WHAT IS THIS SUMMARY ABOUT?This is a summary of a phase 3 clinical trial called CARTITUDE-4. This trial compared the anti-cancer therapy ciltacabtagene autoleucel (or cilta-cel) with standard therapies in people who have multiple myeloma, a cancer that affects specific kinds of blood cells called plasma cells. The people in the study had been treated with 1 to 3 previous treatments for multiple myeloma, including a common anti-myeloma treatment called lenalidomide, but their multiple myeloma did not get better.HOW WAS THE STUDY IN THIS SUMMARY CONDUCTED?About half of the 419 participants in this study received cilta-cel, while the other half received standard therapies, or therapies that are commonly used to treat multiple myeloma. Participants who received cilta-cel had a type of immune cell called T cells collected from their blood and genetically modified to recognize a specific protein found on myeloma cells. These modified T cells, which comprise cilta-cel, were then infused back into the bloodstream.WHAT WERE THE RESULTS OF THE STUDY?After approximately 1 year in the study, more participants were alive without their cancer getting worse in the cilta-cel group (76%) than in the standard therapies group (49%). The most common side effects in both groups were infections and low blood cell counts. Cytokine release syndrome (a potentially serious side effect caused by overactivation of the immune system) was common but mostly mild. Neurotoxicities (including immune effector cell-associated neurotoxicity syndrome, which can cause symptoms such as headaches, changes in consciousness, and difficulty with memory, attention, speaking, or understanding others) were less common and were reported in 20.5% of participants treated with cilta-cel.WHAT WERE THE MAIN CONCLUSIONS REPORTED BY THE RESEARCHERS?In CARTITUDE-4, more participants treated with cilta-cel showed improvements and were alive with control of their disease 12 months after receiving cilta-cel compared with participants who received standard therapies.Clinical Trial Registration: NCT04181827 (CARTITUDE-4) (ClinicalTrials.gov).