Gilead Buys Repare Cancer Drug Ahead of Xeno Takeover

CAMBRIDGE, Mass. & MONTREAL – December 24, 2025 – In a significant move to bolster its oncology pipeline, Gilead Sciences has entered into a definitive agreement to acquire a promising cancer therapy candidate from Repare Therapeutics Inc. (Nasdaq: RPTX). The deal, centered on the polymerase theta (Polθ) ATPase inhibitor known as RP-3467, could be worth up to $30 million for the clinical-stage precision oncology company.

The transaction provides Repare with a $25 million upfront payment, with an additional $5 million contingent upon the successful completion of technology transfer activities. This asset sale comes at a pivotal moment for Repare, which is currently navigating its own acquisition by XenoTherapeutics, Inc., adding a compelling financial layer to the company's final chapter as an independent entity.

The Science of a Precision Strike

At the heart of the deal is RP-3467, a molecule at the forefront of a highly targeted cancer treatment strategy known as synthetic lethality. This approach exploits specific genetic vulnerabilities within cancer cells. RP-3467 is a potent, small molecule inhibitor designed to block the function of Polθ, an enzyme crucial for a particular DNA repair pathway.

In healthy cells, multiple pathways exist to repair DNA damage. However, certain cancers, particularly those with mutations in the BRCA genes (commonly associated with breast, ovarian, and prostate cancers), lack some of these primary repair mechanisms. These cancer cells become heavily reliant on alternative pathways, such as the one involving Polθ, to survive. By inhibiting Polθ with a drug like RP-3467, this last line of defense is removed, leading to a catastrophic pile-up of DNA damage that selectively kills the cancer cells while largely sparing healthy ones.

This “potential best-in-class Polθ ATPase inhibitor,” as described by Repare's President and CEO Steve Forte, is currently being evaluated in a Phase 1 clinical trial named POLAR. The study is assessing the drug's safety, dosage, and preliminary effectiveness, both as a standalone therapy and in combination with olaparib, another targeted therapy known as a PARP inhibitor. The trial is enrolling adult patients with advanced or metastatic cancers, including epithelial ovarian, breast, castration-resistant prostate, and pancreatic adenocarcinoma—all areas with significant unmet medical needs. Gilead's acquisition of the asset signals strong confidence in the therapeutic potential of targeting the Polθ pathway and its own ability to shepherd the drug through further development.

A Deal Within a Larger Deal

While the sale of RP-3467 is significant on its own, its timing adds a layer of intrigue and immediate financial benefit for Repare’s shareholders. The transaction unfolds against the backdrop of Repare's pending acquisition by XenoTherapeutics, a deal first announced on November 14, 2025.

Under the terms of that larger arrangement, Repare shareholders are set to receive a cash payment for each of their common shares. The final per-share price is not fixed but is directly tied to Repare’s net cash balance at the time the acquisition closes. The influx of $25 million in upfront cash from the Gilead agreement directly increases this closing cash amount.

Repare has already revised its estimates based on the new funds. The company now projects that its shareholders will receive approximately US$2.20 per common share when the Xeno acquisition is finalized. This represents a tangible increase in value for investors, directly resulting from the strategic divestment of the RP-3467 asset. This move effectively allows Repare to monetize a key pipeline asset for the immediate benefit of its shareholders before the company itself is absorbed.

Strategic Realignment for Both Parties

For Repare, the sale marks a significant strategic milestone. Steve Forte noted in a statement, “This marks the third and most significant portfolio transaction for Repare this year.” This series of deals suggests a deliberate corporate strategy to streamline its portfolio and crystallize the value of its research and development efforts ahead of the planned merger with Xeno. By selling off assets to well-suited partners like Gilead, Repare ensures its innovations have a path forward while maximizing the return for its investors.

For Gilead Sciences, the acquisition represents a calculated expansion of its growing oncology franchise. Gilead has been actively building its presence in cancer treatment, and acquiring RP-3467 adds a promising, precision-targeted asset to its pipeline. The company can now leverage its extensive resources and deep expertise in oncology research and clinical development to potentially accelerate RP-3467’s journey toward regulatory approval and commercialization. The focus on synthetic lethality aligns with cutting-edge trends in oncology, where therapies are becoming increasingly personalized to the genetic makeup of a patient's tumor.

The next major hurdle for Repare is a special meeting of its shareholders scheduled for January 16, 2026. At this meeting, investors will vote on the proposed acquisition by Xeno. The company has filed and distributed a definitive proxy statement urging shareholders to review the details of the transaction. The successful asset sale to Gilead and the resulting increase in the shareholder payout will likely be a key point of discussion as investors weigh the merits of the final takeover agreement.

The transaction with Gilead is a testament to the value embedded in Repare's synthetic lethality platform and provides a clear path forward for a promising therapeutic candidate. It also serves as a savvy financial maneuver that enhances shareholder value at a critical juncture in the company's history, setting the stage for the final vote on its own acquisition.