Carrick Therapeutics has dosed the first patient in a Phase II clinical study of samuraciclib (CT7001) in combination with Menarini Group’s elacestrant in patients with CDK4/6i resistant HR+/HER2- metastatic breast cancer.

Samuraciclib is an oral and first-in-class inhibitor of CDK7, while elacestrant is an oral selective estrogen receptor degrader (SERD).

Initially, the study will assess the combination’s pharmacokinetics and tolerability. Later, it will recruit an expansion cohort to assess the longer-term progression-free survival benefits.

ctDNA analysis performed through liquid biopsy will serve as a key component of the study to address two issues, including the benefit level in patients without a detectable ESR1 mutation and the subject selection biomarker potential of TP53-mutation status.

The Phase II study is being carried out in partnership with Menarini as part of a clinical trial collaboration and supply agreement for elacestrant.

Carrick Therapeutics CEO Tim Pearson said: “Dosing the first patient in our Phase II clinical trial evaluating the combination of samuraciclib and elacestrant is an important milestone in our goal of improving outcomes for women fighting metastatic breast cancer.

“Our prior studies have validated the biology for elacestrant with CDK7, and we are eager to evaluate the potential synergistic benefit of this fully oral combination therapy in patients with advanced breast cancer.”

In January, ORSERDU (elacestrant), 345 mg tablets, received approval to treat postmenopausal women or adult men with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, ESR1-mutated advanced or metastatic breast cancer with disease progression after a minimum of one line of endocrine therapy.