US-based drug developer Isis Pharmaceuticals has obtained a $10m payment from Biogen Idec for the development of a potential treatment for myotonic dystrophy, a chronic, slowly progressing, highly variable, inherited multisystemic disease.

The funding will be used to develop ISIS-DMPK as a treatment for myotonic dystrophy type I (DM1), a rare genetic disease that causes progressive muscle atrophy, weakness, and disabling muscle spasms.

DM1 is the most common type of muscular dystrophy in adults and is expected to affect about 150,000 patients in the US, Europe, and Japan.

The drug is designed to correct the genetic defect in DM1 caused by the dystrophia myotonica-protein kinase (DMPK) gene.

DMPK gene has three nucleotides that repeat extensively, creating an abnormally long toxic RNA, which accumulates in the cell and prevents the production of proteins needed for normal cellular function.

Developed using antisense technology, ISIS-DMPK Rx targets DMPK to reduce the toxic RNA in the cells.

"In our preclinical studies, we and our collaborators have been able to target the toxic RNA with antisense, remove the toxic RNA and restore normal cell function."

So far, there are no disease-modifying therapies for DM1 patients and the existing treatments are used to manage symptoms and reduce disability.

Previously, Isis Pharma also conducted a study assessing the use of antisense oligonucleotides as a therapeutic approach to target the pathogenic RNA in DM1.

Isis chief operating officer Lynne Parshall said the progress the company has made is evidenced in its spinal muscular atrophy and myotonic dystrophy programs.

"This summer we and Biogen Idec built upon our successful relationship to create a broad strategic alliance that combines our antisense technology with Biogen Idec’s knowledge of neurodegenerative diseases and global reach, with the goal of bringing new drugs to the market to treat patients with neurological disorders," Parshall said.

Isis and Biogen Idec formed an alliance in 2012, under which Isis secured an upfront payment of $12m and is eligible to receive $59m in milestone payments related to the clinical development of ISIS-DMPK, including the $10m milestone payment.

Under the deal, Biogen Idec also has an option to license ISIS-DMPK from Isis up through completion of the Phase II trial.

Isis also expects to get an additional $200m in a license fee and regulatory milestone payments plus double-digit royalties on sales of the drug.

Isis senior vice-president of research Frank Bennett said myotonic dystrophy represents an ideal opportunity for antisense as the disease-causing gene produces a toxic RNA that is not easily targeted with traditional therapeutic approaches.

"In our preclinical studies, we and our collaborators, doctors Charles Thornton and Thurman Wheeler at the University of Rochester, have been able to target the toxic RNA with antisense, remove the toxic RNA and restore normal cell function," Bennett said.