Apitope, a drug discovery and development company focused on treating the underlying cause of autoimmune diseases, announced that its partner, Merck Serono, has completed patient enrollment for the phase IIa study of ATX-MS-1467 (also known as M2736), an investigational immune-tolerising agent.

It is currently being tested in an open-label, one-arm proof-of-principle trial to evaluate its safety and effect on immune tolerance in subjects with relapsing multiple sclerosis (MS). The study involves frequent neuroimaging using magnetic resonance imaging (MRI). The outcome of the study is expected in 2016.

Dr. Keith Martin, chief executive officer of Apitope, commented, “We are pleased that Merck Serono has completed recruitment into a challenging clinical trial. The results of this trial in patients with relapsing MS will hopefully continue to build on the positive data from our first two studies. It will also potentially provide further clinical support for Apitope’s approach in the treatment of serious autoimmune conditions.”

ATX-MS-1467 is a potential novel treatment developed with the aim of working with the immune system to treat the underlying cause of the disease by restoring immunological balance, instead of only treating the symptoms or suppressing the entire immune system. It consists of four synthetic peptides that mimic naturally occurring peptides derived from human Myelin Basic Protein (MBP), a key autoantigen in multiple sclerosis. ATX-MS-1467 has been designed from naturally occurring MBP fragments and is intended to selectively inhibit the immune system's harmful attack on the protective myelin sheath surrounding the nervous cells while preserving the normal immune response to any harmful antigens, such as infections.

Apitope has already successfully completed a phase I clinical trial in six patients with secondary progressive MS (SPMS) and a second phase I trial in 43 relapsing MS patients, assessing safety as well as biological parameters. Examination of the MRI results (new gadolinium and total gadolinium enhancing lesions) demonstrated a significant decrease of 78 per cent in the number of contrast-enhancing brain lesions in patients with relapsing MS treated by intradermal injection of ATX-MS-1467.

Apitope is developing ATX-MS-1467 with Merck Serono, a market leader in the treatment of multiple sclerosis. Under the terms of the agreement, Merck Serono will complete all development activities from the beginning of phase II clinical trials.

MS is a chronic, inflammatory condition of the nervous system and is the most common, non-traumatic, disabling neurological disease in young adults, with most sufferers developing the disease between the ages of 20 and 40 years. The World Health Organisation estimates that up to 2.5 million people suffer from MS worldwide with women affected 1.8 times more frequently than men. While symptoms can vary, the most common symptoms of MS include blurred vision, numbness or tingling in the limbs and problems with strength and coordination.

MS develops as a result of damage to the myelin sheath of the nerves which interferes with their normal function and leads to loss of muscle control. MS can follow various patterns of disease progression. Most patients initially have a relapsing form of the condition, which is characterized by unpredictable relapses followed by periods of months to years of remission. Approximately two-thirds of patients with relapsing disease go on to develop secondary progressive MS, in which progressive neurologic decline continues between acute attacks without any periods of remission.