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Expert Interview

Ask the Expert: S. Kaye Spratt, PhD

Discussing Advanced therapies, early regulatory interactions and her experience at RareMoon

November 17, 2025
3 min read
S. Kaye Spratt, PhD

RareMoon's Senior Regulatory Expert Offers Her Insights.

You've spent more than 30 years in the biotech and pharmaceutical industry. What major shifts or lessons stand out most from your career that are especially relevant to today's rare disease and advanced therapy developers?

During my 30 years in the gene and cell therapy industry, and after decades of anticipation, gene therapy has become a clinical reality, offering clinically meaningful benefits for patients with rare diseases. This shift from experimental to approved therapies is exciting and demands new rigor in trial design, manufacturing, and long-term follow-up. FDA (OTP) and EMA have made significant changes with frameworks for CGT, but developers still face challenges in nonclinical models that reflect human biology, dose determination, endpoint selection, and long-term safety monitoring and post-marketing commitments.

Advanced therapies often challenge traditional development models. How do you approach advising companies when the science or technology is ahead of regulatory precedent?

When the science is ahead and no regulatory precedent exists, the Sponsor's goal becomes more about building bridges between cutting-edge science and regulatory precedent and proposing an acceptable path forward. The goal is to translate the science into regulatory language by applying knowledge of regulatory expectations. Leveraging the FDA's INTERACT, pre-IND, and Type D/C meetings to test ideas and gather (early) feedback can go a long way. Propose novel endpoints or trial designs, manufacturing controls, for instance, and back them with well-characterized/justified components. In our experience, the FDA and EMA are open to innovation, but expect you to bring clear, credible/justified, and responsible plans.

For small or emerging biotech companies, what are the most critical early decisions that can make or break the path to regulatory success?

Selecting an indication with a strong biological rationale, measurable endpoints, and a clear unmet need. My advice is to avoid chasing scientific novelty without a viable development path or clinical relevance. Use early regulatory interactions (e.g., INTERACT, Type D, and pre-IND) to test assumptions and align on expectations. Don't wait until your IND is ready before engaging. Bring in experienced regulatory leaders early who understand accelerated pathways, platform leverage, and global harmonization.

What inspired you to join RareMoon, and how do you see your role as a Senior Regulatory Consultant and Scientific Advisor contributing to the firm's mission and client success?

Working with RareMoon gives me an opportunity to align a shared mission of advancing transformative therapies for rare diseases through strategic consulting, creative regulatory initiatives, and human-centered impact. RareMoon builds strong client relationships and confidence with Sponsors based on consistently successful regulatory interactions and by helping Sponsors navigate the most critical inflection points in development, especially when the science is ahead of regulatory precedent. I'm proud to help our clients not just reach milestones but lead with care and purpose and develop novel cell and gene therapy drugs.

Why Choose Us?

With deep experience and unwavering integrity, we offer expert guidance in navigating the complex regulatory landscape of orphan drugs and cell and gene therapies, delivering streamlined and reliable support.

Developing an advanced therapy?

Our team has supported gene, cell and other advanced therapy programmes from preclinical through approval.

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