First-in-class cancer drug gamitrinib evaluated in phase 1 clinical trial

Cancer cells need large amounts of energy to survive and multiply. To produce that energy, they rely on structures inside the cell called mitochondria, often described as the cell's "powerhouse." Unlike healthy cells, cancer cells rely heavily on specialized helper proteins to keep mitochondria functioning under the high stress of rapid growth. 

This dependency creates an opportunity. If we can interfere with that process in a targeted way, we may be able to harm cancer cells while potentially sparing healthy tissue." 

Anthony Olszanski, MD, RPh, Vice Chair of Clinical Research, Department of Hematology/Oncology and Director of the Early Clinical Drug Development Phase 1 Program, Fox Chase Cancer Center

In a new study presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, Olszanski and colleagues evaluated gamitrinib, an experimental therapy designed to exploit this vulnerability. Gamitrinib is a first-in-class therapy engineered to act inside cancer cell mitochondria, disrupting key survival functions tumors use to grow and resist treatment. 

What makes gamitrinib different 

Many earlier drugs aimed at similar targets caused serious side effects because they acted broadly throughout cells. Gamitrinib was designed to concentrate within mitochondria, where cancer cells may be especially vulnerable. 

Gamitrinib: 

• Targets the mitochondria that help power cancer cells. 

• Disrupts key survival functions tumors use to grow and resist stress. 

• Targets a cellular compartment that may be especially important for cancer cell survival. 

Pre-clinical work done in collaboration with the Wistar Institute in Philadelphia, previously showed that gamitrinib could slow or stop tumor growth in multiple cancer types, leading researchers to move forward with human testing. 

About the clinical trial 

This ongoing phase 1 clinical trial is the first time gamitrinib has been tested in people. 

The study includes adults with advanced solid tumors or lymphoma whose cancer has stopped responding to standard treatments. Patients receive gamitrinib as a weekly intravenous infusion, with doses gradually increased to evaluate safety. 

So far: 

• 18 patients have been treated across multiple dose levels. 

• No dose‑limiting side effects have been observed. 

• Blood samples show the drug behaves as expected in the body. 

The trial remains open, and patient enrollment is continuing. 

Why this matters for patients 

Early‑phase trials are designed primarily to answer one question: Can the drug be given safely? 

"These early findings suggest the drug can be administered safely at the dose levels tested to date," said Olszanski. "That's a critical first step in developing a completely new approach to cancer treatment." 

If future studies confirm effectiveness, this strategy could offer a new option for patients with hard‑to‑treat cancers. 

Looking ahead 

Researchers are continuing to enroll patients to determine the best dose for future studies and to look for early signs that the drug may help slow or shrink tumors. The findings will help guide later‑stage clinical trials designed to test how well gamitrinib works against specific cancer types. 

The study, "A phase 1, first-in-human, open-label, dose escalation and expansion study of Gamitrinib, a first-in-class, mitochondria-directed inhibitor of the molecular chaperone Heat Shock Protein-90 (Hsp90) in patients with advanced cancer," was presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, held May 29-June 2 in Chicago, Illinois.