Dr. Alex Tatem connected human thymosin beta-4 trials, nearly 190,000 compounded vials, FDA's own empty adverse-event searches, and a 503A-quality submission into one forceful PCAC argument.
Dr. Alex Tatem went off script during the July 2026 PCAC hearing and made the case for TB-500 directly to the committee.
He connected TB-500 to human thymosin beta-4 trial data, presented real-world experience from nearly 190,000 vials, highlighted FDA searches that found no adverse-event reports, and challenged the evidence selected for the public record.
Watch Dr. Alex Tatem's TB-500 PCAC testimony.
Human thymosin beta-4 trials belong in the record
Formal human trials have studied full-length thymosin beta-4. Tatem argued that those trials provide relevant safety context because TB-500 corresponds to its active 17–23 fragment.
His point was straightforward: the human experience with thymosin beta-4 should inform the committee's view of the active fragment at the center of the TB-500 discussion.
Nearly 190,000 TB-500-containing vials
Tatem then presented real-world data from one compounding-pharmacy network covering nearly 190,000 vials containing TB-500.
- Seven complaints across the full dataset
- One complaint involving standalone TB-500
- Zero serious complaints identified in the testimony
The scale gave the committee a concrete view of TB-500 use already taking place through compounding pharmacies.
FDA's own searches found no TB-500 reports
FDA's TB-500 briefing document states that its FAERS search retrieved no adverse-event reports associated with TB-500. The agency's literature search also found no published human adverse-event cases.
Tatem put those findings beside the real-world vial data and asked the committee to judge the full record.
The certificate and monograph challenge
Tatem criticized FDA for displaying a research-use-only certificate of analysis while excluding, according to his testimony, a 503A-quality certificate and proposed monograph submitted before the deadline.
That challenge moved the hearing from an abstract debate to a concrete question about which manufacturing and quality materials the committee was allowed to see.
A regulated Category 1 route
Tatem's argument: Category 1 status would move TB-500 production under regulated compounding oversight and give patients an alternative to grey-market research products.
That was the heart of his case. Demand already exists. The stronger answer is a 503A route with pharmacy oversight, documented quality materials, and patient-specific prescriptions.
TB-500 wins the PCAC vote
PCAC voted 8 yes, 6 no, and 1 abstention on TB-500. The favorable result added a third Day 1 win after BPC-157 and KPV.
See the full meeting timeline on Rebody's live PCAC peptide vote tracker, or read the complete July 23 PCAC results recap.
TB-500 PCAC FAQ
How many TB-500-containing vials were represented?
Dr. Alex Tatem presented data covering nearly 190,000 vials from one compounding-pharmacy network.
What did FDA's searches find?
FDA's briefing document says its FAERS search retrieved no TB-500 adverse-event reports and its literature search found no published human adverse-event cases.
How did PCAC vote on TB-500?
TB-500 received 8 yes votes, 6 no votes, and 1 abstention.