The Food and Drug Administration (FDA) has just approved tislelizumab-jsgr (Tevimbra) for use in adult patients with unresectable or metastatic squamous cell cancer of the esophagus. The drug has been approved as a second-line monotherapy and comes from the company BeiGene. What does all of this mean? Stick around to find out as we break it down.
What is Tevimbra and how does it work?
Tevimbra, also called tislelizumab-jsgr, is a humanized monoclonal antibody that targets PD-1. Let’s decipher what that means. Antibodies are naturally produced by the immune system to protect against antigens, or foreign materials. Antibodies are developed by your body to specifically target and bind the foreign materials so the immune system can attack and remove the target. A monoclonal antibody is produced in lab, while a humanized monoclonal antibody combines part of a human antibody to a mouse or rat antibody. Humanized antibodies are less likely to be destroyed by your own immune system. The target of Tevimbra is PD-1, which is a protein that interacts with the immune system to down-regulate activity. This is a key checkpoint in immune system activation/deactivation, hence the drug is also called an immune checkpoint inhibitor for disrupting this pathway. Cancer cells can use PD-1 to down-regulate the immune system and prevent themselves from being attacked. When Tevimbra binds to PD-1 on cancer cells it stops the down regulation of the immune system.
When do you use Tevimbra?
Read MoreWhat phase 3 clinical trial is there for Tevimbra?
For Tevimbra, the phase 3 RATIONALE-302 trial demonstrated efficacy with a reasonable safety profile. In this study Tevimbra was tested against standard chemotherapy in patients with unresectable (unable to get surgery) or metastatic squamous cell cancer of the esophagus that had already progressed through first-line systemic therapy. Prior first-line therapy was defined as standard chemotherapy (no prior immunotherapy). 512 patients were included in the study from 11 countries. Patients were given either Tevimbra every 3 weeks or chemotherapy until the disease progressed, the side effects were too severe, or the patient withdrew from the study.
The main goal of the study was to see if Tevimbra improved overall survival in these patients as compared to traditional chemotherapy. Tevimbra had an improved overall survival of 8.6 months vs. 6.3 months for chemotherapy. Additionally, in patients with more PD-L1 expression in their cancer (meaning more targets for the Tevimbra medication) there was a greater improvement in overall survival (10.3 months vs. 6.8 months for chemotherapy). This improvement in overall survival was seen across all groups of patients regardless of country or race. Tevimbra, in addition to an improved overall survival over traditional chemotherapy, demonstrated better tumor response and less severe side effects.
In summary, if a patient presented with unresectable or metastatic squamous cell carcinoma of the esophagus and had progressed on chemotherapy previously, by taking Tevimbra over additional chemotherapy, the overall survival was improved (8.6 vs. 6.3 months), the response rate of the tumor was better (20.4% vs. 9.8%), the duration of the tumor response was longer (7.1 vs. 4.0 months), and there were less severe (grade 3 and greater) side effects (46% vs. 68%).
Given the benefits of Tevimbra over previous standard-of-care with less side effects, it was approved by the FDA for clinical use.
What does all of this mean?
Tevimbra has FDA approval in the specific setting of second-line monotherapy for squamous cell carcinoma of the esophagus that is unresectable or metastatic, meaning that Tevimbra is used if the initial chemotherapy does not work, and only in patients with disease that cannot be surgically removed or has spread distantly. In these patients, Tevimbra was more effective than additional chemotherapy and had less side effects. Although this is a step in the right direction, further research and testing of new medications is needed to further improve outcomes in this patients population.
What should you ask your doctor?
- When is Tevimbra right for me?
- When is Tevimbra recommended in esophageal cancer?
- What are the main side effects of taking Tevimbra?
- Are there any contraindications (reasons not to take) Tevimbra?
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