Ep163: Sarah Boyce on RNA Medicines for Muscle Diseases

Episode Summary

Executive Summary: Sarah Boyce traces her path from Liverpool to CEO of Avidity Biosciences and explains how the company’s antibody oligonucleotide conjugates are finally delivering RNA medicines to muscle. She highlights clinical progress in DM1 and FSHD, recent positive DMD data, platform safety, and Avidity’s broader ambition to expand into cardiology while building a durable, patient-focused biotech.

Main Topics: Sarah Boyce’s personal and professional origin story (Priority: 4/5): Boyce describes growing up in Liverpool, being shaped by family values, and navigating dyslexia and ADHD, which she says made her a stronger, more adaptive leader. Career path from large pharma to biotech leadership (Priority: 5/5): She explains how roles at Merck, Roche, Novartis, Alexion, and Ionis taught her commercialization, access, business development, and leadership, ultimately preparing her for the CEO role. Avidity’s AOC platform and muscle-targeting strategy (Priority: 5/5): Boyce outlines antibody oligonucleotide conjugates as a delivery system pairing an antibody, linker, and RNA silencing cargo to reach muscle cells, a key challenge in RNA therapeutics. Clinical progress in DM1 and FSHD (Priority: 5/5): The discussion details evidence that Avidity can deliver to muscle, knock down targets, alter downstream biology, and show functional benefit in myotonic dystrophy and facioscapulohumeral muscular dystrophy. Company building, financing, and IPO during COVID (Priority: 4/5): Boyce recounts the Series C financing, the addition of FSHD and DMD programs, and Avidity’s successful virtual IPO in June 2020. Long-term vision: skeletal muscle, cardiology, and culture (Priority: 4/5): She describes Avidity’s future as a platform company with a skeletal muscle franchise, a precision cardiology franchise, and a strong internal culture focused on innovation and community. Community engagement and biotech outreach (Priority: 3/5): Boyce emphasizes philanthropic work in San Diego and programs such as Girls Who Lead to broaden access to biotech careers.

Key Arguments: Boyce argues that her dyslexia and ADHD were advantages, not liabilities, because they pushed her toward pattern recognition, math, science, and nontraditional problem-solving. She contends that business functions in biotech build the bridge from great science to patient access, reimbursement, and standard of care adoption. She says smaller biotech roles let her stay closer to science, data, patients, and teams, which is where she adds the most value. Boyce argues Avidity’s AOC platform has solved a major RNA field problem: delivering therapeutics to muscle cells reliably and with acceptable safety. She maintains the DM1 program is highly de-risked because the phase 3 endpoints align with prior positive phase 1/2 and open-label data. She says FSHD data are important because they show reproducibility across programs, including target knockdown, downstream biomarker changes, and early functional benefit. Boyce argues Avidity is not just a muscle company; it is an RNA delivery company with potential to expand into cardiology and other areas where delivery has been the main barrier. She stresses that culture and innovation are essential for a growing biotech to avoid stagnation and remain ahead of competitors.

Data Points: Series C financing: just over $100 million - Avidity’s Series C round before the company advanced its pipeline IPO date: June 2020 - Avidity went public during the COVID-19 pandemic Company headcount: about 270 - Approximate size of Avidity at the time of the interview Cash position: $1.3 billion - Boyce cited this as enabling in-house development and commercialization in rare disease Ionis/Axia tenure: 5 years total - Boyce’s time at Ionis and its subsidiary Axia

Pivotal Quotes: "I love building things." — Sarah Boyce: Boyce explains why the move from large pharma to smaller biotech fit her temperament and leadership style "The business function builds that bridge to bring great science to people who need it." — Sarah Boyce: She describes the role of commercial, development, and access teams in translating science into patient benefit "We’re looking to revolutionize the RNA space and make a profound impact in people’s lives." — Sarah Boyce: Boyce defines Avidity’s mission and long-term ambition

Implications: Avidity’s muscle data suggest RNA delivery is becoming clinically real, not just conceptual. If phase 3 holds, it could reset treatment expectations for rare muscle diseases and open a path for broader RNA applications in heart disease and beyond.