AstraZeneca and GI Therapeutics, a US clinical-stage oncology company, are collaborating to test a new combination therapy for lung cancer. The parties will evaluate AstraZeneca’s Tagrisso with G1’s oral CDK4/6 inhibitor G1T38 to treat epidermal growth factor receptor (EGFR) mutation-positive non-small cell lung cancer (NSCLC).

Under terms of the agreement, G1 will sponsor and conduct a Phase 1b/2 study together with the Anglo-Swedish drugmaker, in patients with NSCLC who have experienced disease progression on first-line EGFR inhibitors and harbor the EGFR T790M mutation. G1 plans to start the trial in the first quarter of 2018.

 “CDK4/6 inhibitors can enhance the efficacy of targeted therapies, and G1T38 has already shown encouraging preclinical and initial clinical data that support a potential best-in-class profile. The addition of G1T38 to Tagrisso in EGFR mutation-positive NSCLC has the potential to prolong the time to disease progression by overcoming resistance mechanisms,” said Mark Velleca, CEO of G1 Therapeutics.

Tagrisso is currently used as a second-line treatment for patients with EGFR-T790M mutation-positive advanced NSCLC. The European Medicines Agency is now reviewing AstraZeneca’s application to market Tagrisso for the first-line treatment of patients with this form of lung cancer.

According to AstraZeneca, roughly 10-15% of lung-cancer patients in Europe and the US have NSCLC with EGFR mutations.