Precision Medicine: Innovation That Could Transform Personalized Drug Therapy

Increased understanding of the human genome opens up promising new areas for drug research and development.

Precision medicine, an emerging approach to treating disease that focuses on tailoring drugs to a patient’s genes, environment, and lifestyle, is gaining traction among researchers and health care providers, sparking collaborative public and private efforts. The goal of precision medicine is to give health care providers tools to better understand the complex mechanisms of disease so they can select therapies that will work best in each patient, considering his or her health and conditions.

Recently, it became an agenda item for President Obama, who introduced the Precision Medicine Initiative in his State of the Union Address on January 20, 2015.

Obama praised the nation’s victories in 2 areas relevant to this new era of precision medicine: he highlighted researchers’ accomplishments in mapping the human genome, which will help in the research and development of new drug therapies, and celebrated advances in precision therapies, such as a treatment for patients with cystic fibrosis (CF). In 2012, the FDA approved ivacaftor (Kalydeco) for patients with CF who have a specific mutation in the CF gene.

Moving forward, the president said he would like to see the United States lead a new era of medicine. This new initiative, with a $215-million investment proposed in the president’s 2016 budget, will allow for more research so that medications can be individualized for patients instead of being prescribed as “one-size-fits-all.”¹ “Tonight, I’m launching a new Precision Medicine Initiative to bring us closer to curing diseases like cancer and diabetes— and to give all of us access to the personalized information we need to keep ourselves and our families healthier,” Obama said.

Impact of the Precision Medicine Initiative

This individualized approach to treating patients is not new. Patients with melanoma, leukemia, and breast, lung, and colorectal cancers often undergo molecular testing so that their physicians can get a better understanding of how to best treat their disease.¹ Further, genetic testing has been proven beneficial in patients with HIV because it can enable the health care team to determine whether patients will benefit from a new antiviral drug or whether they may experience adverse side effects from therapy.

With the Precision Medicine Initiative, both public and private efforts would be coordinated to seek advances in genomics (see Sidebar), health information technology, and methods of utilizing large amounts of data without breaches in privacy. Americans would be able to play their part; the goal is to obtain 1 million volunteers to contribute their health data to improve health outcomes and treatments. The National Institutes of Health, the FDA, and the Office of the National Coordinator for Health Information Technology would each receive funds for their research efforts in precision medicine.

Among the objectives of the initiative are:

• Improving cancer treatments using more genetically based clinical trials through the National Cancer Institute

• Launching a national volunteer research group aimed to encourage Americans to provide medical data, including genetic information, for research purposes

• Protecting patient privacy while gathering large amounts of data

• Exploring new ways of patient participation and empowerment

GENOME-EDITING TECHNOLOGY

Genome-Editing Technology

At the research level, one example of genomic advances relates to gene therapy, which involves altering or compensating for genetic mutations that cause disease. Currently, the FDA’s Center for Biologics Evaluation and Research has not approved any human gene therapies for use. Glybera, from Dutch biotech firm UniQure, was the first gene therapy approved in Europe in 2012.² Glybera helps to treat lipoprotein lipase deficiency, a rare genetic disease, through a series of 42 injections that provide the body with correct copies of the lipoprotein lipase gene. UniQure is seeking a retail price of about $1.4 million per patient for the drug, which may become commercially available in 2015.³ Although gene therapy holds promise, further research is needed to assess whether such technology can transform medicine on a global scale.

CRISPR’s Search-and-Replace Mechanisms

A promising example of gene-editing technology is clustered regularly interspaced short palindromic repeats (CRISPR), a genome-editing tool that allows faster and more precise changes to genes than previous tools, such as zinc finger nucleases.

