At Fox Chase Cancer Center in Philadelphia, researchers have taken an audacious step toward a new frontier in cancer treatment: they're targeting the very engines that power tumors. In a first-in-human study unveiled at the 2026 American Society of Clinical Oncology Annual Meeting in Chicago, Dr. Anthony Olszanski and his team have successfully tested gamitrinib, an experimental drug designed to disrupt the energy systems cancer cells depend on to survive and multiply.
The science behind gamitrinib rests on a fundamental observation about how cancer differs from healthy tissue. While normal cells operate efficiently, cancer cells demand enormous amounts of energy to fuel their relentless growth. They produce that energy through mitochondria—the cellular structures often called the cell's "powerhouse"—but with a crucial twist: unlike healthy cells, cancer cells rely heavily on specialized helper proteins called heat shock protein-90 (Hsp90) to keep their mitochondria functioning under the intense stress of rapid division. "This dependency creates an opportunity," Olszanski explained. "If we can interfere with that process in a targeted way, we may be able to harm cancer cells while potentially sparing healthy tissue."
Gamitrinib is groundbreaking because it concentrates specifically within cancer cell mitochondria rather than acting broadly throughout the body, which is why earlier mitochondria-targeting drugs caused severe side effects. This first-in-class therapy is engineered to disrupt the key survival functions tumors use to grow and resist treatment, exploiting a vulnerability that earlier approaches had missed. Preclinical research conducted in collaboration with the Wistar Institute in Philadelphia showed the drug could slow or stop tumor growth across multiple cancer types, compelling researchers to begin human testing.
The ongoing phase 1 clinical trial represents the first time gamitrinib has ever been administered to patients. The study enrolled adults with advanced solid tumors or lymphoma whose cancers had become resistant to standard treatments. Patients received gamitrinib as a weekly intravenous infusion, with doses carefully increased over time to evaluate safety. Results to date are striking in their promise: 18 patients have been treated across multiple dose levels without any dose-limiting side effects, and blood samples confirm the drug behaves as expected in the human body. The trial remains open, with patient enrollment continuing.
Early-phase trials answer a single, critical question: can the drug be given safely? On that measure, gamitrinib has cleared an important hurdle. "These early findings suggest the drug can be administered safely at the dose levels tested to date," Olszanski said. "That's a critical first step in developing a completely new approach to cancer treatment." Researchers are now focused on determining the optimal dose for future studies and watching for early signals that the drug may slow or shrink tumors in patients with some of the most difficult-to-treat cancers.
The work ahead is substantial—researchers must still prove the drug actually works against specific cancer types in larger populations—but the foundation has been laid. If gamitrinib proves effective in subsequent trials, it could offer a fundamentally new weapon for patients who have exhausted conventional options, a breakthrough born from understanding cancer cells not as uncontrollable invaders, but as metabolically dependent organisms with exploitable weaknesses.