FDA grants AZ's Imfinzi fast review in new lung cancer use

The FDA has granted AstraZeneca’s Imfinzi immunotherapy a faster six-month review in patients with extensive-stage small cell lung cancer.

AZ is asking the FDA to allow Imfinzi (durvalumab) to be used in the new indication, after previous approvals in certain patients with non-small cell lung cancer and advanced bladder cancer.

The FDA only grants priority reviews for drugs it deems to be a significant improvement on existing therapies for serious diseases.

It has set a decision date for the first quarter of 2020, setting up a potential launch next spring if the review goes AstraZeneca’s way.

FDA regulators will review a dossier of clinical data based on positive results from the phase 3 CASPIAN trial, which has already been published in The Lancet.

These results showed Imfinzi significantly improved overall survival compared with standard of care chemotherapy – etoposide with either cisplatin or carboplatin.

The risk of death was reduced by 27%, with a median overall survival of 13 months for Imfinzi plus chemotherapy compared with 10.3 months for standard of care.

Results showed an estimated 33.9% of patients were alive at 18 months following treatment with Imfinzi plus chemotherapy versus 24.7% of patients receiving standard therapy.

Around 15% of lung cancers are classified as small cell lung cancers (SCLC), and around three quarters of these patients are diagnosed with extensive-stage disease.

This is where the cancer has spread widely through the lung or to other parts of the body.

Prognosis is particularly poor as only 6% of all SCLC patients will be alive five years after diagnosis.

Imfinzi is a human monoclonal antibody that binds to PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80, countering the tumour's immune-evading tactics and releasing the inhibition of immune responses.

Imfinzi is well behind its main immunotherapy rivals, Merck & Co’s Keytruda and Bristol-Myers Squibb’s Opdivo, in terms of sales.

But there is still a lot more to come from Imfinzi – it is also being tested as a monotherapy and in combination with tremelimumab, an anti-CTLA4 monoclonal antibody and potential new medicine, as a treatment for patients with non-small cell lung cancer, SCLC, bladder cancer, head and neck cancer, liver cancer, biliary tract cancer, cervical cancer and other solid tumours.