While current research involving novel designs for vectors, methods of introducing 'naked' deoxyribonucleic acid (DNA), and the use of electroporation to improve DNA uptake into cells have been successful in pre-clinical studies, the gene therapy market has also seen its fair share of clinical failures.
Safety concerns, poorly regulated trials, and high levels of clinical attrition have seen the promise of gene therapy suffer from negative coverage and unsubstantiated claims.
Lack of cellular target specificity is largely responsible for the toxicity issues in gene therapy, as viral vectors, the most commonly used gene delivery system, may infect even healthy cells while transporting genes to the body.
There is the danger of the new gene being inserted in the wrong location in the DNA that can possibly cause cancer or other mutations. Even over-expression of the introduced gene sequences can cause an unfavourable immune reaction.
However, the report identifies the risks of gene therapy are now lessening, predominantly through scientific advances in gene delivery by industry participants. Regulatory restrictions will diminish if the clinical success rate improves and more products are submitted for approval.
The launch of Gendicine in China, the only gene therapy product available in the market, signifies a huge boost for gene therapy and has paved the way for future products of this kind, potentially boosting the fortunes of a $150 million (€124 million) industry in 2005 and which is expected to reach could reach $5.7 billion in 2011.
An increasingly popular method of improving clinical efficiency is to combine gene therapy trials with conventional therapeutics. These combination trials sometimes involve collaborations outside the gene therapy market with companies having established products or expertise in healthcare.
"A second strategy, particularly for companies with fewer products in development, is to work out a suitable exit strategy, should a gene therapy product fail during clinical development," explains Frost & Sullivan industry analyst Phil Webster.
"This involves the objective assessment of a project, which can either be terminated or have its components recycled into a new project," he added.
Trends in clinical development have shown that there is significant focus on terminal diseases such as monogenic and oncology disorders. There is also an increasing trend in non-terminal cardiovascular disorders, wherein existing products are available to significantly prolong the life of a patient but do not necessarily offer a cure.
The report, entitled: "World Gene Therapy Markets," is available to buy now from Frost & Sullivan.