P57 in human testing
Phytopharm plc (PYM: London Stock Exchange) (Phytopharm) announces today the successful completion of the second stage of its clinical study of P57 for obesity. The objectives of this stage of the study include evaluation of the safety, tolerability and pharmacokinetic profile of P57, a patented oral product licensed to Pfizer Inc., which is under development as an appetite suppressant for the treatment of obesity..
The third and final stage of the study has been designed to assess the safety, tolerability, pharmacokinetics and effects on daily calorie intake of P57 compared to placebo when administered repeatedly over at least 10 days to healthy, overweight volunteers. .
Obesity is a global problem, which affects more than 100 million people seriously enough to warrant medical intervention. It is a direct causal contributor to the pathophysiology of many diseases and exacerbates numerous others. Among these are five of the leading causes of death in the industrialized world: stroke, atherosclerosis, cardiovascular disease, diabetes and cancer. According to the World Heath
Organization (WHO), obesity accounts for tens of billions of pounds in direct healthcare costs worldwide. A panel of experts convened by WHO stated on 12 June 1997 that 'obesity's impact is so diverse and extreme that it should now be regarded as one of the greatest neglected public health problems of our time. It has an impact on health, which may well prove to be as great as that of smoking' (World Health Organization, 1997)
Dr Richard Dixey, Chief Executive of Phytopharm, said:
'We are very encouraged by the results of the second stage of the study and await the completion in early November of the third and final stage of this proof of principle study'
P57 - Background to Anti-Obesity Drugs
Obesity is a global problem which affects more than 100 million people seriously enough to warrant medical intervention. It is a direct causal contributor to the pathophysiology of multiple diseases and disorders and exacerbates numerous others. Among these are five of the leading causes of death in the industrialized work: stroke, atherosclerosis, cardiovascular disease, diabetes and cancer. According to the World Heath Organization, obesity accounts for tens of billions of pounds in direct healthcare costs world-wide. A panel of experts convened by WHO stated on 12 June 1997 that 'obesity's impact is so diverse and extreme that it should now be regarded as one of the greatest neglected public health problems of our time with an impact on health which may well prove to be as great as that of smoking'.
Very little is known about the precise disease mechanism in obesity. Excessive dietary intake of fats contributes to obesity but at the same time an imbalance between energy input and energy output is also a cause. It is believed there is a hereditary component and socio-economic factors are known to play a role, particularly in developed countries. Management of obesity can include medical intervention, exercise and diet routines, but the compliance and success rate is typically poor.
Prevalence of Obesity (BMI > 30) in a representative sample between 16-64 years
16-24 25-34 35-49 50-64
Europe 6% 2.1m 10% 5.8m 16% 12.2 m 21% 11.3m
USA 9% 2.7m 18% 7.1m 29% 15m 36% 14m
Total 4.8m 12.9m 27.2m 25.3m
*Adapted from data of White et al 1991, UK Office of Population Consensures and statistics (OPCS) and US National Institute of Health, Office of Health Economics 1994.
Prior to the decision to remove dexfenfluramine and fenfluramine from the world market in September 1997, the prescription market was estimated at approximately US$ 400 million in the United States alone. The underlying medical need for an effective anti-obesity pharmaceutical can be estimated by the dramatic increase in sales of fenfluramine from US$ 600,000 in 1991 to $188 million in 1996 following its approval as a treatment for obesity by the FDA.
The growth potential for an effective pharmaceutical is very high as the obese populations in Europe and the US continue to increase. The current low growth rates and relative market sizes reflects the lack of safe and effective treatments for a condition which is not fully understood.
Few drugs are specifically approved for obesity and those that are suffer from limited efficacy and/or side effects. Most patients become tolerant to these drugs and weight loss greater than 5 -10% is rarely achieved.
P57: A Naturally Occurring Appetite Suppressant
P57 is a plant based product for the treatment of obesity which is now in clinical development. The product was licensed to Pfizer Inc in 1998 in a global licensing agreement
The Hoodia Cactus
P57 is a fully characterized extract derived from a single plant which is subject to patent applications covering raw materials, active substances and mode of action. It appears to have novel pharmacological properties and may in fact be the first ever true appetite suppressant to be discovered. Unlike many of the conventional treatments currently available it has no effects on behavior. The mechanism of action is novel and distinct from those of recently available compounds. Efficacy has been established with a profound weight loss and a good emergent safety profile.
Considerable progress has been achieved with this project. Phase I clinical development continues alongside an extensive research program. In parallel to these activities, additional plantations for the plant material have been established world-wide in collaboration with the CSIR and Pfizer and a clinical supplies unit, dedicated to the manufacture of the material, has been opened in South Africa.
Anecdotal reports of the use of P57 in humans show that it significantly reduces appetite, food intake and body weight. Considerable work has been undertaken to fractionate this plant material and a number of compounds have been isolated from the mixture, some of which have biological activity. The mechanism of action of P57 and its active constituents is currently under investigation. Additional pharmacological properties have recently been established.
To date 24 obese (BMI>26) and 42 non-obese non-patient volunteers have received doses of P57P ranging from 3 to 4000 mg. Primary measures in these studies included clinical toleration, hematological and biochemical assessments of safety and pharmacokinetics. No treatment related serious adverse events have been reported.
Through an extensive program of research a molecule has been identified which appears to be responsible for part if not all of the desired therapeutic activity. This molecule and synthetic derivatives are subjects for patent activity.
A program designed to achieve registration of a product as a prescription medicine for human use in Europe and USA has been initiated.