Long-awaited data from AstraZeneca’s Imfinzi suggest it could become an entirely new standard treatment for mid-stage lung cancer patients whose diseases has not spread widely.
PD-L1 inhibitor Imfinzi (durvalumab) reduced the risk of death by 32% compared to placebo after standard chemotherapy in the PACIFIC trial, consolidating earlier results which showed that the drug extended progression-free survival (PFS) by more than 11 months, from 5.6 to 16.8 months.
The new data in locally-advanced, non-small cell lung cancer (NSCLC) patients whose tumours cannot be removed surgically is a first for an immuno-oncology drug and could quickly accelerate Imfinzi to blockbuster status, according to analysts at Moody’s, who say AZ’s rivals are 18 months to two years behind in development.
Imfinzi has just been approved in Europe for this patient group, having been given the go-ahead by the FDA in February based on PFS data. The new survival results “confirm the drug’s revenue potential [of around $1bn] in this setting alone,” according to Moody’s analyst Knut Slatten. It’s also been approved for this indication in Canada, Switzerland, India, Japan, and Brazil.
The five-year survival rate for these patients has generally been around 15%, and according to AZ Imfinzi is the first drug in over a decade to show a significant clinical benefit in the “curative-intent, stage III NSCLC setting”, and is the first and only immunotherapy to be approved for these patients.
The results of PACIFIC have just been published in the New England Journal of Medicine (NEJM, and AZ says it will follow-up patients for another few years to see if the survival benefit is sustained.
Sean Bohen
Sean Bohen, executive vice president, Global Medicines Development and chief medical officer, said: “Today’s announcement brings new hope to patients in a setting where survival rates have not changed in decades.”
Scott Antonia, MD, Ph.D., chair of the Thoracic Oncology Department at Moffitt Cancer Center in Tampa, Florida, and principal investigator in the PACIFIC trial said: “The five-year survival rate in this setting has historically been around 15% after concurrent chemoradiation therapy. The significant survival benefit observed using the PACIFIC regimen provides confidence and clear rationale for a new standard of care.”
Earlier diagnosis
Commercial success could however depend on improving the diagnosis rate for mid-stage NSCLC, as most patients are picked up in more advanced stages at the moment. However, AZ told the Financial Times that it believes Imfinzi could eventually be used routinely post-chemotherapy in this setting, in the same way Roche’s Herceptin is used in breast cancer patients.
The new data is a big boost to AZ’s ambitions in immuno-oncology after the disappointing results of the MYSTIC trial in first-line advanced NSCLC last year, in which Imfinzi plus experimental CTLA4 inhibitor tremelimumab failed to show improved PFS compared to chemotherapy.
The company is hoping for better news when the OS data from MYSTIC emerges in the coming months, along with additional trials of Imfinzi with and without tremelimumab in first- and second-line head and neck cancer, small cell lung cancer (SCLC) and bladder cancer.
In the meantime, the US approval in NSCLC has already sparked a big increase in sales to $184m in the first half of the year, up from just $19m in 2017.
In an earlier research note, Moody’s said that the data read-outs in the remainder of r2018 and 2019 “will provide more clarity as to whether Imfinzi could yet increase its peak sales potential considerably or, on the contrary, whether it will be confined to more niche-type of treatments within the larger universe of immuno-oncology.”