What to expect in this blog
Each ATMP is unique in its characteristics for one given indication.
Due to their intrinsic and diverse nature, specific challenges are associated with ATMPs development:
- Regulatory complexity and risk-based approach
- Diverse manufacturing processes, sometimes complex
- Challenging Critical Quality Attributes
- Translational & Safety Challenges: no “one-fits-all” solution, and often lack of relevant animal models
- Clinical development is often on small populations, with ethical and operational barriers
However, ATMPs typically follow an accelerated development.
Regulatory Complexity
- Specific legislation in place: EU regulation EC1394/2007 – US FDA Regulation CFR 21 Part 1271
- Most current guidelines outline general principles to address the diverse nature of ATMPs. Developers must balance innovation with safety, relying on scientific rationale rather than strict adherence—essentially adopting a risk-based approach.
- National differences in legislations covering Genetically Modified Organisms (GMOs) and human-cells containing ATMPs.
Manufacturing & CMC
- Specific GMP guidelines: Eudralex Vol 4 part IV.
- Diverse manufacturing processes, sometimes complex, requiring specialized facilities and specific technical and scientific skills. Transitioning from small scale to GMP-compliant, reproducible production remains a major bottleneck.
- Defining Critical Quality Attributes (CQAs) is still challenging and standardization remains difficult. Full product characterization is not always possible given the nature of the product.
Translational & Safety Challenges: no “one-fits-all” solution
- Non-clinical package for ATMPs is often incomplete – some studies are combined (e.g., toxicology and biodistribution) or not possible (metabolism and excretion). Additional safety studies might be needed, depending on the nature of the product (e,.g Immunogenicity, tumorigenicity).
- Many ATMPs are species-specific and lack relevant animal models, making it difficult to assess safety or efficacy in vivo before first-in-human studies.
- => Risk-based approach is the key.
Clinical Trials Conduct
- Small populations: Rare disease indications limit recruitment; traditional randomized trials may be not feasible.
- Ethical and operational barriers: Irreversible interventions and limited comparators raise ethical challenges in trial design.
- Logistics challenges: Due to the nature of the product, requirement of perfect coordination. Specific technical skills and facility/ equipment might be needed.
However, ATMPs typically follow an accelerated development
- Agencies like EMA and FDA offer tailored Scientific advice programs to help navigate complex development.
- ATMPs often fit with designations associated with expedited programs (PRIME (EU), RMAT (US), Sakigate (Japan)).
- ATMPs are often eligible for Orphan Designation, providing market exclusivity and financial advantages.
- Non-clinical package tailored to the specific modality and indication can lead to shorter development time from academic to early clinical phases.
- Due to the nature of ATMPs and the shortage of patients, clinical phases can be combined, reduced, or, in some cases, skipped, leading to shorter development time from early clinical to commercial.
- However, long-term follow-up (up to 15 years), even post-approval is mandatory.
Meet the Authur - Sophie Vériter, PhD, Senior Consultant
I am excited to share my journey as a consultant in ATMP development with 2 Bridge.
As a scientist, I’ve always been driven by a passion for innovative therapies that improve health and quality of life. Over the past 10+ years, I have had the opportunity to contribute to the development of cell therapies, biologics, gene therapies and extracellular vesicles in regenerative medicine.
I was involved in the genesis of a promising Belgian biotech company, helping to translate research from the academic bench into cell therapy products now about to be tested in phase 2b/3 clinical trial. I led the discovery and preclinical development of novel therapies, including cell & gene therapies, and explored early R&D and CMC in extracellular vesicles.
Throughout my career, I have learned to thrive in fastpaced, dynamic environments where adaptability, creativity, and continuous improvement are essential.
Now at 2Bridge, I’m excited to bring this experience to support biotech innovators as they navigate the complex journey of ATMP development — from discovery to clinical translation.
I look forward to connecting and collaborating with others who share the same mission: transforming groundbreaking science into therapies that make a real difference for patients.