Background: Chimeric antigen receptor (CAR) T-cell therapies are in clinical development for multiple myeloma (MM). Patient-reported outcomes (PRO) can provide valuable insights into how patients perceive the relative risks and benefits of these new therapies. This study aimed to evaluate CAR T-cell therapy in relapsed/refractory MM (RRMM) patients. Methods: We utilized HealthTree Cure Hub for Multiple Myeloma to analyze patient-reported data from 17 patients who participated in CAR T-cell clinical trials. In this study, we examined total prior lines of therapy, time to next treatment (TNT), overall survival (OS), patient-reported toxicity and severity, and patient-reported outcomes (myeloma reduction or no myeloma reduction). The Kaplan-Meier model was used to calculate overall survival. The severity of toxicity was assessed using a 1 to 10 scale (1 = minimal and 10 = severe). Results: Our analysis of the 17 patients found a median of 10 lines of therapy prior to CAR T-cell treatment. Ten patients had no new treatments to report at the time of this study, 5 patients reported new treatment with a median TNT of 15.9 months, and for 2 patients we did not have data. The median OS was 24 months (95% CI 21-30 months). The probability that a patient remained alive at 2 years was 0.48 (95% CI: 0.195, 1). Four of the 17 patients died with a median of 22.5 months post-CAR T-cell therapy. Two of these patients died without reporting a change in treatment. There was a total of 36 different side effects reported by patients as a result of the therapy. Table lists the side effects experienced by 2 or more patients and the corresponding average severity. Finally, 76% of patients treated with CAR T-cell therapy reported a reduction in their myeloma, four of these patients had m-protein levels reported and saw an average decrease of 93%. Of the remaining patients, three (18%) reported little to no reduction in their myeloma, and one patient (6%) did not know their response at the time of this analysis. Conclusions: Our investigation of patient-reported results suggests an emerging and viable immunotherapy treatment option for RRMM, with encouraging outcomes and manageable side effects. Future directions include analysis of genetics and treatment options post CAR T-cell therapy. These data highlight the expedited benefit of using PROs via an online platform, like HealthTree Cure Hub, to assess new therapeutics in the research community.