Emodepside Phase II Trial for Treatment of Onchocerciasis

There is an urgent need for a macrofilaricidal drug targeting the adult stage of Onchocerca volvulus, which could be used in individual case management and, after appropriate testing, as an alternative drug to ivermectin in Mass Drug Administration (MDA) programs.

Emodepside is a promising drug candidate to kill the adult and sexually mature Onchocerca volvulus. Emodepside was shown to be macrofilaricidal and microfilaricidal against a variety of filarial nematodes in non-clinical studies, and is a registered drug for animal health, commercialized by Bayer AG under the name of Profender® (in combination with praziquantel) or Procox® (in combination with toltrazuril).

Three Phase I trials of emodepside with single or multiple doses of emodepside have been conducted in healthy Caucasian men. The results are encouraging and support continuation of the clinical development programme of emodepside as treatment for onchocerciasis. One of these trials also enabled the selection of a field-adapted tablet formulation, suitable for use in countries endemic for onchocerciasis.

The present trial is designed in a stepwise approach starting with a proof of concept part, which is further subdivided in steps to investigate the safety, tolerability and pharmacokinetics of emodepside in the target population - Part 0 (pilot group), followed by investigations of the safety of emodepside in low and high-microfilaria carriers - Part 1a, and the dose-response relationship for efficacy of emodepside compared to placebo in microfilaria-positive patients - Part 1b. This approach allows to maximize the information regarding the safety of emodepside in the target population and to establish a dose range, in which emodepside is efficacious. Based on the information obtained from Parts 0 and 1, up to two efficacious dose regimens will be selected to carry forward into the confirmatory, active-controlled Part 2 of the trial, which will investigate the superiority of emodepside over ivermectin assessed using a clinically relevant endpoint, i.e. long-term absence of microfilariae at month 24.