What Is Lynozyfic (linvoseltamab-gcpt)?

LYNOZYFIC™ (also known as linvoseltamab-gcpt , the generic drug name) is a B-cell maturation antigen (BCMA)-CD3-directed bispecific antibody immunotherapy. In July 2025, the U.S. FDA granted accelerated approval of Lynozyfic for the treatment of adult patients with relapsed or refractory multiple myeloma (RRMM) who have received at least four prior lines of therapy, including a proteasome inhibitor, an immunomodulatory agent, and an anti-CD38 monoclonal antibody. 

How Does Lynozyfic Work?

Lynozyfic is an immunotherapy, a treatment that uses the patient’s own immune system to attack their myeloma. Lynozyfic is part of a class of drugs called bispecific antibody therapies. Bispecific antibodies have two (“bi”) arms that target and attach to two types of cells. One arm attaches to a myeloma cell, and the other arm attaches to an immune cell. This is what makes bispecific antibodies a double threat to myeloma. 

Lynozyfic uses one arm to attach to the B-cell maturation antigen (BCMA) on the surface of the patient’s myeloma cells; BCMA is involved in myeloma cell growth and survival. Lynozyfic uses a second arm to attach to the CD3 antigen on the surface of the patient’s T cells (T lymphocytes), a type of white blood cell (WBC). Lynozyfic activates T cells to release lethal particles that connect with and destroy myeloma cells

A similar strategy is already used in myeloma, known as chimeric antigen receptor (CAR) T-cell therapy. For CAR T-cell therapy, T cells are collected from a patient. These T cells are altered in a laboratory so that they can attach to BCMA on the surface of a myeloma cell. These engineered cells are multiplied in a laboratory. Then, they are re-infused into the patient to attack their myeloma cells.  

To treat myeloma with Lynozyfic, there is no need to collect, modify, and manufacture engineered T cells over the course of several weeks. Lynozyfic is an “off-the-shelf” product that’s ready to be used right away. This factor eliminates the wait time for the myeloma patient when compared to CAR T-cell therapy. In addition, patient comfort may be greater than with T-cell harvesting and the re-infusion.  

How Has Lynozyfic Been Used in Clinical Trials?    

A clinical trial is a medical research study with people who volunteer to test scientific approaches for preventing, detecting, diagnosing, or treating cancer, or to answer scientific questions. A clinical trial is launched only after laboratory studies have demonstrated the potential of a treatment or procedure to be more effective and/or less harmful than previously existing methods. The goal of clinical trials is to improve patient care.

Based on the LINKER-MM1 phase I/II clinical trial, the FDA approved Lynozfic for patients with relapsed/refractory myeloma patients. In the trial, myeloma patients were treated with 200 mg of Lynozyfic as monotherapy (single-agent). The median age was 70 years, and 39% of participants had high-risk multiple myeloma (HRMM) based on chromosomal abnormalities. Additionally, 28% of patients were “penta-refractory,” meaning they were resistant to at least 5 drug classes.  

At a median follow-up of 11.1 months, the overall response rate (ORR) was 71%, with 45% achieving complete response (CR) or better. The median duration of response (DoR) was 29.4 months. Lynozyfic at a dose of 200 mg induced deep and durable responses in heavily pre-treated patients with RRMM. 

How to Find a Clinical Trial to Match Your Needs

Participating in a clinical trial may give you access to treatment that is not yet available outside of a study. If you have an interest in participating in a clinical trial, be sure to discuss with the doctor treating your myeloma all the potential risks and benefits that may apply to your particular case.

Clinical research in myeloma has become a robust field, with many studies enrolling patients at any given time. To help myeloma patients with personalized support for identifying and exploring clinical trial options across the U.S., the IMF has partnered with SparkCures. Visit myeloma.org/sparkcures or contact the IMF InfoLine for more information.

The U.S. government maintains the website clinicaltrials.gov, an online database of thousands of research studies from around the world. You may wish to also explore this resource. However, the U.S. government does not review or approve the safety and science of all the studies listed on this website. For more information about what’s involved in study participation, read the IMF’s publication Understanding Clinical Trials in Myeloma. 

How Is Lynozyfic Administered, Dosed, and Scheduled? 

The dose and administration information provided below is based on clinical trial data that served as the basis of the FDA approvals. Your myeloma doctor may modify your dose and schedule based on your response to treatment and factors specific to your case.

Lynozyfic is given as an intravenous (IV) infusion into a vein, and you are monitored after receiving your infusions. 

• “Step-up” dosing is used for the first 2 weeks to help your body adjust to the treatment and to lower the risk of side effects. Typically, patients are hospitalized for 24 hours on Day 1 and 24 hours on Day 8. Yet, some treatment centers administer Lynozyfic on an outpatient basis.  
  • Step-up dose 1 (week 1) of 5 mg Lynozyfic, 4-hour infusion  
  • Step-up dose 2 (week 2) of 25 mg Lynozyfic, 4-hour infusion
• After "step-up dosing" is completed, full dosing is administered once-a-week.
  • Full dose 1 (week 3) of 200 mg Lynozyfic, 4-hour infusion
  • Full dose 2 (week 4) of 200 mg Lynozyfic, 1-hour infusion  
  • Full dose 3 through 13 (weeks 5 through 15), 30-minute infusions
• Full dosing is continued once every 2 weeks for 5 more doses.  
  • Full doses 14 through 18, given as 30-minute infusions
• After your 18th dose, your myeloma doctor will  
  • assess your response to treatment and determine if you should continue receiving Lynozyfic once every 2 weeks, or
  • if you can receive Lynozyfic once every 4 weeks.  

