Ling, Silvia

PURPOSE Venetoclax, an oral BCL-2 inhibitor, has efficacy in t(11;14)-positive relapsed/refractory multiple myeloma (RRMM), which is enhanced by dexamethasone, which promotes BCL-2 dependency. METHODS The randomized, open-label, phase III CANOVA study (ClinicalTrials.gov identifier: NCT03539744 ) enrolled adults with t(11;14)-positive RRMM who had received ≥2 previous lines of therapy. Patients were randomly assigned (1:1) to venetoclax-dexamethasone or pomalidomide-dexamethasone until progression or intolerable toxicity. The primary end point was independent review committee assessed–progression-free survival (PFS) in the intention-to-treat population analyzed by stratified log-rank test (two-sided type I error rate, α = .05), with hazard ratio (HR) and 95% CI estimated by stratified Cox proportional hazard model. Secondary end points included response rates, overall survival (OS), minimal residual disease (MRD) negativity rate (<10 –5 ), and safety. RESULTS Overall, 263 patients were randomly assigned (venetoclax-dexamethasone, n = 133; pomalidomide-dexamethasone, n = 130). Median PFS was 9.9 months (95% CI, 6.9 to 12.6) with venetoclax-dexamethasone versus 5.8 months (95% CI, 3.8 to 9.2) with pomalidomide-dexamethasone (HR, 0.823 [95% CI, 0.596 to 1.136]; P = .24). Overall response and very good partial response or better rates were 62% and 39%, respectively, with venetoclax-dexamethasone versus 35% and 14% with pomalidomide-dexamethasone. MRD negativity rate was 8% with venetoclax-dexamethasone and 0% with pomalidomide-dexamethasone. Median OS was 32.4 months (95% CI, 26.4 to 40.7) with venetoclax-dexamethasone and 26.9 months (95% CI, 20.4 to 38.9) with pomalidomide-dexamethasone (HR, 0.856 [95% CI, 0.612 to 1.197]). Grade ≥3 treatment-emergent adverse event rates were 67% with venetoclax-dexamethasone versus 83% with pomalidomide-dexamethasone. There were 16 (12%) treatment-emergent deaths with venetoclax-dexamethasone versus 8 (6%) with pomalidomide-dexamethasone. CONCLUSION The primary end point of PFS was not met. PFS and OS were numerically longer with venetoclax-dexamethasone versus pomalidomide-dexamethasone in t(11;14)-positive RRMM. Consistent with previous studies, infections were associated with venetoclax-dexamethasone; no new safety signals were observed.

Abstract Introduction: IRAKLIA is an international, open-label, non-inferiority (NI) trial (NCT05405166) investigating isatuximab (Isa) subcutaneous (SC) vs intravenous (IV) administration, plus pomalidomide-dexamethasone (Pd) and the first Phase 3 multiple myeloma (MM) trial using an on-body injector (OBI). IRAKLIA demonstrated NI in its co-primary endpoints: overall response rate (ORR) and steady state trough concentration (Ctrough; Cycle(C) 6 Day(D) 1 predose). IsaOBI offers hands-free administration of flat-dose Isa, a small, hidden, retractable needle to prevent sharps injury and low-pressure delivery. Here, we examine the effect of body weight (BW) on pharmacokinetics (PK) as well as efficacy and safety outcomes with flat-dose IsaOBI vs IV + Pd in IRAKLIA. Methods: Patients (pts) with relapsed/refractory MM ≥18 years (yr) with ≥1 prior line of therapy (LOT) were randomized 1:1 to IsaOBI (1400mg; n=263) or IV (10mg/kg; n=264 weekly in C1, then every 2 weeks + P (4mg/day, D1–21) + d (40mg [20mg if ≥75yr] weekly) in 4-week cycles. This analysis is run by BW (≤65kg, &gt;65–≤85kg, &gt;85kg) which was a