Carrick Therapeutics, an oncology-focused biopharmaceutical company discovering and developing highly differentiated therapies, today announced that the first patient has been dosed in its Phase 2b clinical trial evaluating the combination of samuraciclib (CT7001), an oral and first-in-class inhibitor of CDK7, and fulvestrant, an intramuscular injected selective estrogen receptor degrader (SERD), in women with HR+, HER2- advanced breast cancer previously treated with a CDK4/6 inhibitor.

“We continue to make great progress in evaluating the combination of samuraciclib and fulvestrant with the dosing of the first patient in the Phase 2b study,” said Tim Pearson, Chief Executive Officer of Carrick Therapeutics. “There is a large unmet need in treatment for women with HR+, HER2- breast cancer, which represents more than two thirds of all new female breast cancer cases. We previously announced data from a single-arm Ph2a study with this combination therapy that demonstrated both clinical activity and tolerability. As such, we are encouraged by the potential of samuraciclib to be a first and best-in-class treatment for women with advanced breast cancer.”

The randomized Phase 2b clinical trial will evaluate the Progression Free Survival benefit of the novel combination of samuraciclib with fulvestrant in comparison to fulvestrant alone for patients with breast cancer that have progressed following treatment with a CDK4/6 inhibitor.

The clinical trial is being conducted with support from Pfizer Ignite, a new end-to-end service for biotech companies with high potential science that leverages the company’s significant R&D capabilities, scale and expertise to accelerate the development of breakthrough therapies.

Carrick maintains full economic ownership and control of samuraciclib and its pipeline. Clinical trial details can also be found on under study ID: NCT05963984. For additional information on the clinical trial, please contact

About Samuraciclib (CT7001)
Samuraciclib is the most advanced CDK7 inhibitor in clinical development. Inhibiting CDK7 is a promising therapeutic strategy in cancer as CDK7 regulates the transcription of cancer-causing genes, promotes uncontrolled cell cycle progression and promotes resistance to anti-hormone therapy. Samuraciclib has demonstrated a favorable safety profile and encouraging efficacy in early clinical studies. In addition to the above studies, samuraciclib has further potential in prostate, pancreatic, ovarian and colorectal cancers. Samuraciclib has been granted Fast Track designation from the U.S. Food and Drug Administration (FDA) for use in combination with fulvestrant for the treatment of CDK4/6i resistant HR+, HER2- advanced breast cancer. Carrick is collaborating with Roche, Menarini Group and Arvinas/Pfizer to evaluate novel combinations of samuraciclib with Roche’s oral SERD giredestrant, Menarini Group’s oral SERD elacestrant, and Arvinas/Pfizer’s proteolysis targeting chimera (PROTAC) Estrogen Receptor degrader vepdegestrant (ARV-471) in late-stage CDK4/6i resistant HR+, HER2- metastatic breast cancer.