In October 2025, the U.S. Food and Drug Administration (FDA) granted Fast Track designation to a new treatment called VT3989 for people with unresectable (inoperable) mesothelioma. This applies to patients whose cancer has continued to grow after chemotherapy and immunotherapy.
This follows the Orphan Drug designation that VT3989 received in July 2025, which helps support the development of medicines for rare diseases like mesothelioma.
Mesothelioma can return even after treatment, and when it does, it is often more aggressive and harder to treat. The Fast Track status means the FDA will work closely with Vivace Therapeutics, the company behind VT3989, to help move the drug through testing and review more efficiently.
“We are pleased to receive fast-track designation from the FDA for VT3989 in this patient population, which is in desperate need of new and effective therapeutic options.”
– Dr. Sofie Qiao, president and CEO of Vivace Therapeutics
How VT3989 Works Against Mesothelioma
VT3989 is an oral medication that targets a cancer growth pathway known as the Hippo pathway. This pathway helps control how cells grow and repair themselves. In some cancers, including mesothelioma, the pathway can get “stuck on,” allowing cancer cells to keep multiplying.
VT3989 works by blocking TEAD proteins, which are key parts of this growth system. When these proteins are blocked, cancer cells may stop growing or become more sensitive to other mesothelioma treatments.
Earlier reports said VT3989 worked by blocking FAK and PYK2 proteins. New research shows it actually works by blocking TEAD proteins in the Hippo pathway. Because VT3989 focuses on cancer cells, it may cause fewer side effects than traditional chemotherapy.
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What We Know from Clinical Trials
Researchers are studying VT3989 in an ongoing clinical trial at hospitals in the United States and Australia. So far, the results have been promising. Some patients saw their tumors shrink or stop growing.
The drug worked for both pleural mesothelioma (in the chest) and peritoneal mesothelioma (in the abdomen). Most side effects were mild to moderate and included fatigue, swelling, and protein in the urine.
The study is expanding to enroll more patients and will also test VT3989 combined with immunotherapy drugs like nivolumab (Opdivo®) and ipilimumab (Yervoy®). Researchers hope that combining these treatments will help patients live longer.
What the New FDA Status Means for Patients
The FDA’s Fast Track program helps new treatments for serious conditions move through the testing and approval process more quickly.
Here’s what that could mean for patients and families:
- Faster access to potential treatments. The company can share trial results with the FDA as they come in, which can shorten the review time.
- Continued support for research. The designation makes it easier for Vivace to keep funding and expanding clinical trials.
- Encouraging signal from the FDA. The agency’s decision shows it sees promise in VT3989 as a treatment for hard-to-treat mesothelioma.
The Fast Track designation doesn’t mean the drug has been approved yet, but it’s a positive step that could help bring this treatment to patients sooner.
Hope for Patients and Families
Each FDA milestone for VT3989 gives hope to patients and caregivers who are waiting for better treatment options. Mesothelioma is a rare and aggressive cancer, but progress like this shows that researchers are moving in the right direction.
If you or someone you love has mesothelioma, our nurses and Patient Advocates are here to help.
Our team can:
- Explain your diagnosis and treatment options
- Connect you with top mesothelioma specialists and active clinical trials
- Offer support for managing symptoms and side effects
- Help explore financial and legal options related to your care
You don’t have to face this alone. Contact Mesothelioma Hope now or call (866) 608-8933 to speak with us and get the help you need.