Your doctor may modify your treatment based on your response and factors specific to your particular case. Your doctor will decide how long your treatment should continue.  

In the LINKER-MM1 clinical trial, patients who achieved a very good partial response (VGPR) or better were switched from receiving Lynozyfic once every 2 weeks to once every 4 weeks. VGPR means that your monoclonal protein (myeloma protein, M-protein) in the serum (blood) and in the urine are detectable by the immunofixation test but not by the electrophoresis test (≥ 90% reduction in serum M-protein; <100 mg per 24 hours urine M-protein). For more information about treatment with Lynozyfic, please visit regeneron.com/downloads/lynozyfic_fpi.pdf. 

Prophylactic Tocilizumab  

Myeloma guidelines by the National Comprehensive Cancer Network (NCCN) for the use of bispecific therapies state that the drug tocilizumab can be given as a prophylactic prior to administering a bispecific antibody. Ask your doctor if this is recommended in your case. 

In the LINKER-MM1 phase I/II clinical trial, tocilizumab was given to 22 patients (18.8%) who experienced cytokine release syndrome (CRS) but did not respond to steroid therapy. Prophylactic use of tocilizumab is not a requirement for the clinical use of Lynozyfic. 

What Are Important Safety Precautions for Patients Taking Lynozyfic?  

Before you begin treatment with Lynozyfic, talk with your doctor about  any special precautions and possible side effects that may apply to you. If you have already started treatment with Lynozyfic, promptly report any changes in your health to your doctor, including new or worsening signs or symptoms.

Risk Evaluation and Mitigation Strategy (REMS) and Lynozyfic Use

REMS programs are required by the FDA for treatments that may have  serious safety concerns. REMS programs support the use of treatment and  mhelp ensure that the potential benefits outweigh the risks. Lynozyfic is available through a REMS program

Cytokine release syndrome (CRS)

Cytokines are proteins released by cells that can increase or reduce the growth or activity of other cells. In patients with myeloma, cytokines are produced in the bone marrow and circulate in the bloodstream. Cytokines are normally released in response to low blood counts and infection. 
 

CRS is a potentially fatal, uncontrolled immune reaction in which cytokines  trigger an overwhelming immune system response. A “cytokine storm” can seriously damage body tissues and organs. CRS is the most frequent side effect observed with T-cell therapies, but the frequency and severity of CRS are lower with bispecific antibodies than with CAR T-cell therapies.

Lynozyfic step-up dosing is used to decrease the risk of CRS, and patients are monitored following their IV infusions. At the first sign of CRS, immediate assessment must be made to consider if the patient needs to be hospitalized. Supportive care is provided if needed. Further management should follow current practice guidelines. Depending on how bad CRS might be, Lynozyfic therapy may be paused or stopped. 

Neurologic toxicities

IImmune effector cell-associated neurotoxicity syndrome (ICANS) was reported in 7.7% of the patients in the LINKER-MM1 clinical trial. After treatment with Lynozyfic, ICANS can happen to a patient after they receive Lynozyfic and may happen before, during, or after CRS starts or CRS ends. ICANS can also happen by itself, without CRS.

ICANS may be serious, life-threatening, or deadly. 

Symptoms of neurologic side effects include but are not limited to the following:

• confusion
• disorientation
• loss of consciousness
• seizures
• tremors
• slower movements
• changes in personality
• depression
• tingling and numbness of hands and feet
• leg and arm weakness
• facial numbness
• difficulty speaking, reading, or writing

Patients are monitored during treatment with Lynozyfic. At the first sign of neurologic toxicity, including but not limited to ICANS, patients receive supportive therapy based on how serious their symptoms are, 
and Lynozyfic treatment may be paused or stopped  

What Are Possible Side Effects of Lynozyfic? 

The following were the most common possible side effects of Lynozyfic in the LINKER-MM1 clinical trial.  

Infections 

Lynozyfic can cause serious, life-threatening, or deadly infections. In the LINKER-MM1 clinical trial, 74.4% of patients experienced infections, with the rate and seriousness going down over time. Do not start treatment 
with Lynozyfic if you have an active infection. 

You will be monitored for signs and symptoms of infection prior to and during treatment with Lynozyfic. Antibiotics and/or antivirals may be prescribed. It is critical that you immediately report any infection to your 
doctor. Based on seriousness, treatment with Lynozyfic may be paused  or stopped. 

Your immunoglobulin (Ig) levels will be monitored to assess if you may need to receive intravenous immunoglobulin (IVIG). Be sure to talk to your doctor about the importance of keeping your vaccinations current. 

Neutropenia  

Lynozyfic can cause neutropenia, a reduced level of neutrophils (a type of white blood cell necessary to combat bacterial infection). Having too few neutrophils can lead to infection. Your complete blood counts (CBC) should be tested at baseline and monitored during treatment. 

Febrile neutropenia is the development of fever, often with signs of infection, in a patient with neutropenia. Fever is the most common sign of neutropenia, and it is usually treated with antibiotics. If you have a fever,  you must get immediate medical attention. 

Lynozyfic Support Programs

Patient Wallet Card  

Patients who are prescribed Lynozyfic will receive a Patient Wallet Card. This card summarizes the signs and symptoms of problems that may occur with treatment. Patients who develop any of the signs and symptoms listed on the Lynozyfic Patient Wallet Card must seek medical help immediately.  

Lynozyfic Surround™  

Lynozyfic Surround is a support program offered by Regeneron, the manufacturer of Lynozyfic. This program offers financial and educational resources to help patients throughout their treatment journey with Lynozyfic. Call 1.844.746.4363 and visit regeneron.com for more information.