U.S. FDA staff raises concerns on Spectrum Pharma’s cancer drug
Sept 20 (Reuters) – The U.S. Food and Drug Administration’s (FDA) staff on Tuesday raised concerns over the safety of Spectrum Pharmaceutical’s (SPPI.O) experimental cancer drug and questioned the benefits it provided over existing therapies, dragging its shares 30%.
The concerns over poziotinib were raised in the regulator’s briefing documents ahead of a meeting of its external advisers on Thursday.
The reviewers cited lack of clarity on whether poziotinib provided enough duration of response in treating a type of non-small cell lung cancer, compared with existing drugs like Daiichi Sankyo’s (4568.T) and AstraZeneca’s (AZN.L) Enhertu.
“If granted accelerated approval, this would be the least effective targeted therapy for lung cancer approved to date,” the briefing documents said, citing the 28% overall response rate and duration of 5.1 months for the therapy.
FDA’s questions on the toxicity profile of the drug was due to 85% of patients on the 16 mg once daily dosage experiencing serious adverse effects, while 57% patients experienced dose reductions.
Side effects may reduce if patients receive alternative dosages, but it remains unclear whether efficacy can be maintained based on data submitted to FDA, the documents said.
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