Santhera Pharmaceuticals says it intends to file for regulatory approval of its lead product, Catena®, as a treatment for Leber hereditary optic neuropathy (LHON) on the back of positive results from a single Phase II trial in 85 patients. Data from the six-month Rhodos study showed that Catena consistently led to benefits across all endpoints related to visual acuity.
The results must have come as something of a relief for Santhera, which in May reported that a pivotal Phase III trial with Catena in Friedreich ataxia patients missed its primary endpoint.
The LHON trial was the first-ever placebo-controlled study in patients with the rare genetic eye disease and the second largest trial to be carried out with Catena. Although Rhodos was originally designed as a proof of concept study, Santhera says it now aims to discuss filing strategies with FDA and the European health authorities. The firm projects making regulatory submissions during the first half of 2011.
“Conducting another placebo-controlled trial in such a rare and progressive disorder after evidence of efficacy will be difficult if not impossible,” remarks Klaus Schollmeier, Ph.D., CEO. “We intend to file for marketing approval with these data as expeditiously as possible.”
Catena is a small molecule compound that has already been approved in Canada for the treatment of Friedreich ataxia. The drug is in addition available to individual patients through named patient programs in Europe, Switzerland, and certain other non-U.S. countries. Catena is in parallel undergoing Phase III trials for the Friedreich ataxia indication. A separate Phase III program is investigating the drug for the treatment of Duchenne muscular dystrophy. Phase II trials are evaluating Catena for the treatment of MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes) syndrome and for the treatment of primary progressive multiple sclerosis.
The failure of Catena in the Phase III Miconos trial in Friedreich ataxia was “a major setback for us and the whole Friedreich ataxia community,” admitted Santhera’s CSO Thomas Meier, Ph.D., at the time. “However, we now have results from three clinical studies which, when combined, show a trend for superiority of Catena compared to placebo.” The firm is now waiting for data from two ongoing extension studies before deciding on how to proceed with the Friedreich ataxia development program. Its second lead compound, fipamezole, has successfully completed a Phase IIb study as a treatment for reducing levodopa-induced dyskinesia in Parkinson disease patients.