A real-world retrospective analysis of secondary failures to secukinumab in psoriasis and cost comparison of subsequent switching of biologics in a public-funded setting

Background Biologics for psoriasis are typically administered after failure of conventional therapies, with affordability being an important factor in treatment decisions. Since tuberculosis (TB) is endemic in India, IL-17 monocloncal antibodies (mAbs) are often preferred due to their favourable safety profile compared to tumour necrosis factor (TNF)-α inhibitors. However, treatment failures with these agents do occur, raising concerns about their use across all patients with moderate-to-severe psoriasis. Objective Our objective was to analyse the secondary failures to secukinumab in moderate to severe psoriasis patients. The secondary objective was to analyse the cost and efficacy of other biologics after secondary failure to secukinumab. Methods All patients with psoriasis who had failed conventional therapy were administered secukinumab. After the induction phase (defined as treatment till 16 weeks), secukinumab was continued if psoriasis area severity index (PASI) 75 was achieved. Secondary failure was defined as the loss of response (PASI > 50% of the initial value) in a patient who had previously achieved PASI 50 response at week 16. Intra- or inter-class switching of biologics was attempted in these patients and the cost of therapy was calculated at the end of 16 weeks. Results Out of 42 patients who were administered secukinumab, 14 (33%) experienced secondary failure at a mean duration of 7.5 months. All these patients had received multiple conventional oral agents and 9/14 (64%) had received prior TNF-ɑ inhibitors. While secukinumab was up dosed (repeat loading dose given) in 3 patients, 6 were administered TNF-ɑ biologics and 5 were administered ixekizumab. All the patients who were switched to other biologics achieved improvement in PASI (38.7 at secondary failure - reduced to 26.7, p<0.001) with a significantly lowered PASI in the etanercept and ixekizumab group as compared to the secukinumab loading dose group ( p -value 0.003) at the end of the induction phase. Cost comparison revealed that TNF-ɑ biologics were economical alternatives in cases of secondary secukinumab failure, namely etanercept followed by adalimumab and ixekizumab. Limitations Small cohort and a retrospective single-centre design. Conclusion Our data suggests that in case of secondary secukinumab failure, TNFα biologics are a cost-effective option while updosing secukinumab is not consistently effective. However, more data with evaluation of long-term response and value based pricing is needed to guide public funded health care systems.