The European Medicines Agency (EMA), through its Committee for Veterinary Medicinal Products (CVMP), has established comprehensive guidance for risk management plans (RMPs) for novel therapy veterinary medicinal products (NT-VMPs). This regulatory framework, formalized in March 2026, addresses the unique safety and efficacy challenges posed by advanced therapeutic modalities including cell-based therapies, gene therapies, bacteriophage preparations, and nanotechnology-derived products.
This article provides a detailed analysis of the CVMP guidance, exploring the identification of potential risks, monitoring strategies for early and delayed adverse events, management of clinical consequences, and long-term safety surveillance. Drawing on regulatory documents and real-world examples, this review offers practical insights for manufacturers, veterinarians, and regulatory professionals navigating the complex landscape of novel veterinary therapies.
1. Introduction: The Emergence of Novel Veterinary Therapies
The landscape of veterinary medicine is undergoing a transformative shift. Advanced therapeutic modalities—once confined to human medicine—are increasingly being developed for animal health. These novel therapy veterinary medicinal products (NT-VMPs) include cell-based therapies, gene therapies, bacteriophage preparations, and nanotechnology-derived products. Unlike conventional pharmaceuticals, these products possess unique characteristics that require specialized safety monitoring and risk management approaches.
1.1 Definition of Novel Therapies
According to the EMA/CVMP guidance, novel therapies in the veterinary context encompass products that utilize innovative biological or technological approaches. These include:
- Cell-based therapies: Products containing living cells (e.g., mesenchymal stem cells, chondrocytes) intended to regenerate, repair, or replace damaged tissues
- Gene therapies: Products that deliver genetic material to modify or manipulate gene expression
- Bacteriophage therapies: Viruses that specifically target and lyse bacterial pathogens
- Nanotechnology products: VMPs utilizing particles at the nanoscale for targeted delivery or enhanced efficacy
1.2 Regulatory Framework and Requirements
Under Regulation (EU) 2019/6, Annex II, section V.1.1.6, a risk management plan is mandatory for all novel therapy veterinary medicinal products. The RMP must be submitted as part of the initial marketing authorisation dossier (Part 1a) and will be assessed by the CVMP during the evaluation process. A summary of the RMP is published as part of the European public assessment report (EPAR).
The three primary goals of the RMP, as defined in the regulation, are:
- Detect early or delayed signals of adverse reactions
- Prevent clinical consequences of adverse reactions and ensure timely treatment
- Gain information on long-term safety and efficacy
1.3 The Need for Specialized Risk Management
Conventional pharmacovigilance systems, designed for traditional small molecule drugs, may be inadequate for novel therapies. These products present unique challenges:
| Challenge | Description |
|---|---|
| Persistence in the body | Living cells or genetic vectors may remain active for extended periods |
| Delayed adverse events | Tumorigenicity or autoimmune reactions may manifest months or years after treatment |
| Immunogenicity | Unwanted immune responses can affect safety and efficacy |
| Off-target effects | Genetic therapies may affect unintended genes or cell types |
| Environmental impact | Shedding of vectors or bacteriophages raises ecological concerns |
2. Categories of Novel Veterinary Therapies and Associated Risks
2.1 Cell-Based Veterinary Medicinal Products
Cell-based therapies represent one of the most rapidly advancing areas of veterinary medicine. These products include mesenchymal stem cells (MSCs), chondrocytes, and other cell types intended for regenerative applications.
2.1.1 Key Risks
Tumorigenicity Risk
When manufacturing involves extensive culture of proliferating cells (e.g., mesenchymal stem cells), the differentiation capacity may be affected, potentially leading to a risk of tumorigenicity. This is a significant concern for products where cells are expanded ex vivo before administration.
Risk of Unwanted Immunogenicity
Immune responses to cell-based products can manifest as anaphylaxis, graft-versus-host disease, or hypersensitivity reactions. The immunogenicity risk depends on whether cells are autologous (from the same individual), allogeneic (from another individual of the same species), or xenogeneic (from a different species).
Risk of Disease Transmission
The use of biological materials in cell-based products carries inherent risks of transmitting infectious agents, including viruses, prions, and other pathogens.
Risk of Lack of Expected Efficacy
Quality assurance issues during manufacturing, storage, distribution, or administration can compromise product efficacy. For example, improper handling may reduce cell viability.
Long-term Efficacy Concerns
Repeated exposure may lead to reduced efficacy over time, and treated conditions may flare up after the initial therapeutic effect wanes.
