Growth and safety of infants with cow’s milk allergy receiving a new hydrolyzed rice protein-based formula containing 2-fucosyllactose and lacto-N-neotetraose: protocol for a randomized clinical trial. The RIGHT-GO study

Hydrolyzed rice formulas (HRF) are recommended by expert societies as a suitable option for the management of non-breastfed infants with cow's milk allergy (CMA). There is a growing trend towards the use of HRF driven by their plant-based source, appealing taste, and established safety and efficacy. Human milk oligosaccharides (HMOs) play a significant role in promoting gut and immune health of infants. There is currently no evidence regarding the growth and safety of infants receiving HRF containing two HMOs. The aim of the RIGHT-GO study is to assess the growth, safety and health-related quality of life of infants receiving a new HRF containing two manufactured HMOs, 2-fucosyllactose (2'FL) and lacto-N-neotetraose (LNnT). RIGHT-GO is a randomized controlled blinded multi-center trial (NCT06633250) conducted in Europe. Healthy full-term formula-fed infants ≤ 8 months of age with physician-diagnosed or suspected CMA will be randomized to receive either the new HRF (HRF-HMO) or an extensively hydrolyzed formula (eHF-HMO) for 4 months. Both formulas contain 1.5 g/L of 2'FL and LNnT (2:1 ratio). The primary objective is to demonstrate that infants with CMA fed the new HRF-HMO have age-appropriate growth that is non-inferior to that of infants with CMA fed a control eHF-HMO. The sample size required to demonstrate non-inferiority in weight-for-age z-score with a non-inferiority margin of -0.5 standard deviation is 104 infants (52 per group). Secondary outcomes include other growth parameters (length, head circumference, bone length), allergy symptoms, gastrointestinal tolerance, health-related quality of life, as well as adverse events and formula compliance. Assessments will take place at enrollment, then monthly until 4 months post-enrollment. The RIGHT-GO study will provide strong evidence on the growth, safety and gastrointestinal tolerance of the new HRF-HMO in infants with physician-diagnosed or suspected CMA. The results will be presented at scientific meetings and published in international peer-reviewed journals. Clinical trial registration: https://clinicaltrials.gov/study/NCT06633250, Identifier: NCT06633250.