Unlocking the power of pharmacogenomics: MyCode’s role in safer, smarter prescribing
Author: Ryley Uber
The Geisinger MyCode® Community Health Initiative has been underway for nearly 2 decades, positively influencing our understanding of how genomics affect health while enabling pathways for clinical confirmation of genomic results. Yet a key question remains:
How can MyCode pharmacogenomic (PGx) data be used to improve medication outcomes — specifically medication effectiveness and safety — for enrolled patients?
Like other medication-based laboratory results, PGx findings — even those within normal ranges — enhance pharmacotherapy outcomes and bolster confidence in prescribing decisions. Additionally, PGx clinical testing only needs to be conducted once, as these results are relevant for a patient’s lifetime. This permanence makes PGx data a uniquely valuable resource for long-term medication management. To explore the potential benefits for Geisinger patients, a multidisciplinary team of geneticists and pharmacists examined the population-level implications of how past PGx testing could have benefited patients — and how future testing could continue to do so.
Their initial goal was to estimate how many patients might benefit from testing if conducted today across the entire population. Among more than 170,000 patients with research-only genomic data, an overwhelming 99.8% had at least 1 variant that could influence prescribing decisions, and 91.7% had 3 or more such variants. Additionally, 26.9% of patients had previously received a medication that interacts with their genomic profile (i.e., drug-gene interaction), further demonstrating the value of PGx results at the time of prescribing. These findings underscore the potential for PGx data to proactively guide safer, more effective medication choices.
Ongoing work is focused on retrospectively characterizing responses to these drug-gene interactions, which were unknown at the time of prescribing. Preliminary findings suggest that many adverse medication reactions may be explained by genomics. For instance, patients who are SLCO1B1 Poor Function carriers were more likely to have a documented muscle pain adverse event while taking a statin, compared with those with SLCO1B1 Normal Function.
These insights could inform future prescribing practices and reduce the risk of preventable adverse events.
The genomic data used for these analyses cannot be directly returned to patients, as it does not meet the required clinical standards. It must be clinically confirmed using these standards before returning to patients and their clinicians. Therefore, future efforts will aim to clinically confirm these results and prioritize testing for patients with the greatest need — particularly those with high-risk medication profiles or histories of adverse reactions.
These efforts will also ensure that these strategies may be replicated across other health systems, as this will be essential to advancing public health on a national — and potentially international — scale. By building a framework for clinical confirmation and integration of PGx data into routine care, Geisinger is helping to shape the future of precision medicine and medication safety.
