Armed with first-ever FDA nod, Rigel preps May launch for autoimmune drug Tavalisse

After one false alarm—or false celebration, rather, with a premature website posting last week—Rigel Pharmaceuticals has officially won FDA approval for its main product, Tavalisse.

Regulators greenlighted the product Tuesday, opening up a new treatment avenue for patients with chronic immune thrombocytopenia. The rare disease causes the immune system to attack and destroy platelets, the blood cells responsible for clotting, which causes excessive bruising, bleeding and fatigue.

The drug, which targets the underlying cause of the disease by preventing destruction of platelets, is the first in a new class of oral spleen tyrosine kinase (SYK) inhibitors, and it will roll out to patients beginning in late May, Rigel said.

A spokeswoman said via email that Rigel wouldn’t provide pricing info for the new product before a conference call on May 1.

News of the approval sent Rigel's shares skyward, and it wasn’t the first time that’s happened. Last week, the company’s website displayed info suggesting Tavalisse had already won the FDA’s blessing, and Rigel later issued a press release acknowledging the blunder.

RELATED: Rigel falsely claims FDA approval in ‘website error’

Tavalisse, known in the clinic as fostamatinib disodium hexahydrate, has been Rigel’s central focus for a while now, and the South San Francisco company is also testing the compound in autoimmune hemolytic anemia and IgA nephropathy. The way CEO Raul Rodriguez sees it, Tuesday’s go-ahead bodes well for those trials, both of which are in phase 2.

"This regulatory milestone, our first product approval, validates the therapeutic effect of SYK inhibition in an autoimmune disease,” he said in a statement.