2.1.2 Real-World Context: Regulatory Enforcement
In 2024, the FDA issued a warning letter to Safari Stem Cell, a Texas-based company marketing stem cell and platelet-rich plasma products for pets. The agency determined that these products met the definition of new animal drugs but lacked proper approval. Additionally, the inspection revealed “significant deviations” from Current Good Manufacturing Practice (CGMP) regulations, including failure to test for microorganisms and failure to monitor environmental conditions in aseptic areas .
This case illustrates the importance of regulatory oversight for cell-based veterinary products and the potential risks when products are manufactured without appropriate quality controls.
2.2 Gene Therapy Veterinary Medicinal Products
Gene therapies involve the delivery of genetic material to modify gene expression in target cells. Viral vectors (e.g., adeno-associated virus, lentivirus) are commonly used as delivery systems.
2.2.1 Key Risks
Vector-Related Risks
- Persistence, latency, and reactivation: Vectors may remain in the body for extended periods, with potential for reactivation under certain conditions
- Integration into host genome: Genomic integration carries theoretical risks of insertional mutagenesis and oncogene activation
- Prolonged transgene expression: Sustained expression of therapeutic genes may have unintended long-term consequences
Genetic Modification Risks
- Altered host cell function: Intended or unintended changes in cell growth, differentiation, or apoptosis
- Malignancy risk: Theoretical concern for insertional activation of oncogenes or inactivation of tumor suppressors
- Autoimmunity: Expression of neo-antigens may trigger immune responses against modified cells
Risks Specific to RNAi and RNA Antisense Therapies
- On-target or off-target binding interference
- Pro-inflammatory responses
- Accumulation in tissues
- Crossing of the blood-brain barrier leading to central nervous system disorders
Other Safety Concerns
- Immunotoxicity and exaggerated immune responses
- Toxicity to non-target organs (hepatotoxicity, renal toxicity, thrombocytopenia)
- Germline integration and fetal transmission: Risk to offspring
- Environmental risks: Effects on non-target species
2.3 Bacteriophage Veterinary Medicinal Products
Bacteriophages are viruses that specifically infect and kill bacteria. They represent a promising alternative to antibiotics, particularly for treating multidrug-resistant bacterial infections in animals.
2.3.1 Key Risks
Short-Term Safety Risks
- Inflammatory reactions at the site of administration
- Immune responses against phages (may neutralize therapeutic effect)
- Effects due to disturbance of the normal microbiome
Environmental Risks
- Large-scale application and shedding of bacteriophages may affect environmental bacterial communities
- Potential for horizontal gene transfer between bacteria
2.4 Nanotechnology-Derived Veterinary Medicinal Products
Nanotechnology products utilize particles at the nanoscale (typically 1-100 nm) to achieve targeted delivery, improved bioavailability, or controlled release of therapeutic agents.
2.4.1 Key Risks
- Immunotoxicity and immunomodulation: Nanoparticles may activate or suppress immune responses
- Inflammatory or allergic reactions: Including potential for intravascular coagulation or fibrinolysis
- Tissue accumulation and persistence: Nanoparticles may accumulate in organs (liver, spleen, kidneys) and cause chronic inflammation
- Long-term toxicity: Unknown effects of prolonged tissue residence
3. Components of the Risk Management Plan
3.1 Identification of Risks
The RMP requires a systematic approach to identifying both identified risks (undesirable clinical outcomes with sufficient scientific evidence of causation) and potential risks (outcomes suspected but lacking conclusive evidence).
For each risk, the applicant must describe:
- The evidence linking the risk to the VMP
- The clinical consequences of adverse events
- Available treatment options
- Mechanisms for ensuring timely access to treatment
3.2 Early and Delayed Adverse Event Monitoring
3.2.1 Early Adverse Events
The RMP must address the early signs of adverse events that may occur following administration. For example, fever may be the first indication of a cytokine storm following cell or gene therapy. Early detection protocols should include:
- Specific clinical signs to monitor
- Recommended frequency of observations
- Diagnostic tests to confirm adverse events
- Thresholds for intervention
3.2.2 Delayed Adverse Events
Some adverse events may not manifest until weeks, months, or even years after treatment. These include:
- Tumorigenesis (particularly relevant for cell-based and gene therapies)
- Autoimmune disorders
- Late-onset inflammatory reactions
- Delayed hypersensitivity
The RMP should describe methods for detecting delayed events, which may include:
- Long-term follow-up protocols for treated animals
- Regular health checks at specified intervals
- Owner/caregiver education on signs to monitor
- Use of patient registries
3.3 Long-Term Safety and Efficacy Monitoring
The guidance emphasizes the importance of gathering information on long-term outcomes. Key considerations include:
| Aspect | Questions to Address |
|---|---|
| Need for specific follow-up | Does the VMP require specialized long-term monitoring? |
| Monitoring methods | How will long-term safety and efficacy be assessed? |
| Post-authorisation studies | Are additional studies needed to characterize long-term risks? |
| Protocols for follow-up | What specific procedures should be followed for treated animals? |
3.4 Additional Pharmacovigilance Activities
Standard pharmacovigilance activities (adverse event reporting and signal detection) are mandatory for all VMPs. However, novel therapies may require additional pharmacovigilance activities, including:
- Post-authorisation safety studies (PASS) to further characterize risks
- Post-authorisation efficacy studies (PAES) to confirm long-term effectiveness
- Registry-based surveillance using traceability data (e.g., linking batch distribution records to pharmacovigilance databases)
- Active follow-up of treated animals rather than passive reporting
3.5 Risk Minimisation Measures
The RMP must describe both routine and additional risk minimisation measures.
