InflaRx Advances INF904 for CSU and HS with Phase 2a Study

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InflaRx NV announced today it has initiated a phase 2a basket study of INF904, its oral C5a receptor (C5aR) inhibitor. This milestone represents a significant step in developing treatments for chronic spontaneous urticaria (CSU) and hidradenitis suppurativa (HS), both debilitating immuno-inflammatory conditions with high unmet medical needs.¹

In a news release, Camilla Chong, MD, chief medical officer of InflaRx, commented: “We are pleased to have started our phase 2a trial for INF904 with the first patient dosed at 1 of our US sites, and I am very proud of our team who implemented this important study so rapidly. We believe there is strong evidence of INF904’s anti-inflammatory properties and that its best-in-class potential will go a long way to serve unmet medical needs in both chronic spontaneous urticaria and hidradenitis suppurativa, and in other immuno-inflammatory conditions as well.”

Study Objectives and Design

The phase 2a trial is an open-label, multi-center study involving 75 patients with moderate to severe CSU and HS. It aims to evaluate various dosing regimens of INF904 over a 4-week treatment period, followed by 4 weeks of patient monitoring. Key objectives include gathering safety and pharmacokinetic data and identifying preliminary clinical benefits. According to InflaRx, data from this study will inform the design of a larger phase 2b study planned for late 2025.

For CSU, the trial includes 3 study arms with 45 patients. Participants will receive doses of 60 mg or 120 mg BID (twice daily), with a focus on anti-IgE treatment non-responders in 1 arm. The company stated efficacy will be measured using established clinical tools, including changes in Urticaria Activity Score 7, Hives Severity Score, and Itch Severity Score.

The HS cohort includes 30 patients randomized into 3 dosing arms (60 mg, 90 mg, or 120 mg BID). Evaluations will focus on changes in total abscess, inflammatory nodule, and draining tunnel counts, as well as clinician-reported outcomes. The company stated quality of life metrics and patient-reported outcomes are integral to both groups' assessments.

Foundations for INF904

According to InflaRx, INF904 is a small molecule C5aR inhibitor designed to mitigate inflammatory responses. Its advantages over existing therapies include minimal inhibition of CYP3A4/5 enzymes, which are critical for metabolizing various drugs, including glucocorticoids.

Previous phase 1 studies demonstrated INF904's tolerability and safety, with no concerning signals across a dose range of 3 mg to 240 mg. Data also revealed a ≥90% blockade of C5a-induced neutrophil activation over a 14-day period, underscoring the drug’s potential to disrupt inflammatory cascades.²

While InflaRxis focusing resources on these indications, it also acknowledged broader opportunities in immuno-inflammatory diseases such as nephrology, neurology, and hematology.

Conclusion

The phase 2a study of INF904 signifies a pivotal moment for InflaRx in advancing its portfolio of anti-inflammatory therapeutics. Data expected in 2025 will likely shape the next phase of development, bringing hope to patients with limited treatment options.

References

1. InflaRx announces first patient dosed in phase 2a study for oral C5aR inhibitor INF904. News release. BioSpace. Published December 20, 2024. Accessed December 20, 2024. https://www.biospace.com/press-releases/inflarx-announces-first-patient-dosed-in-phase-2a-study-for-oral-c5ar-inhibitor-inf904
2. InflaRx announces positive topline results from the multiple ascending dose (MAD) phase I study with C5aR inhibitor INF904. News Release. InflaRx. Published January 4, 2024. Accessed December 20, 2024. https://www.inflarx.de/Home/Investors/Press-Releases/01-2024-InflaRx-Announces-Positive-Topline-Results-from-the-Multiple-Ascending-Dose--MAD--Phase-I-Study-with-C5aR-Inhibitor-INF904.html