Pfizer has bought itself an exclusive, worldwide option to license MedGenesis’ glial cell line-derived neurotrophic factor (GDNF) protein and convection enhanced delivery (CED) technology for use in researching Parkinson's disease treatments. 

GDNF is a growth factor known to support the survival of many different types of brain cell, including those lost in Parkinson’s, and despite an early glitch in clinical development which put the drug in limbo for many years, researchers believe it has the potential to halt disease progression.

According to MedGenesis, GDNF has established disease-modifying efficacy in all key animal models of Parkinson’s disease, having displayed neuroprotection, axonal sprouting, and improved motor function in preclinical research. Two open label Phase I studies gave positive results that were sustained “well beyond the end of treatment”, but a subsequent placebo-controlled Phase II study failed to confirm efficacy, it said.

However, the firm believes these results were more likely because of poor drug delivery to the target tissue, given that CED expertise was still immature and technology limited at the time, rather than a reflection of its efficacy. “On the basis of the available preclinical and clinical evidence, GDNF offers the potential for the first ever disease-modifying treatment of Parkinson's disease,” it insists.

Phase II trial underway

Parkinson’s UK also has high hopes for the treatment, having offered up cash to help fund the current UK Phase II trial, at North Bristol NHS Trust, assessing the efficacy of infusing GDNF directly into the brain using CED technology to allow the drug to move across the blood brain barrier.

“By providing funding when industry opted not to progress further research, we’ve breathed life back into a drug which had been shelved for many years,” noted Steve Ford, the charity’s chief executive, and said “we’re delighted Pfizer has recognised the potential of GDNF, and are backing what could be a serious game-changer in the treatment of Parkinson’s”.

Financial terms of the agreement between Pfizer and MedGenesis were not revealed.