Pemivibart for prevention of COVID-19: Subset analysis of CANOPY participants with solid tumor or hematologic malignancies.

2522 Background: Due to the chronic immunosuppression associated with both their condition and treatments, patients with solid tumors or hematologic malignancies experience reduced vaccine protection and are at high risk of infections, including COVID-19. This post hoc analysis of the phase 3 CANOPY study assesses the safety and outcomes of pemivibart in the oncology subset from the open-label, single-arm, immunocompromised Cohort A. Methods: Cohort A dosing: 4500 mg of pemivibart (intravenous) on day 1; 2 nd dose at month 3. Primary objectives: 1) Evaluation of pemivibart safety and tolerability via study drug-related treatment emergent adverse events (TEAEs), serious adverse events (SAEs), and treatment interruption/discontinuation, 2) Evaluation of protection against symptomatic COVID-19 based on sVNA titers against SARS-CoV-2 after receiving pemivibart. Exploratory endpoint: composite incidence of RT-PCR-confirmed symptomatic COVID-19, including COVID-19-related hospitalization and all-cause mortality. Data were analyzed through Month 6. Results: Enrollment began in Sep 2023. The oncology subset included 55 (18.0%) Cohort A participants; median age [range] 65 [35-83] years; 25 (45.5%) female. Eight participants (14.5%) were receiving immunosuppressants, including 6 (10.9%) receiving corticosteroids. Prior to enrollment, 89.1% received ≥1 COVID-19 vaccine; seropositivity: N antigens (43.6%), S antigens (98.2%). Month 6 TEAEs were reported in 32 (58.2%) participants; 5 (9.1%) were considered study drug-related with 1 (1.8%) requiring treatment interruption due to infusion site extravasation and tachycardia (Table). SAEs occurred in 5 (9.1%) participants; none were considered drug-related. Following pemivibart dosing, sVNA titers in the oncology subset were elevated to levels associated with protection against COVID-19 and comparable with Cohort A. No anaphylaxis was reported in the oncology subset; 4 cases among 306 participants in Cohort A. Through Month 6, there was no RT-PCR-confirmed symptomatic COVID-19 in the oncology subset; with 9/298 (3.0%) in Cohort A. Conclusions: Pemivibart was well tolerated in the CANOPY Cohort A oncology subset. These data showed limited events overall and no development of symptomatic COVID-19 in the oncology subset through Month 6. Clinical trial information: NCT06039449 . Select outcomes through month 6. Parameter Immunocompromised Cohort A Cohort A Oncology Subset a Study drug-related TEAE, n (%) - Leading to death - Leading to interruption - Leading to discontinuation 34/306 (11.1)0/306 (0)14/306 (4.6)7/306 (2.3) 5/55 (9.1)0/55 (0)1/55 (1.8)0/55 (0) COVID-19 composite event, n (%)PCR-confirmed COVID-19, n (%)All-cause mortality, n (%) 11/298 (3.7)9/298 (3.0)2/298 (0.7) 1/55 (1.8)0/55(0)1/55 (1.8) b a 20 (36%) were being actively treated for solid tumor or hematologic malignancy; 40 (73%) had a hematologic malignancy. b Unrelated to study drug.