fostamatinib and Diarrhea

This phase III, 52-week study compared fostamatinib with placebo (for 24 weeks) in patients with active rheumatoid arthritis (RA) and an inadequate response to methotrexate (MTX) therapy.. Patients taking MTX were randomized (1:1:1) to receive fostamatinib 100 mg twice daily for 52 weeks (group A), fostamatinib 100 mg twice daily for 4 weeks and then 150 mg once daily (group B), or placebo for 24 weeks and then fostamatinib 100 mg twice daily (group C). At week 24, the co-primary end points were change from baseline in the American College of Rheumatology 20% (ACR20) improvement response rates and change in the modified total Sharp/van der Heijde score of radiographic damage (SHS).. In this study, 918 patients were randomized and received ≥1 dose of study drug (fostamatinib or placebo); the demographic and baseline clinical characteristics were well balanced. Following treatment with both fostamatinib regimens, a statistically significant difference in the ACR20 improvement response was achieved at week 24 as compared with that in patients receiving placebo (49.0% [group A] and 44.4%, [group B] versus 34.2%; P < 0.001 and P = 0.006, respectively), but there was no statistically significant difference in the SHS between either fostamatinib group and placebo (P = 0.25 and P = 0.17, respectively). The most common adverse events in patients in groups A, B, and C were hypertension (15.8%, 15.1%, and 3.9%, respectively) and diarrhea (13.9%, 15.1%, and 3.9%, respectively). Elevated blood pressure (≥140/90 mm Hg) occurred at ≥1 visit in 44.2%, 41.6%, and 19.3% of patients in each respective group.. With the use of either fostamatinib regimen in patients with RA, statistically significant, but not clinically significant, improvements in the ACR20 improvement response over placebo were achieved at 24 weeks, whereas a significant difference in the SHS was not seen. The overall level of response to treatment with fostamatinib was lower than had been observed in the phase II program, but similar adverse events were reported.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Aminopyridines; Antirheumatic Agents; Arthritis, Rheumatoid; Diarrhea; Double-Blind Method; Drug Therapy, Combination; Female; Humans; Hypertension; Intracellular Signaling Peptides and Proteins; Male; Methotrexate; Middle Aged; Morpholines; Oxazines; Protein-Tyrosine Kinases; Pyridines; Pyrimidines; Syk Kinase; Treatment Outcome; Young Adult

Certain malignant B cells rely on B-cell receptor (BCR)-mediated survival signals. Spleen tyrosine kinase (Syk) initiates and amplifies the BCR signal. In in vivo analyses of B-cell lymphoma cell lines and primary tumors, Syk inhibition induces apoptosis. These data prompted a phase 1/2 clinical trial of fostamatinib disodium, the first clinically available oral Syk inhibitor, in patients with recurrent B-cell non-Hodgkin lymphoma (B-NHL). Dose-limiting toxicity in the phase 1 portion was neutropenia, diarrhea, and thrombocytopenia, and 200 mg twice daily was chosen for phase 2 testing. Sixty-eight patients with recurrent B-NHL were then enrolled in 3 cohorts: (1) diffuse large B-cell lymphoma (DLBCL), (2) follicular lymphoma (FL), and (3) other NHL, including mantle cell lymphoma (MCL), marginal zone lymphoma (MZL), mucosa-associated lymphoid tissue lymphoma, lymphoplasmacytic lymphomas, and small lymphocytic leukemia/chronic lymphocytic leukemia (SLL/CLL). Common toxicities included diarrhea, fatigue, cytopenias, hypertension, and nausea. Objective response rates were 22% (5 of 23) for DLBCL, 10% (2 of 21) for FL, 55% (6 of 11) for SLL/CLL, and 11% (1/9) for MCL. Median progression-free survival was 4.2 months. Disrupting BCR-induced signaling by inhibiting Syk represents a novel and active therapeutic approach for NHL and SLL/CLL. This trial was registered at www.clinicaltrials.gov as #NCT00446095.

Topics: Adult; Aged; Aged, 80 and over; Aminopyridines; Antineoplastic Agents; Cohort Studies; Diarrhea; Disease-Free Survival; Female; Hematologic Diseases; Humans; Hypertension; Intracellular Signaling Peptides and Proteins; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphoma, Non-Hodgkin; Male; Middle Aged; Morpholines; Neoplasm Proteins; Oxazines; Protein Kinase Inhibitors; Protein-Tyrosine Kinases; Pyridines; Pyrimidines; Salvage Therapy; Syk Kinase; Treatment Outcome