Early ISM6331 Mesothelioma Trial Results to Be Presented at ESMO 2026

Researchers will present the first clinical findings for ISM6331, an experimental drug being studied in patients with advanced mesothelioma and other solid tumors, at the European Society for Medical Oncology Congress in October 2026.

ISM6331 is an oral targeted therapy designed to interfere with proteins that may help mesothelioma cells grow and survive. The drug was developed with the assistance of an artificial intelligence drug-discovery platform.

The presentation will include early findings from a phase 1 clinical trial. However, the results have not yet been released publicly. It is too soon to know how well ISM6331 works, which patients may benefit, or whether the drug will advance to later-stage testing.

What Is ISM6331?

ISM6331 is an experimental medication known as a pan-TEAD inhibitor. It is designed to block several members of the TEAD family of proteins. TEAD proteins help control genes involved in cell growth, survival, and tissue repair. They are part of a biological signaling system called the Hippo pathway. The Hippo pathway normally helps regulate how cells grow and when they stop dividing. Changes involving this pathway may allow cancer cells to continue growing, resist treatment, or spread.

These changes are especially relevant to mesothelioma. Genetic alterations involving proteins such as NF2 can disrupt Hippo pathway signaling and increase the activity of YAP and TAZ. These proteins work with TEAD to activate genes that may support tumor growth.

By blocking TEAD activity, researchers hope ISM6331 can interrupt those signals and slow or stop the growth of certain cancers.

How Was Artificial Intelligence Used?

Insilico Medicine describes ISM6331 as an AI-designed drug. The company used its Chemistry42 platform to help identify and optimize chemical structures that could potentially block TEAD proteins.

Artificial intelligence can help researchers evaluate many possible drug compounds and predict characteristics such as how strongly a molecule might bind to its intended target. Scientists must still select, test, and refine those compounds through laboratory studies, animal research, and clinical trials.

The use of AI does not mean the drug has been proven effective or can bypass normal testing. ISM6331 must complete the same stages of human research and regulatory review required for other experimental cancer treatments.

What Is the ISM6331 Phase 1 Trial?

The ongoing study is a phase 1, open-label clinical trial designed to enroll approximately 100 adults with advanced or metastatic mesothelioma or another solid tumor.

Phase 1 trials primarily evaluate safety and determine how a drug should be administered. Researchers are studying:

  • How much ISM6331 can be given safely
  • Which side effects occur
  • How the drug is absorbed and processed
  • How it affects its intended biological target
  • Which dose should be used in future studies
  • Whether there are early signs of antitumor activity

All participants receive ISM6331 as an oral medication taken once a day. The trial has two parts. During the first portion, researchers gradually increase the dose in different groups of participants. This helps identify dose-limiting side effects and determine which doses can be administered safely. During the second portion, researchers will evaluate two doses selected by the study review committee in additional participants. This portion is intended to refine the recommended dose for future studies while gathering more information about safety and preliminary antitumor activity.

Who May Be Eligible for the ISM6331 Phase 1 Trial?

The trial includes adults with unresectable advanced or metastatic mesothelioma or other solid tumors that have stopped responding to standard treatment or for which no effective standard therapy is available.

Patients with mesothelioma must previously have received both:

  • Platinum-based chemotherapy
  • An immune checkpoint inhibitor

Participants must also be able to perform most ordinary daily activities. Additional requirements address organ function, life expectancy, previous treatment, and whether the patient has a tumor that can be evaluated using medical imaging.

The complete eligibility criteria are more detailed. Meeting the basic requirements does not guarantee that a patient will qualify.

The trial currently lists treatment centers in the United States and China. Because participating locations and recruitment statuses can change, patients should review the current ClinicalTrials.gov record or contact the study team before making plans.

What Will Researchers Present at ESMO 2026?

Insilico Medicine announced that first-in-human results from the phase 1 study were accepted for a rapid oral presentation at the ESMO Congress 2026 in Madrid, Spain.

The presentation is scheduled for October 25, 2026. It is titled “First-in-Human Multicenter Phase 1 Study of ISM6331, an AI-Designed Pan-TEAD Inhibitor, in Patients With Mesothelioma or Other Advanced Solid Tumors.”

According to the company, the presentation will address safety, pharmacokinetics, and initial antitumor activity. Pharmacokinetics describes how a drug enters, moves through and leaves the body.

The announcement does not provide response rates, the number of patients evaluated, the types or frequency of side effects, or how long any responses lasted. Those details will be necessary to evaluate the findings.

Why Is the Presentation Important?

