Think of SEND as the “official language” for sharing nonclinical lab study results with regulatory agencies like the FDA (in the U.S.) or EMA (in Europe).
If you’ve ever tried to send someone a file in a weird format they couldn’t open, and they sent it back saying “I can’t read this”, that’s exactly what SEND is designed to prevent.
Instead of each company submitting data in their own style, SEND forces everyone to use one standardized format. That way, the reviewer’s software knows exactly where to find:
- Which animal was in which study
- What tests were done
- What results were recorded
- How everything ties together
What is SEND?
SEND is essentially a common language for submitting nonclinical study data to regulatory agencies. It was created by CDISC (Clinical Data Interchange Standards Consortium) to ensure that study results are presented in a consistent, machine-readable format.
A SEND submission includes three key components:
- Datasets – Delivered in XPT (SAS Transport) format, which works like a specialized spreadsheet that regulatory software can read.
- define.xml – A metadata “map” explaining what each variable, column, and code means.
- Nonclinical Study Data Reviewer’s Guide (nSDRG) – A narrative guide for reviewers, based on the PHUSE template, that explains study context and unusual data points.
These datasets must be:
- Complete
- Accurate
- Consistent with the final study report
If your submission includes IND, NDA, or BLA applications with nonclinical data, SEND is likely required.
Why SEND Matters Now
SEND requirements are not just a technical detail, they can determine whether your submission is even reviewed.
In the United States (FDA)
- CDER (Center for Drug Evaluation and Research) has required SEND for most IND-enabling toxicology studies since December 2016.
- CBER (Center for Biologics Evaluation and Research) began requiring SEND for applicable nonclinical studies as of March 15, 2023 (SEND v3.1, v3.1.1, and SEND Genetox v1.0).
- If a submission fails SEND compliance, it can be technically rejected before scientific review begins.
📄 FDA Study Data Standards Resources
In the European Union (EMA)
- The EMA launched a Proof-of-Concept pilot in January 2024 to evaluate SEND for nonclinical data submissions.
- This move is part of a broader strategy to improve regulatory decision-making through structured raw data.
SEND is not just a U.S. requirement anymore, it’s becoming a global standard.
SEND is a Process, Not Just a File
One of the biggest misconceptions about SEND is that it’s just “another dataset to prepare” at the end of a study.
In reality, SEND is an end-to-end process that spans the entire nonclinical study lifecycle:
- Study Protocol & Design – Plan for SEND requirements from day one.
- Data Collection & Annotation – Use compatible systems and consistent variable naming.
- Regulatory Submission & Review – Provide datasets and documentation in the exact structure required.
Benefits of Doing SEND Right
- Clear Data – Reviewers can understand and verify your findings faster.
- Faster Review Cycles – Well-structured data speeds up decision-making.
- Avoiding Rework – Early planning prevents last-minute formatting nightmares.
- Regulatory Confidence – A clean SEND submission signals that you’re organized and reliable.
Key Steps to SEND Success
1. Plan SEND from Day One
Don’t wait until the end of your study to think about SEND. Incorporate it into your protocol design, and make sure your CRO or internal team is prepared.
2. Align Protocols, Data Systems, and CROs
If you’re working with multiple CROs, standardize processes early. Misalignment can cause costly rework later.
3. Quality Control and Validation
Use SEND validation tools before submission to catch errors. Remember: passing technical validation doesn’t guarantee your data makes sense scientifically—check both.
4. Tell a Clear Story
SEND isn’t just about compliance, it’s about communication. Make sure your data supports the conclusions in your final report.
Global Adoption & The Future of SEND
With the EMA’s pilot program underway, SEND is moving toward global adoption. This means that in the near future, both U.S. and European submissions will require SEND compliance.
Organizations that embed SEND planning into their workflows now will be better positioned for smooth, fast approvals later.
Common SEND Challenges (and How to Avoid Them)
Challenge | How to Avoid It |
Incomplete datasets | Build SEND into study design and data collection from the start |
Metadata inconsistencies | Standardize naming conventions and maintain a single metadata source |
CRO coordination issues | Choose CROs with proven SEND experience and communicate expectations early |
Last-minute validation failures | Run validation tools regularly throughout dataset preparation |
Quick FAQs on SEND
Q: What is CDISC SEND?
A standard format for submitting nonclinical study data to regulatory agencies.
Q: Is SEND mandatory for FDA submissions?
Yes, for most IND-enabling toxicology and certain nonclinical studies.
Q: What is included in a SEND dataset?
Datasets in XPT format, define.xml metadata, and an nSDRG guide.
Q: How do I validate SEND datasets?
Use SEND validation tools and run checks early and often during preparation.
Conclusion – SEND Done Right
SEND is here to stay. Whether you’re preparing your first submission or managing multiple CROs, the right approach can turn SEND from a regulatory burden into a tool that actually supports faster, smoother approvals.
Start early, align your teams, validate thoroughly, and make sure your data tells a clear story.
Got a SEND challenge? Contact us, we’re here to help you get it right.