TEL AVIV, Israel Ester Neurosciences said it received regulatory approval in Europe and Israel to conduct Phase Ib trials of EN101, a novel antisense drug for the treatment of myasthenia gravis (MG).

EN101 is the lead compound in Ester’s disease-modifying platform technology for the pre-expression control of the AChE protein, which is applicable to a range of neurological disorders.

The technology is based on balancing cholinergic transmission via controlled modulation of the company’s novel target, a stress-response protein variant of acetylcholinesterase (AChE), a degrading enzyme of the neurotransmitter acetylcholine.

“Ester chose myasthenia gravis as the first indication for its technology due to the relatively rapid and straightforward endpoints, which will allow for conclusive data within three months from the commencement of the study,” said Solli Brawer, director of clinical and regulatory affairs.

Oded Ben-Joseph, Ester’s president, said, “EN101 selectively inhibits the production of the target, a specific stress-response variant of AChE [AChE-R], at the level of transcription before its synthesis to protein, making effective treatment of MG possible for over 40 hours and with minimal side effects, unlike treatments currently in use.

Ben-Joseph said conventional inhibitors are effective for only three to four hours, forcing MG patients to re-medicate four to six times daily.

Ester is targeting various neurological disorders in which AChE-R plays a key pathological role, including Alzheimer’s disease, Parkinson’s disease and head injury. A Science article by Ester scientists in the Jan. 18, 2002, issue provided evidence for the stress-induced accumulation of the AchE-R, “suggesting that its control may also provide a therapeutic benefit for the treatment of post-traumatic stress and other stress-related disorders,” said Mona Soreq, Ester’s chief scientific adviser.