The US Food and Drug Administration (FDA) staff has raised concerns over the safety of an experimental cancer drug by Spectrum Pharmaceutical and also questioned the benefits the drug provided over existing therapies.
The concerns over the cancer drug poziotinib were raised in the US FDA’s briefing documents ahead of a meeting of the regulator’s external advisers. US FDA reviewers cited a lack of clarity on whether poziotinib provided enough response in treating a type of non-small cell lung cancer, compared with several other cancer drugs.
According to the briefing documents, if approved, this will be the least effective targeted therapy for lung cancer approved to date, citing the overall response rate of 28 percent, with 5.1 months duration for the therapy.
Questions from the US FDA on the toxicity profile of the drug were due to 85 percent of patients on the 16 mg dosage experiencing serious adverse effects, while 57 percent of patients experienced dose reductions.
According to the documents, the side effects might decrease if the patients receive alternative dosages, but it is still unclear whether efficacy of the drug maintained based on data submitted to the US FDA.