Pharmacotherapeutic group: Other dermatological preparations, other dermatologicals, ATC code: D11AX22
Mechanism of action
Ivermectin is a member of the avermectin class. Avermectin has anti-inflammatory effects by inhibiting lipopolysaccharide-induced production of inflammatory cytokines. Anti-inflammatory properties of cutaneous ivermectin have been observed in animal models of skin inflammation. Ivermectin also causes death of parasites, primarily through binding selectively and with high affinity to glutamate-gated chloride channels, which occur in invertebrate nerve and muscle cells. The mechanism of action of Soolantra in treating the inflammatory lesions of rosacea is not known but may be linked to anti-inflammatory effects of ivermectin as well as causing the death of Demodex mites that have been reported to be a factor in inflammation of the skin.
Clinical efficacy and safety
Soolantra applied once daily at bedtime was evaluated in the treatment of inflammatory lesions of rosacea in two randomised, double-blind, vehicle-controlled clinical studies, which were identical in design. The studies were conducted in 1371 subjects aged 18 years and older who were treated once daily for 12 weeks with either Soolantra or vehicle.
Overall, 96% of subjects were Caucasian and 67% were female. Using the 5-point Investigator Global Assessment (IGA) scale, 79% of subjects were scored as moderate (IGA=3) and 21% scored as severe (IGA= 4) at baseline.
The co-primary efficacy endpoints in both clinical studies were the success rate based on the IGA outcome (percentage of subjects “clear” and “almost clear” at Week 12 of the study) and absolute change from baseline in inflammatory lesion counts. The IGA scale is based on the following definitions:
Table 2: Investigator Global Assessment (IGA) scale
| Grade | Score | Clinical Description |
| Clear | 0 | No inflammatory lesions present, no erythema |
| Almost Clear | 1 | Very few small papules/pustules, very mild erythema present |
| Mild | 2 | Few small papules/pustules, mild erythema |
| Moderate | 3 | Several small or large papules/pustules, moderate erythema |
| Severe | 4 | Numerous small and/or large papules/pustules, severe erythema |
The results from both clinical studies demonstrated that Soolantra applied once daily for 12 weeks was statistically superior to vehicle cream in terms of IGA success rate and absolute change in inflammatory lesion counts (p<0.001, see table 3 and Figure 1, Figure 2, Figure 3 and Figure 4).
The following table and figures present efficacy outcomes from both studies.
Table 3: Efficacy Results
| | Study 1 | Study 2 |
| Soolantra (N=451) | Vehicle (N=232) | Soolantra (N=459) | Vehicle (N=229) |
| Investigator Global Assessment | | | | |
| Number (%) of Subjects Clear or Almost Clear in the IGA at Week 12 | 173 (38.4) | 27 (11.6) | 184 (40.1) | 43 (18.8) |
| Inflammatory Lesions | | | | |
| Mean Inflammatory Lesion Count at Baseline | 31.0 | 30.5 | 33.3 | 32.2 |
| Mean Inflammatory Lesion Count at Week 12 | 10.6 | 18.5 | 11.0 | 18.8 |
| Mean Absolute Change (%Change) in Inflammatory Lesion Count from Baseline at Week 12 | -20.5 (-64.9) | -12.0 (-41.6) | -22.2 (-65.7) | -13.4 (-43.4) |
Figures 1 and 2: IGA Success Rates Over Time in weeks

Figures 3 and 4: Mean Absolute Change in Inflammatory Lesion Counts from Baseline Over Time in weeks

Soolantra was statistically superior to vehicle cream on the co-primary efficacy endpoints with a time to onset of efficacy of 4 weeks of treatment (p<0.05).
IGA was assessed during the 40-week extension of the two clinical studies and the percentages of subjects treated with Soolantra achieving an IGA score of 0 or 1 continued to increase up to Week 52. The Success Rate (IGA=0 or 1) at Week 52 was 71% and 76% in Studies 1 and 2, respectively.
The efficacy and safety of the medicinal product in the treatment of inflammatory lesions of rosacea were also evaluated in a randomised, investigator-blinded, active-controlled clinical study. The study was conducted in 962 subjects aged 18 years and older who were treated for 16 weeks with either Soolantra once daily or Metronidazole 7.5 mg/g cream twice daily. In this study, 99.7% of subjects were Caucasian and 65.2% were female; on the IGA scale, 83.3% of subjects were scored as moderate (IGA=3) and 16.7% scored as severe (IGA=4) at baseline (see figure 5).
The results of the study demonstrated that Soolantra was statistically superior to Metronidazole 7.5 mg/g cream on the primary efficacy endpoint (Mean Percent Change in Inflammatory Lesion Counts) with a reduction of 83.0% and 73.7% from baseline after 16 weeks of treatment for the ivermectin and metronidazole groups respectively (p<0.001). The superiority of Soolantra at Week 16 was confirmed on Success Rate based on IGA and Absolute Change in Inflammatory Lesion Counts (secondary endpoints (p<0.001).
Figure 5:
Mean percent change over time in weeks

Approximately 300 subjects aged 65 years and older were treated over all clinical trials with the medicinal product. No meaningful differences in the efficacy and safety profile were observed between elderly subjects and subjects 18 to 65 years of age.
The safety profile, as described in section 4.8 remained stable over conditions of long-term use as observed in long-term treatments up to one year.
Treatment with ivermectin plus 40 mg doxycycline modified release capsules
The ANSWER study evaluated the relative efficacy of Soolantra (IVM) in combination with doxycycline 40 mg modified release capsules (DMR) vs IVM plus placebo for DMR (PBO) in the treatment of severe rosacea. It was a 12-week, randomized, investigator-blind, controlled, parallel-group study of 273 male and female subjects aged ≥18 years with 20-70 inflammatory lesions (papules and pustules) on the face and a Baseline Investigator's Global Assessment score (IGA) of 4.
The primary efficacy endpoint was the percentage change from Baseline in inflammatory lesion counts at Week 12. A significantly greater mean percentage reduction in inflammatory lesion count was seen for IVM + DMR compared to IVM + PBO (mean±standard deviation: -80.29 ± 21.65 % vs -73.56 ± 30.52%; p=0.032).
Paediatric population
The European Medicines Agency has waived the obligation to submit the results of studies with Soolantra in all subsets of the paediatric population in papulopustular rosacea (see section 4.2 for information on paediatric use).