0.77, 95% CI 0.64, 0.94; 1-sided P = 0.0052). This retrospective analysis explored whether HFSR was associated with outcomes in CORRECT. Methods: Patients randomized to receive regorafenib 160 mg/day during the first 3 weeks of each 4-week cycle were divided into subgroups based on whether or not they had HFSR. Estimates of OS and progression-free survival (PFS) (95% CI) were calculated using the Kaplan–Meier method. Patients who were randomized, but not treated, were included in the no HFSR group for the analysis of survival. Results: Of the 505 randomized patients, 500 received at least one dose of regorafenib. Among the treated patients, 47% (n = 235) had HFSR of any grade and 17% (n = 83) had HFSR grade 3. Of the patients who had HFSR, 69% (n = 162) had their first HFSR event (any grade) during the first treatment cycle. There was some imbalance in baseline characteristics between groups (Table). Survival was improved in patients who had HFSR at any time vs those who did not (Table). The OS benefit was also observed in patients who had the first HFSR event during Cycle 1 vs those who did not (median OS 7.2 vs 5.7 months; HR 0.66, 95% CI 0.51, 0.87). Conclusions: This post-hoc exploratory analysis suggests that patients who had HFSR had a greater treatment benefit from regorafenib. Since HFSR and survival are post-baseline assessments, results may be confounded by baseline factors or other unknown factors. Clinical trial information: NCT01103323. [Table: see text]