344 Dupilumab significantly improves itch and skin lesions in patients with prurigo nodularis: pooled results from two phase 3 trials (LIBERTY-PN PRIME and PRIME2)

Prurigo nodularis (PN), a chronic inflammatory and pruritic skin condition with severely itchy skin nodules, substantially affects the quality of life and is often inadequately controlled with topical medications. Recently, the US Food and Drug Administration approved dupilumab as the first systemic therapy for PN. Two randomized clinical trials with similar designs, LIBERTY-PN PRIME (NCT04183335) and PRIME2 (NCT04202679), demonstrated the efficacy and safety of dupilumab in adults with PN inadequately controlled with topical medications or for whom those who were inadvisable. To report the efficacy of dupilumab on pruritus and skin lesions in PN, as well as its safety, by analysing pooled data from PRIME and PRIME2 trials, given their similar trial design. PRIME and PRIME2 were multicentre, randomized, placebo-controlled, double-blinded, phase 3 trials, which comprised a 2–4-week screening, 24-week treatment and 12-week follow-up period. Itch severity was measured by Worst Itch Numerical Rating Scale (WI-NRS), ranging from 0 (no itch) to 10 (worst itch imaginable). The severity of skin lesions was assessed using Investigator’s Global Assessment for PN-Stage (IGA PN-S), as score 0 (no nodules), 1 (1–5 nodules), 2 (6–19 nodules), 3 (20–99 nodules) or 4 (over 100 nodules). To be eligible for enrolment patients had WI-NRS ≥7, and IGA PN-S score of 3 or 4. Patients received subcutaneous dupilumab 300 mg (loading dose, 600 mg) or matched placebo every 2 weeks for 24 weeks. Efficacy endpoints were the proportion of patients with a WI-NRS score reduction of ≥4 points, the proportion of patients who achieved an IGA PN-S score of 0 or 1, and the proportion of patients who achieved concomitantly WI-NRS reduction of ≥4 points and IGA PN-S score of 0 or 1, at week 12 and at week 24. At baseline, demographic and disease characteristics were balanced between the PRIME and PRIME2 pooled dupilumab (n = 153), and pooled placebo groups (n = 158). All but 1 patient had used prior topical medications for PN, and 66.2% had used off-label systemic medications. Despite prior therapies, at baseline, the overall mean (standard deviation) WI-NRS score was 8.5 (1.0); 66.3% of patients had 20–99 nodules, and 33.7% had over 100 nodules. At week 12, the ≥4-point reduction in WI-NRS in the dupilumab group was achieved by 62 patients (40.5%), and at week 24, by 90 (58.8%), compared with 30 patients (19.0%) in the placebo group at each time point (P < 0.0001 for both). An IGA PN-S score of 0 or 1 was achieved by 44 (28.8%) patients in the dupilumab group vs. 19 (12.0%) in the placebo group at week 12 (P = 0.0002), and, respectively, by 71 (46.4%) vs. 27 (17.1%) patients at week 24 (P < 0.0001). The concomitant reduction in WI-NRS by ≥4 points and IGA PN-S score of 0 or 1 was achieved by 28 (18.3%) patients in the dupilumab group vs. 11 (7.0%) in the placebo group at week 12 (P = 0.0021), and, respectively, by 54 (35.3%) vs. 14 (8.9%) patients at week 24 (P < 0.0001). The rate of treatment-emergent adverse events was 59.9% with dupilumab and 51.0% with placebo. The most common adverse events were headache (5.3% vs. 5.7%), neurodermatitis (2.0% vs. 5.7%), skin infections (3.9% vs. 7.6%) and injection-site reactions (3.9% vs. 5.7%) in dupilumab vs. placebo groups. Dupilumab demonstrated clinically meaningful and statistically significant improvements in itch and skin lesions vs. placebo in patients with PN, confirming the findings from individual PRIME and PRIME2 studies. The safety profile of dupilumab was consistent with the known safety profile in its approved indications.

341 Dupilumab improves itch and skin lesions in adults with prurigo nodularis regardless of prior use of immunosuppressants or phototherapy: post-hoc results from PRIME and PRIME2 clinical trials

Dupilumab is the only FDA-approved systemic therapy for prurigo nodularis (PN), however, immunosuppressants (IS) and phototherapy have been used off-label for the treatment of this condition. Patients with prior IS/phototherapy treatment may represent a more severe and/or treatment-refractory population of patients with PN. Report post-hoc efficacy of dupilumab in patients with PN, with or without prior use of IS or phototherapy for PN. LIBERTY-PN PRIME and PRIME2 (NCT04183335 and NCT04202679) are randomized, 24-week, phase 3 studies in adults with PN that is inadequately controlled by topical prescription therapies or for whom those therapies are not advisable. Primary outcomes included a ≥4-point improvement in the weekly average of Worst Itch Numerical Rating Scale (WI-NRS) from baseline to week 24, and an Investigator’s Global Assessment for PN stage (IGA PN-S) score of 0/1 (clear/almost clear) at week 24. Safety outcomes included the incidence of treatment-emergent adverse events (TEAEs). Among patients with PN, 8.0% reported prior use of phototherapy, and 36.7% reported prior use of IS; overall, 126 (dupilumab group, n = 62; placebo group, n = 64) patients with and 185 (dupilumab, n = 91; placebo, n = 94) patients without prior IS/phototherapy use were included. A larger proportion of patients with prior treatment vs. patients without prior treatment had severe disease, as measured by IGA PN-S (40.5% vs. 29.0%). The baseline WI-NRS score (SD) for overall patients with prior treatment was 8.6 (1.0) and for patients without prior treatment was 8.4 (1.0). At week 24, 67.7% vs. 15.6% of patients in the dupilumab vs. placebo groups with prior treatment (odds ratio [95% confidence interval]: 13.6 [3.7–49.7]; P < 0.0001), and 52.7% vs. 21.3% of patients without prior treatment (5.8 [2.4–14.0]; P < 0.0001) achieved improvement in WI-NRS. Similarly, 35.5% vs. 10.9% (3.1 [1.2–8.4]; P = 0.0162) of patients with and 53.8% vs. 21.3% (5.0 [2.3–10.8]; P < 0.0001) of those without prior treatment achieved IGA PN-S score of 0/1, respectively. TEAEs were reported by 43 (69.4%) vs. 34 (53.1%) patients (dupilumab vs. placebo groups) with and 54 (60.0%) vs. 55 (59.1%) without prior treatment, respectively. Patients treated with dupilumab experienced a greater and clinically meaningful improvement in itch and achieved skin that was clear/almost clear of nodules at week 24, regardless of prior use of IS/phototherapy for the treatment of PN. The incidence of TEAEs was generally consistent among patients with and without prior IS/phototherapy.