Abstract
The preclinical safety of human-equivalent lactoferrin alpha (heqLFα; effera
®
), produced by
Komagataella phaffii
, was evaluated to support its use as a food ingredient in infant formula and products for young children. Genotoxicity was assessed using a bacterial reverse mutation (Ames) assay in five strains of
Salmonella typhimurium
and
Escherichia coli,
and an in vitro micronucleus assay in TK6 cells. Both studies followed OECD guidelines and were conducted up to the recommended limit concentrations (5000 µg/plate and 2000 µg/mL, respectively). A 14-day non-GLP juvenile dose range-finding study and a 13-week GLP juvenile rat toxicity study with a 4-week recovery phase were conducted under ICH S11 guidance. Neonatal Sprague-Dawley rats received heqLFα at 0, 1500, 3000, or 5000 mg/kg body weight/day by twice-daily oral gavage from postnatal day 7 to 98. Bovine lactoferrin (bLF) and whey protein at 5000 mg/kg body weight/day served as reference controls. heqLFα was non-mutagenic and non-clastogenic in both genotoxicity assays. In the 13-week juvenile rat study, no heqLFα-related mortality, clinical signs, developmental, neurobehavioral, or immune toxicity effects were observed. Minor, non-adverse renal findings consistent with high protein intake were observed and largely reversed during recovery. Clinical pathology parameters fully resolved during recovery. Toxicokinetic evaluation showed no systemic accumulation. Based on the absence of toxicologically relevant adverse findings, heqLFα is well tolerated at doses up to 5000 mg/kg body weight/day, establishing a no observed adverse effect level (NOAEL) of 5000 mg/kg/day, the highest dose tested, and supporting its safety across intended populations from birth to adulthood.