Imfinzi Fails NSCLC Trial, Succeeds in Bladder Cancer Study

AstraZeneca disclosed on Tuesday that its PD-L1 inhibitor, Imfinzi (durvalumab), did not achieve the primary endpoint in the Phase III ADJUVANT BR.31 clinical trial focused on early-stage non-small cell lung cancer (NSCLC). The pharmaceutical company revealed that Imfinzi failed to significantly enhance disease-free survival compared to a placebo in patients with stage IB to IIIA NSCLC following the complete surgical removal of tumors. Details of the trial data will be presented at a future scientific conference, as per AstraZeneca.

Susan Galbraith, AstraZeneca’s executive vice president of oncology R&D, expressed disappointment regarding the trial's outcome. Nonetheless, she emphasized that Imfinzi remains a pivotal cancer treatment, having significantly altered the treatment landscape for lung cancer. Imfinzi has shown promising results in other late-stage studies involving patients in the earlier stages of the disease.

AstraZeneca remains committed to continuing its lung cancer research program for Imfinzi. Currently, Imfinzi is the global standard of care and the only FDA-approved immunotherapy intended for curative purposes in patients with stage III NSCLC who have not shown disease progression following chemoradiotherapy. The company is conducting additional trials, including PACIFIC-4 for inoperable or unresectable stage I to II NSCLC, and PACIFIC-5, -8, and -9 for stage III NSCLC.

In November 2023, the PACIFIC-2 clinical trial also did not meet its primary endpoint. This trial explored the combination of Imfinzi with chemoradiotherapy (CRT) but did not result in significant improvement in progression-free survival compared to CRT alone in patients with stage III NSCLC.

AstraZeneca experienced another setback in its NSCLC research when the Phase III TROPION-Lung01 trial, conducted in collaboration with Daiichi Sankyo, failed to demonstrate significant overall survival benefits for their antibody-drug conjugate, datopotamab deruxtecan.

However, AstraZeneca also reported positive news on Tuesday regarding Imfinzi's performance in the Phase III NIAGARA study for muscle-invasive bladder cancer (MIBC). The PD-1 inhibitor, when used in combination with chemotherapy, resulted in a statistically significant and clinically meaningful enhancement in both event-free and overall survival compared to neoadjuvant chemotherapy alone.

Although specific data from the MIBC study were not disclosed, AstraZeneca plans to present these findings at an upcoming medical congress. Additionally, the company aims to communicate its results to global regulatory authorities to potentially update the standard of care for patients.

In both the NSCLC and MIBC studies, the safety profile of Imfinzi remained consistent with previous trials, showing no new safety concerns. The NIAGARA study also indicated that the inclusion of Imfinzi did not lead to an increased rate of discontinuation, and patients were able to complete their surgeries.

Imfinzi, initially approved in May 2017 for advanced bladder cancer, functions by blocking cancer cells’ ability to evade the immune system, thereby enhancing the body's anti-cancer response. Since its initial approval, Imfinzi has gained approval for several other cancer types, including certain biliary tract cancers and NSCLC.

Recently, the FDA approved Imfinzi for the treatment of primary advanced or recurrent mismatch repair-deficient endometrial cancer.