SUMMARY: Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 36,110 new cases will be diagnosed in 2025, and 12,030 patients are expected to die of the disease. Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile, extramedullary disease or refractory disease have the worst outcomes. The introduction of Proteasome Inhibitors, Immunomodulatory agents and CD38 targeted therapies has resulted in higher Response Rates, as well as longer Progression Free Survival (PFS) and Overall Survival (OS), with the median survival for patients with myeloma approaching 10 years or more. Nonetheless, multiple myeloma in 2025 remains an incurable disease.
Relapsed or Refractory Multiple Myeloma (RRMM) remains a complex clinical challenge, even as therapeutic options continue to expand. Progressive immune dysfunction, cumulative treatment toxicity, and repeated relapses often limit the durability of benefit with conventional salvage regimens. Moreover, the increasingly effective frontline landscape has raised the bar for second- and later-line therapy, leaving fewer highly active, well-tolerated options for patients early in relapse.
BCMA-directed therapies have transformed expectations in advanced disease, particularly with CAR-T cell approaches demonstrating deep responses and prolonged disease control. However, manufacturing timelines, resource intensity, and patient fitness requirements limit universal access. Consequently, there is a critical need for off-the-shelf, immunotherapy-based regimens that deliver CAR-T–like efficacy with broader applicability.
Teclistamab (TECVAYLI®), a bispecific T-cell engaging antibody targeting CD3 on T cells and BCMA on myeloma cells, has previously shown meaningful and durable responses in heavily pretreated RRMM. Daratumumab (DARZALEX®), an anti-CD38 monoclonal antibody, remains a foundational therapy across all disease stages, offering both direct antimyeloma activity and immune modulation. Preclinical and clinical observations suggest that Daratumumab-mediated depletion of immunosuppressive cellular subsets enhances T-cell fitness, providing a strong biological rationale for combination with BCMA-directed bispecific antibodies.
The MajesTEC-3 trial was designed to test whether combining Teclistamab with Daratumumab could improve outcomes compared with established Daratumumab-based regimens in patients with earlier-line RRMM.
Study Design and Patient Population
MajesTEC-3 (NCT05083169) is an ongoing, randomized, open-label, Phase 3 trial conducted across 150 centers in 20 countries. Eligible patients had relapsed or refractory multiple myeloma after one to three prior lines of therapy, including prior exposure to both an immunomodulatory agent and a proteasome inhibitor. Patients with prior BCMA-directed therapy or anti-CD38–refractory disease were excluded.
A total of 587 patients were randomized 1:1 to receive either:
- Teclistamab plus subcutaneous Daratumumab, or
- Investigator’s choice of standard Daratumumab-based therapy, consisting of Daratumumab and Dexamethasone combined with either Pomalidomide (DPd) or Bortezomib (DVd).
Randomization was stratified by choice of control regimen, International Staging System stage, prior exposure to anti-CD38 antibodies, and number of prior treatment lines. The median patient age was approximately 64–65 years, with a median of two prior lines of therapy. Importantly, more than one-third of enrolled patients had high-risk cytogenetic features, reflecting a clinically relevant population.
Treatment Administration: A Patient-Centered, Steroid-Sparing Approach
Patients in the investigational arm received subcutaneous Teclistamab using a step-up dosing strategy, followed by a progressively extended dosing interval, transitioning to monthly administration from cycle 7 onward. Daratumumab was administered subcutaneously according to its approved schedule.
Notably, the regimen became steroid-free after cycle 1, an important quality-of-life consideration for patients requiring long-term therapy. Infection prophylaxis, immunoglobulin supplementation, and monitoring of IgG levels were mandated, with protocol amendments reinforcing best practices for infection prevention during BCMA-directed therapy. The Primary end point was Progression-Free Survival (PFS), as assessed by an Independent Review Committee.
Primary Endpoint: Striking Improvement in Progression-Free Survival
At a median follow-up of 34.5 months, Teclistamab plus Daratumumab demonstrated a highly significant and clinically transformative improvement in PFS compared with DPd or DVd.
