SENDIG-GeneTox v1.0: What You Need to Know

A thorough guide to this new SEND standard to help your team be prepared.

On March 15, 2025, the Standard for Exchange of Nonclinical Data (SEND) Implementation Guide Genetic Toxicology version 1.0 (SENDIG-GeneTox v1.0) will become a regulatory requirement for in vivo genetic toxicology data submissions to the FDA. 

This update is the most significant change to SEND in recent years. It introduces new structured guidelines for reporting genetic toxicology – or GeneTox – study results. Organizations conducting in vivo micronucleus or comet assays must understand the changes and prepare accordingly to ensure compliance and avoid submission delays.

So, what do you need to know about SENDIG-GeneTox v1.0, and how can you ensure a seamless transition ahead of the deadline?

What Is SENDIG-GeneTox v1.0?

SENDIG-GeneTox v1.0 is an implementation guide designed to standardize the submission of in vivo genetic toxicology data in compliance with SEND. It builds on SEND v3.1.1 and Study Data Tabulation Model (SDTM) v1.5, ensuring that nonclinical study data from micronucleus and comet assays are formatted in a structured manner to facilitate regulatory review¹.

Key features of SENDIG-GeneTox v1.0:

• Only one new domain (GV) for genetic toxicology test results.
• Standardized parameters for study design and findings.
• Controlled terminology for GeneTox study terms, supporting consistency in submissions.
• It should be used in conjunction with SENDIG v3.1.1.

Why Does This Update Matter?

Genetic toxicology studies are an essential step in the drug development pipeline; they assess whether a compound could cause DNA damage or mutations. The two study types covered under this update – the in vivo micronucleus and comet assays – are among the most widely used for nonclinical safety assessments:

• The in vivo micronucleus assay detects chromosomal damage, which can indicate that there may be carcinogenic or hereditary disease risks². 
• The comet assay, also known as single-cell gel electrophoresis, measures DNA strand breaks and provides insight into a compound’s genotoxic potential and DNA repair mechanisms³.

With the new SEND mandate for GeneTox studies, data from these two types of studies will be standardized, making it easier for regulatory agencies to assess findings efficiently. Compliance will be mandatory for companies submitting relevant nonclinical studies to the FDA after 15 March 2025^1,4. 

Key Benefits of SENDIG-GeneTox v1.0

1. Regulatory Compliance and Efficiency

SENDIG-GeneTox v1.0 ensures that genetic toxicology study data align with FDA submission requirements, reducing the risk of regulatory delays or rejections⁴. A standardized format allows for greater automation and consistency in FDA reviews, streamlining communication between sponsors and regulators. This enables faster data assessment and drug approvals, with the ultimate goal of supporting patient safety⁵.

2. Improved Scientific Rigor and Comparability

Standardization enhances study-to-study consistency, making it easier to compare results across different GeneTox studies. This structured approach improves data quality, strengthens scientific decision-making, and enables cross-study trend analysis⁶. Moreover, by reducing variability and errors in data reporting, SENDIG-GeneTox v1.0 helps researchers generate more reliable insights into toxicity risks.

3. Enhanced Data Management and Reuse

With structured datasets, organizations can integrate GeneTox study results into larger datasets, improving accessibility and long-term data archiving⁶. Researchers can also repurpose existing datasets, reducing redundancy and maximizing the value of GeneTox studies.

How to Prepare for SENDIG-GeneTox v1.0

With the deadline for adopting SENDIG-GeneTox v1.0 coming up soon, affected companies need to plan ahead to ensure a smooth transition to the new SEND standard. Our recommended approach differs depending on the number of GeneTox studies conducted annually.

Organizations Conducting More Than 10 Genetic Toxicology Studies Annually:

• Work with SEND specialists to ensure internal teams are trained and ready for the update.
• Implement validated tools to support SEND-compliant data management, conversion, and submission.
• Conduct independent quality control reviews of SEND datasets to identify and correct errors before submission.
• Utilize automated reporting tools to generate define.xml files and study data reviewers’ guides efficiently.

Organizations Conducting Fewer Than 10 Genetic Toxicology Studies Per Year:

• Consider outsourcing SEND dataset preparation to a specialist vendor. This is often the most cost-effective and resource-efficient approach for companies with limited GeneTox study requirements who don’t already have significant in-house expertise.

Next Steps

With the March 2025 deadline quickly approaching, organizations must act now to ensure compliance with SENDIG-GeneTox v1.0. Whether your organization decides on internal training, process optimization, or outsourcing SEND dataset preparation, taking a proactive approach will help streamline regulatory submissions and minimize compliance risks.

Is your team ready for SENDIG-GeneTox v1.0? For a detailed breakdown of the new requirements and best practices for implementation, download our recent white paper.

References

1. SENDIG-Genetox v1.0 | CDISC. June 28, 2023. Accessed February 10, 2025. https://www.cdisc.org/standards/foundational/send/sendig-genetox-v1-0

2. Hayashi M. The micronucleus test—most widely used in vivo genotoxicity test—. Genes Environ. 2016;38(1):18. doi:10.1186/s41021-016-0044-x

3. Langie SAS, Azqueta A, Collins AR. The comet assay: past, present, and future. Front Genet. 2015;6:266. doi:10.3389/fgene.2015.00266

4. SEND | CDISC. March 30, 2021. Accessed February 11, 2025. https://www.cdisc.org/standards/foundational/send

5. Choudhary S, Walker A, Funk K, Keenan C, Khan I, Maratea K. The Standard for the Exchange of Nonclinical Data (SEND): Challenges and Promises. Toxicol Pathol. 2018;46(8):1006-1012. doi:10.1177/01926233188057436.

6. Briggs K. Making sense of SEND; the Standard for Exchange of Nonclinical Data. Regul Toxicol Pharmacol. 2017;91:77-85. doi:10.1016/j.yrtph.2017.10.012