Dose Range-Finding Toxicity Study in Rats With Recombinant Human Lactoferrin Produced in Komagataella phaffii

Int J Toxicol. 2024 Jul-Aug;43(4):407-420. doi: 10.1177/10915818241247013. Epub 2024 Apr 22.


The oral toxicity of recombinant human lactoferrin (rhLF, Helaina rhLF, Effera™) produced in Komagataella phaffii was investigated in adult Sprague Dawley rats by once daily oral gavage for 14 consecutive days. The study used groups of 3-6 rats/sex/dose. The vehicle control group received sodium citrate buffer, and the test groups received daily doses of 200, 1000, and 2000 mg of rhLF in sodium citrate buffer per kg body weight. Bovine LF at 2000 mg/kg body weight per day was used as a comparative control. Clinical observations, body weight, hematology, clinical chemistry, iron parameters, immunophenotyping, and gross examination at necropsy were used as criteria for detecting the effects of treatment in all groups and to help select dose levels for future toxicology studies. Quantitative LF levels were also analyzed as an indication of bioavailability. Overall, administration of Helaina rhLF by once daily oral gavage for 14 days was well tolerated in rats at levels up to 2000 mg/kg/day, or 57 × Helaina's intended commercial use in adults, and indicating that a high dose of 2000 mg/kg/day is appropriate for future definitive toxicology studies.

Keywords: Komagataella phaffii; immunophenotyping; lactoferrin; recombinant protein; toxicity.

MeSH terms

  • Administration, Oral
  • Animals
  • Body Weight / drug effects
  • Dose-Response Relationship, Drug*
  • Female
  • Humans
  • Lactoferrin* / toxicity
  • Male
  • No-Observed-Adverse-Effect Level
  • Rats
  • Rats, Sprague-Dawley*
  • Recombinant Proteins* / toxicity
  • Saccharomycetales


  • Lactoferrin
  • Recombinant Proteins

Supplementary concepts

  • Komagataella pastoris