GALAPAGOS REPORTS PRIMARY ENDPOINT FOR THE ONGOING FILGOTINIB MANTA AND MANTA-RAy SAFETY STUDIES

 

• 8.3% patients on placebo and 6.7% patients on filgotinib had a 50% or more decline in sperm concentration at week 13
• No new safety findings were identified
• Data will be submitted to the relevant regulatory authorities

Mechelen, Belgium, 4 March 2021, 07.40 CET, regulated information –Galapagos NV (Euronext & Nasdaq: GLPG) today announced interim results from MANTA and MANTA-RAy, two ongoing safety studies investigating the effect of Jyseleca (filgotinib) on sperm parameters in males with inflammatory bowel disease (MANTA) or rheumatic conditions (MANTA-RAy).

In total, 248 patients were randomized 1:1 to receive filgotinib 200 mg once daily or placebo for an initial 13-week, double-blind treatment period. The primary endpoint in both trials was the proportion of patients who had a reduction of 50% or more in sperm concentration at Week 13. Patients who met this endpoint discontinued study treatment at Week 13, were switched to standard of care treatment and were monitored for reversibility every 13 weeks for up to 52 weeks.

Out of the 248 randomized patients, 240 reached Week 13 with two evaluable semen samples at baseline and Week 13. Of those, 18 patients showed a ≥50% decline in sperm concentration, with 10/120 (8.3%) patients on placebo and 8/120 (6.7%) patients on filgotinib. These studies, which were designed with the input of the relevant health authorities, are not powered for statistical comparison between groups. These data will now be submitted to relevant regulatory authorities.

Beyond the double-blind, placebo-controlled, 13-week period, for which MANTA and MANTA-RAy results are pooled, patients who did not meet the primary endpoint of 50% or more decline in sperm motility or morphology could continue under their respective trial protocol on blinded treatment, receive open-label filgotinib or receive standard of care therapy based on disease response, for another 13 weeks before entering a long-term extension period. At any point, patients exhibiting a predetermined sperm decline enter a monitoring phase in which they are assessed every 13 weeks for reversibility for up to 52 weeks.