Pfizer's two-time loser dacomitinib finally wins in phase 3 against AstraZeneca's Iressa

Pfizer HQ
Pfizer's dacomitinib flopped two phase 3 studies back in 2014.

CHICAGO—Pfizer’s EGFR lung cancer candidate, dacomitinib, doesn’t have a pretty past. But the New York drugmaker has finally rung up a phase 3 victory.

On Monday, the American Society of Clinical Oncology announced that dacomitinib had topped AstraZeneca’s Iressa in delaying cancer growth in newly diagnosed patients, slashing the risk of progression or death by 41%. With dacomitinib, trial participants went a median 14.7 months without their cancer worsening, compared with 9.2 months on Iressa. Both drugs are part of the tyrosine kinase inhibitors (TKI) class of meds.

RELATED: A top Pfizer drug flops in two PhIII lung cancer studies

It’s the first positive set of phase 3 results for the Pfizer prospect, which flopped in two late-stage studies back in early 2014. In one, the med failed to improve progression-free survival compared with Roche’s Tarceva, and in the other, also versus Tarceva, it couldn’t significantly increase overall survival.

As a Pfizer spokeswoman explained via email, however, since then, “our understanding of EGFR TKIs has evolved, and we now know that these agents are most effective in patients with EGFR-activating mutations.” The study “specifically studied use of dacomitinib in subpopulations … of the EGFR mutation,” which were “selected based on the outcomes from several previous clinical trials,” she said.

“As the field has evolved with TKI agents that address the EGFR mutation, we’ve become, I think, as a company and certainly more broadly as an industry, attuned to so many of the subpopulations that need to be addressed,” Matt Shaulis, Pfizer’s North American oncology president, added in an interview.

Now, the company is preparing to talk over the data with health authorities; it’s going to “certainly use it as a basis for discussion with regulators,” Shaulis said.

But if dacomitinib can win an approval, it’ll have to face down some stiff competitors. That includes Iressa, Boehringer Ingelheim's Gilotrif and Tarceva, which has already trumped the Pfizer med.

“Given the strong mutational basis for this type of lung cancer, we felt it was very important to have an additional treatment option available to patients,” Shaulis said.