Repare Therapeutics Jumps After Hours On $267M Global Licensing Deal With Debiopharm; Retail Traders Rush In

The deal builds on an existing collaboration around lunresertib and hands development control to Debiopharm, allowing Repare to focus on its Phase 1 trials for RP-1664 and RP-3467.

Repare Therapeutics saw its stock climb in after-hours trading Tuesday after disclosing a global licensing deal with Switzerland-based Debiopharm International for lunresertib, a first-in-class PKMYT1 inhibitor aimed at treating hard-to-tackle solid tumors.

The agreement gives Repare a $10 million upfront boost, with the potential to bring in up to $257 million more through clinical, regulatory, and commercial milestones, including $5 million in possible near-term payouts. 

Repare will also earn single-digit royalties on future global net sales.

RPTX’s stock closed Monday down 8.9% at $1.43, but rebounded 22.4% in after-hours trading to $1.75.

The agreement builds on an existing collaboration between the two companies that explored the synergy of lunresertib with Debiopharm’s Debio 0123, a selective WEE1 inhibitor. 

As part of the deal, Debiopharm will take over sponsorship of the Mythic trial and assume all development activities related to lunresertib moving forward.

Repare remains on track to report initial data from two ongoing Phase 1 trials—the Lions trial for its PLK4 inhibitor RP-1664 and the Polar trial for its Polθ ATPase inhibitor RP-3467—in the second half of 2025.

As of March 31, Repare had $124.2 million in cash and marketable securities on hand, which it says should be enough to fund its operations through 2027. 

The company reported a net loss of $0.71 per share in the first quarter, swinging from a profit of $0.30 per share in the same period last year. 

Repare has said it continues to explore strategic alternatives across its pipeline, including out-licensing and partnerships.

On Stocktwits, retail sentiment for RPTX was ‘extremely bullish’ amid ‘extremely high’ message volume.

One Stocktwits user expressed optimism about their position in the stock, noting an entry point at $1.62 with 10,000 shares and indicating confidence heading into the pre-market session. 

Another user encouraged buying, citing the stock’s after-hours gain.

RPTX’s stock has risen 8.3% so far in 2025.

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