FLORHAM PARK, N.J.—Protalex, Inc., a clinical-stage biopharmaceutical company, announced today that they have 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.
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. 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 is a highly purified form of SpA, an immunomodulatory protein known to modify aspects of the human immune system. PRTX-100 has the ability, at very low concentrations, to bind to human B-lymphocytes and macrophages and to modulate immune processes. Pre-clinical data indicate that PRTX-100 may have the potential to treat ITP by reducing the immune-mediated destruction of the platelets. PRTX-100 is given as a short intravenous infusion.
ITP is an autoimmune condition characterized by bruising and increased bleeding due to immune-mediated accelerated destruction of platelets and impaired production of platelets. The diagnosis of ITP is based upon a low platelet count, usually less than 100,000 per microliter of blood, in the absence of other possible causes of reduced platelet numbers such as an underlying illness or medication.
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.
“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.”