Retrospective, observational study to describe the clinical characteristics, management, and outcomes of bispecific anti-gprc5d antibody in patients with relapsed refractory multiple myeloma treated outside clinical trials in Spain.

Abstract

e19542 Background: Talquetamab (TAL), a pioneering bispecific antibody targeting GPRC5D, received approval in Europe in August 2023. Before this, in November 2022, Spanish health authorities authorized Pre-Approval Access programs (PAA) for TAL as monotherapy. This was offered for adult patients (pts) with relapsed refractory multiple myeloma (RRMM) who were triple-class exposed (TCE) and had no remaining treatment alternatives, after reviewing for program eligibility based on specified PAA treatment guidelines. From November 2022 to 2024, until TAL became reimbursed, 215 patients across 87 academic and non-academic centers began treatment through PAA, underscoring the unmet medical need for this population in Spain. We present the preliminary baseline characteristics and effectiveness results of BiTAL study included pts. Methods: This is a retrospective, non-interventional, multicenter study, still recruiting. Here we included an interim analysis of data collected between September and October 2024. Data collection will continue until March 2025. Eligible pts had initiated TAL monotherapy treatment in line with EMA recommendations. Participants were adults with a diagnosis of RRMM TCE and had received their first TAL monotherapy dose at least 30 days prior to the start of the study. Results: From 17 sites, 24 pts were evaluable at data cut-off for baseline characteristics. The median age was 65.5 years, 16.7% of pts were over 75 years old. Less than half of pts were males (45.8%). The median time from diagnosis was 7.9 years. ECOG score ≥ 2 was reported for 16.7%. Comorbidities were present in 50% of pts, including cardiovascular (29.2%), diabetes (16.7%), renal insufficiency and history of severe infections (12.5% each). Effectiveness results were available for 5 pts at the time of the database cut-off. Overall rate response was 80.0%, with a complete response or better in 40.0% of the evaluable pts. Very good partial response or better was observed in 80.0% (all with negative immunofixation in serum and urine). Median time to follow-up from the date of the first dose of TAL was 6.2 months and the median duration of response was 7.8 months. Updated data on effectiveness and safety will be presented during the ASCO 2025 Annual Meeting (next data cut-off February 25, >90 expected included patients). Conclusions: The BiTAL study may represent one of the largest single-country cohorts of RRMM TCE pts treated with TAL outside registrational clinical trials. In this initial analysis focusing on pts characteristics and treatment effectiveness, the results obtained highlighted the heterogeneity of RRMM in a setting comparable to real-world conditions, and the effectiveness outcomes observed thus far appeared to align with those reported in the MonumenTAL-1 trial.