Routine measures include:
- Product information (Summary of Product Characteristics, package leaflet)
- Warning statements
- Contraindications
- Precautions for use
Additional measures may include:
- Educational guides for veterinarians
- Owner/caregiver diaries to record observations
- Checklists for risk minimisation
- Specialized training programs for administering the product
- Controlled distribution systems
4. Examples of Risk Management in Practice
4.1 Monoclonal Antibody Therapies: CVMP Safety Reviews
Monoclonal antibodies represent a growing class of novel veterinary therapies. The CVMP has actively monitored safety signals for these products.
Case Example: Librela (bedinvetmab) for Canine Osteoarthritis
In July 2025, the CVMP announced it was reviewing potential risks of musculoskeletal disorders associated with Librela, a monoclonal antibody for pain caused by osteoarthritis in dogs. The committee was aware of suspected adverse event reports not currently listed in the EU product information, including very rare cases suggesting abnormal progression of osteoarthritis following treatment .
The CVMP requested the marketing authorisation holder (Zoetis) to conduct an in-depth analysis of all available information on suspected musculoskeletal disorders reported since the medicine’s authorisation .
This example demonstrates the importance of ongoing safety surveillance for novel biological products, even after marketing authorisation.
4.2 Positive CVMP Opinion for Novel mAb Therapy
In September 2025, the CVMP adopted a positive opinion for Portela® (relfovetmab), a monoclonal antibody therapy for alleviating pain associated with osteoarthritis in cats. As a long-acting anti-NGF monoclonal antibody, this product represents the type of novel therapy requiring comprehensive risk management planning .
5. Comparative Analysis of Risks by Novel Therapy Type
| Risk Category | Cell-Based | Gene Therapy | Bacteriophage | Nanotechnology |
|---|---|---|---|---|
| Tumorigenicity | High (with extensive cell culture) | Moderate (insertional mutagenesis) | None identified | Low |
| Immunogenicity | Moderate to High | Moderate | Low to Moderate | Moderate |
| Persistence in body | Variable (weeks to months) | Long-term (months to years) | Short-term (days) | Long-term (accumulation) |
| Delayed adverse events | Possible (tumorigenesis) | Yes (late-onset effects) | Unlikely | Possible (chronic inflammation) |
| Environmental risk | Low | Low to Moderate | Moderate (shedding) | Low |
| Off-target effects | Low | Moderate to High | Low (bacteria-specific) | Low |
| Germline integration risk | No | Yes (with integrating vectors) | No | No |
6. Practical Guidance for RMP Development
6.1 Key Questions for Risk Identification
When developing an RMP for a novel veterinary therapy, applicants should consider:
For all novel therapies:
- What adverse events may be expected, and how should they be managed?
- What early signs of adverse events may occur, and how can they be detected?
- How can delayed adverse events be identified?
- Are standard pharmacovigilance measures sufficient?
For clinical consequences:
- What clinical consequences are associated with identified adverse events?
- What treatment options are currently available for these consequences?
- How can timely access to treatment be ensured?
For long-term outcomes:
- Does the VMP require specific long-term follow-up?
- How will long-term safety and efficacy be monitored?
- Are post-authorisation studies necessary?
