Protalex, Inc. (PRTX) Fourth Cohort Dosing of Phase 1/2 Study of PRTX-100 in Immune Thrombocytopenia


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

Protalex, Inc. (PRTX), a clinical-stage biopharmaceutical company, today 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.”

About Immune Thrombocytopenia (ITP)

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.

About PRTX-100

PRTX-100, a new generation immunomodulatory therapy, 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. The two most recently approved drugs used to treat ITP, Nplate® (romiplostin) and Promacta®/Revolade™ (eltrombopag) both increase the production of platelets but do not appear to affect the underlying platelet destruction process. The safety, tolerability, and pharmacokinetics of PRTX-100 have been characterized in six clinical studies, and PRTX-100 has been granted Orphan Drug Designation in the U.S. and Europe for the treatment of ITP. In two Phase 1b clinical trials in adult patients with active Rheumatoid Arthritis (RA), PRTX-100 was generally safe and well tolerated at all dose levels, and at certain higher doses, more patients showed improvement in measures of RA disease activity than did patients at the lower dose or placebo cohorts. PRTX-100 is given as a short intravenous infusion.

Nplate® is a registered trademark of Amgen, Inc. and Promacta®/Revolade™ are registered trademarks of Novartis AG.

About Protalex, Inc.

Protalex, Inc. is a clinical-stage biopharmaceutical company focused on the development of a class of drugs for treating autoimmune and inflammatory diseases including RA and Immune Thrombocytopenia (ITP). In the U.S., Protalex has open INDs for the treatment of RA and ITP and in Europe, an open IMPD for ITP. Please visit the Protalex website at to learn more about Protalex and its lead drug candidate, PRTX-100.


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