Insilico Medicine announced on January 22, 2025, that a mesothelioma patient had received the first dose of its new treatment, ISM6331, in an ongoing phase I trial. Since then, the drug has continued to make progress.
On July 29, 2026, the U.S. Food and Drug Administration (FDA) granted ISM6331 Fast Track Designation for advanced mesothelioma, and Insilico announced it will present the drug’s first-in-human trial results at ESMO 2026 in Madrid on October 25.
Mesothelioma is a rare and aggressive cancer that’s very hard to treat. New therapies are urgently needed, and ISM6331 could be a promising option if it shows continued benefits in clinical trials.
Find out what’s new with ISM6331, including its new FDA designation and its upcoming presentation at a major cancer conference.
FDA Grants ISM6331 Fast Track Designation
On July 29, 2026, Insilico Medicine announced that the FDA gave ISM6331 Fast Track Designation for advanced mesothelioma. It’s the company’s very first Fast Track designation for any of its drugs.
“Receiving Fast Track Designation validates the strong clinical potential of ISM6331,” said Halle Zhang, Ph.D., Vice President of Clinical Development – Oncology at Insilico Medicine.
Fast Track status is a special label the FDA gives to promising treatments for serious diseases that don’t have good options yet. It means the FDA will work more closely with Insilico going forward, and opens the door to a faster approval process if the drug keeps performing well.
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Phase 1 ISM6331 Results to Be Presented at ESMO 2026
Two days before that announcement, on July 27, 2026, Insilico Medicine announced that early results from ISM6331’s first-in-human trial will be presented at the European Society for Medical Oncology (ESMO) Congress 2026, taking place October 23-27 in Madrid, Spain.
This presentation will share how the drug performed in its first clinical trial in people, including how safe it was and any early signs it’s working against mesothelioma tumors.
“Presenting our first-in-human phase 1 study at ESMO marks an important clinical milestone,” said Zhang.
The trial is currently running at hospitals in both China and the United States, and researchers are still collecting data on how patients respond to the drug over time.
Together, these two updates suggest ISM6331 is picking up real momentum — though it’s still early days, and the actual trial results won’t be public until the ESMO presentation this fall.
What Is ISM6331?
ISM6331 is a promising new therapy for mesothelioma and other cancers. It works by blocking a protein called TEAD that helps cancer cells grow.
It’s already shown strong potential to fight metastatic cancer that’s spread to other parts of the body, possibly making it one of the most effective treatments of its kind.
Along with shrinking tumors, ISM6331:
- Caused few side effects
- Had a low risk of drug interaction
- Proved to be safe in animals
- Was well tolerated, even at high doses
- Worked effectively when taken as a pill
“The potential applications are vast, including the promising enhancement of chemotherapy efficacy, bolstering tumor immunity, improving small molecule targeting, and overcoming current drug resistance challenges,” explained Dr. Feng Ren, co-CEO and Chief Scientific Officer of Insilico.
How Does ISM6331 Work?
Cancer cells need certain “on switches” to keep growing and spreading. ISM6331 works by blocking one of these switches, a protein called TEAD, which helps slow down or stop tumor growth.
Many mesothelioma patients have a gene change that turns this switch on too strongly, letting cancer cells grow out of control. By blocking TEAD, ISM6331 aims to shut that process back down.
This approach may help with:
- Cancer spreading to other parts of the body
- How mesothelioma cells get their energy
- Its resistance to other drugs
- Tumor growth in general
“About 10% of cancer patients are affected by abnormalities in the Hippo signaling pathway,” explained Dr. Ren. “By inhibiting TEAD, ISM6331 has the potential to suppress tumor growth and progression.”
Even better, ISM6331 may work well alongside chemotherapy, immunotherapy (treatment that boosts the immune system), and other targeted cancer drugs.
Adding ISM6331 to a treatment plan could possibly kill more mesothelioma cells or help patients whose cancer hasn’t responded to other therapies.
ISM6331 Treatment Timeline: What Comes Next?
The time it takes for a new mesothelioma treatment like ISM6331 to be researched, tested, and approved can vary quite a bit.
Our team will keep you updated as ISM6331 heads toward its ESMO 2026 presentation and beyond.
Here’s where things stand so far:
- September 2020: The launch of Chemistry42, Insilico’s generative AI platform, leads researchers to develop ISM6331.
- June 2023: Insilico recommends ISM6331 for preclinical studies, allowing researchers to see if the drug is effective.
- April 2024: Insilico shares that ISM6331 shows broad cancer-killing effects and high safety margins in animal studies at the American Association for Cancer Research (AACR) Annual Meeting.
- June 2024: The U.S. Food and Drug Administration (FDA) grants ISM6331 Orphan Drug Designation, offering more funding and support to encourage its development.
- August 2024: ISM6331 receives Investigational New Drug (IND) clearance from the FDA, allowing clinical testing in humans to start.
- January 2025: The first ISM6331 dose is given to a Chinese mesothelioma patient in a phase 1 clinical trial.
- July 27, 2026: Insilico announces that early trial results for ISM6331 will be presented at ESMO Congress 2026.
- July 29, 2026: The FDA grants ISM6331 Fast Track Designation for advanced mesothelioma.
- October 25, 2026: Insilico is scheduled to share its trial results publicly for the first time at ESMO 2026 in Madrid.
“We look forward to further clinical validation of ISM6331 and to translating these promising preclinical findings into tangible clinical benefits for patients,” said Dr. Ren.
Get Help Accessing Mesothelioma Treatment
If you or a loved one has been diagnosed with mesothelioma, new treatments like ISM6331 have the potential to improve your survival.
A mesothelioma doctor can determine the best treatment plan for your case, which may include emerging therapies.
Top mesothelioma doctors can help by:
- Assembling a care team of nurses and cancer specialists
- Creating a treatment plan customized to your diagnosis
- Recommending clinical trials that could work for you
At Mesothelioma Hope, we can assist patients and families at any stage of their cancer journey and offer personalized support.
We can even match you with a mesothelioma doctor in your area and help you prepare for your first appointment. Reach out to us at (866) 608-8933 right now to get started.
