Puma Biotechnology's in-development breast cancer treatment demonstrated some clinical benefit in a Phase II trial, but the high rates of serious diarrhea that have long plagued the drug again resurfaced, clouding the therapy's regulatory future.
Puma Biotechnology said European regulators have opened a path to approval for its in-development breast cancer drug, clearing the way for a treatment that has divided analysts over the past few years.
Puma Biotechnologies is walking back some bullish prognostications for its breast cancer treatment, delaying its planned FDA submission by as much as a year and lending weight to some creeping doubts about its top prospect.
Puma Biotechnology's closely watched neratinib failed to beat out the blockbuster Herceptin in a mid-stage breast cancer trial, a miss the company said was no surprise as it touted success on a secondary goal.
Shares of Puma Biotechnology soared more than 220% after the markets closed on Tuesday as investors cheered the biotech's positive Phase III numbers for a late-stage study of their lead drug neratinib (PB272).
Puma Biotechnology's stock plunged 25% on Monday after investors soured on its "positive" news about neratinib, or PB272, with only three of 40 breast cancer patients in a study demonstrating a partial response.
Puma Biotechnology is boasting that its experimental cancer drug neratinib bested Herceptin in a head-to-head study of HER2-positive breast cancer when used ahead of surgery.
The brouhaha that erupted on Twitter when Puma Biotechnology switched to a Bayesian statistical model in its I-SPY 2 study to predict the likelihood of late-stage success of neratinib for metastatic HER2-positive breast cancer indicates that this approach could make the industry pause before the Bayesian predictive formula is widely adopted in the biotech world.
Karyopharm has scored an additional $19 million for its Series B round of financing, padding the $48.2 million raised for the round in May, for a total of more than $67 million, among the largest this year for a drug developer.
The cancer drug developer's shares have risen more than 50% in 2013 as the company begins late-stage development of its lead drug neratinib for patients with metastatic HER2-positive breast cancer.