InflaRx flatlines after skin disease drug flops in midstage trial

Shares in German biotech InflaRx have plummeted 92% after it reported a comprehensive miss for its lead drug IFX-1 in a debilitating skin disease.

The phase 2b SHINE study of the anti-human complement factor C5a antibody was conducted in hidradenitis suppurativa (HS), a chronic inflammatory skin disease with limited treatment options that causes symptoms including inflamed nodules or boils in the armpits, groin and genital area.

Unfortunately for InflaRx, the 179-patient study appears to be a near-total bust, with IFX-1 showing no improvement over placebo on symptoms after 16 weeks’ treatment.

Most worryingly, there was no evidence of any dose response with the four IFX-1 dose levels tested, which was the trial’s primary endpoint, and the responses were significantly lower than had been previously reported in phase 2a.

But for that earlier result it would be tempting to suggest that the primary problem is that C5a’s role in HS had been dramatically overstated.

The only crumb of comfort for the Nasdaq-listed biotech came from a secondary endpoint – the dermatology life quality index (DLQI) – which just scraped a statistically significant improvement over placebo for the four IFX-1 groups as a whole.

“We are disappointed that we were not able to demonstrate a significant signal on dose response for the treatment with IFX-1,” commented Othmar Zenker, InflaRx’s chief medical officer.

“While we are still analysing additional data, we note that the trial demonstrated an unusually high placebo [Hidradenitis Suppurativa Clinical Response or HiSCR] rate at week 16.”

The fallout from the failure also drew in rival company Chemocentryx, which is developing a C5a receptor inhibitor called avacopan for HS, as well as other indications including ANCA-associated vasculitis (AAV) and C3 glomerulopathy. Its shares closed down almost 20% after InflaRx’ announcement.

InflaRx pipeline still includes earlier-stage trials of IFX-1 in AAV, pyoderma gangrenosum and other inflammatory and cancer indications, but its only other asset is IFX-2, a follow-on C5a inhibitor which is in preclinical development.

The company, which ended the first quarter with cash and cash equivalents of €47 million, says it will sift through the data to see if it can find an explanation for the disappointing result.