Parkinson's has long been associated with the accumulation and clustering of a protein, called alpha-synuclein. This protein has been considered a central player in the condition, and as a result numerous clinical trials are being conducted to remove it from the body of people with Parkinson's

The biotech company Enterin has been developing a drug - called ENT-01 - which is based on a naturally occurring protein called squalamine. Discovered in the dogfish sharks, squalamine has recently been shown to have a powerful effect on alpha-synuclein protein, reducing the clustering of it and helping cells to function better. The only problem with squalamine (and ENT-01) is that it does not get into the body or brain very well.

Despite this limitation, the biotech firm Enterin began a clinical trial to evaluate this new therapy in people with Parkinson's, and they have focused their test of efficacy on one of the most common non-motor problems associated with Parkinson's: constipation.

The results of the first clinical trial of ENT-01 indicate that the drug was safe and well tolerated. They also suggest that 80% of the participants taking part in the study had significant improvements in their bowel movements. This was an open-label study (meaning that everyone involved knew what they were being treated with and there was no placebo group), but the company is now conducting a larger double-blind trial to test the efficacy of the drug.