Dive Brief:
- The Food and Drug Administration announced on May 1 the approval of AstraZeneca's PD-L1 inhibitor durvalumab, which will be sold under the brand name Imfinzi.
- The drug was okayed for the treatment of patients with locally advanced or metastatic urothelial carcinoma — one of the most common forms of bladder cancer — who have progressed from platinum-based chemotherapy.
- Imfinzi was approved six weeks ahead of its user fee goal date through the accelerated approval process. AstraZeneca will be required to complete ongoing clinical trials to confirm the effectiveness of the drug, which is the fifth PD1/PDL1-targeting checkpoint inhibitor to reach markets in the U.S.
Dive Insight:
Editor's Note: This article was updated with the price of the drug.
AstraZeneca finally gets to join the immunotherapy race, although competitors like Bristol-Myers Squibb, Merck & Co. and Roche all have a strong lead.
Roche's Tecentriq (atezolizumab) was the first PD-1/L1 inhibitor to be approved in bladder cancer (and got a first-line indication in April). Bristol-Myer's Opdivo (nivolumab) secured a greenlight in February in the indication and Merck's Keytruda (pembrolizumab) has an application in both first- and second-line pending.
The immuno-oncology space has been closely watched for the last several years as Merck and Bristol-Myers competed to hit the market first, battling ever since to add indications, as well as market share. While Opdivo continues to lead with outsized revenues of more than $1 billion a quarter, Keytruda has been able to make up ground after Opdivo's stumble in the highly lucrative lung cancer market. Other big pharmas are racing to catch up in the PD-1/L1 space.
For AstraZeneca, which rejiggered its key Phase 3 MYSTIC trial earlier this year, the immuno-oncology strategy has been based firmly in the success of combinations. The drug is currently being tested in the Phase 3 DANUBE study both as a monotherapy and in combination with CTLA-4 inhibitor tremelimumab as a first-line treatment for urothelial carcinoma.
"Imfinzi is the cornerstone of our extensive immuno-oncology programme, in development across many tumour types, as monotherapy and in combination. This first approval for Imfinzi is an important milestone in our return to growth and brings us another step closer to our goal of redefining the way cancer is treated," said AstraZeneca CEO Pascal Soriot.
The drug will have an estimated wholesale acquisition cost of $15,000 per month before any discounts or rebates. "The average monthly cost will vary based on an individual’s health insurance status and the amount of medicine they are prescribed based on their individual treatment needs," noted an AstraZeneca spokesperson in an email.
Imfinzi's approval was based on data from a Phase 1/2 trial of 182 patients with advanced bladder cancer whose disease had progressed after treatment with chemotherapy. The 10 mg/kg dose was given every two weeks and showed an objective response rate (ORR) of 17%. In those patients with high levels of the PD-L1 biomarker, the ORR was significantly higher at 26.3%, while in patients with no- or low-levels of PD-L1, the ORR was only 4.1%.
Patient's PD-L1 levels were evaluated by the VENTANA PD-L1 assay, which the FDA approved in conjunction with the drug.
Biomarker strategy has played a key role in the development of the immuno-oncology landscape. It is becoming increasingly clear that levels of PD-L1 expression play a role in the success of the therapies. Yet, drugmakers are still trying to determine at what threshold the expression of the biomarker becomes relevant and if other factors play a role.