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Genovese M.C.,Stanford University | Kavanaugh A.,University of California at San Diego | Weinblatt M.E.,Harvard University | Peterfy C.,Spire science | And 5 more authors.
Arthritis and Rheumatism | Year: 2011

Objective To assess the efficacy and safety of R788 (fostamatinib disodium), an inhibitor of spleen tyrosine kinase (Syk), in patients with active rheumatoid arthritis (RA) that did not respond to biologic therapies. Methods. A total of 219 patients with active RA in whom treatment with biologic agents had failed were enrolled in a 3-month multicenter, randomized, double-blind, placebo-controlled trial of R788. The primary end point was the percentage of patients who met the American College of Rheumatology 20% improvement criteria (achieved an ACR20 response) at month 3. Secondary end points included changes in inflammation and damage, as assessed by magnetic resonance imaging (MRI), and changes in the Disease Activity Score. Results. The ACR20 response in the R788 100 mg twice daily group was 38%, versus 37% in the placebo group, at month 3. No significant differences were achieved in the ACR20, ACR50, or ACR70 response levels at 3 months. There were differences between the groups from baseline to month 3 in the secondary end points C-reactive protein (CRP) level and synovitis score on MRI. There were baseline differences in steroid use, prior biologic use, and synovitis score on MRI between the R788 group and the placebo group that may have affected the outcomes. A high placebo response rate was seen in this trial, and exploratory analysis suggested that this may in part have been driven by patients who entered the trial with an elevated erythrocyte sedimentation rate but normal CRP level. Conclusion. Our findings indicate that there were no differences in the primary end point between the R788 and placebo groups. Differences were observed between the R788 and placebo groups in secondary end points, particularly in those patients who entered the study with an elevated CRP level. © 2011 by the American College of Rheumatology.

Holland S.J.,Rigel Inc | Pan A.,Rigel Inc | Franci C.,Rigel Inc | Hu Y.,Rigel Inc | And 16 more authors.
Cancer Research | Year: 2010

Accumulating evidence suggests important roles for the receptor tyrosine kinase Axl in cancer progression, invasion, metastasis, drug resistance, and patient mortality, highlighting Axl as an attractive target for therapeutic development. We have generated and characterized a potent and selective small-molecule inhibitor, R428, that blocks the catalytic and procancerous activities of Axl. R428 inhibits Axl with low nanomolar activity and blocked Axl-dependent events, including Akt phosphorylation, breast cancer cell invasion, and proinflammatory cytokine production. Pharmacologic investigations revealed favorable exposure after oral administration such that R428-treated tumors displayed a dose-dependent reduction in expression of the cytokine granulocyte macrophage colony-stimulating factor and the epithelial-mesenchymal transition transcriptional regulator Snail. In support of an earlier study, R428 inhibited angiogenesis in corneal micropocket and tumor models. R428 administration reduced metastatic burden and extended survival in MDAMB-231 intracardiac and 4T1 orthotopic (median survival, >80 days compared with 52 days; P < 0.05) mouse models of breast cancer metastasis. Additionally, R428 synergized with cisplatin to enhance suppression of liver micrometastasis. Our results show that Axl signaling regulates breast cancer metastasis at multiple levels in tumor cells and tumor stromal cells and that selective Axl blockade confers therapeutic value in prolonging survival of animals bearing metastatic tumors. ©2010 AACR.

Duncton M.A.J.,Evotec | Duncton M.A.J.,Rigel Inc
MedChemComm | Year: 2011

The addition of a radical to a heteroaromatic base is commonly referred to as a Minsici reaction. Such reactions constitute a broad-set of selective CH-functionalization processes. This review describes some of the major applications of Minisci reactions and related processes to medicinal or biological chemistry, and highlights some potential developments within this area. © 2011 The Royal Society of Chemistry.

Sweeny D.J.,Rigel Inc | Li W.,Rigel Inc | Clough J.,Rigel Inc | Bhamidipati S.,Rigel Inc | And 5 more authors.
Drug Metabolism and Disposition | Year: 2010

The metabolism of the spleen tyrosine kinase inhibitor N4-(2,2-dimethyl-3- oxo-4-pyrid[1,4]oxazin-6-yl)-5-fluoro-N2-(3,4,5-trimethyoxyphenyl)-2, 4-pyrimidinediamine (R406) and its oral prodrug N4-(2,2-dimethyl-4- [(dihydrogenphosphonoxy)methyl]-3-oxo-5-pyrid[1,4]oxazin-6-yl)-5-fluoro-N2-(3,4, 5-trimethyoxyphenyl)-2,4-pyrimidinediamine disodium hexahydrate (R788, fostamatinib) was determined in vitro and in humans. R788 was rapidly converted to R406 by human intestinal microsomes, and only low levels of R788 were observed in plasma of human subjects after oral administration of 14C-R788. R406 was the major drug-related compound in plasma from human subjects, and only low levels of metabolites were observed in plasma. The plasma metabolites of R406 were identified as a sulfate conjugate and glucuronide conjugate of the para-O-demethylated metabolite of R406 (R529) and a direct N-glucuronide conjugate of R406. Elimination of drug-related material into the urine accounted for 19% of the administered dose, and the major metabolite in urine from all the human subjects was the lactam N-glucuronide of R406. On average, 80% of the total drug was recovered in feces. Two drug-related peaks were observed; one peak was identified as R406, and the other peak was identified as a unique 3,5-benzene diol metabolite of R406. The 3,5-benzene diol metabolite appeared to result from the subsequent O-demethylations and dehydroxylation of R529 by anaerobic gut bacteria because only R529 was converted to this metabolite after the in vitro incubation with human fecal samples. These data indicate that the major fecal metabolite of R406 observed in humans is a product of a hepatic cytochrome P450-mediated O-demethylation and subsequent O-demethylations and dehydroxylation by gut bacteria. Copyright © 2010 by The American Society for Pharmacology and Experimental Therapeutics.

