Eli Lilly and devices specialist Medtronic have entered into a collaboration using “a new approach to treating Parkinson's disease” that involves delivering a medicine to the brain using an implantable drug delivery system.

The approach the companies will adopt “combines the strengths of Lilly's biologic, a modified form of glial cell derived neurotrophic factor (GDNF), with Medtronic's implantable drug infusion system technology”, the partners claimed. Lilly says it has designed its GDNF variant “with the intent to achieve increased distribution in targeted brain regions”, while Medtronic has developed a drug pump and catheter “to enable precise delivery of the GDNF variant…consistently over time”. The idea is that this combination “has the potential to impact the neurodegeneration that leads to worsening symptoms and progression of Parkinson's”.

Delivering GDNF to the brain has proved extremely difficult for a number of companies. In 2004, Amgen abandoned clinical trials of its experimental GDNF product, which used Medtronic technology, after safety risks, including irreversible brain damage, were observed amongst trial patients.

However, Michael Hutton, chief scientific officer of the neurodegeneration team at Lilly, says “we believe we have biosynthetically engineered this GDNF variant to overcome technical hurdles of previous research in this area”. He added that the company is  hopeful that “early testing of our biologic with Medtronic's device will provide the necessary data to safely advance into human studies”.

Steve Oesterle, head of medicine and technology at Medtronic, noted that "one of the most significant challenges in delivering a biologic treatment for neurodegenerative diseases is crossing the blood brain barrier”. He claimed that “we have extensive experience in targeted drug delivery and technology that allow delivery of therapeutic agents directly to the brain”.

News of the alliance was met with optimism by patient groups and Katie Hood, chief executive of the Michael J Fox Foundation for Parkinson's Research, said that “while a potential treatment approach resulting from this research is many years away, we are heartened by Lilly and Medtronic's commitment to develop a neurotrophic-based therapy “. She noted that the foundation has funded separate, ongoing work in neurotrophic factors  “for years, and we continue to believe in their promise to lead to a critically needed disease-modifying treatment for Parkinson's”.