A major international clinical trial shows the immunotherapy teclistamab dramatically outperforms standard treatments for patients whose multiple myeloma has returned. Nearly two-thirds of patients achieved complete remission, and many showed no detectable cancer on the most sensitive available tests.
An international phase 3 trial has found that the immunotherapy drug teclistamab extends survival and deepens remissions in patients with relapsed multiple myeloma far beyond what standard treatments can deliver. The trial, known as MajesTEC-9, enrolled 593 patients across 24 countries, all of whom had experienced a return of multiple myeloma after one to three prior rounds of treatment.
The research, published May 29 in The New England Journal of Medicine and presented the same day at the 2026 American Society of Clinical Oncology Annual Meeting, was led by C. Ola Landgren, the chief of the Sylvester Myeloma Institute at Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine.
The Numbers Behind the Breakthrough
Among patients treated with teclistamab, roughly 70% showed no disease progression at the 18-month mark — compared with approximately 27% of those receiving conventional therapies. Nearly two-thirds of patients on teclistamab achieved complete remission, meaning standard diagnostic tests could no longer detect signs of myeloma. In many of those cases, even highly sensitive minimal residual disease testing came back negative, indicating cancer had been reduced to undetectable levels.
Patients on the drug also reported longer periods of symptom control and slower overall deterioration compared with those on standard regimens.
“Now we have chemotherapy-free immunotherapy options for patients whose myeloma has relapsed for the first time,” Landgren said in a news release. “We are seeing very deep responses and long clinical benefit from these therapies. This is part of a much bigger transformation happening in myeloma care.”
How Teclistamab Works
Teclistamab belongs to a class of drugs called bispecific antibodies. Rather than broadly attacking the body like traditional chemotherapy, it acts as a molecular bridge — connecting T cells, a key component of the immune system, to BCMA, a protein that sits on the surface of myeloma cells. That connection enables the immune system to home in on and destroy cancer cells with greater precision.
The approach is part of a broader shift in oncology away from cytotoxic chemotherapy and toward therapies that enlist the body’s own defenses. Landgren noted that when he entered medicine more than three decades ago, chemotherapy was essentially the only tool available for myeloma. The current landscape looks dramatically different.
Effective Even for Hard-to-Treat Patients
About three-quarters of trial participants had already stopped responding to widely used therapies, including immune-modulating drugs like daratumumab and lenalidomide — leaving them with few remaining options in standard clinical practice. Teclistamab improved outcomes even in that group.
“To see that this drug is so efficacious and so safe across patients from all these locations worldwide is a very strong signal,” Landgren added. “To see that in patients who have been exposed and refractory to commonly used myeloma treatments is very important.”
Managing the Risks
Because teclistamab activates immune cells, it can temporarily weaken normal immune defenses. Patients face an elevated infection risk, especially during the first six months of treatment. Clinical teams manage this through routine monitoring, preventive antiviral and antibiotic medications, and immunoglobulin infusions for patients whose antibody levels fall below normal thresholds.
Why It Matters — and What Comes Next
Multiple myeloma is a cancer of plasma cells in the bone marrow. It is not typically considered curable with current treatments, but it is increasingly manageable — and trials like MajesTEC-9 are pushing that boundary further. For students pursuing medicine, oncology, pharmacology or biomedical research, this study represents a real-world example of how immune-based approaches are reshaping cancer care across disease types.
Researchers are now exploring whether bispecific antibodies like teclistamab could offer benefit even earlier in the disease course, before patients have exhausted other options. Landgren said the long-term vision goes further still.
“For me, the goal is to develop curative strategies,” added Landgren. “We are working toward treatments that can either eliminate the disease entirely or control it for very long periods while minimizing the burden on patients and preserving quality of life.”