Protalex, Inc. (PRTX), a clinical-stage biopharmaceutical company, today announced preliminary findings following completion of its Phase I/II open-label, single group study with former participants from its U.S.-based PRTX-100-104 Study. In this continuation study (“PRTX-100-105 Study”), rheumatoid arthritis (RA) patients received a fixed dose of PRTX-100 over a 6-month period in combination with either methotrexate or leflunomide.
PRTX-100, Protalex’s lead drug candidate, is a highly purified form of Staphylococcal protein A (SpA) and has been the subject of ongoing clinical development in both RA and Immune Thrombocytopenia (ITP). PRTX-100 was recently granted Orphan Drug Designation in the U.S. and in Europe for the treatment of ITP and is currently the subject of clinical studies in both the U.S. and Europe.
Eight of eleven patients in the 105 Study completed the study per protocol, which consisted of four weekly doses, followed by five monthly doses of PRTX-100 over a 6-month period at a single site in the U.S. The primary study endpoint of the 105 Study was the safety and tolerability of a fixed dose of PRTX-100 administered over an extended period. The secondary endpoints included immunogenicity, effects on measures of RA disease activity, evaluation of anti-PRTX-100 antibody presence, and feasibility of joint evaluations with ultrasound and biomarkers as disease markers.
A preliminary interim analysis indicated that for patients who completed per protocol, PRTX-100 exhibited an acceptable safety profile and RA disease activity was improved in a majority of patients at the end of the study as compared to baseline. No serious adverse events (SAEs) were reported. At study day 196, one month after the final dose, patients who completed the study per protocol demonstrated a mean reduction of the DAS28CRP score from 5.25 to 2.52, suggesting a clinically meaningful improvement in disease activity. Additionally, clinical assessment by Ultrasound Power Doppler Joint Counts (UPD), also revealed a reduction in average disease severity by day 196, and the correlation between the UPD and the DAS28CRP was r=0.624 (p<.0005).
William E. Gannon, Jr., M.D., Protalex’s Chief Medical Officer, commented on the 105 Study’s findings, “Our ongoing development program is focused on determining whether PRTX-100 modifies the disease course of RA with an improved safety profile and a dosing regimen comparable to current therapies such as the Humira®, Enbrel® and Remicade®, all of which can provoke adverse events. The 105 Study data are consistent with trends we saw in prior RA trials of PRTX-100. Additionally, incorporation of ultrasound joint count technology into small open-label trials may offer enhanced assessment of clinical efficacy.”
The Company expects to submit the final clinical report to the FDA in the next several months.
PRTX-100 is a new generation immunomodulatory therapy which has the ability, at very low concentrations, to bind to human B-lymphocytes and macrophages and to modulate immune processes. The safety, tolerability and pharmacokinetics of PRTX-100 have been characterized in six clinical studies. In three Phase 1b clinical trials in adult patients with active 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 administered as a short intravenous infusion.
Humira® is a registered trademark of Abbvie, Enbrel® is a registered trademark of Amgen and Remicade® is a registered trademark of Janssen Biotech.
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 ITP. In the U.S., Protalex has open INDs for the treatment of RA and ITP and in Europe, an open IMPD for ITP. PRTX-100 was granted orphan drug status for ITP both by the US FDA and by the European regulatory bodies. Please visit Protalex’s website at www.protalex.com to learn more about Protalex and its lead drug candidate, PRTX-100.