Filgotinib: selective JAK1 inhibitor with a potential best-in-class product profile

R&D CSR report
Galapagos NV • Annual Report 2018

Based on results from our Phase 2 trials and the FINCH Phase 3 trials, we believe that filgotinib is a promising candidate for the treatment of RA, CD and potentially other inflammatory diseases. We are party to a collaboration agreement with Gilead to develop and commercialize filgotinib in multiple diseases. Under the terms of the collaboration, Gilead is primarily responsible for development and seeking regulatory approval of the licensed product. We are required to use commercially reasonable efforts as requested by Gilead to assist Gilead with certain development activities. Gilead initiated Phase 3 clinical programs in RA, CD, and UC in 2016, and we and Gilead initiated Phase 2 trials with filgotinib in additional indications in 2017, with the first readouts from these trials reported in 2018. The following table highlights our filgotinib program and status at the time of publication of this report:

We build a filgotinib franchise

Building the filgotinib franchise (graphic)

Markets for inflammation drugs are considerable and growing. We estimate that the inflammation market could grow to approximately $65 billion by 2027, driven by new drugs filling the current unmet need for oral, monotherapy treatments with a rapid response, and higher efficacy maintained over time. RA remains the largest single market indication, which we estimate to be approximately $30 billion, with the other main markets combined representing a slightly larger opportunity than in RA:

Inflammation market in ~2027, $B

Estimated 2027 inflammation market size (pie chart)

Based on the Phase 2 and 3 data observed with filgotinib in RA and Phase 2 data in CD, AS, and psoriatic arthritis (PsA) thus far, we believe that filgotinib has the potential to improve treatment standards substantially in RA, inflammatory bowel diseases (IBD), AS, and PsA. Compared with biologic agents, filgotinib is orally administered, with a rapid onset, sustained response, and potential for monotherapy. American College of Rheumatology (ACR) scores with filgotinib in Phase 2 and 3 trials in RA patients are encouraging, and CDAI remission and SES-50 scores are similarly promising with filgotinib in a Phase 2 trial in CD patients who are naïve to TNF therapy. ACR and enthesitis scores were encouraging with filgotinib in PsA in the EQUATOR Phase 2 trial, while spine mobility and function were significantly improved with filgotinib in AS patients in the TORTUGA Phase 2 trial. Filgotinib is highly selective for JAK1, resulting in favorable tolerability so far, including low rates of infection reported in all trials.