AstraZeneca formally removes two failed Phase III studies of cancer drug Imfinzi

The studies – in lung and head and neck cancers – produced negative results late last year. Several Phase I Imfinzi and tremelimumab studies were also removed, but others were added to the company’s pipeline.

British drugmaker AstraZeneca has dropped two Phase III clinical trials of its approved immuno-oncology drug following the studies’ failure late last year.

In its fourth quarter earnings Thursday, the London-based pharmaceutical giant said it had removed the EAGLE and MYSTIC studies. The Phase III trials test the approved PD-L1 inhibitor Imfinzi (durvalumab) and the investigational CTLA-4 inhibitor tremelimumab in second-line head and neck cancer and first-line non-small cell lung cancer, respectively. The company announced MYSTIC’s failure to show an improvement in overall survival for the two-drug combination in November, followed by similar news for EAGLE in December.

EAGLE and MYSTIC are still listed on as “Active, not recruiting,” having been last updated on Jan. 28 and Jan. 21, respectively.

The MYSTIC results hit especially hard, sending the company’s shares down 3.5 percent on the New York Stock Exchange at the time. The first-line NSCLC setting is currently dominated by Merck & Co.’s PD-1 inhibitor Keytruda (pembrolizumab). MYSTIC’s success would not only have meant Imfinzi not only competing directly against Keytruda, but doing so as part of a doublet combination that could potentially provide better efficacy. Tremelimumab itself would have competed against Yervoy (ipilimumab), Bristol-Myers Squibb’s CTLA-4 inhibitor that in some indications is combined with its PD-1 inhibitor, Opdivo (nivolumab). Like MYSTIC, EAGLE’s failure also left Keytruda, along with Opdivo, as the dominant checkpoint inhibitors in head and neck cancer.

Imfinzi is currently approved for unresectable, Stage III NSCLC that has not progressed following concurrent platinum-based chemotherapy and radiation therapy. AstraZeneca reported that the drug had strong uptake in that indication and expects US peak sales to exceed $1 billion. Sales for 2018 were $633 million, including $262 million in the fourth quarter.

Other Imfinzi studies that AstraZeneca pulled included three Phase I trials – two in solid tumors and one in diffuse large B-cell lymphoma that also combined the drug with tremelimumab. However, it also added two Phase II tremelimumab trials in solid tumors and three pivotal trials of the drug, including two in NSCLC and one in bladder cancer.

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