Omalizumab in the treatment of bullous pemphigoid resistant to first-line therapy: a French national multicentre retrospective study of 100 patients.

BACKGROUND: Interest in the use of omalizumab to treat bullous pemphigoid (BP) in the event of resistance or contraindication to conventional therapies is currently based on limited evidence. OBJECTIVES: To assess the effectiveness and safety of omalizumab in BP and to identify predictive factors in response to treatment. METHODS: We conducted a French national multicentre retrospective study including patients with a confirmed diagnosis of BP treated with omalizumab after failure of one or several treatment lines. We excluded patients with clinically atypical BP, as per Vaillant's criteria. The criteria for clinical response to omalizumab were defined according to the 2012 international consensus conference. Anti-BP180-NC16A IgE enzyme-linked immunosorbent assay was performed on sera collected before initiating omalizumab, when available. RESULTS: Between 2014 and 2021, 100 patients treated in 18 expert departments were included. Median age at diagnosis was 77 years (range 20-98). Complete remission (CR) was achieved in 77% of patients, and partial remission in an additional 9%. CR was maintained 'off therapy' in 11.7%, 'on minimal therapy' in 57.1%, and 'on non-minimal therapy' in 31.2%. Median time to CR was 3 months (range 2.2-24.5). Relapse rate was 14%, with a median follow-up time of 12 months (range 6-73). Adverse events occurred in four patients. CR was more frequently observed in patients with an increased serum baseline level of anti-BP180-NC16A IgE (75% vs. 41%; P = 0.011). Conversely, urticarial lesions, blood total IgE concentration or eosinophil count were not predictive of CR. Patients with an omalizumab dosage > 300 mg every 4 weeks showed a similar final outcome to those with a dosage ≤ 300 mg every 4 weeks, but control of disease activity [median 10 days (range 5-30) vs. 15 days (range 10-60); P < 0.001] and CR [median 2.4 months (range 2.2-8.2) vs. 3.9 months (range 2.3-24.5); P < 0.001] were achieved significantly faster. CONCLUSIONS: We report the largest series to date of BP treated by omalizumab and confirm its effectiveness and safety in this indication. Serum baseline level of anti-BP180-NC16A IgE may predict response to treatment.

Anti-BP180 IgG antibody ELISA values correlate with adverse pregnancy outcomes in pemphigoid gestationis.

BACKGROUND: Adverse pregnancy outcomes (APO) occur in 35% of patients with pemphigoid gestationis (PG). No biological predictor of APO has been established yet. OBJECTIVES: To assess a potential relationship between the occurrence of APO and the serum value of anti-BP180 antibodies at the time of PG diagnosis. METHODS: Multicentre retrospective study conducted from January 2009 to December 2019 in 35 secondary and tertiary care centres. INCLUSION CRITERIA: (i) diagnosis of PG according to clinical, histological and immunological criteria, (ii) ELISA measurement of anti-BP180 IgG antibodies determined at the time of PG diagnosis with the same commercial kit and (iii) obstetrical data available. RESULTS: Of the 95 patients with PG included, 42 had one or more APO, which mainly corresponded to preterm birth (n = 26), intrauterine growth restriction (IUGR) (n = 18) and small weight for gestational age at birth (n = 16). From a ROC curve, we identified a threshold of 150 IU ELISA value as the most discriminating to differentiate between patients with or without IUGR, with 78% sensitivity, 55% specificity, 30% positive and 91% negative predictive value. The threshold >150 IU was confirmed using a cross-validation based on bootstrap resampling, which showed that the median threshold was 159 IU. Upon adjusting for oral corticosteroid intake and main clinical predictors of APO, an ELISA value of >150 IU was associated with the occurrence of IUGR (OR = 5.11; 95% CI: 1.48-22.30; p = 0.016) but not with any other APO. The combination of blisters and ELISA values higher than 150 IU led to a 2.4-fold higher risk of all-cause APO (OR: 10.90; 95% CI: 2.33-82.3) relative to patients with blisters but lower values of anti-BP180 antibodies (OR of 4.54; 95% CI 0.92-34.2). CONCLUSION: These findings suggest that anti-BP180 antibody ELISA value in combination with clinical markers is helpful in managing the risk of APO, in particular IUGR, in patients with PG.

3D Coculture Models Underline Metastatic Melanoma Cell Sensitivity to Vemurafenib.

IMPACT STATEMENT: Three dimensional in vitro cell culture systems better reflect the native structural architecture of tissues and are attractive to investigate cancer cell sensitivity to drugs. We have developed and compared several metastatic melanoma (MM) models cultured as a monolayer (2D) and cocultured on three dimensional (3D) dermal equivalents with fibroblasts to better unravel factors modulating cell sensitivity to vemurafenib, a BRAF inhibitor. The heterotypic 3D melanoma model we have established summarizes paracrine signalization by stromal cells and type I collagen matrix, mimicking the natural microenvironment of cutaneous MM, and allows for the identification of potent sensitive melanoma cells to the drug. This model could be a powerful tool for predicting drug efficiency.