Faeth Therapeutics, a clinical-stage biotechnology company pioneering metabolism-based cancer therapies, announced a $25 million strategic financing round to advance its lead program, PIKTOR, in endometrial cancer. The raise brings Faeth’s total funding to $92 million and will support the company’s expansion across oncology and metabolic diseases. The funding round was led by S2G Ventures with participation from existing investors Khosla Ventures, Future Ventures, Digitalis Ventures, KdT Ventures, and Cantos, as well as new investors B Capital Group, Avicella, and THO Seed Fund.
The financing follows strong clinical progress for Faeth’s PIKTOR regimen—a combination of serabelisib, sapanisertib, and paclitaxel—which achieved an 80% overall response rate and 11-month median progression-free survival in a Phase 1b study for endometrial cancer. This represents a significant improvement over the historical three-to-four-month progression-free survival seen with chemotherapy alone. Based on these results, the Gynecologic Oncology Group (GOG) Foundation has initiated a Phase 2 trial (GOG-3111; NCT06463028), which is now enrolling patients. The study also includes a substudy assessing whether precision nutrition-based insulin control can enhance clinical outcomes under trial conditions.
Faeth’s approach targets the PI3K/AKT/mTOR signaling axis, one of the most frequently altered pathways in solid tumors, including endometrial, breast, lung, and ovarian cancers. Unlike conventional therapies that inhibit single nodes and often lead to resistance, Faeth employs a selective multi-node inhibition strategy that simultaneously targets PI3Kα, mTORC1, and mTORC2 while controlling the tumor’s nutrient supply. This comprehensive yet selective blockade aims to prevent feedback reactivation and minimize toxicity, addressing limitations of pan-pathway inhibitors.
In preclinical models, Faeth’s selective multi-node inhibition achieved a more complete shutdown of the PI3K/AKT/mTOR pathway compared to single-agent inhibitors. These findings, coupled with Faeth’s clinical data, highlight the potential for its approach to redefine treatment outcomes across multiple tumor types where PI3K alterations drive disease.
The funding will be used for the ongoing Phase 2 trial through a full data readout expected in Q3 2026 and expand the company’s MetabOS platform—an AI-driven system that integrates genomic, transcriptomic, and microenvironment data to identify and exploit tumor metabolic dependencies. The financing will also support Faeth’s non-oncology pipeline, including a Phase 1 study in locally advanced rectal cancer and a new program for Hereditary Tyrosinemia Type 1 (HT1), a rare pediatric metabolic disorder.
Faeth’s MetabOS platform represents a foundational shift in therapeutic development, recognizing that cancer cells’ metabolic needs can be exploited to block tumor survival and adaptation. By controlling tumor “fuel” supply and combining it with multi-node inhibition, Faeth is advancing metabolism as a critical therapeutic discipline—potentially the “fifth pillar” of cancer treatment, alongside surgery, radiation, chemotherapy, and immunotherapy.
KEY QUOTES:
“We’ve achieved the optimal balance in PI3K pathway inhibition, comprehensive enough to prevent resistance, selective enough to avoid immunosuppression. The 80% response rate, 11-month progression-free survival, initiation of a trial by the GOG Foundation, and recognition as a late-breaking oral presentation at ESMO show that Faeth is executing as a clinical-stage company positioned to expand across the solid tumors where PI3K alterations drive disease.”
Anand Parikh, CEO of Faeth Therapeutics
“We’re seeing validation of multi-node targeting in recent phase 3 studies. Insider participation in this financing reflects conviction in Faeth’s progress, while new investors recognize metabolism as a category entering the clinic. Faeth’s selective multi-node approach positions the company to capture value as metabolism becomes established as the ‘fifth pillar’ of cancer treatment.”
Sanjeev Krishnan, Chief Investment Officer and Managing Director, S2G Ventures
“If the cell is the unit of life, then metabolism is the first verb in its sentence. Faeth is intervening where cellular decisions are made fastest: at the metabolic switches tumors rely on to adapt, long before mutations accumulate. That is why metabolism is emerging alongside the genome and immunogenicity as a therapeutic discipline.”
Siddhartha Mukherjee, Co-Founder of Faeth Therapeutics
