TABLE 2.

Summary of key findings from clinical trials on isotretinoin new formulations

STUDY	OUTCOME MEASURES	KEY FINDINGS
Strauss et al, 200137	Decrease in number of total nodules; % of patients achieving 90% clearance	Efficacy: Micronized isotretinoin (a more bioavailable formulation of isotretinoin) at 0.4mg/kg once daily under fasted conditions was clinically equivalent to the standard isotretinoin (1.0mg/kg in 2 divided doses) under fed conditions in treatment of severe recalcitrant nodular acne for 20 weeks.
Strauss et al, 200136	AEs during 20 weeks of therapy	Safety: The proportion of AEs in most body systems was generally lower in patients receiving once-daily micronized isotretinoin than in those receiving twice-daily standard isotretinoin. Micronized isotretinoin had a safety profile similar to that of standard isotretinoin but a lower risk of mucocutaneous events and hypertriglyceridemia.
Webster et al, 20138	Plasma levels of isotretinoin and its metabolites	The pharmacokinetic profile of lidose isotretinoin was bioequivalent to that of standard isotretinoin formulation under fed conditions, but the novel formulation delivered twice as much isotretinoin and 4-oxo-isotretinoin after an overnight fast, resulting in significantly better absorption of the drug.
Webster et al, 201433	Noninferiority trial on efficacy, safety	Efficacy and safety of lidose isotretinoin, irrespective of food intake, were noninferior to the standard isotretinoin.
Del Rosso et al, 20196	Lesion counts, acne severity, QoL, AEs	After lidose isotretinoin taken without food for 20 weeks, 82.5% patients required no retreatment over the 104-week post-treatment period. Long-term relapse rates were at the low end of those published (5–65%, though variable) for standard isotretinoin taken with an HF/HC meal.
Madan et al, 20207	Pharmacokinetic profiles of fed-state and fasted-state in healthy adults	Micronized isotretinoin 32mg and lidose isotretinoin 40mg were bioequivalent under fed state. Under fasted conditions, micronized isotretinoin 32mg had ~2 times higher bioavailability relative to lidose isotretinoin 40mg. The absorption rate and marginal effect thereof of low-dose micronized isotretinoin were food-independent.
Zaenglein et al, 202038	Lesion counts, QoL, acne severity, and safety assessment	Twice-daily lidose isotretinoin without food for 20 weeks significantly improved patient QoL, lesion counts, and acne severity as early as Week 4.
Epidermolysis Bullosa Burden of Disease (EB-BoD)18	20-item questionnaire for burden on families of children	Epidermolysis bullosa in children
Family Burden Ichthyosis (FBI)19	5 dimensions; for families	Ichthyosis in children
Kingston Caregiver Stress Scale (KCSS)20	10-item scale consisting of 3 sections, “Care-giving issues,” “Family issues,” and “Financial issues,” to assess the multidimensional caregiver stress.	Highly validated scale, mostly used in caregivers of patients with dementia; These authors feel its use may be extrapolated to chronic skin diseases.

AE: adverse event; HF/HC: high-fat/high-calorie; QoL: quality of life