Mesothelioma can be difficult to treat, particularly when it progresses after chemotherapy and immunotherapy. Patients whose disease has stopped responding to those treatments may have limited remaining options.

ISM6331 uses a different approach. Instead of damaging rapidly dividing cells or helping the immune system recognize cancer, it targets a signaling pathway that may contribute directly to mesothelioma growth.

The trial may provide some of the first evidence showing whether blocking TEAD proteins can be done safely and whether it produces measurable activity in people with mesothelioma.

Acceptance as a rapid oral presentation indicates that the findings were selected for presentation during an oral conference session. It does not establish that the drug is effective or represents a treatment breakthrough.

The Trial Does Not Yet Prove ISM6331 Works

ISM6331 remains investigational. It has not been approved by the U.S. Food and Drug Administration as a treatment for mesothelioma or another cancer.

Phase 1 trials generally include relatively small groups and focus primarily on safety and dose selection. Early tumor responses may help researchers decide whether a drug deserves further study, but they cannot establish that the treatment helps patients live longer.

Important questions to consider once the findings are available include:

  • How many patients with mesothelioma were evaluated?
  • Which mesothelioma cell types and tumor locations were represented?
  • How many patients experienced tumor shrinkage or stable disease?
  • How long did those responses last?
  • Did responses differ based on Hippo pathway alterations?
  • What side effects occurred?
  • Did any patients stop treatment because of side effects?
  • Which dose was selected for future testing?

Encouraging results would still need to be confirmed in larger clinical trials.

Could ISM6331 Become a Mesothelioma Treatment?

ISM6331 could advance to additional testing if the phase 1 results demonstrate an acceptable safety profile and meaningful signs of antitumor activity. Researchers may eventually study the drug in a larger group of patients or combine it with another treatment. However, these possibilities remain speculative until the clinical findings are released and analyzed.

Many experimental cancer drugs that appear promising during early research do not ultimately receive FDA approval. The ESMO presentation should provide a clearer indication of whether ISM6331 warrants further development for mesothelioma.

Considering a Mesothelioma Clinical Trial

Clinical trials can provide eligible patients with access to treatments that are not otherwise available. Experimental therapies may not work and can cause side effects that are not yet fully understood.

Patients interested in the ISM6331 trial should discuss it with a mesothelioma specialist who can review their diagnosis, previous treatments, overall health, and the study’s requirements.

Questions to ask include:

  • What is the primary purpose of the study?
  • What is already known about the treatment?
  • What side effects have occurred?
  • How often will I need to visit the treatment center?
  • What tests and procedures are required?
  • Which expenses will the study cover?
  • What treatments are available outside the trial?
  • Can I leave the study if I decide it is not right for me?

Mesothelioma Hub can help patients and families connect with experienced mesothelioma doctors and treatment centers. A specialist can explain available therapies and help determine whether a clinical trial may be appropriate. Patients and families can also download our free mesothelioma guide for more information about treatment, support, and legal options. If you or a loved one was diagnosed with mesothelioma, request a free case evaluation to learn whether you may be eligible for compensation.

Author Madeline May

Madeline works for the patient advocate team and writes about asbestos exposure and mesothelioma. She is passionate about helping families in the mesothelioma community.

Sources

ClinicalTrials.gov. (n.d.). Study of ISM6331 in participants with advanced/metastatic malignant mesothelioma or other solid tumors (Clinical Trial No. NCT06566079). U.S. National Library of Medicine. Retrieved July 29, 2026, from https://clinicaltrials.gov/study/NCT06566079

European Society for Medical Oncology. (n.d.). European Society for Medical Oncology. Retrieved July 29, 2026, from https://www.esmo.org/

Fu, M., Hu, Y., Lan, T., Guan, K.-L., Luo, T., & Luo, M. (2022). The Hippo signaling pathway and its implications in human health and diseases. Signal Transduction and Targeted Therapy, 7, Article 376. https://doi.org/10.1038/s41392-022-01191-9

Insilico Medicine. (2026, July 27). Insilico Medicine announces oral presentation at ESMO 2026 for phase 1 clinical study of ISM6331 in mesothelioma and advanced solid tumors. PR Newswire. https://www.prnewswire.com/news-releases/insilico-medicine-announces-oral-presentation-at-esmo-2026-for-phase-1-clinical-study-of-ism6331-in-mesothelioma-and-advanced-solid-tumors-302835019.html

National Cancer Institute. (n.d.). Pan-TEAD inhibitor ISM6331. NCI Drug Dictionary. Retrieved July 29, 2026, from https://www.cancer.gov/publications/dictionaries/cancer-drug/def/pan-tead-inhibitor-ism6331