Protalex Initiates Fourth Cohort Dosing of Phase 1/2 Study of PRTX-100 in Immune Thrombocytopenia

Protalex, Inc. announced that the Company has enrolled the first of three patients in cohort four of its U.S./U.K. Phase 1/2 trial evaluating PRTX-100 for the treatment of adults with persistent/chronic Immune Thrombocytopenia (ITP) (PRTX-100-202 Study). The fourth cohort was initiated after a planned, interim analysis of safety and efficacy data from cohort three. Patient one, based in the U.S., received 12.0 micrograms/kg, double the dose used in the prior cohort of 6.0 micrograms/kg.

PRTX-100 has been granted Orphan Drug Designation in the U.S. and in Europe for the treatment of ITP. The number of clinical trial sites in the 202 Study has been expanded to the U.K to support enrollment and broaden access to the potential patient pool.

The 202 Study is an open-label, dose-escalation study that can enroll patients in up to six cohorts. Under the study protocol, patients receive four weekly intravenous doses of PRTX-100 and are monitored for up to 48 weeks thereafter. The primary endpoint of the 202 Study is a platelet response to PRTX-100. Secondary endpoints include safety, immunogenicity, and pharmacokinetics. Enrollment is currently underway at several clinical sites in the U.S. and in the U.K.

“We are excited to open cohort four in the U.S. and UK, as it demonstrates progress in our evaluation of PRTX-100 in the treatment of ITP, a serious condition that is still under-served from a therapeutic perspective. Opening additional clinical sites in the U.K. will facilitate increased enrollment, and support trial completion within the next several months,” said Richard J. Francovitch, Ph.D., Protalex’s Vice President, ITP Programs. “As noted previously, we are encouraged by the data collected in prior cohorts treated at lower doses. The ability to compare dosing outcomes at multiple levels will inform our next step for the development of PRTX-100.”