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# CBER Offers Tips for Cell/Gene Therapy BLA Submissions
- URL: https://www.fdaweb.com/cber-offers-tips-for-cell-gene-therapy-bla-submissions/
- Published: 2026-07-27T12:00:00.000Z
- Updated: 2026-09-14T13:43:48.000Z
- Author: David McFarland
- Tags: Biologics, #legacy-id-D5161519

CBER recently used a virtual town hall to urge developers of cell and gene therapies to take advantage of early engagements with the agency well before a BLA filing to help avoid delays and common regulatory pitfalls. According to a [just posted transcript,](https://www.fda.gov/media/193796/download?attachment&ref=fdaweb.com) officials from CBER's Office of Therapeutic Products (OTP) outlined best practices for preparing BLA submissions, with a particular focus on first-time applicants developing advanced therapies.

“In terms of where first-time submitters most commonly run into trouble, CMC \[chemistry, manufacturing and controls\] is probably the biggest one, FDA said. “We see submissions where the manufacturing process description is incomplete, specifications aren't adequately justified, or stability data doesn't cover the proposed shelf life. “It's worth investing real time there before you submit.

“On the clinical side,” the agency continued, “make sure your integrated summaries of safety and efficacy are thorough and clearly tied to your labeling claims. We often see a disconnect between what the data shows and what the sponsor is proposing in the label, and that's something we'll need to work through during review. For nonclinical, ensure your studies are GLP-compliant where required and that study reports are complete. Missing raw data or incomplete reports are more common than you'd think. And don't underestimate information in Module 1\. Missing forms, incomplete financial disclosures, and labeling formatting issues are surprisingly common and can slow things down significantly.”

FDA officials repeatedly highlighted the value of pre-BLA meetings, describing them as the most effective opportunity for sponsors to identify deficiencies before filing. Although such meetings are not mandatory, OTP strongly recommended that companies request them about four months before their planned submission date. Officials said sponsors should arrive with focused questions rather than lengthy presentations and avoid introducing new issues during the meeting that were not included in briefing materials.

The town hall also addressed technical aspects of the BLA process, including rolling reviews, electronic submission requirements and filing reviews. FDA reminded sponsors that rolling review is available only for products that have received RMAT \[Regenerative Medicine Advanced Therapy\], Breakthrough Therapy or Fast Track designations and that review timelines do not begin until the final module of a rolling submission has been received. Officials also warned that missing eCTD components, incomplete FDA Form 356h submissions and improperly structured electronic files remain frequent causes of technical rejection or refuse-to-file decisions.

During a discussion of expedited reviews, FDA officials also disclosed that artificial intelligence (AI) is playing a limited supporting role in the agency reviews. According to OTP, AI is used to summarize large data sets, aggregate information and assist in preparing presentations, while all scientific evaluation and regulatory decision-making remained the responsibility of FDA reviewers. “The actual scientific thinking, the weighing of evidence, the decisions — all of that was done by the review team,” FDA said. “AI helped them work smarter and more efficiently with a dense file, but it didn't do the reviewing. AI is a tool for reviewers, but not a replacement for their judgment in the review.”