Teclistamab + Daratumumab EC Approval: Phase 3 OS Proof Reshapes Second-Line RRMM, But HTA Pricing Wall Looms

EC Approves Teclistamab Plus Daratumumab for RRMM

The European Commission has approved Johnson & Johnson's TECVAYLI® (teclistamab) in combination with daratumumab for adults with relapsed or refractory multiple myeloma (RRMM) who have received at least one prior therapy. This approval, announced on August 21, 2026, is based on data from the Phase 3 MajesTEC-3 study, which demonstrated statistically significant and clinically meaningful improvements in progression-free survival (PFS) and overall survival (OS) compared to standard of care regimens. The immunotherapy doublet offers a potential new standard of care as early as second line, showing durable disease control with over 90% of patients remaining progression-free at three years if they were progression-free at six months.

• The Phase 3 MajesTEC-3 study showed that teclistamab plus daratumumab SC significantly reduced the risk of disease progression or death by 83.4% (HR, 0.17; 95% CI, 0.12-0.23; p<0.001) compared to standard of care. Overall survival also significantly favored the combination (HR, 0.46; 95% CI, 0.32-0.65; p<0.0001), with three-year OS rates of 83.3% versus 65.0% for standard of care.
• The combination leverages the complementary mechanisms of teclistamab, a BCMAxCD3 bispecific antibody, and daratumumab, a CD38-directed antibody, to enhance T-cell activation and myeloma cell killing. This off-the-shelf, steroid-sparing immunotherapy offers a new treatment option as early as second line for RRMM patients, aiming to influence disease trajectory earlier in the treatment journey.
• The regimen demonstrated durable disease control, with more than 90% of patients who were progression-free at six months remaining progression-free at three years. The safety profile was consistent with individual therapies, with no new safety signals identified. All cytokine release syndrome cases were Grade 1/2, and treatment discontinuations due to adverse events were low and similar across study arms.

Addressing the Persistent Challenges in Relapsed/Refractory Multiple Myeloma

Relapsed/refractory multiple myeloma (RRMM) remains one of oncology's most formidable therapeutic challenges, with prognosis worsening substantially as patients progress through successive lines of therapy. The emergence of novel immunotherapeutic modalities has expanded the treatment landscape, yet critical unmet needs persist across efficacy, safety, and biological understanding.

• Poor survival outcomes in heavily pretreated populations: Patients with double-class refractory disease have a median overall survival (OS) of 22.3 months, which declines to 11.6 months in triple-class refractory settings. Among patients with prior lenalidomide and anti-CD38 monoclonal antibody exposure, no uniform standard of care exists; real-world data demonstrate median progression-free survival (PFS) of 4.4–5.3 months and median OS of 14.2–23.1 months, with outcomes significantly worse in those refractory to both drug classes.

• Severe and difficult-to-manage toxicities from novel immunotherapies: CAR-T cell therapies and bispecific T-cell–recruiting antibodies carry a distinct and serious toxicity profile, including cytokine release syndrome (CRS), immune effector cell-associated neurotoxicity syndrome (ICANS), cytopenias, and infection. Immune effector cell-associated hemophagocytic lymphohistiocytosis-like syndrome (IEC-HS) presents particular diagnostic and therapeutic complexity due to its phenotypic overlap with CRS and HLH, and effective treatments for delayed neurotoxicity and IEC-HS remain lacking. Prolonged hematologic toxicity represents an additional ongoing management challenge.

• Diagnostic ambiguity complicating clinical decision-making: CRS and sepsis share overlapping clinical features—including fever, hypotension, and multi-organ dysfunction—necessitating timely and accurate differentiation. In practice, diagnostic uncertainty frequently leads to empirical treatment of both conditions simultaneously, risking immunosuppression-mediated worsening of sepsis or, conversely, unnecessary antibiotic use in CRS cases that contributes to antimicrobial resistance.

• Resistance and antigen escape following targeted therapies: The mechanisms underlying relapse after CAR-T therapy—including T-cell exhaustion, antigen escape, and an immunosuppressive tumor microenvironment—remain incompletely characterized. Immunoselection of BCMA- or GPRC5D-negative or mutant clones represents a well-documented tumor-intrinsic resistance mechanism; TNFRSF17 gene deletions can abrogate BCMA expression following any BCMA-directed therapy, precluding response to subsequent anti-BCMA agents, while GPRC5D protein downregulation is frequently observed at relapse after anti-GPRC5D CAR-T therapy.

• Incomplete understanding of disease biology and toxicity pathophysiology: RRMM is defined by substantial clinicopathologic and molecular heterogeneity, with persistent clonal evolution driving the acquisition of high-risk mutational signatures and resistance to standard-of-care regimens. The pathophysiology and risk factors underlying immunotherapy-associated toxicities are not yet comprehensively defined, limiting the development of targeted preventive and therapeutic strategies.

MajesTEC-3 Data Redefines Outcomes for Earlier-Line RRMM

Recent clinical trials in relapsed or refractory multiple myeloma (RRMM) have evaluated both BCMA-directed and GPRC5D-directed agents, spanning CAR-T cell therapies and bispecific antibodies. These studies collectively demonstrate high response rates in heavily pretreated populations, with manageable but notable safety profiles including cytokine release syndrome and cytopenias.

