In the Cartitude 1 trial, the strongest predictor of long-term remission with Siltacel was a lower burden of disease (measured by bone marrow percentage and soluble BCMA levels), rather than the number of prior treatments. This implies using CAR-T therapy earlier in the disease course is more effective.

In a crowded multiple myeloma market, treatment sequencing is critical. The International Myeloma Working Group (IMWG) recommends using BCMA CAR-T therapies like Carvykti before BCMA bispecifics. This guidance helps defend Carvykti's position, as prior bispecific use may reduce CAR-T efficacy.

Clinicians must weigh the immediate benefit of using community-accessible belantumab against the risk of reducing the efficacy of future BCMA-targeted therapies like CAR-T or bispecifics. This decision hinges on a patient's ability to travel and access advanced care, creating a complex treatment sequencing challenge.

Unlike older IMiDs where T-cell effects are secondary, CELMoDs have a powerful, independent pro-T-cell mechanism. This dual action is so significant that in the future, CELMoDs will be prescribed not just for their direct anti-myeloma effects, but specifically to enhance the efficacy of T-cell therapies like CAR-T and bispecific antibodies.

Using a BCMA bispecific antibody first can exhaust a patient's T-cells or cause tumors to lose the BCMA target, rendering a subsequent BCMA-targeted CAR-T therapy ineffective. The optimal sequence is CAR-T first, which preserves T-cell function and BCMA expression, leaving bispecifics as a viable later-line option.

In a heavily pretreated population, mezigdemide plus dexamethasone achieved a 50% response rate in patients refractory to prior BCMA-based approaches, including antibody-drug conjugates, bispecifics, and CAR T-cell therapy. This demonstrates a distinct mechanism that can overcome resistance to the latest immunotherapies.

Belantamab's primary mechanism, immunogenic cell death, does not exhaust T-cells. This unique quality allows clinicians to use it as a first BCMA-targeted agent without compromising the efficacy of subsequent T-cell redirecting therapies like CAR T or bispecifics.

Beyond their direct anti-myeloma effects, CELMoDs potently activate the immune system. This positions them as ideal partners for immunotherapies like CAR T and bispecifics, with the potential to restore immune function and overcome resistance to T-cell redirecting therapies.

Clinicians report significant and durable responses using Belantamab in patients who have relapsed after BCMA-targeted CAR-T. This success may be due to Belantamab's immunogenic mechanism, which doesn't rely on endogenous T-cells and may favorably interact with the post-CAR immune environment.