InflaRx (NASDAQ:IFRX) highlighted progress on its oral C5a receptor 1 (C5aR) antagonist izicopan and outlined upcoming development plans during a presentation at the Guggenheim Outlook Biotech Summit 2026. Chief Financial Officer Thomas Taapken and investor relations executive Jan Medina also discussed recent cost-cutting actions following the company’s decision to deprioritize its antibody program, vilobelimab.
Company focus shifts toward oral complement inhibition
Taapken said InflaRx, which is based in Germany and the U.S. and has been public on Nasdaq since 2017, has historically focused on “terminal complement” inhibition of C5a. The company’s programs include vilobelimab, an anti-C5a antibody, and izicopan, a small-molecule inhibitor of C5aR1.
Izicopan positioned against Amgen’s avacopan
In discussing differentiation, Taapken said C5aR inhibition has been a difficult area for drug development and pointed to avacopan—originally from ChemoCentryx and later acquired by Amgen—as the first approved drug in the class for ANCA-associated vasculitis (AAV). He described avacopan as a “blueprint” for InflaRx’s discovery efforts, noting that izicopan was designed to target a similar receptor region while improving pharmacology.
Taapken listed several areas where he believes izicopan improves on avacopan, including:
- Higher availability/bioavailability and higher plasma levels at comparable dosing
- Faster onset of receptor inhibition, reaching peak levels and steady state within days (versus what he said can take “in the range of three months” for avacopan)
- Lower CYP3A4 inhibition, which he said is “36 times lower,” potentially reducing drug-drug interaction risk
Taapken also said the company has not observed hepatotoxicity signals to date in its own clinical experience. He stated that InflaRx has treated “in the range of 200 patients” at different dose levels, including high doses, without seeing liver toxicity signals.
Asked about hepatotoxicity reported with avacopan in certain Japanese patients, Taapken said InflaRx believes this is likely molecule-related rather than pathway-related. He linked the avacopan observations to CYP3A4-related liver enzyme interactions and the potential accumulation of other hepatically cleared drugs that patients may be taking, including glucocorticosteroids. However, the discussion also noted that this interpretation remains speculative.
Early hidradenitis suppurativa (HS) signal and next steps
Taapken said the Phase 2a work with izicopan included a “basket” approach in hidradenitis suppurativa (HS) and chronic spontaneous urticaria (CSU), with multiple doses evaluated over four weeks. He emphasized the study was intended for signal-finding and was not placebo-controlled, adding that the four-week duration reflected that long-term toxicology data were not available at the time the trial started.
Despite limitations, Taapken described the HS results as “quite remarkable” when compared with published Phase 2 and Phase 3 HS trials, saying the four-week responses appeared in-line with, and potentially better than, other molecules tested in HS. He highlighted two findings he viewed as especially notable:
- Reduction of draining tunnels, which he characterized as a unique feature observed even after a short treatment period, particularly at the highest dose
- Pain reduction, which he said was pronounced versus what has been observed with other drugs at four weeks and suggested reduced deep skin inflammation
The executives also referenced prior avacopan HS data, arguing that avacopan’s slower time to steady-state exposure may have limited observed effects earlier in dosing, while izicopan reaches full exposure within days.
On next steps, Taapken said the company has completed long-term toxicology enabling longer dosing, including a nine-month non-human primate study that he said was “clean” and supports “indefinite dosing.” He added that InflaRx is still working on dose selection for a Phase 2b HS study, including additional pharmacokinetic simulations, and plans to engage with the FDA on design considerations. He said a Phase 2b trial will be required and that the four-week Phase 2a trial would not support moving directly into a pivotal Phase 3 program.
CSU remains a potential expansion opportunity
While Taapken said HS is InflaRx’s primary focus as a smaller company, he described the CSU dataset as “quite encouraging” and said external key opinion leaders have supported further evaluation. Medina added that particularly strong signals were seen in subsets including more severe CSU patients and those with angioedema, though he noted the numbers were small. Management suggested CSU could be pursued with additional resources or through partnership.
Capital Markets Day planned for spring; cost base reduced after vilobelimab changes
InflaRx said it intends to host a Capital Markets Day in the spring after finalizing Phase 2b trial design elements such as endpoints, doses, and the number of arms, following discussions with regulators and key opinion leaders. The company also indicated it may discuss additional indications beyond HS and CSU, including AAV, at that event.
On finances and operations, Taapken said the company reduced its fixed cost base by roughly 30% after deprioritizing vilobelimab as a development and commercial asset. He noted InflaRx stopped a Phase 3 vilobelimab study in 2025 and also removed activities tied to a COVID opportunity, which he described as niche.
About InflaRx (NASDAQ:IFRX)
InflaRx N.V. is a clinical‐stage biopharmaceutical company focused on the discovery, development and commercialization of novel therapies targeting the complement system, with an emphasis on the complement‐1a (C5a) pathway. The company’s lead product candidate, vilobelimab (IFX‐1), is a monoclonal antibody designed to selectively inhibit C5a, a potent pro‐inflammatory peptide implicated in a range of autoimmune and inflammatory diseases. InflaRx seeks to address high‐unmet medical needs by advancing treatments for conditions such as hidradenitis suppurativa, pyoderma gangrenosum and other rare and severe inflammatory disorders.
Vilobelimab has been evaluated in multiple Phase II trials, demonstrating proof of concept in reducing key inflammatory markers and improving clinical outcomes.
