Aug 30 2012
Protalex, Inc. (OTCBB: PRTX), a clinical stage biopharmaceutical company
focused on the development of a class of drugs designed to treat
autoimmune and inflammatory diseases including rheumatoid arthritis
(RA), today announced results from its recently completed Phase 1b
randomized, multiple-dose, dose-escalation study. The study conducted in
South Africa of PRTX-100 in adult patients with active RA demonstrated
that the drug was generally safe and well-tolerated at all dose levels
and at the higher doses, more patients showed improvement in their CDAI
(Clinical Disease Activity Index for RA) than did patients at the lower
dose or placebo cohorts.
A total of 37 patients who had active RA on methotrexate were enrolled
in four dose-escalating cohorts ranging from 0.15 μg/kg to 1.50 μg/kg
PRTX-100 or placebo, administered weekly for four weeks. Safety and
disease activity were evaluated over sixteen weeks following the first
dose. 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 sixteen week study evaluation period, and that the
maximum tolerated dose was not reached at the highest dose level.
Additionally, in this study 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 CRP is a statistically important
component of the DAS28-CRP score, we performed a post-hoc analysis using
CDAI scores, which do not include CRP. In the placebo, 0.15 µg/kg, and
0.45 µg/kg dose groups, one of eight patients in each group attained low
disease activity (CDAI ≤10) on two or more consecutive visits. In the
0.90 µg/kg and 1.50 µg/kg dose groups, two of eight and two of five
patients, respectively, attained this same endpoint, and maintained a
CDAI < 10 through the week sixteen final visit. Of the four apparent
responders in the 1.50 µg/kg group, two 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 previously noted, the initial disease activity results demonstrated
an acceptable safety profile and at the higher dose levels, more
patients showed improvement as scored by the CDAI. These results warrant
further study of PRTX-100 at doses of 1.50 µg/kg and higher, and the
next trial which will have study centers in both the U.S. and South
Africa, should provide a better understanding of safety and treatment
effect on RA disease activity measurements. The new trial should also
help us define the optimal dose", stated William E. Gannon, Jr.,
M.D., Chief Medical Officer of Protalex.
Patient enrollment in the first cohort of the new study is expected to
commence later in the 4th quarter of 2012.
New study reveals silent onset of rheumatoid arthritis