CRISPR uses guide-RNA and Cas9 nucleases to target and cut DNA. Once broken, a gene can be altered by deleting it, adding nucleotides, shutting it down, or turning on its activity. This technology has led to successful outcomes. A study published in Genome Research stated that researchers had been able to “seamlessly” correct disease- causing mutations responsible for b-thalassemia, a group of inherited blood disorders.⁴

In another study, published in Circulation Research, researchers were able to lower blood cholesterol levels in mice using CRISPR technology. The study authors concluded that their results could potentially lead to more effective prevention of cardiovascular disease in humans.⁵

Both AstraZeneca and Novartis announced in late January 2015 that they would be using CRISPR to develop new medicines. While no drugs have yet been designed using CRISPR, drug manufacturers could use this technology to create new treatments for metabolic problems and genetic diseases.

Pharmacogenomics and Medication Therapy Management

Pharmacogenomics, the study of the role of genetics in drug response, is a big part of precision medicine, according to Shawn Desai, PhD, JD, a chemist and a cofounder of and chief technology officer at a clinical laboratory in Georgia.

In a recent podcast featured on Pharmacy Times’ website, Dr. Desai related that for a few decades now, scientists have known that genetic mutations affect how quickly or slowly patients metabolize medications. What is new is that some health insurance plans have made DNA analysis more cost-effective, he said.

Furthermore, Dr. Desai maintained that pharmacogenomics can dovetail with medication therapy management (MTM). While typical MTM explores the patient’s age, race, sex, and the dosage of their medications, Dr. Desai said pharmacogenomics can take that analysis a step further, adding a deeper layer to the study of patients’ medications.

“It’s almost Star Trek-like, in my opinion,” Dr. Desai said in the podcast. “You’re looking at the individual patient’s needs on a much deeper level than just the generic age, sex, race analysis.”

A white paper from the American Pharmacists Association (APhA) delved further into the relationship between MTM and pharmacogenomics. The APhA notes that pharmacists can play a vital role in helping to assess what drug would be best for a patient based on their genetic makeup. Namely, pharmacists’ in-depth knowledge of medications will be useful in reviewing prescribed medications based on the patients’ genomic data. They could potentially offer assessments on whether a new drug would be effective in a specific patient.

The 2011 paper highlighted a few actions that need to take place before pharmacogenomics can be integrated into clinical practice via MTM. First, a specific process would need to be defined for applying pharmacogenomics data to MTM delivery. Second, a viable business model would have to be put in place. Finally, new health information technology would be needed to support pharmacists in their new role.

Conclusion

Precision medicine may usher in a fruitful period of medical breakthroughs, which could improve patient outcomes and may place pharmacists in a more prominent role in patient care. The Precision Medicine Initiative represents an important step in advancing personalized therapy. Industry experts contend a coordinated and sustained national effort is necessary to translate these initial successes on a larger scale.¹

References

• Fact sheet: President Obama’s precision medicine initiative [news release]. Washington, DC: The White House Web Office of the Press Secretary; January 30, 2015. www.whitehouse.gov/the-press-office/2015/01/30/fact-sheet-president-obama-s-precision-medicine-initiative. Accessed February 5, 2015.
• Pollack A. European agency backs approval of a gene therapy. The New York Times. July 20, 2012. www.nytimes.com/2012/07/21/health/european-agency-recommends-approval-of-a-gene-therapy.html?_r=0.
• Burger L, Hirschler B. Exclusive: first gene therapy drug sets million-euro price record. Reuters. November 26, 2014. www.reuters.com/article/2014/11/26/us-health-genetherapy-price-idUSKCN0JA1TP20141126. Accessed February 5, 2015.
• Xie F, Ye L, Chang JC, et al. Seamless gene correction of β-thalassemia mutations in patient-specific iPSCs using CRISPR/Cas9 and piggyBac. Genome Res. 2014;24(9):1526-1533. doi: 10.1101/gr.173427.114.
• Ding Q, Strong A, Patel KM, et al. Permanent alteration of PCSK9 with in vivo CRISPR-Cas9 genome editing. Circ Res. 2014;115(5):488-492. doi: 10.1161/CIRCRESAHA.115.304351.