Shares in Puma Biotechnology Inc. plunged nearly 29 percent on Wednesday, Jan. 24 after it announced its breast cancer drug faced regulatory headwinds in Europe.

The West Los Angeles drug maker announced late Tuesday, Jan. 23 that its Nerlynx therapy for early stage HER2-positive breast cancer was not likely to be approved by European regulators without more data.

Puma’s share price fell from a Tuesday close of nearly $91 on the Nasdaq to $64.70 – the lowest for the stock since May 2017.

The reaction by investors came after Puma announced its breast cancer drug known as Neratinib received a negative trend vote from an advisory committee to the European Medicines Agency.

Puma said the committee for medicinal products for human use commented it was unlikely to recommend approval of the drug during a formal vote next month after taking issue with the drug’s benefit-risk assessment.

The issue for the committee was with the study results based on a Phase 3 clinical trial, and whether there was enough clinical evidence observed at two and five years for disease-free survival benefits, according to Puma.

Puma’s Nerlynx drug, designed to prevent an aggressive breast cancer after chemotherapy, was approved by the U.S. Food and Drug Administration in July.

In November, Puma reported a third-quarter net loss of $77.2 million, or $2.07 a share, compared to a net loss of $65.8 million, or $2.02 a share, in the same quarter a year earlier. Revenue for the biotech firm founded by Alan Auerbach was $6.1 million, fueled by initial sales of its Nerlynx cancer drug.

Health business reporter Dana Bartholomew can be reached at [email protected]. Follow him on Twitter @_DanaBart.