- AstraZeneca's chances of catching rivals in the fast-growing immmuno-oncology field got a boost Friday, after the British pharma reported its flagship immunotherapy Imfinzi (durvalumab) extended progression-free survival in Stage 3 unresectable non-small cell lung cancer (NSCLC).
- Shares in AstraZeneca rose more than 8% Friday morning on the news, which increases confidence that Imfinzi could compete with already approved checkpoint inhibitors from Bristol-Myers Squibb, Merck and Roche in the lucrative lung cancer space.
- AstraZeneca expects to submit the initial results for presentation at an upcoming medical meeting and said it is discussing plans for regulatory submission with authorities.
All eyes have been on another study, known as MYSTIC, that is expected to read out sometime around mid-year. So the early positive results from the Phase 3 PACIFIC trial came as an unexpected lift for AstraZeneca — setting up a potential approval in what would be a unique indication among the PD-1/L1 inhibitors currently approved in lung cancer.
The PACIFIC study tested Imfinzi in patients with locally advanced, unresectable, Stage 3 NSCLC who had not progressed following platinum chemotherapy concurrent with radiation therapy.
Other immunotherapy drugs are currently approved for use against cancers that have spread, giving AstraZeneca an opportunity to secure a foothold in a new (albeit narrow) indication before its competitors.
According to the planned interim analysis, which was conducted by an independent data monitoring committee, Imfinzi met its primary endpoint of demonstrating superior PFS compared to placebo. Data comparing overall survival rates is not yet available.
Unresectable, Stage 3 lung cancer represents roughly one-sixth of NSCLC incidence in developed countries, according to estimates cited by AstraZeneca in its statement.
Imfinzi is a key drug for AstraZeneca in oncology. While the pharma has growing brands like Tagrisso (osimertinib) and Lynparza (olparib), the market for immuno-oncology drugs is expected to grow rapidly. Merck and Bristol-Myers have already built blockbuster franchises around Keytruda (pembrolizumab) and Opdivo (nivolumab), respectively. Roche is pushing ahead with its own drug, Tecentriq (atezolizumab).
For AstraZeneca to keep pace, it needs to win big with Imfinzi. Positive PACIFIC results are a solid first step, but investors will be watching the MYSTIC study carefully. MYSTIC is testing a combination of Imfinzi along with an unapproved CTLA-4 inhibitor known as tremelimumab in first-line treatment of locally advanced or metastatic NSCLC.
Success there could vault AstraZeneca into a competitive position to steal share away from Keytruda and Opdivo.
MYSTIC is doubly important, too, because it tests Imfinzi in combination with tremelimumab. Although checkpoint inhibitors have demonstrated undeniable efficacy, many patients still don't respond. Combination therapies are seen as a way to broaden the number of patients who might benefit from immunotherapy treatment.
Merck has taken the first round, winning approval for its combo of Keytruda and chemo this week in first-line metatstatic NSCLC. But Roche and Bristol-Myers are moving forward quickly, too.
If any combo can demonstrate a significant benefit in overall survival ahead of its rivals, the commercial returns will likely be large.
For AstraZeneca, patent expiries for drugs like Crestor (rosuvastatin) and Nexium (esomeprazole) have put pressure on the company to deliver in oncology. This year could determine whether AstraZeneca will be a player or an also-ran.