- Red Hill Biopharma aims to be a player in the growing — and competitive — market for Crohn's disease therapies, and believes results from the first Phase 3 study of its fixed-dose antibiotic combination RHB-104 put it one step closer toward that goal.
- In the late-stage trial, treatment with RHB-104 helped a significantly greater proportion of patients achieve remission after six months than those given placebo, the biotech reported Monday. Remissions reported in the treatment arm were also more likely to be durable, although some patients did appear to relapse by the one-year mark.
- RedHill said it plans to discuss a path forward for RHB-104 with regulators, but did note that additional studies would "most likely" be required to support a potential application for approval of the drug.
The pipeline of Crohn's disease therapies has become more crowded recently, as new JAK inhibitors and anti-IL23 inhibitors move through late-stage testing for the inflammatory bowel disease. Many of the available and experimental treatments aim to tap down that inflammation by targeting cytokines.
RedHill is taking a slightly different approach, zeroing in on a bacterial infection known as MAP that it believes could play a role in the disease's development. Studies cited by RedHill give some evidence that MAP, or Mycobacterium avium subspecies paratuberculosis, can be present in the blood of Crohn's patients, and animal studies have shown that the infection causes an intestinal disease that bears some similarities to Crohn's.
RHB-104 consists of three old, now generic antibiotics in a fixed-dose combination designed to treat MAP and, hopefully, help address Crohn's.
In the Phase 3 study RedHill reported Monday, 37% of patients treated with RHB-104 achieved remission by week 26, compared to only 23% of those on placebo. For the trial's purposes, remission was defined as a Crohn's Disease Active Index value of less than 150 (moderately to severely active disease is typically scored between 220 and 450).
Investors initially seemed pleased with the results, sending RedHill stock higher in early Monday trading. Sentiment shifted by mid-morning, however, with shares dropping by more than 4% in value.
RHB-104 also met a number of secondary goals, outperforming placebo in response rate, speed to remission and the durability of remission.
Some patients appeared to have relapsed, however, with only 27% on RHB-104 remaining in remission at one year.
Hard numbers around the drug's safety profile weren't disclosed, but RedHill did say that both treatment and control groups experienced "similarly low rates of serious adverse events and treatment emergent adverse events leading to study drug discontinuation."
RedHill plans to discuss a path forward for RHB-104 with regulators, likely to determine how to design further study of the drug. In the meantime, an open-label extension trial will continue for all patients — both those on the drug and in the placebo arm — who still had active Crohn's disease after 26 weeks of treatment during the main Phase 3 study.
RedHill also said it would continue talks with potential pharma partners for RHB-104.