- The estimated 36-month PFS rate was 83.4% with Teclistamab–Daratumumab versus 29.7% with standard Daratumumab-based therapy.
- This translated into an 83% reduction in the risk of disease progression or death (HR 0.17; 95% CI, 0.12–0.23; P<0.001).
- The prespecified boundary for superiority was crossed at the first interim analysis.
Importantly, the PFS advantage was consistent across all prespecified and clinically relevant subgroups, including patients with high-risk cytogenetics and those treated in earlier versus later relapse.
Depth and Durability of Response
Beyond delaying progression, Teclistamab–Daratumumab induced exceptionally deep and durable responses:
- Complete Response or better was achieved in 81.8% of patients receiving the combination, compared with 32.1% in the control arm.
- Overall Response Rates were also higher (89.0% vs. 75.3%).
- Rates of Minimal Residual Disease negativity at a sensitivity of 10⁻⁵ were more than threefold higher with Teclistamab–Daratumumab (58.4% vs. 17.1%).
Responses occurred rapidly, with a median time to first response of just over one month, and deepened over time. At three years, nearly 90% of responders in the investigational arm remained in response, suggesting the emergence of a plateau in disease control.
Overall Survival and Symptom Outcomes
Although follow-up for overall survival continues, early analyses favored Teclistamab–Daratumumab, with a high proportion of patients remaining alive beyond two years. Improvements were also observed in time to worsening of myeloma-related symptoms, underscoring the regimen’s clinical and patient-reported benefit.
Safety and Tolerability: Manageable With Established Protocols
The safety profile of Teclistamab–Daratumumab was consistent with the known risks of BCMA-directed bispecific antibodies and Daratumumab. Serious adverse events occurred more frequently in the investigational arm, driven primarily by cytopenias and infections.
- Cytokine Release Syndrome was common but predominantly low grade and largely confined to the step-up dosing period.
- Importantly, the incidence of CRS was lower than that reported with Teclistamab monotherapy, supporting a favorable interaction between the two agents.
- Fatal adverse events were infrequent and decreased following protocol-reinforced infection-prevention strategies.
The trial highlights the critical importance of early immunoglobulin replacement, antimicrobial prophylaxis, and vigilant monitoring, now well established in guidelines for patients receiving BCMA-targeted therapies.
Context Within the Evolving Treatment Landscape
The magnitude of benefit observed with Teclistamab–Daratumumab is particularly notable given the strong performance of the control arm, which exceeded historical expectations from prior DPd and DVd studies. Even in this context, the combination delivered superior depth, durability, and consistency of response. As CAR-T therapies move earlier in the disease course, off-the-shelf immunotherapies such as Teclistamab–Daratumumab offer a complementary strategy, one that combines accessibility, scalability, and sustained disease control. Monthly dosing after the initial treatment phase further supports feasibility in community oncology settings.
Clinical Implications
The MajesTEC-3 trial establishes Teclistamab plus Daratumumab as a highly effective immunotherapy-based option for patients with early relapsed multiple myeloma, delivering unprecedented Progression-Free Survival and deep molecular responses without the logistical barriers of cellular therapy. With appropriate supportive care and infection-prevention strategies, this regimen may meaningfully reset expectations for long-term disease control in a population historically characterized by inevitable relapse.
Conclusion
In patients with multiple myeloma who had received one to three prior lines of therapy, Teclistamab combined with Daratumumab significantly outperformed established Daratumumab-based regimens, offering durable disease control, deep responses, and a manageable safety profile. These findings position Teclistamab–Daratumumab as a potential new standard in earlier-line Relapsed or Refractory Multiple Myeloma, and signal continued progress toward prolonged survival in this traditionally incurable disease.
Teclistamab plus Daratumumab in Relapsed or Refractory Multiple Myeloma. Costa LJ, Bahlis NJ, Perrot A, et al. for the MajesTEC-3 Trial Investigators. N Engl J Med. Published December 9, 2025. DOI: 10.1056/NEJMoa2514663
