PRTX-100 shows measurable activity in a standard mouse model of autoimmune
arthritis. A substantial body of published literature and proprietary data
delineate the immune-modulatory activities of PRTX-100, which are distinct from
those of current major biologic treatments for rheumatoid
arthritis. Accordingly, we believe that RA represents a potentially important
clinical indication for treatment with PRTX-100. While recent advances in
biologic treatments for RA (with monoclonal antibodies) have improved the
prognosis for many patients, many others continue to live with debilitating RA
disease activity due either to the cost, side-effects, or limited effectiveness
of these newer therapies.
20 The PRTX-100-103 Study
The primary disease activity response endpoint was the number of patients with a DAS28-CRP < 3.2 at week six. The results showed that the PRTX-100 patients as a group had more responders than placebo at all times, that responders increased over time during the 16 week study evaluation period, and that the maximum tolerated dose was not reached at the highest dose level.
Additionally, the results indicated that PRTX-100 did not decrease CRP (C-Reactive Protein) levels, even in those patients whose swollen and tender joint count and global VAS (Visual Analogue Scale) scores had decreased to low levels after treatment. Because of the influence of the CRP component on the DAS28-CRP score, a post-hoc analysis was performed examining changes in the CDAI scores in all patients to remove the influence of changes in CRP. In the placebo, 0.15 micrograms/kg, and 0.45 micrograms/kg dose groups, one out of eight patients in each group attained low disease activity (CDAI ? 10) on two or more consecutive visits. In the 0.90 micrograms/kg and 1.50 micrograms/kg dose groups, two of eight and two of five patients, respectively, attained this same endpoint, and maintained a CDAI < 10 until the week 16 final visit. Of the 4 apparent responders in the 1.50 micrograms/kg group, 2 attained a CDAI ? 6 (remission), one attained a CDAI ? 10 (low activity), and one achieved a CDAI of 10.1 at one or more visits. The mean time to peak response in this group occurred six weeks after their last dose.
As the disease activity results from the PRTX-100-103 Study demonstrated an acceptable safety profile, we commenced the PRTX-100-104 Study in