An FDA advisory panel on Wednesday voted 12-4 that the benefits of Puma Biotechnology's neratinib for the extended adjuvant treatment of HER2-positive early-stage breast cancer outweighed the drug's risks. However, panellists suggested that neratinib should be restricted to patients who have received Roche's Herceptin (trastuzumab) within the past two years, while some also thought its use should be limited to those with ER-positive tumours. Puma shares rose nearly as much as 10 percent on news of the panel's recommendation.
Stan Lipkowicz, who backed approval, said "I don't think I'd treat as broadly as the patients prescribed," while Lori Minasian, who also voted in favour of approving neratinib, felt "the indication as stated is far too broad." Committee member Grzegorz Nowakowski noted "the benefit in absolute terms is relatively modest," but the "toxicity appears to be manageable." However, two patient advocates serving on the advisory committee voted against approval, with panellist Patricia Spears saying "we tend to put a lot of patients at risk to benefit just a few." Meanwhile, some patients presented stories of neratinib being used to treat cancer that has spread, not to prevent recurrence after treatment, which was the issue being discussed at the advisory meeting. Panellist Stacy Nerenstone questioned whether that would be a "backdoor" to use neratinib in metastatic disease, although she still voted in favour of the drug.
In documents released ahead of the advisory committee meeting, FDA staff found that neratinib was associated with a 2.8-percent improvement in invasive disease-free survival after two years. However, agency reviewers noted that nearly all treated patients in one study had experienced diarrhoea, which was deemed severe in 40 percent of cases, but that data from an ongoing Phase II trial suggest the incidence and severity of the side effect can be alleviated with antidiarrhoeal prophylaxis.
Puma requested FDA approval of neratinib, formerly known as PB272, in July last year for the extended adjuvant treatment of patients with early-stage HER2-positive breast cancer who have received prior adjuvant Herceptin-based therapy. The drugmaker previously delayed its submission after the FDA had asked the company to change how the data were analysed. The agency accepted Puma's filing last September.
For related analysis, see ViewPoints: Puma's day at the FDA nears – how many lives has this cat got?
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