FDA Approval: Teclistamab (Tecvayli) for Multiple myeloma

What the FDA signed off on

On October 25, 2022, the FDA granted accelerated approval to teclistamab-cqyv, sold as Tecvayli. The approval package gives the wording exactly. It covered adults with relapsed or refractory multiple myeloma who had already had at least four prior lines of therapy. Those lines had to include three specific drug types: a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody.

"Relapsed" means the myeloma came back. "Refractory" means it stopped responding. Accelerated approval means the FDA cleared the drug on an early measure of benefit while confirmatory trials continued.

The label has since grown. The prescribing information on file in 2026 also covers teclistamab given with two other drugs, daratumumab and hyaluronidase-fihj. In that combination it can be used after only one prior line of therapy.

What myeloma is, in one paragraph

Plasma cells are white blood cells that make antibodies. In multiple myeloma, abnormal plasma cells build up in the bone marrow and form tumors in bone. NCI explains that they crowd out normal blood cell production. They also weaken bone. And they pump out a useless antibody called M protein. That protein can thicken the blood and harm the kidneys.

How a bispecific antibody works

Teclistamab is a bispecific antibody, meaning one molecule that grabs two different targets at once.

One end binds BCMA. That is a protein found on plasma cells, usually at higher levels on myeloma cells. The other end binds CD3, a protein on T cells. NCI describes the result as a bridge. The drug pulls a T cell up against a myeloma cell, and the T cell then kills it.

That places it near the family described in our guide to immunotherapy, but not inside it. Nothing is removed from the body and re-engineered. The drug comes off the shelf as an injection under the skin.

The trial behind the approval

The approval rested on a trial called MajesTEC-1. NCI's account describes 165 adults with relapsed or refractory myeloma. All had already had at least three types of myeloma drug. Half had been through five prior lines of treatment. Eighty-two percent had already had a stem cell transplant.

Participants got teclistamab once a week by injection under the skin. Median follow-up was 14.1 months.

Nearly two thirds had at least a partial response, and almost 40% had a complete remission. The median time before the cancer got worse again was 11.3 months. Responses lasted a median of 18 months.

For context, NCI quotes an investigator saying people at that stage of myeloma have usually lived only 8 or 9 months.

The side effects that shape the schedule

This is the part that explains how the drug is given.

The label carries a boxed warning, which is the FDA's strongest. It covers two problems. The first is cytokine release syndrome, or CRS. That is a whole-body immune reaction that can be life-threatening. The second is neurologic toxicity. That includes a syndrome known as ICANS, short for immune effector cell-associated neurotoxicity syndrome.

In MajesTEC-1, CRS happened in 119 of the 165 participants. It was mild or moderate in most, but nearly all of those people needed supportive care.

To blunt it, treatment starts with two smaller "step-up" doses. They are given two to four days apart, before the full dose. Patients stayed in the hospital for those doses and the first full dose. CRS usually shows up after the first two or three doses.

Infections are the other major issue. BCMA sits on healthy plasma cells too. So the drug lowers the body's supply of infection-fighting antibodies. Infections and low blood counts were the most common serious side effects. In all, 95% of participants had at least one serious side effect. Twelve of the 165 died of COVID-19 during a trial that began enrolling in March 2020.

Because of these risks, the drug is only available through a restricted FDA program. It is called a Risk Evaluation and Mitigation Strategy, or REMS.

When to get checked

Myeloma is sometimes silent and turns up on a blood or urine test done for something else. NCI says to check with a doctor about:

• Bone pain, especially in the back or ribs.
• Bones that break easily.
• Fever with no known cause, or frequent infections.
• Easy bruising or bleeding.
• Trouble breathing, or weakness in the arms or legs.
• Feeling very tired.

High blood calcium is a specific myeloma complication. Its signs include heavy thirst, frequent urination, constipation, nausea, muscle weakness, restlessness, and confusion. Those are worth a same-day call.

Anyone already on teclistamab should treat a fever as urgent, because that is often the first sign of CRS or of infection.

The survival picture

SEER is the federal cancer surveillance program. It estimates about 36,000 new myeloma diagnoses and 10,850 deaths in the United States in 2026. Five-year relative survival for people diagnosed from 2016 through 2022 was 63.7%.

That figure covers everyone with myeloma at any stage. Most never reach the heavily pretreated group this approval was written for. It is a group average from past years, and it does not describe one person.

What this approval cannot tell you

Accelerated approval is a conditional decision, not a final verdict. The FDA required the maker to finish MajesTEC-1 and report longer-term response data. Approvals like this can be withdrawn.

The 2022 approval also did not make teclistamab a first treatment. It was written for people who had exhausted three whole drug classes. Even the later combination use still requires a prior line of therapy.

Finally, the trial had no comparison group. It reports how many tumors shrank. It does not show whether people lived longer than they would have on something else. Our explainer on clinical trial phases covers why that gap matters.

Sources

• FDA approval package for TECVAYLI (teclistamab-cqyv), BLA 761291
• Drugs@FDA overview: TECVAYLI, BLA 761291
• DailyMed: TECVAYLI (teclistamab-cqyv) prescribing information
• NCI: Tecvayli Produces Promising Results in Multiple Myeloma
• NCI PDQ: Plasma Cell Neoplasms (Including Multiple Myeloma) Treatment
• NCI SEER Cancer Stat Facts: Myeloma

How this article was prepared

An AI-assisted editorial system helped prepare this page. No named medical reviewer has reviewed it unless one is listed.

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