Ab = antibody; CAR-T = chimeric antigen receptor T-cell; CR = complete response; CRS = cytokine release syndrome; DLT = dose-limiting toxicity; DoR = duration of response; ICANS = immune effector cell-associated neurotoxicity syndrome; ORR = overall response rate; OS = overall survival; PFS = progression-free survival

Reshaping the RRMM Treatment Landscape with a Novel Immunotherapy Doublet

The treatment landscape for relapsed or refractory multiple myeloma (RRMM) has undergone a profound transformation over the past five years, propelled by the clinical development and regulatory approval of multiple novel immunotherapeutic classes. BCMA-directed CAR T-cell therapies have established a new efficacy benchmark, with idecabtagene vicleucel (ide-cel) and ciltacabtagene autoleucel (cilta-cel) demonstrating unprecedented response rates in pivotal trials including CARTITUDE-1 and KarMMa-3. Comparative analyses favor cilta-cel, which confers a 1.2-fold higher likelihood of overall response, a 1.3-fold higher likelihood of achieving very good partial response or better, and a 1.9-fold higher likelihood of complete response or better versus ide-cel — alongside a significant 49% reduction in risk of disease progression or death. These findings have repositioned CAR T-cell therapy as a preferred intervention in early relapse settings (1–3 prior lines), with cilta-cel recognized as the most efficacious product currently available. Concurrently, four bispecific antibodies — teclistamab, elranatamab, linvoseltamab (BCMA-targeting), and talquetamab (GPRC5D-targeting) — have received FDA approval for late relapse (≥4 prior lines), demonstrating compelling single-agent activity; talquetamab, for example, achieved an overall response rate of approximately 70% in triple-class-exposed populations, contrasting sharply with a historical benchmark of 29.5%.

Beyond cellular and bispecific immunotherapies, anti-CD38 monoclonal antibodies and antibody-drug conjugates have been further integrated across the RRMM treatment continuum. Phase III data from the CASTOR and POLLUX trials established the superiority of daratumumab-based triplets — daratumumab-bortezomib-dexamethasone and daratumumab-lenalidomide-dexamethasone — over doublet standards in terms of overall response rate and progression-free survival. Anti-CD38/carfilzomib-based combinations remain a cornerstone option for patients not refractory to this class. Additionally, belantamab mafodotin-based triplets have demonstrated meaningful efficacy in lenalidomide- and anti-CD38-refractory patients, though ocular toxicity continues to require careful monitoring and management.

Emerging evidence is also shaping treatment sequencing strategies and addressing unmet need in heavily pre-treated populations. Current data support prioritizing CAR T-cell therapy before bispecific antibodies when clinically feasible, as sequential efficacy appears to be compromised in the reverse order. For patients with BCMA- and GPRC5D-refractory disease, investigational options including the FcRH5-targeting bispecific antibody cevostamab, BCL2 inhibitors for t(11;14)-positive disease, and novel trispecific constructs targeting BCMA×CD38 and BCMA×GPRC5D represent a promising next frontier. Across all these modalities, unique toxicity profiles — encompassing cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome (ICANS), delayed neurotoxicity, cytopenias, and infectious complications — necessitate multidisciplinary oversight and proactive safety management as standard components of care.

Teclistamab-Daratumumab: Reshaping Early-Line RRMM Treatment

The European Commission's approval of teclistamab in combination with daratumumab for relapsed or refractory multiple myeloma (RRMM) marks a pivotal moment, shifting a potent bispecific antibody into earlier lines of therapy. This move, based on compelling Phase 3 data, positions the combination as a potential new standard of care for patients who have received at least one prior therapy. The MajesTEC-3 study showcased remarkable efficacy, with significantly longer progression-free survival and higher rates of complete response and minimal residual disease negativity compared to established standard of care regimens. This deep and durable disease control, with over 90% of patients remaining progression-free at three years if they were progression-free at six months, offers new hope for patients seeking more effective early intervention.

Strategically, this approval allows for a substantial expansion of teclistamab's market reach, enabling Johnson & Johnson to target a broader patient population earlier in their treatment journey. This could exert significant competitive pressure on existing second-line therapies and potentially impact the landscape for later-line bispecific antibodies and CAR-T cell therapies by achieving more profound responses upfront. Furthermore, it validates the growing trend of combining novel immunotherapies to enhance efficacy in multiple myeloma.

However, this advancement is not without considerations. The combination therapy was associated with a higher incidence of serious adverse events and deaths from adverse events compared to standard of care, underscoring the need for vigilant patient monitoring and proactive management of potential toxicities, including infection risks. From an economic perspective, while clinically effective, the cost per month of progression-free survival for teclistamab has been noted as higher than some other advanced therapies, which could present challenges for market access and reimbursement negotiations. Additionally, the complex dosing schedule, including step-up doses and specific guidelines for managing dose delays, highlights the practical considerations for healthcare providers and the importance of patient adherence to maximize real-world outcomes. As the treatment landscape for RRMM continues to evolve rapidly, the integration of such powerful combination regimens will require careful balancing of efficacy, safety, and economic value.