stratification factor, and extreme BW (≤50kg, &gt;50–≤100kg, &gt;100kg). Results: Number of pts per BW group were: ≤50kg [OBI n=16, IV n=14], ≤65kg [OBI n=84, IV n=85], &gt;65–≤85kg [OBI n=117, IV n=118], &gt;85kg [OBI n=62, IV n=65], and &gt;100kg [OBI n=22, IV n=22]. Baseline (BL) demographic and disease characteristics were generally balanced across BW groups for IsaOBI vs IV, including age (median 66yr) and prior LOT (median 2). However, in the &gt;100kg group, more IsaOBI vs IV pts exhibited poor prognostic characteristics including plasmacytoma, International Staging System Stage II/III disease, beta 2-microglobulin level ≥5.5mg/L, estimated glomerular filtration rate &lt;60mL/min/1.73m2 and a lower very good partial response (VGPR) rate as best overall response at last regimen. Flat-dose IsaOBI showed adequate exposure (C2D1 Ctrough) for all BW groups, with geometric mean ratios (90% CI) vs IV &gt;1: ≤65kg (1.628 [1.294–2.048]), &gt;65–≤85kg (1.303 [1.089–1.560]) and &gt;85kg (1.006 [0.817–1.239]). IsaOBI ORRs were comparable to IV across BW: ≤65kg, 66% vs 71% (relative risk [RR]: 0.928), &gt;65–≤85kg, 70% vs 70% (RR: 1.009), and &gt;85kg, 81% vs 72% (RR: 1.115). For extreme BW groups, ORRs (95% CI) were similar between IsaOBI and IV for ≤50kg group [56% vs 60%] and for &gt;50–≤100kg [72(66–78)% vs 70(63–76)%] but lower [68% vs 86%] in &gt;100kg group. An exposure-response (E-R) analysis showed the impact of BW on response: IsaOBI pts ≤50kg tended to respond less vs IsaOBI pts &gt;50kg despite correct exposure because they were confounded by BL disease characteristicsincluding a higher proportion of high-risk cytogenetics and plasma cells in the bone marrow vs other BW group pts. For IsaOBI and IV, Grade (Gr)≥3 treatment-emergent adverse events (TEAEs) and Gr≥3 treatment-related TEAEs decreased with increasing BW. They were similar between arms in ≤65kg group (OBI vs IV, Gr≥3 TEAEs: 87% vs 88%; Gr≥3 treatment-related TEAEs: 73% vs 77%). A similar trend was observed in extreme BW groups along with similar incidences between arms in ≤50kg group. While TE serious AEs (TESAEs) and treatment-related TESAEs decreased with increasing BW for IsaIV, incidence was stable in the IsaOBI arm. OBI arm OBI Gr5 TEAEs were similar between groups and arms, except for higher incidence in ≤65kg group (12% vs 5%) with OBI vs IV that was not reflected in ≤50 or &gt;50–≤100kg groups. Treatment discontinuation rates for all drugs with IsaOBI vs IV were 14% vs 6% (≤65kg), 8% vs 10% (&gt;65–≤85kg), and 2% vs 10% (&gt;85kg). Similar incidence of Gr≥3 laboratory (lab) neutropenia was observed across BW in IsaOBI: 86.9% (≤65kg), 83.5% (&gt;65–≤85kg) and 83.9% (&gt;85kg). Higher rates of Gr≥3 lab neutropenia were observed in ≤50kg group (93.8%, IsaOBI vs 71.4%, IsaIV), which did not translate into higher rates of neutropenic complications (18.8% vs 14.3%). The E-R analysis revealed no relationship between Isa PK exposure and safety for OBI and IV arms. Conclusions: No notable impact from IsaOBI flat dosing was observed across BW groups. Flat-dose Isa OBI showed consistent safety and efficacy across different BW groups, with differences likely linked to BL disease characteristics according to the E-R analysis. The IsaOBI C2D1 Ctrough, a time-independent predictor of efficacy, was similar to, or higher vs IsaIV in each BW group, supportive of a flat dose providing adequate exposure without need for adjustment.

