Mezigdomide Combo Delays Progression in Multiple Myeloma Phase 3 Trial

The SUCCESSOR-2 phase 3 clinical trial has met its primary goal, showing that an oral medication called mezigdomide, when used in combination with Kyprolis (carfilzomib) and dexamethasone, significantly improved the time patients with relapsed or refractory multiple myeloma lived without their disease worsening, Bristol Myers Squibb announced.

The interim results from this study provide a potential new treatment path for patients whose cancer has returned or stopped responding to previous therapies, specifically those who have already been treated with anti-CD38 and Revlimid (lenalidomide).

Main data that support the findings

The interim data from the SUCCESSOR-2 study indicate that the three-drug combination, referred to as MeziKd, achieved a statistically significant and clinically meaningful improvement in progression-free survival compared to the two-drug regimen of Kyprolis and dexamethasone alone. Progression-free survival measures the length of time during and after treatment that a patient lives with the disease without it getting worse.

According to the findings, mezigdomide is part of a class of drugs known as CELMoD agents. These are specifically optimized for enhanced myeloma cell killing and immune activation compared with older immunomodulatory drugs. The results reinforce the value of the targeted protein degradation platform, which provides new avenues to degrade proteins that were previously considered "undruggable."

Medical experts involved in the study noted that while treatment advances for multiple myeloma have been meaningful, many patients still experience a relapse or stop responding to current options. The data underscore the potential of MeziKd as an oral regimen that could address a key unmet need for patients previously exposed to anti-CD38 and Revlimid. Investigators noted that it is important for patients to have options that offer enduring disease control, and these positive interim data show that adding mezigdomide to Kyprolis and dexamethasone may provide clinical benefit in earlier relapse.

The success of the MeziKd regimen in this trial strengthens the confidence in bringing forward effective, accessible oral treatment options for patients with difficult-to-treat blood cancers. These results are expected to be presented at a future medical meeting and will be shared with health authorities.

Trial details

The SUCCESSOR-2 study is an inferential, seamless phase 2/3, multicenter, randomized, open-label trial. It was designed to evaluate the efficacy and safety of mezigdomide in combination with Kyprolis and dexamethasone versus the combination of Kyprolis and dexamethasone alone in patients with relapsed or refractory multiple myeloma.

The primary endpoint of the phase 3 portion of the study is progression-free survival. In addition to this primary goal, the researchers are tracking several key secondary endpoints to gain a more comprehensive understanding of the treatment’s impact, including:

• Overall survival (OS): The length of time patients remain alive after starting treatment.
• Overall response rate (ORR): The percentage of patients whose cancer shrinks or disappears after treatment.
• Duration of response (DoR): How long the cancer remains in a state of response without growing.
• Time to progression (TTP): The time from the start of treatment until the disease starts to grow again.
• Time to next treatment (TTNT): How long a patient can go before needing to start a different therapy.
• Minimal residual disease (MRD) negativity: A sensitive measure of whether any cancer cells remain in the body after treatment.
• Health-related quality of life (HR-QoL): Information regarding the well-being of patients during the trial.

The trial remains ongoing, and patients will continue to be followed by the research teams to collect long-term data on survival and safety.

Safety

Safety findings reported in the interim analysis of the SUCCESSOR-2 study were consistent with the known safety profile of mezigdomide and the combination regimen. No new or unexpected safety concerns were identified during this phase of the trial.

The study investigators confirmed that patients will continue to be followed for safety as the trial progresses. Monitoring the safety of patients remains a priority to ensure the treatment is well-tolerated. This ongoing follow-up is intended to provide a complete picture of the long-term safety and survival outcomes for patients with relapsed or refractory multiple myeloma using the MeziKd regimen

Editor's note: This article is for informational purposes only and is not a substitute for professional medical advice, as your own experience will be unique. Use this article to guide discussions with your oncologist. Content was generated with AI, reviewed by a human editor, but not independently verified by a medical professional.

Reference

1. “Bristol Myers Squibb Announces Positive Phase 3 Results from the SUCCESSOR-2 Study of Oral Mezigdomide in Relapsed or Refractory Multiple Myeloma,” news release; https://www.businesswire.com/news/home/20260308945507/en/Bristol-Myers-Squibb-Announces-Positive-Phase-3-Results-from-the-SUCCESSOR-2-Study-of-Oral-Mezigdomide-in-Relapsed-or-Refractory-Multiple-Myeloma

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