Study of Two Dosages of Roaccutane in Cystic Acne

Randomised Controlled Trial of Two Different Cumulative Dosages of Roaccutane for Cystic Acne

This randomized, single-blind, controlled trial was initiated in 2001 to compare two cumulative isotretinoin doses (120 mg/kg vs 150 mg/kg) in patients with moderate-to-severe nodulo-cystic acne. Participants were assigned to receive a cumulative dose of either 120 mg/kg or 150 mg/kg, administered according to body weight and clinical response.

The primary objectives were to evaluate changes in total acne lesion counts and global acne severity grade from baseline through mid-treatment and end of treatment. Secondary objectives included assessing acne recurrence within 12 months after treatment completion and evaluating changes in acne scarring on the face, chest, and back over follow-up.

A small post-hoc extension cohort included patients who had not achieved satisfactory improvement after reaching their assigned cumulative dose and continued isotretinoin beyond standard targets. These patients were analysed descriptively.

Study Overview

• Status: Completed
• Conditions: Acne Cystic
• Intervention / Treatment: Drug: isotretinoin (Roaccutane); Drug: isotretinoin (Roaccutane)

• Study Type: Interventional
• Enrollment (Actual): 91
• Phase: Phase 4

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Male or Female subjects, of any age and any race
• Clinical diagnosis of nodulo-cystic acne as well as patients who have been unresponsive to standard acne vulgaris treatments

Exclusion Criteria:

• Pregnant or lactating female patients
• Female patients with polycystic ovarian syndrome, insulin resistance syndrome, previous use of Roaccutane, patients with congenital adrenal hyperplasia, patients with any internal malignancy (excluding skin cancer)
• Females of reproductive potential who refuse to take the oral contraceptive pill to take Roaccutane; patients who in the investigator's opinion would be unlikely to be compliant

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Roaccutane 120 mg/kg Group; Participants in this arm received a cumulative dose of approximately 120 mg/kg of Roaccutane (isotretinoin) administered over the treatment period. Dosing was adjusted according to body weight and clinical response, following standard isotretinoin treatment protocols. The outcomes in this group were compared with those in the 150 mg/kg group to assess differences in efficacy, relapse rate, and adverse effects.	Drug: isotretinoin (Roaccutane); Oral administration of isotretinoin (Roaccutane) in capsule form, with cumulative dosage of 120 mg/kg. Dosing was adjusted according to body weight and administered over a period consistent with standard clinical protocols. The intervention was conducted as part of a randomized, single-blind controlled trial with blinded outcome assessment evaluating efficacy, relapse rates, and adverse events in patients with cystic acne.; Drug: isotretinoin (Roaccutane); Oral administration of isotretinoin (Roaccutane) in capsule form, with cumulative dosage of 150 mg/kg. Dosing was adjusted according to body weight and administered over a period consistent with standard clinical protocols. The intervention was conducted as part of a randomized, single-blind controlled trial with blinded outcome assessment evaluating efficacy, relapse rates, and adverse events in patients with cystic acne.
Experimental: Roaccutane 150 mg/kg Group; Participants in this arm received a cumulative dose of approximately 150 mg/kg of Roaccutane (isotretinoin) administered over the treatment period. Dosing was adjusted according to body weight and standard clinical guidelines for isotretinoin therapy. The outcomes for this group were compared with those of the 120 mg/kg group to evaluate differences in efficacy, relapse rates, and adverse effects.	Drug: isotretinoin (Roaccutane); Oral administration of isotretinoin (Roaccutane) in capsule form, with cumulative dosage of 120 mg/kg. Dosing was adjusted according to body weight and administered over a period consistent with standard clinical protocols. The intervention was conducted as part of a randomized, single-blind controlled trial with blinded outcome assessment evaluating efficacy, relapse rates, and adverse events in patients with cystic acne.; Drug: isotretinoin (Roaccutane); Oral administration of isotretinoin (Roaccutane) in capsule form, with cumulative dosage of 150 mg/kg. Dosing was adjusted according to body weight and administered over a period consistent with standard clinical protocols. The intervention was conducted as part of a randomized, single-blind controlled trial with blinded outcome assessment evaluating efficacy, relapse rates, and adverse events in patients with cystic acne.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Total Acne Lesion Count During Isotretinoin Treatment	Change in the total number of acne lesions (whiteheads, blackheads, papules, pustules, nodules, and deep pustules) measured on the face, chest, and back from baseline to week 16, and to the cumulative doses of 120 mg/kg and 150 mg/kg isotretinoin (Roaccutane). Results will be reported as the mean number of lesions at each time point. Lower counts indicate better clinical response.	Baseline, Week 16, and end of treatment (defined as the visit at which the assigned cumulative dose of 120 mg/kg or 150 mg/kg was reached)
Change in Acne Severity Grade During Isotretinoin Treatment	Change in acne severity grade, ranging from 1 (least severe) to 8 (most severe), according to the classification described in Dermatology 1999;198:278-283 (Karger). Assessments are performed at baseline, week 16, and at cumulative isotretinoin doses of 120 mg/kg and 150 mg/kg. Results will be reported as mean acne grade (1-8 scale); lower scores indicate better outcome.	Baseline, Week 16, and end of treatment (defined as the visit at which the assigned cumulative dose of 120 mg/kg or 150 mg/kg was reached)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of Acne Relapse at 3 Months After End of Treatment	Proportion of participants experiencing recurrence of inflammatory acne lesions requiring further systemic or topical therapy within 3 months following completion of isotretinoin treatment (at either 120 mg/kg or 150 mg/kg cumulative dose). Results will be expressed as percentage of participants with relapse.	3 months after completion of isotretinoin treatment
Rate of Acne Relapse at 12 Months After End of Treatment	Proportion of participants experiencing recurrence of inflammatory acne lesions requiring further systemic or topical therapy within 12 months following completion of isotretinoin treatment (at either 120 mg/kg or 150 mg/kg cumulative dose). Results will be expressed as percentage of participants with relapse.	12 months after completion of isotretinoin treatment
Change in Acne Scarring Over Time	Change in the number of atrophic and hypertrophic scars on the face, chest, and back from baseline to end of treatment and to 12-month follow-up. Results will be reported as mean scar counts at each time point.	Baseline, end of treatment (defined as the visit at which the assigned cumulative dose of 120 mg/kg or 150 mg/kg was reached) and 12 months after completion of treatment

Collaborators and Investigators

• Sponsor: Premier Specialists, Australia
• Collaborators: Roche Products Limited

Study record dates

Study Major Dates

• Study Start (Actual): June 26, 2001
• Primary Completion (Actual): March 1, 2025
• Study Completion (Actual): May 10, 2025

Study Registration Dates

• First Submitted: November 7, 2025
• First Submitted That Met QC Criteria: November 11, 2025
• First Posted (Estimated): November 14, 2025

Study Record Updates

• Last Update Posted (Actual): December 23, 2025
• Last Update Submitted That Met QC Criteria: December 19, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Organic Chemicals; Retinoids; Carotenoids; Polyenes; Alkenes; Hydrocarbons, Acyclic; Hydrocarbons; Cyclohexenes; Cyclohexanes; Cycloparaffins; Hydrocarbons, Alicyclic; Hydrocarbons, Cyclic; Terpenes; Pigments, Biological; Biological Factors; Isotretinoin
• Other Study ID Numbers: ROC-ACNE

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data (IPD) will not be shared. The study was conducted before data sharing requirements were established, and participants did not provide consent for their data to be publicly released. No data-sharing infrastructure or plan was created at the time of the study.