Inconsistent clinical practices thwart wider use of personalized medicine

The promise of personalized medicine — safer and more effective treatments tailored to each individual’s body and needs — isn’t being fully met because of challenges associated with its implementation in clinical practice.

In a special report published today in JCO Precision Oncology, we and our colleagues from Diaceutics, the Personalized Medicine Coalition, and Reservoir Communications provide the first in-depth look at the efforts of United States health systems to deploy potentially paradigm-shifting drugs that can be used to target specific genetic vulnerabilities in cancer cells.

The study focused on a cohort of people with non-small cell lung cancer because this disease presents major opportunities for a genetically personalized approach, with more than 70% of non-small cell lung cancer tumors having genetic alterations known to have outsized effects in driving tumor growth. In many cases, doctors can use available therapies that target those genes, which are more common in cancerous cells than in healthy ones. This approach is designed to inhibit or stop cancer growth while minimizing damage to healthy cells.

Genetically guided personalized medicine can make a big difference for patients with lung cancer. For example, individuals with lung tumors containing mutations in genes known as EGFR and ALK who receive genetically targeted therapies tend to live longer than those who do not receive targeted therapies. In fact, the National Cancer Institute partly credits targeted therapies and immuno-oncology drugs for more than a decade’s worth of declining death rates for people with lung cancer.

Yet these therapies are being woefully underused.

Our JCO Precision Oncology report examined Medicare claims and laboratory data from 38,068 people diagnosed with advanced non-small cell lung cancer in 2019. Due to difficulties in testing and treatment at each of the seven steps in the precision oncology pathway, personalized therapies benefitted only about one-third of the individuals whose tumors may have contained genes that could be targeted by available therapies.

In this study, the gaps in clinical practice that limited the possibility of personalized medicine included failures to order tests to identify genes that may be associated with targeted treatment options, failures to collect the tissue or blood samples needed for those tests, errors in collecting or processing tissue or blood sample, testing results that were inconclusive or provided false negatives, extended turnaround times for reporting results that prompted doctors to prescribe one-size-fits-all treatments for patients who did not have the time to wait any longer, and failures to prescribe the appropriate therapies to patients who tested positive for actionable biomarkers.

The results suggest that standardizing test ordering and processing and creating broader educational initiatives for medical professionals can help ensure that more people benefit from the latest developments in personalized medicine. The implications go beyond non-small cell lung cancer. According to the Personalized Medicine Coalition’s latest estimates, more than 75,000 genetic testing products and 300 personalized medicines are on the market for people with multiple types of cancers, genetic rare diseases, and a range of chronic and infectious diseases.

Doing more to take full advantage of personalized medicine makes sense from both clinical and economic perspectives. In 2015, researchers from Intermountain Healthcare reported on the outcomes and costs associated with their implementation of genetically guided personalized medicine among a cohort of 36 people with advanced cancer compared to a control group of 36 others with advanced cancer who received standard chemotherapy. Those treated with personalized medicine survived longer: progression-free survival was 23 weeks for the treatment group and 12 weeks for the control group. Equally important, the approach did not increase treatment costs, which were $3,204 per week in the targeted group vs. $3,501 in the control group.

A 2019 economic modeling study on the cost-effectiveness of multi-gene panel sequencing among a cohort of 5,688 people with advanced non-small cell lung cancer suggested that multi-gene sequencing tests could deliver even more value if individuals with test results identifying actionable genetic mutations consistently received genetically guided treatments.

Given the practice gaps revealed by the JCO Precision Oncology study, one can only imagine what the picture of clinical adoption looks like in disease states where personalized medicine is even less established, even though it is equally promising for patients and their families.

As the 20th anniversary of the completion of the Human Genome Project approaches next year, it is becoming increasingly clear that a paradigm shift toward personalized medicine won’t occur just because new tests and treatments have become available. Reaping the full scope of personalized medicine’s benefits will require more focused attention on updating policies and practices that optimize the delivery of personalized health care.

Daryl Pritchard is the senior vice president for science policy at the Personalized Medicine Coalition. Susanne Munksted is the chief precision medicine officer of Diaceutics, which provides pharmaceutical companies with solutions to support the launch of precision medicine diagnostics.