SOUTH SAN FRANCISCO, Calif.,
July 16, 2014 /PRNewswire/ -- Rigel
Pharmaceuticals, Inc. (Nasdaq: RIGL) today announced the initiation
of a Phase 3 clinical program for its oral SYK inhibitor,
fostamatinib, in patients with ITP (immune thrombocytopenic
purpura). The focus of these clinical studies is to evaluate the
potential of fostamatinib to increase the platelet counts of
patients with chronic ITP. Fostamatinib may provide a novel
therapeutic for the underlying cause of this autoimmune disease of
the blood.
"Based on our extensive clinical experience with this product
candidate, which includes more than 4,500 patient-years of data, we
hope to demonstrate that fostamatinib can provide a new treatment
option for patients with chronic ITP," said James M. Gower, chairman and chief executive
officer of Rigel. Results of Rigel's Phase 2 clinical study,
published in Blood (volume 113, number 14), showed
that fostamatinib significantly increased the platelet counts of
certain ITP patients, including those who had failed other
currently available agents.
Fostamatinib in ITP Phase 3 Program Design
A total of
150 ITP patients will be randomized into two identical
multi-center, double-blind, placebo-controlled clinical
studies. The patients will have been diagnosed with
persistent or chronic ITP, and have blood platelet counts
consistently below 30,000 per microliter of blood. Two thirds of
the subjects will receive fostamatinib orally at 100 mg bid (twice
daily), the other third will receive placebo on the same
schedule. Subjects are expected to remain on treatment for 24
weeks. At week 4 of treatment, subjects who meet certain platelet
count and tolerability thresholds will have their dosage of
fostamatinib (or corresponding placebo) increased to 150 mg
bid.
The primary efficacy endpoint of this program is a stable
platelet response by week 24 with platelet counts at or above
50,000 per microliter of blood for at least 4 of the final 6
qualifying blood draws. Results are expected at
year-end 2015.
Immune Thrombocytopenic Purpura
Chronic ITP affects an
estimated 60,000 – 125,000 people in the US. In patients with ITP,
the immune system attacks and destroys the body's own blood
platelets, which play an active role in blood clotting and
healing. ITP patients can suffer extraordinary bruising,
bleeding and fatigue as a result of low platelet counts.
Current therapies for ITP include steroids, blood platelet
production boosters (TPOs) and splenectomy. Fostamatinib is
the only potential therapy that may address the autoimmune basis of
the disease.
Taken in tablet form, fostamatinib blocks the activation of SYK
kinase inside immune cells. ITP causes the body to produce
antibodies that attach to healthy platelets in the blood stream.
Immune cells recognize these antibodies and affix to them, which
activates the SYK enzyme inside the immune cell, and triggers the
destruction of the antibody and the attached platelet. When SYK is
inhibited by fostamatinib, it interrupts this immune cell function
and allows the platelets to escape destruction.
About Rigel (www.rigel.com)
Rigel Pharmaceuticals,
Inc. is a clinical-stage drug development company that discovers
and develops novel, small-molecule drugs for the treatment of
inflammatory and autoimmune diseases, as well as muscle disorders.
Rigel's pioneering research focuses on intracellular signaling
pathways and related targets that are critical to disease
mechanisms. Rigel currently has five product candidates in
development: fostamatinib, an oral SYK inhibitor in Phase 3
clinical trials for ITP and expected to enter into a Phase 2
clinical trial for IgA nephropathy in the second half of 2014;
R348, a topical JAK/SYK inhibitor currently in Phase 2 clinical
trials for dry eye; R118, an AMPK activator in Phase 1 development;
and two oncology product candidates in Phase 1 development with
partners BerGenBio and Daiichi Sankyo.
This press release contains "forward-looking" statements,
including, without limitation, statements related to Rigel's
clinical development plans, including the timing, design and nature
of planned clinical trials and the timing and nature of results of
those trials, as well as the potential activity of fostamatinib
with respect to ITP and the ability of fostamatinib to provide a
new treatment option for patients with chronic ITP. Any
statements contained in this press release that are not statements
of historical fact may be deemed to be forward-looking statements.
Words such as "planned," "will," "may," "expect," and similar
expressions are intended to identify these forward-looking
statements. These forward-looking statements are based on
Rigel's current expectations and inherently involve significant
risks and uncertainties. Actual results and the timing of events
could differ materially from those anticipated in such forward
looking statements as a result of these risks and uncertainties,
which include, without limitation, the availability of resources to
develop Rigel's product candidates, Rigel's need for additional
capital in the future to sufficiently fund Rigel's operations and
research, the uncertain timing of completion of and the success of
clinical trials, market competition, risks associated with and
Rigel's dependence on Rigel's corporate partnerships, as well as
other risks detailed from time to time in Rigel's reports filed
with the Securities and Exchange Commission, including its
Quarterly Report on Form 10-Q for the quarter ended
March 31, 2014. Rigel does not
undertake any obligation to update forward-looking statements and
expressly disclaims any obligation or undertaking to release
publicly any updates or revisions to any forward-looking statements
contained herein.
Contact: Raul Rodriguez
Phone: 650.624.1302
Email: invrel@rigel.com
Media Contact: Susan C. Rogers,
Rivily, Inc.
Phone: 650.430.3777
Email: susan@rivily.com
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SOURCE Rigel Pharmaceuticals, Inc.