Amgen Inc, the world’s largest pharmaceutical company, announced on Monday that its new drug Kyprolis delays the worsening of multiple myeloma when combined with standard therapy compared with standard therapy alone. Amgen acquired Kyprolis after its purchase of Onyx Pharmaceuticals for $10 billion last year. Sales of the drug have already accounted for $146 million in the first half of this year.

Researchers conducting a study called Aspire are following 792 patients with relapsed multiple myeloma who received prior treatment. On standard treatment consisting of Celgene’s existing drug Revlimid combined with dexamethasone, patients averaged 17.6 months of progression-free survival. Patients who received the standard treatment plus Kyprolis averaged 26.3 months of life before worsening of their disease.

These interim results are expected to boost sales of Kyprolis and accelerate its pending regulatory review while data from another Phase III trial called Focus are gathered. Amgen expects results from Focus within the current quarter.

“The Aspire study is critical for the conversion of the drug’s current approval from accelerated, or conditional, approval to full approval in the U.S., as well as for initial approval of the drug in Europe,” said Geoffrey Porges, an analyst with Sanford Bernstein and who has forecast Kyprolis sales of $425 million in 2015 reaching $800 million in 2017.

Amgen’s sales of Kyprolis trail behind another new drug designed for treating multiple myeloma made by Celgene Corporation called Pomalyst, which generated $296.5 million in sales over the last six months.

Amgen shares were up $1.42, or 1.1 percent at $126.96 on Nasdaq. Celgene shares were also up at $87.30, a 0.7 percent rise.