Nasdaq-listed Gilead Sciences Inc. (GILD) said its momelotinib drug to treat the bone marrow disorder myelofibrosis failed in two Phase 3 clinical trials.

One of the Phase 3 trials assessed the momelotinib drug against Incyte Corp.’s (INCY) Jakafi (ruxolitinib), which was approved by the U.S. Food And Drug Administration (FDA) in 2011 for treating myelofibrosis.

Gilead’s momelotinib met its primary endpoint of non-inferiority to Jakafi. However, momelotinib missed the secondary endpoint for response rate related to symptom scores. Gilead has now decided to discontinue evaluation of momelotinib for three more secondary endpoints.

Can't Compete with Rival 

The second Phase 3 trial involved administering momelotinib to patients who were previously treated with Jakafi, to see if the drug resulted in improved splenic response rates compared to Jakafi.

Unfortunately, Gilead’s JAK inhibitor drug failed to deliver. Afterward, Gilead decided to discontinue sequential statistical testing.

The Foster City, California-based company will now have to decide on another course of action. (For more, see Gilead Fatty Liver Drug Advances to Phase 3.)

Myelofibrosis is a severe bone marrow disorder that affects the production of blood cells. It results in extensive scarring in the bone marrow, which leads to anemia, weakness, fatigue and often an enlarged spleen.

Challenging Times

Gilead got the momelotinib drug in its portfolio following its $510 million acquisition of YM Biosciences in 2013. Gilead’s takeover was seen as a boost to the anemia drug that could help surge it past rival Incute's Jakafi therapy. However, the recent failures proved otherwise.

Though Gilead recently secured FDA approval for its hepatitis B drug, it has had a series of failures this year. (For more, see Gilead Gets FDA OK for Hepatitis B Drug.)

Momelotinib joins the likes of cardiovascular drug eleclazine, ulcerative colitis drug GS-5745, and fibrosis drug simtuzumab, all of which reported weak data this year for Gilead. (For more, see Gilead May Lose Sovaldi's European Patent.)

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