Pipeline update:
>>SOUTH SAN FRANCISCO, Calif., July 6 /PRNewswire-FirstCall/ -- Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL - News) today provided an update on its hepatitis C virus (HCV) program and its clinical development and research pipeline.
"We are extremely pleased with the progress of our clinical and research programs," said James M. Gower, chairman and chief executive officer of Rigel, "and we remain committed to initiating clinical trials with at least one new product candidate each year, and believe our pre-clinical pipeline is a robust source for such candidates."
HCV Program Update
Rigel will undertake the development of other chemical scaffolds in its hepatitis C virus (HCV) polymerase inhibitor program, because preliminary findings from pre-clinical studies of a pro-drug of R803 showed insufficient bioavailability. Rigel has alternative chemical scaffolds that may have better bioavailability and will seek to bring those forward into pre-clinical studies during 2006.
"We believe we have a great program against the HCV polymerase target and chemical scaffolds with excellent potential, and we will pursue these rather than the R803 approach," said James M. Gower, chairman and chief executive officer of Rigel.
Results from a previous Phase I/II study of R803 indicated that the drug was well-tolerated with no major adverse side effects; however the study showed that the drug was only present in the blood stream for a limited number of hours during the course of each dosing day which was insufficient to produce a meaningful antiviral effect.
Clinical Program Review
"We anticipate an exciting second half of 2005, as we initiate the next phase of testing with our allergy and rheumatoid arthritis product candidates, and we look forward to updating the scientific and investor communities with our progress on these efforts," said Elliott D. Grossbard, M.D., Rigel's senior vice president of medical development.
Outline of Second Phase II Study for R112
Rigel's lead product candidate, R112, continues to show strong potential for the treatment of allergic rhinitis, which causes chronic congestion and general inflammation of the upper respiratory tract in more than 59 million people in the United States. Rigel expects to commence a second, longer-term, double-blind, randomized Phase II trial of R112 in the third quarter, coinciding with the summer and fall pollen season. The trial will assess and compare the safety and efficacy of R112 over a seven-day period versus placebo and versus a nasal steroid. The study will take place at 25 sites across the United States, with approximately 375 patients with symptomatic seasonal allergic rhinitis. Patients will be assessed based on a scale of five nasal symptoms during the seven-day period. In addition to safety measurements, the objective of the study is to show superiority over placebo and non-inferiority to the nasal steroid, though possibly with a faster onset in symptom relief. Data from this trial is expected in the fourth quarter of 2005.
R112 demonstrated statistically significant efficacy in ameliorating symptoms of allergic rhinitis, including sneezing, stuffy nose, running nose, itchy nose, itchy throat, post nasal drip, cough, headache and facial pain, and had a rapid onset of action as early as 30-45 minutes in an earlier Phase II "park study" clinical trial over a two day period. In all clinical studies to date, R112 has been shown to have a favorable safety profile.
R406/788 Begins Further Clinical Studies
Rigel has initiated a study of R406/788 in a single center, double-blind, randomized, placebo-controlled trial to investigate the safety and pharmacokinetics of escalating single and multiple doses of an oral solid dosage formulation of R406 called R788 (and sometimes referred to as R406/788). The sequential four-part study will be conducted with approximately 60 healthy volunteers. The results from this study are expected later this year. We plan to initiate further clinical studies in the fall of this year. We anticipate that these results will allow us to enter broader, longer-term safety, efficacy, and pharmacokinetic studies in early 2006.
Results of a Phase I trial of R406 demonstrated a favorable safety profile and generated pharmacokinetic and pharmacodynamic data that established a correlation between R406 plasma levels and the inhibition of its target.
Rheumatoid arthritis is a chronic inflammatory disease that progressively destroys joint cartilage and bone, and affects nearly 2.1 million Americans. Current treatments have significant potential side effects, and most patients eventually require some form of disease modifying anti-rheumatic drug, or DMARD. Based on previous studies of R406/788, Rigel believes it may have the potential to provide rheumatoid arthritis patients an oral DMARD with a favorable safety profile that can be used earlier in the course of the disease than currently available DMARDs, which may prevent bone and cartilage destruction that occurs as the disease progresses.
Pipeline Opportunities and Advancements
"Rigel's highly productive research team continues to discover and validate new targets in our therapeutic areas," said Donald G. Payan, M.D., executive vice president and chief scientific officer of Rigel. "We remain on track to deliver on our strategy of initiating clinical trials with at least one new product candidate each year -- this year will be our fourth year in accomplishing this goal."
R763, a potent, highly-selective, small-molecule inhibitor of aurora kinase, has been identified as a lead product candidate for Rigel's cancer program. Aurora kinase plays a central role in the cell division process, and the over expression of aurora kinase can cause cells to quickly form an abnormal number of chromosomes. As such, aurora kinase is frequently associated with various solid and hematological human cancers, such as cancers of the breast, bladder, colon, ovary, head and neck and pancreas. Rigel expects to file an IND for R763 by the end of 2005.
Rigel's collaborative research and license agreement with Pfizer, which was announced earlier this year, is focused on the development of inhaled products for the treatment of allergic asthma and other respiratory diseases, and a product candidate for the treatment of asthma is expected to be identified in 2006.
Later this year Rigel expects to have announcements in its other pre-clinical programs, specifically in immunology and oncology, which are expected to result in INDs in 2006 and beyond.<<
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Cheers, Tuck |
