Galapagos (GLPG) last night announced that Gilead Sciences (GILD) received a Complete Response Letter from the Food and Drug Administration for the New Drug Application for filgotinib, an investigational treatment for moderately to severely active rheumatoid arthritis.

Gilead is the market authorization holder for filgotinib in the United States and is responsible for potential commercialization in the U.S., the company said in a statement. The FDA has requested data from the MANTA and MANTA-RAy studies before completing its review of the NDA. The FDA also has expressed concerns regarding the overall benefit/risk profile of the filgotinib 200 mg dose, Galapagos notes. "This CRL issued by the FDA is very disappointing given the robust and comprehensive data package provided.

Despite today's news, we continue to believe filgotinib has the potential to provide an effective, new treatment option for patients with rheumatoid arthritis, where there remains a significant unmet need," said Dr. Walid Abi-Saab, Chief Medical Officer, Galapagos.

Under the terms of the agreement with Gilead, Galapagos is entitled to an approval milestone of $100M for the approval of filgotinib in the U.S., which was included in the Galapagos cash burn guidance. Following this CRL, Galapagos revises its full year 2020 operational cash burn guidance to between EUR 490M and EUR 520M. Shares of Galapagos are down 29%, or $55.45, to $132.63 in premarket trading.