Rigel Suffers More Clinical Trial Disappointments

Rigel Pharmaceuticals said it will not initiate any new studies of R348 for the treatment of dry eye disease, after the compound failed to meet its primary and secondary endpoints in a recently completed Phase II trial.

The San Francisco drugmaker will, however, continue its Phase II study of dry eye in patients with graft versus host disease.

The endpoints were measured by changes in corneal fluorescein staining, tear production and dry eye symptoms over 12 weeks compared with a placebo, the company said.

Rigel also halted development of R118 — an AMP-activated protein kinase inhibitor intended to treat peripheral artery disease — due to its side effect profile in a Phase I clinical trial.
The latest setbacks are “disappointing,” but not back-breaking for the company, says Brian Abrahams, a senior analyst with Wells Fargo.

“We believe expectations were relatively low for the [R348] program given historical challenges in this indication,” he writes in a Wednesday research note. The company’s efforts to develop a compound called fostamatinib could help soften the blow, he adds.

Rigel recently started a Phase III trial of fostamatinib to treat patients with immune thrombocytopenic purpura, a bleeding disorder. A Phase II study of patients with the kidney autoimmune disease IgA Nephropathy is expected to launch by the end of this year.

Abrahams notes that fostamatinib already has an established safety profile.
AstraZeneca handed the rights to fostamatinib to Rigel last year after a late-stage trial for rheumatoid arthritis showed mixed results.

Rigel is no stranger to drug development setbacks. Last year, the company ditched a compound called R333 to treat skin lesions in patients with discoid lupus erythematosus because a Phase II trial didn’t meet an endpoint.

Rigel posted a net loss of $47.7 million for the first six months of 2014, according to its most recent financial report.

The drugmaker did not return a request for comment by press time. — Robert King

Originally appeared in Drug Industry Daily, the pharmaceutical industry’s number one source for regulatory news and information. Click here for more information.