Phase 2 Study of Vilobelimab Fully Enrolled in Europe

InflaRx has completed enrollment in its Phase 2 trial evaluating vilobelimab (IFX-1) for people with ANCA-associated vasculitis (AAV) in Europe.

“We are pleased to have met our enrollment goal in the vilobelimab European phase II trial in AAV,” Korinna Pilz, MD, global head of clinical research and development of InflaRx, said in a press release.

Vilobelimab is a first-in-class antibody designed to target and block the activity of the complement activation C5a protein. A component of the complement system — a set of more than 20 blood proteins that form part of the body’s immune defenses — the C5a protein is thought to participate in the excessive inflammatory response seen in AAV patients.

The IXCHANGE Phase 2 study (NCT03895801), taking place across 76 clinical sites in Europe, is evaluating the safety and efficacy of vilobelimab in adults with active granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) receiving standard immunosuppressive therapy with either rituximab or cyclophosphamide, plus glucocorticoids.

The trial has two parts. In the first part, which completed enrollment of 30 patients in April, participants will be randomly assigned to vilobelimab plus a reduced dose of glucocorticoids, or to a placebo in combination with a standard dose of glucocorticoids.

Its second part, which enrolled an additional 27 patients, will compare the benefits of vilobelimab alone to those obtained with a standard dose of glucocorticoids. In both parts, participants will receive treatment for 16 weeks, followed by eight weeks of observation.

All patients will continue to receive standard immunosuppressive therapy, with either rituximab or cyclophosphamide, along with their assigned treatment.

The trial’s main goal is to determine the proportion of patients who achieve a clinical response — defined as a 50% reduction in their Birmingham Vasculitis Activity Score, a measure of disease activity — after the 16 weeks.

Secondary measures include clinical remission, changes in organ damage, reduction in glucocorticoid toxicity, kidney function, and patient-reported outcomes. Final results are expected by the end of the year.

A similar trial is also exploring the safety and efficacy of vilobelimab in GPA and MPA patients in the U.S. The IXPLORE Phase 2 study (NCT03712345) is investigating two dosing regimens of vilobelimab, versus a placebo, plus standard care immunosuppressive therapy and a high-dose of glucocorticoids.

As vilobelimab has not been previously tested in AAV patients in the U.S., the main goal of IXPLORE is to determine the treatment’s safety in this population. Secondary goals include the efficacy measures also used in the European trial.

To date, all 19 patients enrolled have completed the study; final results are expected in the next few months.

“ANCA-associated vasculitis is a rare but recurring and life-threatening disease for which new treatment options are urgently needed,” said Pilz. “Given the suggested important role of the C5a signaling pathway, especially for the life-threatening flare phases in this disease, we believe that vilobelimab could be a promising therapeutic option and look forward to seeing the results from [the European] trial and the US safety trial later this year.”

Besides AAV, vilobelimab is being tested for two skin disorders called pyoderma gangrenosum and hidradenitis suppurativa, and as a potential treatment for patients with severe pneumonia associated with COVID-19.