Ciltacabtagene Autoleucel for Triple-Class Exposed Multiple Myeloma: Adjusted Comparisons of CARTITUDE-1 Patient Outcomes Versus Therapies from Real-World Clinical Practice from the LocoMMotion Prospective Study

• Published in: Blood 2021-11, Vol.138 (Supplement 1), p.550-550
• Main Authors: Mateos, Maria-Victoria, Weisel, Katja, Martin, Thomas, Berdeja, Jesús G., Jakubowiak, Andrzej, Stewart, A. Keith, Jagannath, Sundar, Lin, Yi, Diels, Joris, Ghilotti, Francesca, Perualila, Nolen J, Cabrieto, Jedelyn, Haefliger, Benjamin, Erler-Yates, Nichola, Hague, Clare, Jackson, Carolyn C., Strulev, Vadim, Nesheiwat, Tonia, Pacaud, Lida, Moreau, Philippe, Einsele, Hermann
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2021-146200

Background: Patients with relapsed and refractory multiple myeloma (RRMM) who have triple class exposure to immunomodulatory drugs (IMiDs), proteasome inhibitors (PIs) and anti-CD38 monoclonal antibodies (MoABs) have a poor prognosis and high unmet medical need. Ciltacabtagene autoleucel (cilta-cel) is a chimeric antigen receptor T-cell therapy which may offer long-term disease control for these patients. CARTITUDE-1 is an open-label, single arm phase 1b/2 clinical trial conducted to characterize the safety and efficacy of cilta-cel in adult patients with triple-class exposed RRMM. Since CARTITUDE-1 is a single-arm study, adjusted comparisons to other currently available therapies can provide valuable information on relative efficacy and safety benefits of cilta-cel over current real-world clinical practice (RWCP). LocoMMotion is the first prospective study of RWCP efficacy and safety outcomes in triple-class exposed patients with RRMM. It was designed a priori to serve as an external control cohort for CARTITUDE-1, using aligned inclusion criteria and endpoint definitions, to enable robust, high quality indirect comparisons vs. cilta-cel. Objective: To compare patient outcomes of cilta-cel vs. RWCP, including overall response rate (ORR), complete response or better rate (≥CR rate), progression-free survival (PFS) as assessed by a review committee and overall survival (OS) in patients with triple-class exposed RRMM. Methods: Individual patient level data available from both CARTITUDE-1 (clinical cut-off February 2021) and LocoMMotion (clinical cut-off March 2021) were pooled to conduct the comparative analyses. Imbalances between both cohorts on key prognostic baseline characteristics, including refractory status, ISS stage, time to progression on prior line, number of prior lines, average duration of prior lines, age, creatinine clearance, ECOG PS and MM type were adjusted for using inverse probability weighting. Average treatment effect on the treated (ATT) weights derived from propensity scores estimated using multivariable logistic regression modeling were applied to the LocoMMotion patients to have the weighted RWCP cohort reflecting the CARTITUDE-1 patient population. Balance between the ATT weighted RWCP cohort versus the CARTITUDE-1 population was evaluated based on reduction of standardized mean differences and overlap of propensity score distributions. Weighted logistic and Cox proportional hazards regression were used to estimate the relative tr