Our team is running a disseminated AML xenograft model (luciferase-tagged cell line, NSG mice, IV injection) to support lead compound efficacy studies. Over the last three cohorts, engraftment has been inconsistent: bioluminescence signal is present but highly variable between animals within the same cohort & roughly 30% of animals show no detectable engraftment by day 14. This is delaying our IND-enabling efficacy timeline and we can’t yet tell whether the issue is cell-line related, technical (injection/handling), or model-related (mouse strain/age/irradiation conditioning).

Scope of work:

• Review current SOP (cell prep, viability/counting method, injection technique, conditioning regimen, imaging schedule)
• Identify likely root cause(s) for engraftment variability
• Recommend specific protocol modifications (e.g., conditioning irradiation dose, cell viability thresholds, injection site/technique, mouse age/vendor sourcing)
• Optional: recommend a small confirmatory pilot cohort design to validate the fix before returning to full efficacy studies