Galapagos bolsters case for Gilead-partnered Crohn’s drug with 20-week data

Galapagos ($GLPG) has added more data to the growing repository supporting the use of its Gilead ($GILD)-partnered JAK1 inhibitor in patients with Crohn’s disease. The latest readout, which comes from an extension to the Phase II trial that reported results in December, suggests that responses to the drug continue up to week 20 while also hinting at the potential to lower the dosing.

In the second part of the Phase II trial, Galapagos monitored the progress of patients who received the treatment in the first stage of the study for a further 10 weeks. Galapagos is planning to share a detailed breakdown of the data at a medical conference but has already reported that the clinical responses seen over the first 10 weeks continued through the second part of the trial. No new safety issues emerged in the extended trial, which has yet to report any gastrointestinal perforations, cancers or deaths.

As well as continuing the treatment arm, the extension also began nonresponders from the placebo group of the original trial on 100-mg doses of the JAK1 inhibitor, filgotinib. Patients in the original treatment arm received once-daily 200-mg doses. Again, Galapagos has yet to release detailed data but is reporting improvements in clinical remission among the ex-placebo cohort.

If the rate of remission is comparable to that seen in the original 200-mg treatment arm, it could enable Galapagos and Gilead to advance at the lower dose. Given the concerns about the preclinical testicular toxicity findings for the higher dose in rheumatoid arthritis--which may affect the design of the upcoming Phase III trial in that indication--the option to drop down to 100 mg without compromising on efficacy could prove attractive.

Mechelen, Belgium-based Galapagos and its partner Gilead have this and other decisions coming up. Gilead, which struck a $2 billion (€1.8 billion) deal for filgotinib in December after AbbVie ($ABBV) walked away from the program, is planning to start a Phase III trial of the JAK1 inhibitor in Crohn’s disease later this year. Work on the trial is advancing in parallel with preparations for a Phase III trial in rheumatoid arthritis, which is the bigger of the two opportunities for the drug.

The aforementioned concerns over the effect of preclinical testicular toxicity data on dosing are one of the outstanding uncertainties about the study. Galapagos is expected to clarify the situation soon. “We understand meetings with the FDA and EMA to finalise the [rheumatoid arthritis] Phase III trial design for filgotinib have taken place, and that the minutes should be released shortly,” Jefferies analyst Peter Welford wrote in a note to investors.

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