The trial of 10 mg/kg tremelimumab monotherapy in second or third-line treatment of unresectable malignant mesothelioma failed to hit its primary target.
AstraZeneca senior vice president, head of immuno-oncology, global medicines development, Robert Iannone said: "We are disappointed that tremelimumab monotherapy did not demonstrate a survival benefit in this patient population with no approved medicines beyond first-line treatment.
"However, we remain confident in tremelimumab’s clinical activity in combination, as shown in our recently published Study 006 trial of tremelimumab and durvalumab in non-small cell lung cancer."
Tremelimumab is also being studied in combination with AstraZeneca’s anti-PD-L1 investigational immunotherapy durvalumab in various tumour types such as non-small cell lung cancer, squamous cell carcinoma of the head and neck, bladder, pancreatic, gastric and liver cancers.
The drug is designed to block the activity of cytotoxic T- lymphocyte-associated protein 4 (CTLA-4) to releases the brakes on T cell activation and boost the immune response against cancer cells.
AstraZeneca said the preclinical data indicates that targeting both PD-L1 and CTLA-4 may have additive or synergistic effects.
The US Food and Drug Administration granted tremelimumab fast track designation and orphan drug designation as a potential treatment for malignant mesothelioma, which affects the lining of the lungs and abdomen.