Estimation of patients with psoriasis potentially eligible and currently untreated with biological drugs in Italy

Background: Psoriasis (PSO) patients can benefit from the growing availability of novel biological agents, that are often underused or discontinued. This real-world analysis estimated PSO patients potentially eligible and currently untreated with biologics in Italy. Methods: An observational analysis was performed on administrative databases of a pool of healthcare entities, covering 11.3% of Italian population. During the inclusion period (2010- 2020), patients were identified by: 1) at least one prescription of topical drugs for PSO; or 2) active exemption for PSO; or 3) at least one PSO hospital discharge diagnosis. The index-date was the first PSO identification across inclusion period. Eligibility for biologics was evaluated prior to index-date (characterization period) through two not-mutually exclusive criteria: Criterion A, failure of at least one systemic treatment, and/or Criterion B, onset of psoriatic arthritis (PsA). Data were re-proportioned to the Italian population. Results: The study sample showed a PSO prevalence of 2%. Projection to 2020 national population (N=59,236.213) estimated 1.43 million Italian patients affected by PSO: 95% treated with conventional therapies, 4% with biologics, and 1% untreated. Among those non-treated with biologics, 3.8% of overall PSO patients met one or both eligibility criteria for biologics, specifically 25% met criterion A (failure to conventional treatments), 68% criterion B (PsA co-diagnosis), and 7% met both. About half of them had 1 or 2 comorbidities and 30% above 3. Conclusions: These findings from real clinical practice estimated about 4% PSO patients potentially eligible for biologics, but still untreated, with nearly one-third exhibiting a complex comorbidity profile.