Gilead, Galapagos report positive follow-up data for arthritis drug, but regulatory risk remains

An analyst wrote that while filgotinib’s profile appears clean overall, even minor safety imbalances could derail its approval, while a slight imbalance in the number of deaths between the Phase III study arms could also attract scrutiny.

Phase III data slated for presentation at an upcoming rheumatology conference on a drug under development for rheumatoid arthritis show durable safety and efficacy, the companies developing it said Thursday. However, an analyst wrote that the drug faces regulatory risks.

Foster City, California-based Gilead Sciences and Mechelen, Belgium-based Galapagos said they would present 52-week data from the Phase III FINCH 1 and FINCH 3 studies of filgotinib at the European League Against Rheumatism’s virtual annual meeting.

Gilead’s shares were up more than 1.4% in midday trading on the Nasdaq, while Galapagos’ shares were down 2.3% on the Euronext Amsterdam exchange when that market closed.

The data from FINCH 1, evaluating the drug in patients who had not achieved adequate response to the commonly used drug methotrexate, was an update from prior data showing that those receiving filgotinib at 200mg had met the primary endpoint of at least a 20% improvement in the number of tender and swollen joints after 12 weeks of treatment. The updated data showed that at 52 weeks, patients in the 200mg group as well as those in the 100mg group had sustained efficacy on the primary as well as secondary endpoints. Filgotinib was given at 200mg and 100mg and compared with AbbVie’s Humira (adalimumab) or placebo.

FINCH 3 tested the drug at the same doses combined with methotrexate and compared it against methotrexate alone, also meeting its primary endpoint and showing sustained efficacy after 52 weeks.

The drug is a JAK inhibitor that Gilead and Galapagos have been developing for RA and other autoimmune diseases under a nearly $5 billion partnership the two companies formed last year.

In a note to investors, RBC Capital Markets analyst Brian Abrahams wrote that an analysis of the data did not reveal any major new concerns, and there appeared to be a good likelihood of the drug receiving approval from the Food and Drug Administration. However, some potential risks still existed, particularly in terms of safety.

“While [filgotinib’s] profile has been quite clean so far, given the history of Jak inhibitor approvals/rejections, we believe the biggest risk to the program remains if any safety imbalances (even if seemingly minor) emerge and derail approvability of the most active high dose (200mg) of the drug, or of the drug altogether,” Abrahams wrote.

On the one hand, Abrahams pointed out, there was a low rate of serious infections that could be advantageous for the drug, but there also appeared to be a slight imbalance in overall deaths between the 100mg and 200mg dose arms, which risks attracting regulatory scrutiny.

The company reported that in FINCH 1, there were five deaths reported before the 24-week mark, including one in the 100mg dose group, two in the 200mg dose group and two in the placebo group. FINCH 3 saw three deaths in the 200mg group and one in the 100mg group. Generally, infections were balanced across treatment groups, though FINCH 1 reported a numerically higher incidence in herpes zoster infection for the 200mg group compared with the 100mg group.

Photo: Tomsmith585, Getty Images