Onyx gets green light from US FDA for multiple myeloma drug

The US Food and Drug Administration (FDA) has granted Onyx Pharmaceuticals accelerated approval for its multiple myeloma drug Kyprolis, prompting a 12 per cent surge in the company's share price.

The agency cleared Kyprolis (carfilzomib) as a treatment for patients with multiple myeloma whose disease had progressed despite two prior rounds of therapy, including Takeda/Millennium Pharma's Velcade (bortezomib) and an immunomodulatory agent such as thalidomide.

The approval was based on the results of a single-arm phase IIb study which found an overall response rate (ORR) of 22.9 per cent with Kyprolis and a median response duration of 7.8 months.

Currently, no data are available for Kyprolis that demonstrate an improvement in progression-free survival or overall survival, but approval has been given on the basis of the surrogate endpoint because it is "reasonably likely to predict a clinical benefit to patients," said the FDA.

Kyprolis treatment is associated with some significant safety issues, including heart failure, and the approval includes a requirement for close monitoring of patients receiving the drug.

Enrolment for a confirmatory phase III clinical trial called ASPIRE has been completed and this study should provide further insight into Kyprolis' safety and clinical efficacy.

"The approval of Kyprolis provides a treatment option to patients with multiple myeloma whose disease has progressed despite use of available therapies," commented the FDA's Richard Pazdur.

Multiple myeloma is the second most common haematologic cancer and currently affects more than 50,000 people in the US.

Treatment has been transformed in the last decade with several new drugs to treat the disease coming to market, including Velcade and Celgene's Revlimid (lenalidomide) and Thalomid brand of thalidomide.

Thomson Reuters has predicted that the multiple myeloma market could reach $5.4bn by 2016, with Kyprolis contributing sales of more than $550m from the US market alone and up to $1.5bn if it can also secure approval in the EU and other markets.