Efficacy and safety of topical acetylcysteine combined with the use of an overcurvature-correcting device in patients with pincer nail deformity: a randomized, vehicle-controlled, investigator-blinded study

Figures & data

Figure 1. Patient disposition. The full analysis set (N = 70) used for efficacy outcomes included all patients randomized to treatment in the main part of the study. The safety set (N = 78) included an additional eight patients. AC: acetylcysteine gel; AE: adverse event.

Table 1. Baseline demographic and clinical characteristics (safety set).

	Efficacy analysis				Additional patients included in the safety analysis
	AC gel			Vehicle	AC gel
	10% (n = 18)	20% (n = 18)	30% (n = 17)	(n = 17)	30% (n = 8)
Female sex, n (%)	16 (88.9)	12 (66.7)	10 (58.8)	15 (88.2)	8 (100)
Age
Mean (SD)	49.3 (7.7)	49.3 (13.3)	47.6 (9.3)	50.5 (12.5)	55.3 (10.5)
Range	30–63	21–68	30–61	28–66	37–70
Distal narrowed nail width ratio (%)
Mean (SD)	39.8 (8.4)	38.9 (7.4)	38.6 (5.9)	38.9 (7.9)	32.7 (8.8)
Range	20.5–49.5	20.4–49.5	27.1–46.8	23.9–50.0	20.0–45.0
Proximal narrowed nail width ratio (%)
Mean (SD)	69.0 (4.2)	69.3 (5.4)	70.9 (5.3)	68.3 (4.3)	65.0 (4.0)
Range	58.5–75.3	58.7–79.5	63.3–82.9	61.4–75.6	60.5–71.9
Medical history of ingrown nail, n (%)
Yes	3 (16.7)	5 (27.8)	4 (23.5)	2 (11.8)	2 (25.0)
No	15 (83.3)	13 (72.2)	13 (76.5)	15 (88.2)	6(75.0)
Patient questionnaire, n (%)
Dissatisfaction with shape
Very dissatisfied	5 (27.8)	6 (33.3)	8 (47.1)	4 (23.5)	–
Moderately dissatisfied	11 (61.1)	7 (38.9)	4 (23.5)	7 (41.2)	–
Slightly dissatisfied	2 (11.1)	3 (16.7)	5 (29.4)	5 (29.4)	–
Not at all dissatisfied	0	2 (11.1)	0	1 (5.9)	–
Pain caused by pincer nail in the past year
Yes	8 (44.4)	6 (33.3)	5 (29.4)	4 (23.5)	–
No	10 (55.6)	12 (66.7)	12 (70.6)	13 (76.5)

AC: acetylcysteine; PK: pharmacokinetic; SD: standard deviation.

Figure 2. Distal narrowed nail width ratios. (A) Time course of change, (B) absolute change, and (C) rate of change (full analysis set). Data are shown as mean ± standard deviation, and missing values were not imputed.

Figure 3. Assessments of morphological changes in distal narrowed nail width. (A) Absolute improvement in narrowing, (B) rate of change of narrowing, and (C) reduction in excessive transverse curvature (full analysis set). in panel ‘C’, 1 denotes no ‘excessive transverse curvature’ was observed on distal bilateral margins of nail plate, and the patient was judged to be recovered; 2 denotes slight ‘excessive transverse curvature’ was observed on distal bilateral margins of nail plate, and the patient was not recovered (corrective treatment may or may not be given); 3 denotes ‘excessive transverse curvature’ on distal bilateral margins of the nail plate was observed, and corrective treatment was recommended.

Table 2. Summary of safety outcomes (safety set).

	AE regardless of causality				Drug-related AE				Non-drug-related AE
	AC 10%	AC 20%	AC 30%	Vehicle	AC 10%	AC 20%	AC 30%	Vehicle	AC 10%	AC 20%	AC 30%	Vehicle
	(n = 18)	(n = 18)	(n = 25)	(n = 17)	(n = 18)	(n = 18)	(n = 25)	(n = 17)	(n = 18)	(n = 18)	(n = 25)	(n = 17)
AE, n (%)	3 (16.7)	5 (27.8)	7 (28.0)	1 (5.9)	1 (5.6)	3 (16.7)	2 (8.0)	0 (0)	2 (11.1)	2 (11.1)	5 (20.0)	1 (5.9)
Serious AE, n (%)	1 (5.6)	0	0	0	0	0	0	0	1 (5.6)	0	0	0
Death, n (%)	0	0	0	0	0	0	0	0	0	0	0	0
AESI, n (%)
Inflammation^a	1 (5.6)	0	0	0	0	0	0	0	1 (5.6)	0	0	0
AE requiring device removal	0	0	1 (4.0)	1 (5.9)	0	0	1 (4.0)	0	0	0	0	1 (5.9)
Other AE occurring at the site of AC application	2 (11.1)	5 (27.8)	7 (28.0)	1 (5.9)	1 (5.6)	3 (16.7)	2 (8.0)	0	1 (5.6)	2 (11.1)	5 (20.0)	1 (5.9)

AC: acetylcysteine gel; AE: adverse event; AESI: adverse event of special interest.

^aInflammation around the nail to which AC gel was applied (i.e. erythema, oedema).

Data availability statement

The research data underlying this study are subject to restrictions and cannot be shared.