Opinion: Gene Therapy

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DNA, the molecule that holds our genes.

 

Gene Therapy: Is It Time Yet?

By Reece Akana

On August 1, 2016, Pfizer, one of the world’s largest pharmaceutical companies, acquired Bamboo Therapeutics, a biotechnology company seeking cures for rare diseases using a state-of-the-art technology called gene therapy. This move signifies Pfizer’s increasing interest and investment in the development of gene therapy, a technology it believes “may hold the promise of bringing true disease modification for patients suffering from devastating diseases.” (1) Pfizer’s acquisition is a notable event for gene therapy in the U.S., where strict regulatory institutions have made it difficult for any gene therapy products to enter the market.

But what exactly is gene therapy? Gene therapy is a rapidly developing technology that alters the genetic makeup of an individual for therapeutic purposes. (2)  For example, a patient that has a faulty, disease-related gene can be given a normal version of that gene as compensation. Drug makers often employ modified noninfectious viruses to deliver these foreign genes into a patient’s cells. (3)

Interestingly, while gene therapy has been around since the 1980s, the U.S. still has not approved any gene therapies. This is due, at least in part, to the stringent regulations placed on clinical trials for drugs that alter human DNA. First, two oversight bodies, the Institutional Biosafety Committee and the Institutional Review Board, must independently determine whether or not to approve a clinical trial. (4) If they think further review is needed, then a more specialized committee called the Recombinant DNA Advisory Committee must determine whether or not to give the trial its stamp of approval. (5) Meanwhile, gene therapy manufacturers must also pass the Food and Drug Administration’s (FDA) strict safety requirements before beginning trials. (5)  Although these regulatory bodies are in place to protect the people, they also hinder the development of incredibly promising therapeutic products.  These regulations should be revised to permit scientists to pursue the development of gene therapy freely and should only exist to safeguard against the exploitation of gene therapy for dangerous or unethical ends.  

…[gene therapy] regulations should be revised to permit scientists to pursue the development of gene therapy freely and should only exist to safeguard against the exploitation of gene therapy for dangerous or unethical ends.  

Gene therapies have shown great success in treating difficult diseases in other countries, but they continue to be blocked from American pharmacies. For instance, in 2003 China approved its first gene therapy, Gendicine. The drug treats head and neck squamous cell carcinoma, an aggressive cancer that affects millions of Chinese residents each year. (6) Carefully crafted, the drug consists of a virus that inserts tumor-suppressing genes into the patient’s cells without causing deleterious modifications to the rest of the patient’s genes. (6) After a five-year trial period, 16 out of 26 treated patients were tumor-free, a significant upgrade from the 10 out of 27 tumor-free patients who did not receive Gendicine. (7)  Unfortunately, in the U.S., a similar drug called Advexin was turned down by the FDA for undisclosed reasons. (8)

Europe has also recently approved its first gene therapy drug, Glybera, which was developed by Dutch company UniQure and approved in 2012.  This treatment is geared towards patients who have a deficiency in lipoprotein lipase, an enzyme essential for breakdown of dietary fatty particles in the blood.9 Glybera uses a non-pathogenic virus known as an “adeno-associated virus” to deliver DNA into a patient’s cells without disrupting other genes. (10) Patients who received Glybera during clinical trials saw astounding results, including drastically reduced bouts of pancreatitis for more than two years post-treatment. (11) Nevertheless, when UniQure attempted to seek approval for Glybera in the U.S., the FDA demanded another more expansive clinical trial. (12) Unfortunately, because of the financial and temporal burden of running another trial, UniQure decided to drop its efforts to bring its drug to the U.S. market in 2015. (13)

But while gene therapy has on the whole produced exciting results, this  does not mean that human genetic alteration carries no risks. One of the greatest blows to the field of gene therapy in the United States occurred in 1999, when patient Jesse Gelsinger entered a coma and died a few days after receiving gene therapy for a genetic disease called ornithine transcarbamylase deficiency. (14) This event raised serious questions about the safety and ethics of gene therapy and understandably caused regulations on clinical trials to become even stricter.

Nonetheless, Pfizer has placed its faith (and dollars) in the astounding efficacy of gene therapy. With pharmaceutical titans like Pfizer accelerating their gene therapy development programs, hopefully regulatory bodies in the U.S. will also recognize the tremendous potential of these therapies and revise their policies to make them less obstructive. To be sure, their policies should continue to ensure that the development of gene therapies is conducted ethically and does not pose a reasonable danger to anyone. But for now, efforts should be focused on the well-overdue release of the first available gene therapy products in the U.S. There are patients waiting to be treated.  

References

  1. “PFIZER AIMS TO BECOME INDUSTRY LEADER IN GENE THERAPY WITH ACQUISITION OF BAMBOO THERAPEUTICS, INC. | Pfizer: One of the World’s Premier Biopharmaceutical Companies.” Pfizer. Pfizer, 1 Aug. 2016. Web. 09 Aug. 2016.
  2. “What Is Gene Therapy?” Genetics Home Reference. U.S. National Library of Medicine, 2 Aug. 2016. Web. 02 Aug. 2016.
  3. Piguet, Pascale, and Philippe Poindron. “Genetically modified organisms and genetic engineering in research and therapy.” Dev Neurosci 36.1 (2014): 1-72.
  4. National Institutes of Health. NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules. Revised April, 2016.
  5. “Gene Therapy Legislation in the United States of America.” Gene Therapy Legislation in the United States of America. Gene Therapy Net, n.d. Web. 08 Aug. 2016.
  6. Pearson, Sue, Hepeng Jia, and Keiko Kandachi. “China Approves First Gene Therapy.” Nat Biotechnol Nature Biotechnology 22.1 (2004): 3-4. Web.
  7. “Gene Dreams Troubled by Market Realities.” Gene Dreams Troubled by Market Realities. Royal Society of Chemistry, 31 Aug. 2007. Web. 12 Aug. 2016.
  8. “Introgen Critically Hurt by FDA Advexin Snub.” TheStreet. TheStreet, 02 Sept. 2008. Web. 12 Aug. 2016.
  9. Pollack, Andrew. “European Agency Backs Approval of a Gene Therapy.”The New York Times. The New York Times, 20 July 2012. Web. 02 Aug. 2016.
  10. Valdmanis, Paul N., Leszek Lisowski, and Mark A. Kay. “rAAV-mediated tumorigenesis: still unresolved after an AAV assault.” Molecular Therapy20.11 (2012): 2014.
  11. Richards, Sabrina. “Gene Therapy Arrives In Europe.” The Scientist. The Scientist, 6 Nov. 2012. Web. 2 Aug. 2016.
  12. Taylor, Nick Paul. “UniQure Mulls Options for $1M Gene Therapy after FDA Demands Extra Trial.” Biotech Industry, Biotech News, Biotechnology Articles. Questex, 27 Aug. 2015. Web. 12 Aug. 2016.
  13. Taylor, Nick Paul. “UniQure Mulls Options for $1M Gene Therapy after FDA Demands Extra Trial.” Biotech Industry, Biotech News, Biotechnology Articles. Fierce Biotech, 27 Aug. 2015. Web. 12 Aug. 2016.
  14. Obasogie, Osagie K. “CGS : Ten Years Later: Jesse Gelsinger’s Death and Human Subjects Protection.” Center for Genetics and Society. N.p., 22 Oct. 2009. Web. 10 Aug. 2016.