Clinical Outcomes for Patients with Triple Class Exposed Relapsed and Refractory Multiple Myeloma in Alberta, Canada

Background: Despite advances in treatment options, multiple myeloma (MM) remains generally incurable and most patients become relapsed or refractory to drug classes and require additional lines of therapy. Patients who are considered triple class exposed (TCE) (i.e., treated with three drug classes) may have limited treatment options and poor prognosis once they become relapsed/refractory MM (RRMM). There are limited published data available that examine real world treatment patterns and clinical outcomes in the TCE RRMM patient population. The purpose of this project was to explore Canadian-specific real-world treatment patterns and clinical outcomes in TCE RRMM patients in Canada. Methods: We leveraged multiple, population-based data sources from Alberta, Canada to identify TCE patients. The TCE cohort included individuals who have received a subsequent line of anti-myeloma treatment after prior exposure to a proteasome inhibitor (PI), an immunomodulatory drug (IMiD), and a monoclonal antibody (MAb), regardless of the sequence or combination used. Results: In total,1835 patients were evaluated. The TCE cohort included individuals who have received a subsequent line of anti-myeloma treatment after prior exposure to a PI, an IMiD, and a MAb, regardless of the sequence or combination used. 567 were consistent with the definition of TCE RRMM. Most patients with TCE MM were treated in the modern era (2020-present, 79%) and only 27% were >75 years old. 221 (39%) of TCE RRMM received a subsequent line of therapy. Median time to next therapy (TTNT) in the TCE RRMM was 18.1 months (8.4-13.3) and median TTNT and death was 10.1 months. Post TCE MM therapies will be presented in a Sankey diagram but as expected for the period of evaluation, no BCMA directed therapies were funded and publicly available for treatment of RRMM. Conclusion: The present study provides important insights into the treatment patterns and outcomes of patients with TCE RRMM. The advent of novel approaches such as CART's and bispecific is expected to address an unmet need in this growing population.

Jimenez-Zepeda:GSK: Honoraria; Sanofi: Honoraria; Takeda: Honoraria; Pfizer: Honoraria; BMS: Honoraria; Johnson & Johnson: Honoraria. Cheung:Johnson & Johnson: Research Funding. Mathew Stephen:Johnson & Johnson: Research Funding. Chan:Abbvie: Consultancy; Johnson & Johnson: Current Employment.