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 (https://www.myeloma.org/news-events/multiple-myeloma-news/fda-approval-lynozfic-linvoseltamab-rrmm) 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 engages the patient’s own immune system to attack their myeloma. Lynozyfic is part of a drug class called bispecific antibody therapies (sometimes simply called “bispecifics”). Bispecific antibodies have two (“bi”) arms that target and attach to two types of cells. One arm attaches to a myeloma cell, while the other arm attaches to an immune cell. This is what makes bispecific antibodies a dual threat to myeloma.

Lynozyfic is a bispecific antibody. It 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 granules that engage 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 (https://www.myeloma.org/videos/linker-mm1-linvoseltamab-rr-multiple-myeloma-deep-durable-responses-14-month-follow), 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 (https://www.myeloma.org/sparkcures) or contact the IMF InfoLine (https://www.myeloma.org/infoline) for more information.

The U.S. government maintains the website clinicaltrials.gov (https://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 (https://www.myeloma.org/resource-library/understanding-clinical-trials-myeloma). 

How Is Lynozyfic Administered, Dosed, and Scheduled? 

Lynozyfic is given as an intravenous (IV) infusion. You will be 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
• Full dosing is administered once-a-week after step-up dosing is completed.  
  • 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 (https://www.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?  

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

Cytokine release syndrome (CRS)

Cytokines are proteins secreted by cells which can stimulate or inhibit the growth or activity in 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 hematologic-related events (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. Yet, the incidence and severity of CRS are lower with bispecific antibodies than with CAR T-cell therapy.  

Prevention and treatment of CRS  

Patients are monitored following their IV administration. Lynozyfic step-up dosing schedule lowers the risk of CRS. At the first sign of CRS, patients must be evaluated immediately to be considered for hospitalization. Supportive care is administered based on severity of CRS. Further management should follow current practice guidelines. Depending on severity of CRS, Lynozyfic therapy may be interrupted or discontinued. .  

Neurologic toxicities

Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 7.7% of patients in the LINKER-MM1 clinical trial.  

• After treatment with Lynozyfic, ICANS can occur before, during, or after CRS onset, or after CRS resolution.  
• ICANS can also occur in the absence of CRS.  
• ICANS may be severe, life-threatening, or fatal.

Symptoms of neurologic side effects include, but are not limited to  

• 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, and  
• difficulty speaking, reading, or writing. 

Prevention and treatment of neurologic toxicities

Patients must be monitored for signs and symptoms of neurologic toxicity during treatment with Lynozyfic. At the first sign of any neurologic toxicity, patients should receive supportive therapy based on severity, and Lynozyfic treatment may also be withheld.   

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 

Infections were reported in 74.4% of patients in the clinical trial, with the frequency and severity declining over time. Lynozyfic can cause severe, life-threatening, or fatal infections. Do not start treatment with Lynozyfic if you have an active infection.  

Prevention and treatment of infections  

You must be monitored for signs and symptoms of infection before and during treatment with Lynozyfic. It is essential that you promptly report any infection to your doctor. Antibiotics and/or antivirals may be prescribed. Treatment with Lynozyfic may be interrupted or discontinued based on severity.  

Your immunoglobulin (Ig) levels should also be monitored to assess if you may need to receive intravenous immunoglobulin (IVIG). Ask your doctor about keeping current with your vaccinations. 

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. Febrile neutropenia is the development of fever, often with signs of infection, in a patient with neutropenia. Febrile neutropenia is usually treated with antibiotics even if an infectious source can’t be identified.

Prevention and treatment of neutropenia  

When undergoing Lynozfic therapy, complete blood counts (CBC) should be measured at baseline and monitored periodically. Fever is the most common sign of neutropenia. 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.