Resomelagon and Methotrexate

Resomelagon (also known as AP1189) is a novel, first-in-class, oral, biased melanocortin receptor agonist being developed for rheumatoid arthritis treatment[1]. It specifically targets melanocortin receptor 1 (MC1) and melanocortin receptor 3 (MC3)[1]. The combination of resomelagon with methotrexate (MTX) is being investigated as a treatment option for rheumatoid arthritis, particularly for newly diagnosed patients with high disease activity[1][5].\n\n## Patent Protection and Development Status\n\nSynAct Pharma has secured significant patent protection for this combination therapy:\n\n- In April 2025, the United States Patent and Trademark Office (USPTO) issued a Notice of Allowance for SynAct Pharma's patent application covering the use of resomelagon in combination with methotrexate for rheumatoid arthritis treatment[2][6].\n- This patent will provide market exclusivity until at least 2040[2][5].\n- More recently, in May 2025, SynAct received USPTO Issue Notification for patent 12,303,489, which includes a significant Patent Term Adjustment of 769 days, extending market exclusivity until June 15, 2042[3].\n\n## Clinical Development\n\nThe combination therapy is currently undergoing clinical evaluation:\n\n- A Phase IIb clinical trial called ADVANCE is underway in both the US and EU, with patient enrollment expected to be completed in Q4 2025[2][5].\n- Previous clinical data from the EXPAND trial showed promising results in a specific patient population. While there was no observed difference between AP1189 in combination with MTX and placebo+MTX in the study cohort as a whole, post hoc analyses in newly diagnosed RA patients with high disease activity (including elevated hsCRP) suggested that AP1189 could be a promising treatment option in this patient group[1][2].\n- SynAct has focused on positioning resomelagon as "a new innovative oral treatment option in early RA with high disease activity where there is a need for new safe" treatment options[8].\n\nThis combination therapy represents a novel approach to treating rheumatoid arthritis, with SynAct Pharma building a strong intellectual property portfolio to support its commercial development.