Rheumatoid arthritis unresponsive even to targeted therapies ... HanAll Biopharma drug candidate posts a 92.5% response rate

[Financial News] A new treatment option may be within reach for patients with “highly refractory” rheumatoid arthritis, for whom there have been no suitable treatment alternatives. HanAll Biopharma’s drug candidate imeroprubart (IMVT-1402) met the primary endpoint in a trial of patients who had not responded to existing targeted therapies.
HanAll Biopharma said its global partner Immunovant disclosed the results of a trial of imeroprubart in patients with difficult-to-treat rheumatoid arthritis (D2T RA) during its quarterly earnings presentation on the 9th (U.S. local time).
The trial enrolled patients whose symptoms had not improved despite treatment with at least two advanced targeted therapies with different mechanisms of action. In Period 1, patients received a high dose of imeroprubart (600 mg) for 16 weeks. Responders were then randomly assigned in Period 2 to a high-dose group (600 mg), a low-dose group (300 mg) or a placebo group and received treatment for an additional 12 weeks. Results previously disclosed for week 16 of Period 1 showed ACR20, ACR50 and ACR70 response rates—measures of symptom improvement—of 72.7%, 54.5% and 35.8%, respectively.
In Period 2, the week 28 ACR20 response rate—the primary endpoint in the high-dose group—was 92.5%, statistically significantly higher than the 75.6% in the placebo group (p=0.0139). The response rates for ACR50 and ACR70, exploratory endpoints, also rose to 80% and 52.5%, respectively, at week 28.
In particular, among patients whose symptoms had not improved sufficiently despite treatment with both JAK and TNF inhibitors, week 28 ACR20, ACR50 and ACR70 response rates were 92%, 76% and 56%, respectively, showing a treatment effect consistent with that in the overall patient population.
The Clinical Disease Activity Index (CDAI) and Simplified Disease Activity Index (SDAI), secondary endpoints measuring disease activity, showed a tendency to remain stable compared with the placebo group, but did not reach statistical significance.
Overall, the treatment showed good tolerability. No serious adverse events or discontinuations due to adverse events were reported. Immunovant plans to discuss further development plans with the U.S. Food and Drug Administration (FDA) this year to seek approval for the refractory rheumatoid arthritis indication.
Trials for other indications are also progressing smoothly. Topline results for Graves’ disease (GD) and myasthenia gravis (MG) are expected in 2027, while results for chronic inflammatory demyelinating polyneuropathy (CIDP) are expected in 2028. However, the company said it is unlikely to pursue further development of the treatment for Sjögren’s syndrome (SjD) after the ongoing Phase 2 trial, given changes in the market environment and the competitive landscape.
[email protected] Jung Myung-jin, reporter