The management of moderate-to-severe psoriasis has advanced over the past decade with the introduction of biologic therapies targeting interleukin (IL)-17A and IL-23. IL-17A inhibitors are associated with rapid and highly effective action and provide lasting clearance of lesions, whereas IL-23 inhibitors provide more sustained responses with less frequent dosing.

Bimekizumab is an immunoglobulin G1 monoclonal antibody that selectively inhibits both IL-17A and IL-17F, extending beyond the mechanism of earlier IL-17-targeted therapies.

Findings presented in the Journal of Allergy and Clinical Immunology suggested that dual inhibition of IL-17A and IL-17F may combine rapid response with sustained efficacy, reflecting the key advantages of both IL-17 and IL-23 pathway inhibitions.

Sustained Response

In the phase 3 trials, BE VIVID, BE READY, and BE SURE, 865 of 989 patients (87.5%) receiving 320 mg of bimekizumab for 4 weeks achieved at least a 90% improvement in the Psoriasis Area and Severity Index (PASI 90) at week 16, while 620 (62.7%) achieved complete skin clearance (PASI 100).

Among the patients who achieved PASI 90 at week 16, 79 were re-randomized to receive placebo in the BE READY trial, while 503 continued bimekizumab and entered the BE BRIGHT open-label extension study.

Cost Trade-Offs

Among patients who achieved complete skin clearance (PASI 100) at week 16, 71.6% maintained this response throughout year 4. Overall, disease control remained high, with 91.3% of patients responding. Similar outcomes were observed with doses administered every 4 or 8 weeks.

In the BE READY study, patients with PASI 100 at week 16 who were re-randomized to receive placebo (n = 79) showed a gradual loss of response. The median times from re-randomization to loss of PASI 100, PASI 90, and PASI 75 were 20, 24, and 28 weeks, respectively. When measured from the last bimekizumab dose at week 12, the corresponding median times were 24, 28, and 32 weeks.

These findings demonstrated that bimekizumab provides both rapid and sustained efficacy. More than 87% of patients achieved PASI 90 at week 16, and approximately 70% of those who achieved PASI 90 or PASI 100 maintained this level of response for 4 years.

The availability of bimekizumab for moderate-to-severe psoriasis is clinically important. However, its high cost may have important economic implications for patients and the healthcare system.

Despite its strong efficacy, cost remains a significant limitation. A US-based simulation comparing first-year treatment strategies in 500,000 adults evaluated three options: (1) treatment with bimekizumab, a highly and durably effective biologic; (2) narrowband ultraviolet B phototherapy, a classic treatment that has proven effective; and (3) a stepwise strategy starting with phototherapy for 16 weeks, followed by biologic therapy for 16 weeks if a PASI 90 score is not achieved, and then continuing with the most effective treatment.

At 32 weeks, PASI reduction reached approximately 92% with bimekizumab, 71% with phototherapy, and 95% with the stepwise strategy.

Response variability was low with the stepwise strategy and high with phototherapy. Gains in quality-adjusted life years appeared greater with biologic therapy, followed by the stepwise strategy, than with phototherapy alone.

The annual total costs were $84,034 for bimekizumab, $14,760 for clinic-based phototherapy, and $6222 for home phototherapy. According to this US study, the patient cost was $2000 for biologic therapy compared with $5004 for clinic-based phototherapy, which has limited insurance coverage, and $1450 for at-home phototherapy. Insurer costs followed the opposite pattern.

However, these findings may not be generalizable to all healthcare systems. Although biologic therapies remain expensive in all settings, reimbursement for phototherapy, both in clinics and at home, varies widely.

Clinical Balance

A phased strategy, such as the one outlined here, may offer a reasonable compromise by limiting costs while maintaining satisfactory clinical outcomes. However, its feasibility depends on whether the phototherapy coverage is adequate and acceptable to the patient.

This study has several limitations. Researchers evaluated only one biologic therapy among the most expensive options. Other agents, such as adalimumab, are less costly and may be considered even if their efficacy is lower. Nevertheless, the findings highlighted the persistent gap between what is optimal for patients and what is considered “acceptable” from a payer perspective.

Until biosimilars become available, a measurement approach is necessary. This position aligns with current practice in France, where prescribing biologic therapies is legally considered “acceptable” only after failure of conventional treatments such as methotrexate, cyclosporine, acitretin, or phototherapy.

This story was translated from JIM, part of the Medscape Professional Network.