Apilimod mesylate

Brief report: a phase IIa, randomized, double-blind, placebo-controlled trial of apilimod mesylate, an interleukin-12/interleukin-23 inhibitor, in patients with rheumatoid arthritis.[Pubmed:22170479]

Arthritis Rheum. 2012 Jun;64(6):1750-5.

OBJECTIVE: To investigate the safety, tolerability, pharmacokinetics, and efficacy of Apilimod mesylate, an oral interleukin-12 (IL-12)/IL-23 inhibitor, in patients with rheumatoid arthritis (RA). METHODS: We performed a phase IIa, randomized, double-blind, placebo-controlled proof-of-concept study of apilimod, in combination with methotrexate, in 29 patients with active RA (3:1 ratio of apilimod-treated to placebo-treated patients) in 3 stages. Patients received apilimod 100 mg/day or placebo for 4 weeks (stage 1) or 8 weeks (stage 2). In stage 3, patients received apilimod 100 mg twice a day or placebo for 8 weeks, with an optional extension of 4 weeks. Clinical response (Disease Activity Score in 28 joints [DAS28] and American College of Rheumatology [ACR] criteria) was assessed throughout; synovial tissue samples collected at baseline and on day 29 (stages 1 and 2) or day 57 (stage 3) were stained for cellular markers and cytokines for immunohistochemistry analysis. RESULTS: While only mild adverse events were observed in stages 1 and 2, in stage 3, all patients experienced headache and/or nausea. Among apilimod-treated patients (100 mg/day), there was a small, but significant, reduction in the DAS28 on day 29 and day 57 compared with baseline. ACR20 response was reached in only 6% of patients on day 29 and 25% of patients on day 57, similar to the percentage of responders in the placebo group. Increasing the dosage (100 mg twice a day) did not improve clinical efficacy. Consistent with clinical results, apilimod did not have an effect on expression of synovial biomarkers. Of importance, we also did not observe an effect of apilimod on synovial IL-12 and IL-23 expression. CONCLUSION: Our results do not support the notion that IL-12/IL-23 inhibition by apilimod is able to induce robust clinical improvement in RA.

Randomized, double-blind, placebo-controlled trial of the oral interleukin-12/23 inhibitor apilimod mesylate for treatment of active Crohn's disease.[Pubmed:19918967]

Inflamm Bowel Dis. 2010 Jul;16(7):1209-18.

BACKGROUND: Interleukin-12 (IL-12) and interleukin-23 (IL-23) are inflammatory cytokines linked to the Th-1 and Th-17 phenotypes associated with Crohn's disease (CD). We investigated the activity and safety of Apilimod mesylate (formerly STA-5326), an oral IL-12 and IL-23 inhibitor, in patients with active CD. METHODS: We performed a multicenter, Phase 2, randomized, double-blinded, placebo-controlled study to evaluate the efficacy of Apilimod mesylate in treating 220 adult patients with moderate-to-severe CD (Crohn's Disease Activity Index [CDAI] score 220-450). Patients were stratified according to C-reactive protein (CRP) levels and corticosteroid use and were randomly assigned to receive placebo or Apilimod mesylate 50 mg daily or 100 mg daily. The study was divided into an induction phase (43 days) and a maintenance phase (125 days). The primary analysis involved a comparison of the proportion of patients experiencing clinical response, defined as at least a 100-point decrease in CDAI score from baseline at day 29. Data on adverse events were also collected. RESULTS: In all, 220 of the planned 282 patients were enrolled when the Data Monitoring Committee determined that the drug was not efficacious as a treatment and closed enrollment. A clinical response was experienced by 18 patients (24.7%) in the 50-mg daily (QD) group (n = 73) and 19 patients (25.7%) in the 100 mg QD group (n = 74), as compared with 21 patients (28.8%) in the placebo group (n = 73) on day 29 (P = 0.71 for each comparison). No significant adverse safety signal was observed. CONCLUSIONS: Apilimod was well-tolerated but did not demonstrate efficacy over placebo in patients with active CD.