PURPOSE To report the results of the multicenter, open-label IRAKLIA trial (ClinicalTrials.gov identifier: NCT05405166 ) of isatuximab subcutaneous (SC) versus intravenous (IV), plus pomalidomide and dexamethasone, in relapsed/refractory multiple myeloma (MM), to our knowledge, the first phase III MM trial using an on-body injector (OBI). METHODS Patients with ≥1 prior line of therapy were randomly assigned 1:1 to Isa OBI (1,400 mg) or IV (10 mg/kg) once weekly in cycle (C)1 and then every 2 weeks, plus pomalidomide (4 mg once daily, day [D]1-21) and dexamethasone (40 mg once weekly [age ≥75: 20 mg]) and treated until progression, unacceptable toxicity, or patient request. Coprimary end points were overall response rate (ORR; noninferiority margin, 0.839) and Isa C trough (C6D1 predose; noninferiority margin, 0.8). Noninferiority of OBI versus IV was demonstrated if both coprimary end points achieved noninferiority. RESULTS IRAKLIA randomly assigned 531 patients (OBI, n=263; IV, n=268). After 12-month median follow-up, the ORR was 71.1% (OBI) and 70.5% (IV; relative risk, 1.008 [95% CI, 0.903 to 1.126]; lower CI exceeded noninferiority margin). The mean (standard deviation) C6D1 C trough was 499 (259) μg/mL (OBI) and 340 (169) μg/mL (IV). The C trough geometric mean ratio (90% CI) was 1.532 (1.316 to 1.784); lower CI exceeded noninferiority margin. Grade ≥3 treatment-emergent adverse event incidences were 81.7% (OBI) and 76.1% (IV); infusion reaction incidences were 1.5% and 25.0%. Injection site reactions occurred in 0.4% of OBI injections (all grade 1-2); 99.9% of injections completed without interruption. CONCLUSION IRAKLIA demonstrated efficacy and pharmacokinetic noninferiority between Isa OBI and IV. No unexpected safety signal was observed, with excellent local tolerability of Isa OBI. Efficacy and safety were comparable with Isa IV in ICARIA-MM, except the lower OBI infusion reaction rate. These results support potential use of the OBI, designed to improve practice efficiency.

7506 Background: IV Isa-Pd is approved to treat RRMM patients (pts) based on the ICARIA-MM study. A Phase 1b study showed safety and efficacy of Isa SC via an OBDS, an investigational wearable bolus injector, plus Pd, in RRMM pts. Isa SC offers shorter duration, fixed dose and smaller administration volume. Here, we report results of the IRAKLIA trial (NCT05405166); Isa SC vs IV + Pd in RRMM pts, the first Phase 3 myeloma trial reporting the use of an OBDS. Methods: This multicenter, open-label study enrolled pts aged ≥18 years with ≥1 prior line of therapy (LOT). Pts were randomized 1:1 to Isa SC (1400 mg) or Isa IV (10 mg/kg) weekly in Cycle (C)1, then every 2 weeks + P (4 mg/day, Day [D]1–21) + d (40 mg [20 mg if age ≥75 years] weekly). Pts had 4-week cycles until progression, unacceptable toxicity or patient request. Co-primary endpoints were overall response rate (ORR; non-inferiority [NI] margin of 0.839) and Isa trough level (C trough ) at steady state (predose at C6D1; NI if lower limit of 90% CI of geometric mean ratio ≥0.8). Results: 531 pts (SC n=263; IV n=268 [4 not treated]) were randomized. Baseline characteristics were balanced (median age 66 years; median 2 prior LOT). After median 12 months follow-up, ORR was 71% (SC arm) and 71% (IV arm; relative risk [95% CI] = 1.008 [0.903–1.126]; lower CI > NI margin). Mean (SD) C trough at C6D1 was 499 (259) μg/mL for SC and 340 (169) μg/mL for IV. C trough geometric mean ratio (90% CI) was 1.532 (1.316–1.784); lower CI > NI margin. Co-primary and all 4 key secondary endpoints including pt experience are in the Table. Grade ≥3 treatment-emergent adverse events occurred in 82% (SC) and 76% (IV) of pts; with treatment discontinuation rates of 8% and 9%. Injection site reactions (ISRs) occurred in 4% (11/263) of the SC arm and in 19 (0.4%) of 5145 SC injections (all Grade 1–2). 