(Reuters) - Significantly more patients with relapsed multiple myeloma responded to a three-drug regimen including Amgen Inc's Kyprolis than those who got the standard two-drug treatment, according to results from a late-stage trial. Patients with the blood cancer who received the Kyprolis regimen for 18 months also had a longer duration of response and reported better health-related quality of life, data presented on Saturday showed. Overall survival data was not yet available, but researchers reported a trend toward improved survival seen with the three-drug regimen. The Phase III Aspire trial tested Kyprolis in combination with Celgene's Revlimid and the chemotherapy drug dexamethasone versus the two drugs without Kyprolis in 792 patients whose disease relapsed after prior treatments. Amgen previously reported the Kyprolis regimen achieved the primary goal of the study by significantly increasing the time before the disease began to worsen. Details and results of secondary goals were being presented at the American Society of Hematology meeting in San Francisco. The data should help increase use of Kyprolis - the drug at the center of Amgen's nearly $10 billion purchase of Onyx Pharmaceuticals. Kyprolis had $94 million in third quarter sales. "This is really an important study that's going to set the stage for improved therapy for patients worldwide," said Dr. Keith Stewart, the study's lead investigator from Mayo Clinic in Arizona. "It probably establishes this (regimen) as the standard of care." The overall response rate was 87 percent for the three drugs versus 67 percent for the current standard of care. Three times as many patients had a complete response to the Kyprolis regimen - meaning no detectable sign of cancer - 32 percent versus 9 percent. The median duration of response was 28.6 months for the Kyprolis group compared with 21.2 months for the control arm. Stewart said researchers now believe the results could have been even better had patients stayed on the Kyprolis regimen for longer than 18 months. About 114,000 new case of multiple myeloma - the second most common blood cancer - are diagnosed annually worldwide, according to the International Agency for Research on Cancer. The rate of adverse side effects and discontinuations due to side effects were nearly identical in the two groups, providing evidence that adding Kyprolis did not cause additional toxicities. "It was very reassuring with respect to the tolerability of the three-drug cocktail," Stewart said.