European regulators have cleared the use of Amgen's Kyprolis in combination with just dexamethasone to treat certain adults with multiple myeloma.

The drug was initially approved last year for use alongside dexamethasone and lenalidomide (Celgene's Revlimid) for patients who have received at least one prior therapy.

Amgen says its clearance in combination with just one other medicine is important because patients living with myeloma relapses often have to use elaborate combinations of medicines to help keep the disease at bay.

The decision was based on data from the Phase III head-to-head ENDEAVOR trial, in which patients with multiple myeloma treated with Kyprolis plus dexamethasone achieved superior progression-free survival (PFS) of 18.7 months compared to 9.4 months in those receiving Velcade (bortezomib) plus dexamethasone.

The 'doublet' therapy also demonstrated an improvement on secondary endpoints, including rates of complete response or better, which were double in patients treated with the Kyprolis/dexamethasone therapy.

On the safety side, tolerability was similar in the two arms, although patients treated with the new Kyprolis regimen experienced a significantly lower rate of grade 2 or higher neuropathy events than those treated with Velcade/dexamethasone.

"Kyprolis-based regimens have now shown superiority over two former standard-of-care treatment options for relapsed multiple myeloma patients, reinforcing Kyprolis' place as a foundational therapy in this patient population," noted Sean Harper, executive vice president of R&D at Amgen.

Around 39,000 patients are diagnosed with multiple myeloma in Europe each year, and 24,000 patient deaths are reported annually.