Exscientia acquires CDK7 drug for $20M, plans breast cancer trial

Exscientia has taken full ownership of the oral CDK7 inhibitor candidate by purchasing its partner GT Apeiron for $20 million. The AI-enabled biotech is planning to push the molecule forward into a breast cancer combination trial.

GT Healthcare, an investor in Exscientia, founded GT Apeiron in 2019 and promptly signed an agreement to fund the discovery of cancer drugs using AI technology. However, by 2021, Exscientia and GT Apeiron had ended their initial agreement and entered a joint operation and cost-sharing arrangement for the development and commercialization of multiple programs.

In July 2023, the partners initiated a phase 1/2 clinical trial for their leading candidate, the oral CDK7 inhibitor GTAEXS617. Recently, Exscientia moved to fully acquire its partner, GT Apeiron. The last disclosed funding for GT Apeiron was a $17.5 million series A round in March 2022.

The financial aspect of the takeover sees Exscientia paying $10 million in upfront cash and an additional $10 million in equity to assume total control of the program along with all related intellectual property. Although GT Apeiron will receive single-digit royalties if GTAEXS617 makes it to the market, Exscientia will bear the existing development costs but still projects its financial runway to extend well into 2027.

This acquisition provides Exscientia with full ownership of an asset it believes can overcome the limitations that have previously hindered CDK7 inhibitors. For instance, Eli Lilly tested a CDK7 inhibitor in humans in 2019 but halted the trial due to a lack of efficacy. Similarly, Syros Pharmaceuticals abandoned one asset, SY-1365, while another, SY-5609, is currently sidelined. Meanwhile, Carrick Therapeutics has advanced its candidate, samuraciclib, into phase 2 trials.

In a May earnings call, Exscientia elaborated on the strategic positioning of GTAEXS617, indicating that while some monotherapy activity is expected, the primary clinical focus will be on combinations. The main obstacle to successful combinations, particularly with immunotherapies, is toxicity. Ben Taylor, Exscientia’s chief financial and strategy officer, explained why GTAEXS617 might avoid the issues that have plagued competing molecules.

Taylor noted, "It was specially designed to get around an issue that a number of the other competitive molecules have, which is being a transporter substrate. We think we've got a really nice advantage there and hopefully you'll be able to see that in the data. Because if we can get a nice safe profile, this is a mechanism that clearly should work, and there's a number of different combination opportunities for it."

Exscientia is targeting the publication of monotherapy dose escalation data within this year. If everything proceeds as planned, the biotech aims to initiate a dose escalation study combining GTAEXS617 with a selective estrogen receptor degrader in breast cancer towards the end of the year.