Some of the most promising and powerful applications of GM technology are in the field of biomedical sciences. Since 1982, microorganisms have been genetically modified to produce pharmaceuticals for the treatment of human diseases. More recently, through what is known as “biopharming”, scientists have explored genetically modifying plants and animals so that these become living “factories” producing pharmaceuticals. Gene therapy trials have also been used with some success for the treatment of diseases such as severe combined immunodeficiency (SCID).

The first genetically engineered drug is human insulin, produced under the trade name Humulin®. Approved by the United States Food and Drug Administration (USFDA) in 1982, Humulin® is produced by genetically engineering Escherichia coli bacterium to express DNA encoding human insulin. Before genetically engineered insulin became available, diabetic patients had to rely on insulin derived from the pancreases of animals such as cows and pigs. Patients can sometimes develop allergic reactions towards insulin derived from animal sources, especially if the preparations are of low purity. GM technology has thus provided diabetic patients with a source of low-cost, reliable, and high-quality insulin.

Numerous genetically engineered drugs have been subsequently developed and approved for use. The list includes, among others, human growth hormones, Orencia® for the treatment of rheumatoid arthritis, Remicade® for the treatment of Crohn’s disease and Herceptin® for the treatment of advanced breast cancer. In 1986, the USFDA’s approval of a genetically engineered hepatitis B vaccine marked the start of the use of genetically engineered vaccines for humans.

Many more genetically engineered drugs are in the pipeline.

Biopharming (or pharming) refers to the use of GM technology to insert genes encoding useful pharmaceuticals into host animals or plants that would otherwise not express those genes. The host animals or plants then become living “factories”, from which useful pharmaceutical products can be harvested.

Proponents believe that biopharming offers an easily controllable, safe, and cost-effective method for manufacturing pharmaceuticals. While genetically engineered drugs are most commonly produced today using microorganisms in bioreactors, pharming requires less expensive infrastructure and production can be scaled up quickly in response to demands.

In 2006, the European Commission approved the first transgenic animal-derived drug – ATryn®.  Derived from the milk of GM goats, ATryn® is a recombinant form of human antithrombin and can be used therapeutically as an anticoagulant. Rhucin®, an experimental GM rabbit-milk anti-inflammatory drug, is currently under Phase III clinical trials. To provide another example, scientists are also working on GM chickens capable of laying eggs containing anti-cancer proteins.

Biopharming in plants also presents excellent potential. Although no such products have been approved for marketing as yet, some scientists and industry players are hopeful that GM plants can be “pharmed” to develop treatments for some of the most serious diseases such as cancer, HIV, Alzheimers, diabetes, and arthritis.

DNA is the blueprint determining the characteristics of living organisms. Genes are specific segments of DNA and each gene encodes a product with a biological effect.

Sometimes, individual genes may become defective, leading to disease manifestations. Many diseases including cystic fibrosis, severe combined immunodeficiency (SCID), thalassemia, and sickle-cell anaemia are the result of just one malfunctioning gene.

Gene therapy has the potential to treat these genetic diseases. In a nut shell, it consists of the following steps:

Before the marketing of any new drug or therapy, regulators and scientists have the responsibility to carefully weigh the risks and benefits involved. Although gene therapy holds great promises, the biology involved is very complex and has not been fully understood.

Potential dangers of gene therapy include:

In a gene therapy trial held in 1999, ten patients were successfully treated for X-linked severe combined immunodeficiency (SCID), a rare genetic disorder that typically causes death within the first year of life unless effectively treated. However, in 2003, two of the boys were found to have developed a leukaemia-like condition possibly linked to the therapy. The United States Food and Drug Administration (USFDA) therefore halted all gene therapy trials using retroviral vectors in blood stem cells. The ban was eventually eased a few months later to allow such trials for the treatment of life-threatening diseases, with the condition that appropriate safeguards must be in place.

Therefore, there is a need to better understand the science behind gene therapy before this form of treatment can be approved for routine clinical use.

The potential dangers of gene therapy have been answered.

All pharmaceuticals, whether GM-derived or not, are subjected to stringent scrutiny for efficacy and safety before they can be approved for marketing. Countless people have benefited since the first genetically engineered drug was approved in 1982.

Biopharming can present risks in the absence of appropriate measures. Gene flows (i.e. transfers of DNA from one population to another) and human errors can result in the contamination of conventional crops and accidental releases of pharm crops into the food supply. These undesirable effects can be minimized by using self-pollinating crops such as rice and flax to avoid gene flows, or non-food crops such as tobacco.

It is difficult to establish the absolute safety of any new technologies and GM technology is no exception. However, with proper regulatory safeguards, it is possible to derive benefits without compromising on safety.

In Singapore, pharmaceuticals, medicinal products, and clinical trials, whether GM-derived or not, are regulated by the Health Sciences Authority established under the Ministry of Health.

The agriculture sector is modest in land-scarce Singapore. It is therefore unlikely that any pharm crop will be cultivated on a large scale here. Nonetheless, should any party wish to carry out such agricultural activity, the Agri-Food & Veterinary Authority will ensure that the necessary safety measures are in place. The Singapore Guidelines on the Release on Agriculture-Related GMOs will apply and GMAC will provide advice accordingly.