PhIII lung cancer data signal potential approval for AstraZeneca's Imfinzi
The data on AstraZeneca’s Phase III Imfinzi trial are out, and it bodes well for the UK outfit’s bid to get their signature immunotherapy approved for frontline small-cell lung cancer (SCLC).
Patients receiving the PD-L1 Imfinzi (alongside a standard chemotherapy regimen) in AstraZeneca’s CASPIAN study survived for 13 months on average, compared with 10.3 months for patients receiving the standard of care. Those numbers compare favorably to the results of the pivotal study that pushed Roche’s PD-L1 Tecentriq across the finish line. Tecentriq patients had an OS of 12.3 months in that study, which was announced six months before the FDA approved the drug for frontline SCLC.
Investigators also touted their drug’s durability, with 33.9% of patients still alive at 18 months following treatment with Imfinzi plus chemotherapy vs 24.7% of patients following the standard of care.
The study may prove a major boon for AstraZeneca in the heady race to expand their markets for PD-1/L1 drugs — and in the drugmaker’s steady growth in the lung cancer market. Last year, its standout Tagrisso was approved for frontline treatment of EGFR-mutated non-small cell lung cancer. And Imfinzi has seized an important niche in the lung cancer market with its approval for stage III non-small cell lung cancer.
Although it accounts for less than 20% of lung cancer cases, SCLC remains particularly difficult to treat.
PD-1 and PD-L1 drugs work by inhibiting proteins cancer cells use to block T cells from attacking them. This makes them a prime focus for oncology research, and six PD-1/L1 immunotherapies, both for SCLC and a slew of other cancers, have already been approved by the FDA, with a host of trials underway to expand their use.
Merck has been the leader in PD-1/L1 thus far, with its signature drug Keytruda projected to be a global top-10 blockbuster by 2024.
For AstraZeneca, the Phase III CASPIAN results come as welcome news after its combination of Imfinzi and tremelimumab failed trials for head and neck cancer, and for another form of lung cancer. The study was conducted on 537 patients receiving first-line treatment for non-small cell lung cancer in over 200 centers, across 22 countries and four continents.
“We are encouraged to see more than a third of small cell lung cancer patients treated with Imfinzi plus chemotherapy alive at the 18-month landmark, which is remarkable given the aggressive nature of the disease,” José Baselga, AstraZeneca’s executive vice president of oncology R&D, said in a statement.
Imfinzi, already approved for unresected stage III SCLC, is also being tested with concurrent chemotherapy for limited-stage SCLC in AstraZeneca’s Phase III ADRIATIC trial. Roche announced today it will conduct a Phase I/II trial with KAHR medical to treat NSCLC patients who are refractory, or resistant, to checkpoint inhibitors.
Correction: An earlier version of this article incorrectly identified Merck as Merck KGaA. References to Merck KGaA have been removed.