Ligand gets royalties on sales of Amgen's Kyprolis drug, which treats a form of incurable blood cancer. The drug generated $172 million in revenue in the second quarter, according to Reuters, and was expected to generate peak annual sales of about $2.3 billion.
Amgen Executive Vice President of Research and Development Sean Harper said the study was designed to explore Kyprolis dosing regimens, noting that the the trial did not meet its goal in improving progression-free survival versus Velcade in patients who had not yet been treated for the disease.
"We remain committed to exploring Kyprolis in combination with other agents to advance the treatment of multiple myeloma," Harper said.
Kyprolis has already been approved by the U.S. Food and Drug Administration for patients with relapsed or refractory multiple myeloma, who have previously been treated.
Dr. Andrzej Jakubowiak from the University of Chicago Medical Center said during a conference call that although the results were disappointing, they were predictable to some extent.
"This was the wrong combination chosen for this evaluation, wrong duration of treatment as well, which we now know and is potentially important," he said.
Kyprolis is also being tested in a separate late-stage trial in combination with Celgene's Revlimid and the steroid dexamethasone, or KRd.
Shares of Ligand have fallen 8 percent for the year, closing at $99.64 a share. Amgen was down about 1 percent for the day, but up more than 5 percent for the year, closing at $171.63 a share.
--Reuters contributed to this report.