Impact of First-of-Its-Kind Patient-Facing Pharmacogenetics Tool on Dosing Decisions and Treatment Outcomes.

Germline pharmacogenetics (PGx) is increasingly used to tailor medication selection/dosing. However, existing systems primarily communicate PGx results to providers, limiting direct patient engagement. To address this, we developed YourPGx Oncology, an innovative patient-facing portal that delivers multi-gene PGx results (CYP2D6, UGT1A1, DPYD) through 33 unique, patient-friendly summaries. The utility of this tool was prospectively evaluated in an oncology population, where these pharmacogenes impact high-stakes treatments. Patients enrolled in the PhOCus study (NCT04541381) participated in single-session evaluations of the tool in-person or via videoconference, with a pharmacist available for questions and administering pre- and post-surveys that assessed educational impact. Each patient viewed their own previously obtained PGx results. Of 190 eligible patients, 70 responded to solicitations via email, phone, and in-person, of whom 51 (73%) completed an observed session and completed surveys. Patients spent a median of 13.4 minutes (range 8.1-21.0) navigating YourPGx Oncology. After portal interaction, patients' ability to identify individual efficacy and safety estimates for chemotherapies and pain medications significantly improved, with the proportion accurately recognizing PGx-informed drug efficacy likelihoods rising from 32% to 72% (Odds Ratio [OR] = 5.8 for the shift from discordant to concordant efficacy knowledge, P < 0.001), and PGx-related toxicity recognition increasing from 31% to 57% (OR = 3.2, P = 0.01). Our findings show that a customized patient-facing PGx results portal enhances patient understanding of individual medication efficacy and toxicity likelihoods, highlighting the potential key role of direct-to-patient PGx tools to facilitate optimized treatment-informed care and promote genetically guided shared decision-making.