6.2 RMP Table Structure
The CVMP provides a standardized table format for summarizing risks and associated measures:
| Element | Description |
|---|---|
| Identified or potential risk | Name and description of the risk |
| Evidence linking risk to VMP | Summary of scientific evidence |
| Additional pharmacovigilance activities | Description of studies or monitoring beyond standard PV |
| Additional risk minimisation measures | Educational materials, training, or other measures |
7. The Role of Traceability and Registries
7.1 Traceability Requirements
Given the unique nature of novel therapies, traceability is essential. The RMP should address:
- Batch tracking: Ability to link specific batches of VMP to treated animals
- Record linkage: Connecting pharmacovigilance databases with distribution records
- Long-term follow-up: Mechanisms for tracking outcomes over extended periods
7.2 Patient and Owner Registries
Registries are valuable tools for monitoring novel therapies. They enable:
- Systematic collection of long-term safety and efficacy data
- Identification of rare adverse events
- Assessment of real-world effectiveness
- Characterization of risk factors for adverse outcomes
8. Future Directions and Evolving Standards
8.1 Harmonization of Elemental Impurity Requirements
In February 2026, the EMA published final guidance on risk management for elemental impurities in all veterinary medicinal products, including novel therapies. This guidance establishes a harmonized approach to the identification, assessment, and control of elemental impurities (including heavy metals) across all VMP categories .
For novel therapies, this means manufacturers must apply risk management principles aligned with European Pharmacopoeia requirements, even for product types previously excluded from comparable human medicinal product guidelines .
8.2 Phased Implementation for Low-Risk Products
For immunological veterinary medicinal products (including some novel vaccines), the guidance introduces a phased implementation approach. This reflects their generally low-risk profile and provides additional regulatory flexibility while maintaining alignment with overall quality and safety objectives .
8.3 Use of Bibliographic Evidence
In cases where direct testing for elemental impurities is not feasible or relevant, the guidance allows use of bibliographic data to support conclusions of negligible risk. This flexibility is particularly relevant for novel therapies where traditional analytical methods may be inadequate .
9. Implications for Stakeholders
9.1 For Manufacturers
- Develop robust RMPs early in the product development lifecycle
- Conduct thorough risk assessments based on product characteristics
- Design appropriate pharmacovigilance systems for long-term monitoring
- Prepare educational materials for veterinarians and animal owners
- Establish traceability systems and registries where indicated
9.2 For Veterinarians
- Understand the unique risks associated with novel therapies
- Participate in long-term follow-up protocols
- Report suspected adverse events to pharmacovigilance systems
- Educate animal owners about potential risks and monitoring requirements
- Consider alternative treatments when risk-benefit balance is unfavorable
9.3 For Regulatory Professionals
- Stay informed about evolving CVMP guidance and requirements
- Understand the scientific basis for risk identification and management
- Ensure alignment between RMPs and product information
- Monitor compliance with post-authorisation commitments
10. Conclusion
The EMA/CVMP guidance on risk management plans for novel therapy veterinary medicinal products represents a significant advancement in regulatory science for advanced veterinary medicines. By establishing a structured framework for identifying, monitoring, and mitigating risks, the guidance supports the safe development and use of innovative therapies while protecting animal health and welfare.
Key takeaways:
- Risk-based approach: RMP requirements are proportionate to the inherent risks of the specific novel therapy
- Long-term perspective: Unique risks of novel therapies (tumorigenicity, immunogenicity, delayed effects) require extended monitoring
- Active surveillance: Standard pharmacovigilance may be insufficient; additional measures (registries, follow-up protocols) are often needed
- Flexibility in implementation: Phased approaches and bibliographic evidence options reduce unnecessary burden
- Evolving standards: Ongoing safety reviews (as demonstrated with Librela) ensure continuous benefit-risk assessment
As the field of veterinary regenerative medicine continues to advance, robust risk management planning will be essential for translating scientific innovation into safe, effective treatments for animals.
References
- European Medicines Agency. Committee for Veterinary Medicinal Products. Guidance and template on the risk management plan (RMP) for novel therapy veterinary medicinal products. EMA/CVMP/NTWP/201952/2025. 20 March 2026.
- U.S. Food and Drug Administration. FDA Warns Company Making Stem Cell Products for Pets. MedPage Today. 5 June 2024.
- Zoetis Inc. Zoetis Receives Positive Opinion from CVMP for Portela® (relfovetmab) to Alleviate Pain Associated with Osteoarthritis in Cats. 12 September 2025.
- European Medicines Agency. Meeting highlights from the Committee for Veterinary Medicinal Products (CVMP) 15-17 July 2025. 18 July 2025.
- European Medicines Agency. EMA Issues Final Elemental Impurity Risk Management Guidance for Veterinary Medicinal Products. RegASK. 23 February 2026.
- U.S. Food and Drug Administration. FDA’s Letter to Veterinary Schools regarding Animal Cell-Based Products. Center for Veterinary Medicine. 6 April 2023.
- Regulation (EU) 2019/6 of the European Parliament and of the Council on veterinary medicinal products.
- Council for International Organizations of Medical Sciences (CIOMS). Practical aspects of signal detection in pharmacovigilance. CIOMS Working Group VIII.