99.9% of OBDS injections were completed without interruption. Conclusions: IRAKLIA met its co-primary endpoints, showing efficacy and pharmacokinetic NI between Isa SC vs IV + Pd. No new safety signal besides a low ISR incidence was observed, showing excellent Isa SC tolerability. Far fewer infusion reactions and higher pt satisfaction were also noted for SC vs IV. Efficacy and safety are comparable to Isa IV in ICARIA-MM. These results support potential use of Isa SC delivered via the OBDS, designed to improve pt experience and practice efficiency. Clinical trial information: NCT05405166 . Isa SC + Pd Isa IV + Pd Efficacy, % N=263 N=268 ORR 71 71 ≥VGPR 46 46 PK*, µg/mL N=131/121 N=126/121 Geometric mean Isa C trough at C2D1 / C6D1 360/426 277/278 Safety, % N=263 N=264 All grade IR 2 25 Pt satisfaction with injection method at C5D15, % 70 53 *PK was analyzed at C6D1 with PP PK population and at C2D1 with PP CT4W population. CT4W, C trough at 4 weeks; IR, infusion reaction; PK, pharmacokinetics; PP, per protocol; VGPR, very good partial response.

7510 Background: The randomized Phase 3 CANOVA study’s (NCT03539744) primary analysis showed multiple numerically improved efficacy endpoints with VenDex v PomDex, but the primary endpoint of mPFS by IRC was not statistically significant. Here, we report correlative biomarker analyses from CANOVA. Methods: CANOVA is a randomized, global, open-label Phase 3 study of VenDex v PomDex in pts with t(11;14)+ RRMM and ≥2 prior lines of therapy (LOTs). The primary endpoint was mPFS by IRC. Key secondary endpoints included ORR, ≥VGPR, mOS, and MRD negativity (<10-5). In post hoc mPFS sensitivity analysis, disease progression, death, and start of next LOT were defined as events. BCL2 gene expression by RNAseq (3.7 log2 FPKM prespecified median cutoff for BCL2high v BCL2low) and chr1q abnormalities by whole-exome sequencing (normal, gain, or amp) were assessed centrally from pretreatment, CD138-enriched BM aspirates. Results: mPFS, post hoc mPFS, and mOS in the VenDex arm were similar by BCL2 status, with numerically higher ORR, ≥VGPR, and MRD negativity rates in the BCL2highsubgroup. In contrast, mPFS and mOS within the PomDex arm were numerically longer in the BCL2lowsubgroup, despite equal ORR in both subgroups (Table). Presence of 1q abnormalities was evenly distributed across BCL2high v BCL2low subgroups in the VenDex arm (51% v 45%) but not in the PomDex arm (59% v 31%). Normal 1q and gain(1q) subgroups had numerically improved mPFS, mOS, ORR, ≥VGPR, and MRD negativity with VenDex; pts with amp(1q) had poor outcomes regardless of treatment, albeit the sample size was small. Conclusions: Pts with BCL2high or gain(1q) had numerically improved clinical efficacy with VenDex v PomDex. Clinical benefit was consistent across BCL2 subgroups ( BCL2high or BCL2low) with VenDex but not PomDex. Pts with amp(1q) fared poorly irrespective of treatment arm. Clinical trial information: NCT03539744 . [Table: see text]