Dubowy, Ronald L.

2537 Background: Orva-cel is a B-cell maturation antigen–targeted chimeric antigen receptor (CAR) T cell therapy being evaluated in the phase 1/2 EVOLVE study (NCT03430011) in pts with RRMM who had at least 3 prior lines of therapy (Tx). We previously reported safety and efficacy in the phase 1 study and established the recommended dose (RD) of orva-cel as 600 × 106 CAR+ T cells (Mailankody et al, ASCO 2020). Cytokine release syndrome (CRS), a dominant toxicity of CAR T cell therapy, is mediated in part by IL-1. We explore the role of ppx with AKR, an IL-1 signaling inhibitor, on reducing the incidence of grade (G) ≥2 CRS after orva-cel treatment at the RD. Methods: Fourteen pts were enrolled sequentially for AKR ppx and treated with orva-cel at the RD. The non-AKR ppx control group comprised the remainder of the phase 1 pts receiving orva-cel at the RD (n = 19). The median follow-up (range) was 3.0 mo (1.8–6.2) for the AKR ppx group and 8.8 mo (5.3–12.2) for the non-AKR ppx group. AKR was administered as 100 mg SC the night before orva-cel infusion, 3 h before the infusion (Day 1), and q24 h on Days 2–5. Dosing was increased to q12 h if CRS developed. CRS was graded by Lee (2014) criteria. Tocilizumab (T) and steroids (S) were used per protocol-specified treatment management guidelines. Results: Disease characteristics and outcomes are shown in the table. In AKR ppx and non-AKR ppx groups, median number of prior regimens was 6 and 5, and bridging Tx was used in 57% and 68% of pts, respectively. The total frequency of CRS was similar in the 2 groups, but with less G 2 in the AKR ppx pts; relative risk (95% CI) = 0.54 (0.21, 1.38). No G ≥3 CRS was seen in either group. The incidence of neurological events (NE), G ≥3 infection, and macrophage activation syndrome/hemophagocytic lymphohistiocytosis (MAS/HLH) was similar. T and S use was numerically lower with AKR ppx. Orva-cel expansion kinetics were similar in the 2 groups. All pts had a 2-month efficacy assessment, with ORR in 100% of AKR ppx and 95% of non–AKR ppx pts. Conclusions: In this nonrandomized evaluation of AKR ppx with orva-cel treatment, the incidence of G ≥2 CRS was lower in pts receiving AKR ppx. The use of AKR ppx produced no adverse effect on the incidence of NE, infection, or MAS/HLH, nor on orva-cel expansion or disease response. These results warrant further study of AKR ppx in CAR T cell therapy. Clinical trial information: NCT03430011. [Table: see text]

7000 Background: MMB, an oral JAKi, has been shown in early trials to reduce spleen volume, improve disease associated symptoms (Sx) and improve RBC transfusion (Tx) requirements in patients (pts) with MF. This study was designed to test non-inferiority of MMB vs RUX in splenic volume reduction and Sx amelioration, and superiority in Tx requirement, in JAKi naïve MF pts. Methods: Eligibility: MF, IPSS high risk, Int-2, or symptomatic Int-1; palpable spleen ≥5cm; platelets ≥ 50 K/μl, and no Gr ≥2 peripheral neuropathy (PN). Stratification by Tx dependency and platelets (<100, 100-200 and >200 K/μl). Pts were randomized 1:1 to 24 wks of MMB 200 mg qd + RUX placebo or RUX 20 mg bid (or modified per label) + MMB placebo, after which all pts could receive open label MMB. Assessments: spleen volume by MRI, and pt reported Sx using a daily eDiary of modified MPN-SAF Total Sx Score (TSS). Primary endpoint was splenic response rate (SRR; ≥35% reduction in volume from baseline) at 24 wks. Secondary endpoints, evaluated sequentially at 24 wks, were rates of TSS response (≥50% reduction from baseline), RBC Tx independence (TI), RBC Tx dependence (TD) and of RBC Tx . Results: 175 of 215 (81%) and 201 of 217 (93%) pts randomized to MMB and RUX, respectively, completed the 24 wk DB phase. Efficacy results are shown in Table. Most common Gr ≥3 AEs in the DB phase with MMB were thrombocytopenia (7%) and anemia (6%), and with RUX were anemia (23%), thrombocytopenia (5%) and neutropenia (5%). Gr ≥3 infections occurred in 7% of MMB and 3% of RUX pts. Treatment emergent PN occurred in 22 (10%) of MMB (all Gr ≤2) and 10 (5%) of RUX (9 Gr ≤2, 1 Gr 3) pts in DB phase, none discontinuing study drug for PN. Overall, AEs led to study drug D/C in 13% of MMB and 6% of RUX pts in DB phase. Conclusions: In pts with JAKi naive MF, 24 weeks of MMB is non-inferior to RUX for spleen response but not for symptom response. MMB treatment is associated with a reduced transfusion requirement. NCT01969838. [Table: see text]

Purpose We evaluated the efficacy and safety of momelotinib, a potent and selective Janus kinase 1 and 2 inhibitor (JAKi), compared with ruxolitinib, in JAKi-naïve patients with myelofibrosis. Patients and Methods Patients (N = 432) with high risk or intermediate-2 risk or symptomatic intermediate-1 risk myelofibrosis were randomly assigned to receive 24 weeks of treatment with momelotinib 200 mg once daily or ruxolitinib 20 mg twice a day (or per label), after which all patients could receive open-label momelotinib. The primary end point was a ≥ 35% reduction in spleen volume at 24 weeks of therapy. Secondary end points were rates of symptom response and effects on RBC transfusion requirements. Results A ≥ 35% reduction in spleen volume at week 24 was achieved by a similar proportion of patients in both treatment arms: 26.5% of the momelotinib group and 29% of the ruxolitinib group (noninferior; P = .011). A ≥ 50% reduction in the total symptom score was observed in 28.4% and 42.2% of patients who received momelotinib and ruxolitinib, respectively, indicating that noninferiority was not met ( P = .98). Transfusion rate, transfusion independence, and transfusion dependence were improved with momelotinib (all with nominal P ≤ .019). The most common grade ≥ 3 hematologic abnormalities in either group were thrombocytopenia and anemia. Grade ≥ 3 infections occurred in 7% of patients who received momelotinib and 3% of patients who received ruxolitinib. Treatment-emergent peripheral neuropathy occurred in 10% of patients who received momelotinib (all grade ≤ 2) and 5% of patients who received ruxolitinib (all grade ≤ 3). Conclusion In JAKi-naïve patients with myelofibrosis, 24 weeks of momelotinib treatment was noninferior to ruxolitinib for spleen response but not for symptom response. Momelotinib treatment was associated with a reduced transfusion requirement.