Puma Biotechnology has taken a big step toward securing approval of neratinib. A panel of experts voted 12 to 4 in favor of approving the breast cancer adjuvant therapy, although the reservations of people who were both for and against the drug suggest further challenges await Puma.
For now, Puma is basking in the glow of breezing past an obstacle many thought could scuttle its attempt to win approval. The support of the experts increases the likelihood the FDA will approve neratinib, although the agency isn’t bound to follow the recommendation.
Shares in Puma jumped 30% following the news. With the gains adding to those made after the FDA released its briefing document on Monday, Puma is up almost 100% this week.
The surge reflects the level of uncertainty about what the FDA and its panel of independent experts would make of Puma’s filing. In the end, most panelists felt the data showed neratinib can reduce the rate of recurrence of breast cancer, squashing fears the efficacy results would be seen as too marginal. Many on the panel also looked benignly on the side effects which, Puma argued, are reversible and can be controlled using other drugs.
That was enough for three-quarters of the panel to voice their support for neratinib. But caveats raised by these panelists—and more critical comments from those who voted no—suggest the FDA could add restrictions to the label or physicians could limit uptake.
In explaining their "yes" votes, several panelists said they felt the indication being sought by Puma was too broad. Panelists suggested narrowing the target population by limiting use to patients who have received Roche’s Herceptin within the past two years—And by restricting use to patients with tumors that tested positive for the estrogen receptor. The data suggest neratinib is of greatest benefit to this genetic subset of patients.
The "no" votes came from two patient representatives, who felt the indication sought was too broad, and two medical oncologists. Of the oncologists, Dana-Farber Cancer Institute’s Harold Burstein, M.D., Ph.D., delivered the most comprehensive review of the perceived weaknesses of the filing. According to Burstein, while the drug will benefit some people, the existing disease-free survival rates for other groups targeted by the filing make it hard to justify the risk-benefit profile.
With the advisory panel voting in favor of the drug, the decision about who should get neratinib moves on to the FDA—and, potentially beyond that, to physicians and patients.