Shares in drug maker Phytopharm PLC (PYM.LN) more than quadrupled Wednesday after it said its experimental Parkinson's disease treatment Cogane showed promise in two early-stage studies.

Phytopharm said a study funded by the Michael J. Fox Foundation, a Parkinson's research charity founded by the Hollywood actor, showed use of Cogane led to a 43% reduction in Parkinson's symptoms among monkeys given a drug to replicate those symptoms.

This type of study in monkeys is considered the gold-standard model for assessing experimental Parkinson's medicines before testing them on humans, according to Jonathan Brochtie, a senior scientist at Toronto West Hospital who conducted the study.

"Cogane holds the promise to be the first in a new class of treatments," he said.

A second study in a small number of healthy human volunteers showed Cogane was safe and also demonstrated some evidence of pharmacological activity, Phytopharm said.

The firm now plans a phase II clinical study of Cogane in patients next year.

At 1435 GMT, shares in Phytopharm were 18.87 pence higher at 25 pence, making it the biggest riser in a 0.5% higher FTSE Fledging index.

Cogane is far from starting the big human trials needed to win regulatory approval. But Paul Cuddon, an analyst at Phytopharm's broker KBC Peel Hunt, said the results of these trials show real promise because this type of primate trial has been shown to be "highly predictive" of a similar response in humans. He rates the stock "buy" and Wednesday upped his price target to 50 pence from 25 pence.

It has been a tough year for Phytopharm. The stock has languished ever since a planned collaboration with Unilever NV (UNA.AE) to develop a Slim Fast diet drink based on the hoodia plant was called off last November.

Robin Davison, an analyst at Edison Investment Research, said Wednesday's share price rise shows investors are still interested in Phytopharm.

"The company has shown it still has a drug, where previously people had written them off," said Davison.

It might also signal renewed interest in the U.K. small-cap drug sector, which has suffered from a dearth of funds and several company failures, he added.

Company Web site: www.phytopharm.com

-By Jason Douglas, Dow Jones Newswires; 44-20-7842-9272; jason.douglas@dowjones.com