Recursion's REC-617 Phase 1 Data Highlights Potential Best-in-Class CDK7 Inhibitor
Recursion shared early results from the Phase 1/2 ELUCIDATE trial of REC-617 for advanced solid tumors.
Breaking News
Dec 10, 2024
Simantini Singh Deo

Recursion shared early results from the Phase 1/2 ELUCIDATE trial of REC-617, a selective CDK7 inhibitor, for advanced solid tumors. The data was presented after the market closed at an AACR Special Conference on Cancer Research. The company will host a webinar on December 10 at 6:30 AM MT / 8:30 AM ET / 1:30 PM GMT to discuss the findings. The event will be streamed live on Recursion’s X (formerly Twitter), LinkedIn, and YouTube, where viewers can also submit questions.
David Hallett, Ph.D., Chief Scientific Officer of Recursion, said in a statement, “Cell cycle dysregulation and transcriptional 'addiction' are both hallmarks of many aggressive cancers. By inhibiting CDK7, we have the potential to target both mechanisms while fine tuning the therapeutic index. Using our precision design platform, we created a molecule with rapid oral absorption to reduce GI tissue exposure, a suitable half life to manage side effects, and target engagement covering the IC80 level.”
ELUCIDATE is an ongoing Phase 1/2 study testing REC-617 in patients with advanced solid tumors to evaluate its safety, tolerability, pharmacokinetics (PK), pharmacodynamics (PD), and the maximum tolerated dose (MTD). As of the data cutoff on November 15, 2024, 18 patients were evaluated in the monotherapy dose-escalation phase, with doses ranging from 2 mg to 20 mg once daily (QD) and 1 mg twice daily (BID). REC-617 was generally well-tolerated at all dose levels, with no patients discontinuing due to side effects. Most side effects were mild (Grade 1-2), on-target, and reversible. The MTD has not yet been determined.
Although the primary goal of this Phase 1 study was not to assess efficacy, a confirmed durable partial response (PR) was observed in a patient with metastatic, platinum-resistant ovarian cancer who received REC-617 monotherapy. This response lasted for more than 6 months after treatment. The patient had previously progressed after 4 lines of therapy. Additionally, four other patients showed stable disease (SD) as their best response, which lasted for up to 6 months across various dose levels.
Najat Khan, Ph.D., Chief R&D Officer and Chief Commercial Officer, Recursion, commented, "These initial findings for REC-617 represent an exciting step forward in the development of CDK7 inhibitors, with a favorable PK/PD profile and a durable confirmed partial response observed in dose escalation in a highly pre-treated patient population. Designed using our AI-powered OS platform, REC-617 reflects our focus on enhancing the therapeutic index to deliver more effective and safer treatment options for patients. We are eager to continue this momentum in dose escalation and to initiate the next phase of the program next year.”
Alongside the ongoing monotherapy dose escalation (QD and BID), combination studies for ELUCIDATE are planned to begin in the first half of 2025. The company also expects to present more data from the ELUCIDATE study, as well as preclinical REC-617 findings, at upcoming medical meetings.