SAN DIEGO – A novel oral drug for inflammatory bowel disease showed good safety and efficacy data in preliminary clinical trial results.
Among a group of 32 patients with ulcerative colitis, the investigative drug ABX464 showed a decrease in Mayo score of over 50% and a drop in fecal calprotectin to near-normal levels. The safety profile was reassuring, and results were durable at the 9-month mark.
Coauthor Jean-Marc Steens, MD, presented results of the randomized, double-blind, placebo-controlled phase 2a study at the annual Digestive Disease Week®, and noted that ABX464 is also being investigated as antiviral therapy for individuals with HIV/AIDS.
“Despite the major advances in the last 10 years with the introduction of biologics and [Janus kinase] inhibitors, there is still a huge unmet medical need for these patients,” said Dr. Steens, chief medical officer of Abivax (Paris), in an interview. “Large phase 3 studies with these recent drugs have shown that about two-thirds of the patients show a clinical response during induction, but that half of these responders will lose their response within the next 6-12 months. The safety profile of these drugs also includes severe infections, which is a major concern,” he said.
Dr. Steens presented the findings on behalf of first author Severine Vermeire, MD, chair of the department of chronic diseases, metabolism, and aging at Catholic University, Leuven, Belgium.
ABX464, a small-molecule oral medication, has been evaluated for safety among more than 180 patients with HIV as well as the patients with ulcerative colitis (UC) studied in the current trial. The drug increases expression of the microRNA precursor miR-124, with the result that “the inflammatory brake is applied,” explained Dr. Steens.
In the present study, whose primary outcome was safety, 23 patients with moderate to severe active UC were randomized to ABX464 50 mg once daily, and 9 to placebo. Patients were included if they had failed or were intolerant to immunomodulators, anti–tumor necrosis factor–alpha therapies, vedolizumab, or corticosteroids; the two groups had balanced disease and demographic characteristics. At baseline, patients had a total Mayo score of 6-12, and an endoscopic subscore of 2 or 3.
Three patients withdrew from the ABX464 arm by the end of 8 weeks: one because of adverse events (AEs), one withdrew consent, and the third declined to undergo endoscopy at the 8-week mark.
All treatment-emergent AEs were mild or moderate, with gastrointestinal disorders occurring in eight of the ABX464 patients and two placebo patients (34.8% and 22.2%, respectively.) Five ABX-464 patients (21.7%) experienced nervous system symptoms – mostly headaches, said Dr. Steens. No patients in the placebo arm had headache or other neurological AEs.
By the end of 8 weeks, 30% of the intention-to-treat ABX464 group was in clinical remission, compared with 11% of the placebo group; this was not a statistically significant difference (P = .16). The proportion of ABX464 patients who had a clinical response just missed statistical significance, compared with placebo (61% versus 33%; P = 06).
However, significant endoscopic improvement was seen in the ABX464 arm, with 43% having a Mayo endoscopy subscore of 0 or 1, compared with 11% in the placebo arm (P = .03).
The total Mayo score dropped by 53% in the ABX464 group, compared with 27% in the placebo group (P = .03); a partial Mayo score dropped by 62% for those in the active arm, compared with 32% in the placebo arm (P = .02).