trans-2-(Trifluoromethyl)cyclopropylboronic acid N-methyliminodiacetic acid (MIDA) ester 5 was synthesized as a pure diastereomer from vinylboronic acid MIDA ester and (trifluoromethyl)diazomethane in a single step. An X-ray study confirmed the trans-stereochemistry around the cyclopropyl ring. Use of 5 in Suzuki reactions, with a variety of aryl or heteroaryl coupling partners, provided trans-2-(trifluoromethyl)cyclopropyl products in moderate to excellent yields (17-90%). © 2013 American Chemical Society.

Weinblatt M.E.,Harvard University | Kavanaugh A.,University of California at San Diego | Genovese M.C.,Stanford University | Musser T.K.,Rigel Inc | And 2 more authors.
New England Journal of Medicine | Year: 2010

BACKGROUND: Spleen tyrosine kinase (Syk) is an important modulator of immune signaling. The objective of this phase 2 study was to evaluate the efficacy and safety of R788, an oral inhibitor of Syk, in patients with active rheumatoid arthritis despite methotrexate therapy. METHODS: We enrolled 457 patients who had active rheumatoid arthritis despite long-term methotrexate therapy in a 6-month, double-blind, placebo-controlled trial. The primary outcome was the American College of Rheumatology (ACR) 20 response (which indicates at least a 20% reduction in the number of both tender and swollen joints and improvement in at least three of five other criteria) at month 6. RESULTS: R788, at a dose of 100 mg twice daily and at a dose of 150 mg once daily, was significantly superior to placebo at month 6 (ACR 20 response rates of 67% and 57%, respectively, vs. 35%; P<0.001 for the comparison of both doses with placebo). It was also significantly superior with respect to ACR 50, which indicates at least a 50% improvement (43% and 32% vs. 19%; P<0.001 for the comparison of the 100-mg dose with placebo, P = 0.007 for the comparison of the 150-mg dose with placebo) and ACR 70 (28% and 14% vs. 10%; P<0.001 for the comparison of the 100-mg dose with placebo, P = 0.34 for the comparison of the 150-mg dose with placebo). A clinically significant effect was noted by the end of the first week of treatment. Adverse effects included diarrhea (in 19% of subjects taking the 100-mg dose of R788 vs. 3% of those taking placebo), upper respiratory infections (14% vs. 7%), and neutropenia (6% vs. 1%). R788 was associated with an increase in systolic blood pressure of approximately 3 mm Hg between baseline and month 1, as compared with a decrease of 2 mm Hg with placebo; 23% of the patients taking R788 vs. 7% of the patients receiving placebo required the initiation of or a change in antihypertensive therapy. CONCLUSIONS: In this phase 2 study, a Syk inhibitor reduced disease activity in patients with rheumatoid arthritis; adverse events included diarrhea, hypertension, and neutropenia. Additional studies will be needed to further assess the safety and efficacy of Syk-inhibition therapy in patients with rheumatoid arthritis. Copyright © 2010 Massachusetts Medical Society. All rights reserved.

This invention is directed to compounds of formula (I): where n, m, Y, R^(1), R^(2), R^(3), R^(4 )and R^(5 )are disclosed herein, as isolated stereoisomers or mixtures thereof, or pharmaceutically acceptable salts thereof; pharmaceutical compositions comprising the compounds of formula (I); and methods of using the compounds and the pharmaceutical compositions in treating diseases or conditions associated with JAK2 activity.

News Article | November 1, 2016

SOUTH SAN FRANCISCO, Calif., Nov. 1, 2016 /PRNewswire/ -- Rigel Pharmaceuticals, Inc. (Nasdaq:RIGL) today reported financial results for the third quarter and nine months ended September 30, 2016. During the third quarter of 2016, Rigel accomplished a number of noteworthy milestones, m...

News Article | November 10, 2016

SOUTH SAN FRANCISCO, Calif., Nov. 10, 2016 /PRNewswire/ -- Rigel Pharmaceuticals, Inc. (Nasdaq: RIGL) today announced that Raul Rodriguez, the company's president and chief executive officer, is scheduled to present a company overview at the Jefferies 2016 London Healthcare Conference on...

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