(Adds analyst comment, background)
By Aakash B
Aug 16 (Reuters) - The U.S. Food and Drug Administration on Friday approved Celgene Corp's Inrebic to treat certain rare forms of bone marrow cancer called myelofibrosis, making it the second approved drug to treat the disease.
Inrebic belongs to a class of drugs known as JAK inhibitors that work by blocking inflammation-causing Janus kinases enzymes. It will compete with Incyte Corp's Jakafi, also a JAK inhibitor, which was approved in 2011 for treating the same condition.
However, Inrebic's approval comes with a boxed warning, the drug regulator's harshest, that flags concerns such as serious and fatal brain damage.
Analysts said Inrebic's approval does not pose a meaningful threat to Jakafi, which generated $1.4 billion in revenue for Incyte in 2018.
RBC Capital Markets analyst Brian Abrahams said that though Inrebic's label is broad it comes with a black box warning, and given Jakafi's significant clinical experience and survival benefits, he does not expect the drug to disrupt Incyte's core Jakafi franchise.
The approval comes at a time when Celgene is in the process of being acquired by Bristol-Myers Squibb Co in the largest pharmaceutical industry merger ever.
In June, Bristol offered to divest Celgene's psoriasis treatment Otezla to allay concerns raised by U.S. antitrust regulators, and pushed back the closing of the $74 billion deal.
Inrebic was approved based on results from a trial of 289 patients with myelofibrosis where the drug was tested against a placebo.
Celgene shares were up 1.3% at $94.56, while those of Bristol rose 2.3% to $46.82 in afternoon trading. (Reporting by Aakash Jagadeesh Babu in Bengaluru; Editing by Shinjini Ganguli and Sriraj Kalluvila)