RE: Warming up Nicely30 Jan 2026 23:46
VLP, the FDA's decision to clear the pediatric expansion for Hemogenyx’s HG-CT-1 trial after just two patients from the adult group is less about the "number" of patients and more about the specific safety results and the unmet medical need in children with Relapsed/Refractory Acute Myeloid Leukaemia (R/R AML).
While it may seem fast, several factors explain why the FDA allowed this transition so early:
1. Exceptional Safety Profile (DSMB Clearance)
In late 2025, an independent Data Safety Monitoring Board (DSMB) reviewed the data from the first three adult patients. Crucially, they found no dose-limiting toxicities (DLTs). In the world of CAR-T therapy—which can often cause severe side effects like Cytokine Release Syndrome (CRS)—a clean safety report from the initial cohort is a powerful "green light" for regulators to allow expansion into more vulnerable populations.
2. High Unmet Need in Pediatrics
Pediatric R/R AML is notoriously difficult to treat and often fatal once standard chemotherapy fails. The FDA frequently uses accelerated pathways or allows earlier pediatric inclusion for life-threatening diseases where no alternative treatments exist. In this case, the potential benefit to children who have no other options was deemed to outweigh the risks of moving forward with limited adult data.
3. Protocol Design & "Dose Escalation"
The pediatric trial isn't jumping straight into high doses. The FDA cleared the pediatric arm to begin at the same lowest dose used in the successful adult cohort. This "dose-parallel" approach allows researchers to gather data on children safely while the adult trial continues to escalate to higher, more experimental doses.
4. Direct Benefit Justification
Under FDA regulations (specifically 21 CFR 50.52), clinical trials involving children are permitted if the research holds out the prospect of direct benefit to the individual subject. Because HG-CT-1 showed early signs of anti-leukemic activity in the first adults, it met the criteria for a "potential benefit" that justified the risk of enrollment.
The above explains why I have constantly stated that I do not believe Hemogenyx will get anywhere near having to treat the ‘up to’ eighteen adult and eighteen children specified. Due to the very criteria set out by the FDA themselves, I firmly believe HG-CT-1 will be fast tracked through the phases and designated a breakthrough therapy, which could lead to it progressing to Phase 3 or best case straight to commercial. Maybe that’s why Vlad is transitioning to Made with their commercial scalability capabilities.
Anyway for that to happen I think we have to successfully treat the next adult at the higher dose and the first child. But I do believe they’ll be treated in February which should mean the technology transfer completion should be announced soon. If I’m right, in March we’ll know just how safe and efficacious HG-CT-1 is and just how valuable.
Lots to be excit