AstraZeneca has secured FDA approval for its checkpoint inhibitor Imfinzi in non-small cell lung cancer, opening up a big potential market for the drug as it chases the leaders in the cancer immunotherapy sector.
PD-L1 inhibitor Imfinzi (durvalumab) was approved by the US regulator just ahead of the weekend as a maintenance therapy for NSCLC patients with inoperable stage III disease, ie that has not spread widely around the body after platinum chemotherapy or radiotherapy.
AZ’s drug is the first PD-1/PD-L1 inhibitor to be approved for this indication and according to analysts it could kickstart sales of the drug in a market segment according to analysts could unlock up to $2bn in additional sales for the drug. The FDA granted the drug a breakthrough designation in non-metastatic NSCLC last July.
Before now Imfinzi was only approved for bladder cancer – where it has to compete head-to-head with other checkpoint inhibitors including Bristol-Myers Squibb’s Opdivo (nivolumab) and Merck & Co/MSD’s Keytruda (pembrolizumab) – so the new indication should inject some sales momentum. In 2017 AZ recorded $19m in sales of the drug – $18m in the fourth quarter – so it has a long way to go to catch its blockbuster rivals, but has a couple of year’s head start in the new indication.
The approval is based on the results of the PACIFIC trial, which showed that patients treated with Imfinzi gained an extra 11 months of progression-free survival (PFS) compared to placebo. Patients on AZ’s drug had a PFS of 16.8 months, compared to 5.6 months in the control group. The benefits were seen across all patient subgroups, regardless of PD-L1 status, and AZ’s drug was also associated with a lower incidence of metastasis.
“The approval of Imfinzi in this earlier stage of NSCLC is a truly meaningful milestone for patients who, until now, had no FDA-approved treatment options following chemoradiation therapy,” commented Dave Fredrickson, head of AZ’s cancer business unit.
“Globally, approximately 30% of patients with NSCLC present with stage III disease and we are excited to launch the first immunotherapy into this setting.”
Looking ahead to the next few months, AZ is also waiting for data read-outs from the ARCTIC trial of Imfinzi plus its CTLA4 inhibitor tremelimumab in third-line NSCLC, final overall survival data from the MYSTIC trial in first-line NSCLC (after disappointing progression-free survival results) looking at the combination as well as Imfinzi on its own, and results of the NEPTUNE trial of the Imfinzi plus tremelimumab in first-line NSCLC.
AZ is also expecting read-outs from The KESTREL and EAGLE trials of Imfinzi with and without tremelimumab in head and neck cancer.