XOMA, a US-based biotechnology firm, has initiated its pivotal Phase III trial of gevokizumab in patients with active pyoderma gangrenosum (PG), a rare neutrophilic dermatosis of expanding necrotic skin ulcers.

The trial will evaluate the efficacy and safety of gevokizumab in treating the active ulcers caused by PG.

The US Food and Drug Administration (FDA) granted orphan drug designation in February to gevokizumab for PG.

XOMA chief medical officer and senior vice-president of Research and Development Paul Rubin said: "Patients with PG experience deep and painful skin ulcers that often become chronic wounds. In our pilot study, five of the six patients enrolled responded to gevokizumab, and four experienced complete wound closure by three months.

"The trial will evaluate the efficacy and safety of gevokizumab in treating the active ulcers caused by PG."

"We believe gevokizumab has the potential to help PG patients reduce the amount of time it takes to heal from this painful and unsightly condition.

"With the first US only study open for enrolment, we will complete the necessary steps to open the second pivotal PG Phase III study, which will include both US sites and centres outside of the United States."

Around 58 patients with active PG will be enrolled in the randomised, placebo-controlled Phase III trial and they will be given gevokizumab 60mg or placebo dosed subcutaneously once monthly, in addition to their current treatment regimen of low-dose corticosteroids and/or immunosuppressants.

The trial’s primary endpoint is complete closure of the PG target ulcer determined at day 126 with confirmation a minimum of two weeks later at day 140.