Two-thirds of U.S. physicians report high unmet need in chronic spontaneous urticaria (CSU) despite two recent FDA approvals, according to new market data that also show divergent adoption patterns by specialty and shifting referral behavior.
The core development is a recalibration of the CSU treatment landscape following the approvals of dupilumab and remibrutinib. Early post-approval tracking indicates dupilumab uptake among allergists is nearly double that of dermatologists, while omalizumab remains the dominant biologic with approximately twice the brand share among allergists versus dermatologists. Dermatologists, leveraging familiarity with dupilumab from other indications, are increasingly managing CSU in-house, reducing referrals to allergists. Parallel to this shift, Novartis’ remibrutinib, the first oral BTK inhibitor approved for CSU, is positioned for rapid use in refractory patients, with physicians expecting a substantial proportion of these patients to be appropriate candidates.
Strategically, the market is sorting into mechanism-led lanes with distinct specialty anchors: anti-IgE rooted in allergy clinics, IL-4/IL-13 pathway modulation gaining traction in dermatology-led settings, and a new oral small-molecule option that could blur lines by appealing to both. The immediate tension is ownership of refractory care and second-line sequencing. Dermatologists’ growing retention of CSU patients threatens the historical referral pipeline to allergists, while allergists’ deeper biologic experience sustains their influence on second- and third-line decisions. For sponsors, this creates a tactical imperative to segment messaging, trial designs, and site networks by specialty behaviors and prior-line exposure rather than by broad disease labels.
The operational implications are nontrivial. Sites should anticipate bidirectional referral patterns and a more heterogeneous mix of prior therapies at screening, complicating stratification and powering. Sponsors and CROs will need balanced networks across allergy and dermatology to avoid accrual bottlenecks and to capture real-world practice splits that regulators increasingly scrutinize. CSU trials skew heavily on patient-reported outcomes; as oral therapy enters the mix, adherence and diary compliance will become differentiators in both studies and post-market data. Safety and monitoring expectations for an oral BTK inhibitor, even in a dermatologic condition, may also alter visit schedules and lab workflows, affecting feasibility and site throughput. Payers are likely to enforce step therapy anchored to omalizumab, making sequencing and time-to-response endpoints operationally relevant for both trials and market access studies.
Near term, watch the first 6–12 months of remibrutinib utilization: persistence, discontinuation drivers, and how quickly it penetrates beyond deeply refractory cohorts. If oral convenience and rapid symptom control are borne out in practice without unexpected safety friction, the agent could pressure omalizumab’s hold on second line and constrain dupilumab’s growth in centers without strong dermatology leadership. Conversely, if payer controls or monitoring burdens erode the convenience narrative, adoption may concentrate in select specialist hubs. Expect sponsors to test head-to-head or pragmatic designs to clarify sequencing, with stratification by prior biologic failure becoming standard. The unresolved question is whether CSU will settle into stable mechanism niches by specialty or consolidate around a best-sequenced pathway that crosses settings. The answer will shape site mix, eligibility criteria, and comparator choices for the next wave of studies—and determine which companies control the refractory segment where unmet need remains most acute.
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
