Pharmaceutical companies should increase their investment in weight loss therapies to support the growing number of clinically obese individuals worldwide.

That is the key message from a study from business intelligence specialist GlobalData, which notes that the obesity market is lucrative, primarily driven by the adoption of sedentary lifestyles, high cholesterol diets and reduced physical activity. However, it claims that "the current anti-obesity therapeutics market lacks products that patients find attractive".

The market currently contains only one approved prescription drug, Roche's Xenical (orlistat), which has adverse side-effects that include gastrointestinal problems, incontinence and oily spotting. Additionally, Sanofi's Acomplia (rimonabant) and Abbott Laboratories' Meridia (sibutramine) were removed from the market in 2009 and 2010, respectively, due to neuropsychiatric side-effects.

These cases "have led to a decline in the anti-obesity therapeutics market and a decrease in public confidence", GlobalData notes, adding that the treatment-seeking rate for obese patients is very low, despite the increasing patient pool. It argues that weak patient compliance also discounts the effectiveness of therapeutics, which are generally only prescribed for one year, and obese patients in the main are "showing an increasing preference for lifestyle modification and bariatric surgery over pharmacological therapy".

The analysis claims that the anti-obesity pipeline contains 86 treatments, 66 being first-in-class molecules, "which implies the emergence of numerous unique treatment mechanisms". GlobalData adds that "several late-stage pipeline molecules have displayed remarkable effectiveness and safety in medical trials, which may provide significant breakthroughs in the near future".

Things have moved on since the report was written and last month advisors to the US Food and Drug Administration overwhelmingly recommended Vivus' Qnexa (phentermine/topiramate) for approval. GlobalData's analysis shows that the global anti-obesity therapeutics market stood at around $1.10 billion in 2005 and declined 3.8% at a compound annual growth rate (CAGR) to $890.3 million in 2010. Growth is forecast at a CAGR of 9.3% in the future, to reach $1.82 billion by 2018.