How does nipocalimab compare to efgartigimod and rozanolixizumab? FcRn class battlelines in gMG and beyond

Johnson & Johnson’s IMAAVY (nipocalimab-aahu) is shaping the evolving field of FcRn-targeted therapies following its U.S. FDA approval in April 2025 for the treatment of generalized myasthenia gravis (gMG). With sustained efficacy data through 24 weeks now publicly available, attention has shifted to how this monoclonal antibody compares with its class peers—Argenx’s efgartigimod (Vyvgart) and UCB’s rozanolixizumab (Rystiggo). As all three drugs compete for formulary space and clinical preference in a growing biologics market, evaluating efficacy, safety, administration, pricing, and sentiment has become critical.

FcRn inhibitors represent a new class of targeted autoimmune treatments designed to reduce circulating immunoglobulin G (IgG) antibodies by blocking the neonatal Fc receptor. Unlike broad immunosuppressants, these drugs aim to achieve symptom control with fewer systemic risks. While each therapy shows promise, differences in trial design, route of administration, and patient experience are now influencing prescribing patterns, especially in the high-need gMG population.

What are the comparative efficacy outcomes of nipocalimab, efgartigimod, and rozanolixizumab across phase 3 trials and indirect comparisons?

Phase 3 trial data have shown that all three FcRn inhibitors provide clinically significant improvements in MG-ADL (Myasthenia Gravis–Activities of Daily Living) scores, a standard measure of daily function. Efgartigimod, evaluated in the ADAPT study, achieved a 68% response rate among anti-AChR positive patients versus 30% for placebo. Rozanolixizumab, tested in the MycarinG trial, showed a statistically significant 3.4-point improvement in MG-ADL from baseline at Day 43 compared with 0.8 points for placebo. IMAAVY, based on data from the 24-week Vivacity-MG3 trial, demonstrated an average 4.7-point improvement in MG-ADL compared to 3.25 for placebo.

Recent indirect treatment comparisons (ITCs), including those presented at the 2025 European Academy of Neurology Congress, suggest IMAAVY may offer more consistent disease control from Week 8 to Week 24, particularly in population-adjusted models. In network meta-analyses published in peer-reviewed journals, efgartigimod still ranks highest in overall response probability, but the gap is narrowing as real-world data emerges and statistical methods improve.

Experts have cautioned that while ITCs are useful in the absence of head-to-head trials, they cannot replace direct evidence. Nonetheless, institutional sentiment indicates that clinicians increasingly rely on such comparisons to guide decisions in complex, biologics-dense spaces like gMG.

How do safety profiles and adverse event rates differ among these FcRn-targeted therapies?

Across the class, safety profiles are generally favorable, with no major immune-compromising signals observed to date. Efgartigimod’s most frequently reported side effects include upper respiratory tract infections, headache, and urinary tract infection. Rozanolixizumab is associated with headaches, diarrhea, and hypersensitivity events—particularly infusion-related reactions due to its subcutaneous pump delivery. Nipocalimab has shown a safety profile comparable to efgartigimod, with no major differentiating adverse events flagged in Vivacity-MG3.

Meta-analyses indicate that the number needed to harm (NNH) is low across all three drugs, with some models suggesting efgartigimod may have a slight edge in tolerability. However, due to differing dosing regimens and monitoring protocols, real-world data may eventually reveal more nuanced safety differentiators.

What are the key differences in dosing regimens, route of administration, and patient experience among these therapies?

Efgartigimod was initially approved in an intravenous form but gained U.S. FDA approval in 2023 for a subcutaneous formulation branded as Vyvgart Hytrulo, offering flexibility in outpatient settings. Rozanolixizumab is administered via subcutaneous infusion through an on-body pump, typically in six-week cycles with dosing every seven days. In contrast, IMAAVY uses a fixed biweekly intravenous regimen that does not require disease relapse to trigger retreatment, unlike cyclic regimens.

The ability to plan treatment in advance, without clinical reevaluation or flare-based cycles, is being marketed by Johnson & Johnson as a key differentiator. Institutional feedback suggests that this predictability may improve adherence, particularly in patients with variable disease courses or transportation barriers to infusion centers.

How does the cost of therapy and reimbursement environment compare across nipocalimab, efgartigimod, and rozanolixizumab?

Cost-effectiveness is emerging as a critical consideration for payers. Efgartigimod is priced around USD 6,600 per 20 mL vial, with total treatment cycle costs varying based on patient weight and disease severity. Rozanolixizumab is reported to cost approximately USD 3,275 per 140 mg vial, translating to over USD 40,000 for a typical six-week course. IMAAVY, newly launched, is priced at approximately USD 12,480 per 1,200 mg vial, positioning it at the higher end of the FcRn class.

While Johnson & Johnson has not yet released detailed economic modeling, payers will likely weigh IMAAVY’s higher acquisition cost against its biweekly schedule, potential reduction in relapse-associated healthcare utilization, and broader approved patient population—including adolescents. Early formulary wins in the U.S. have been reported but not publicly detailed.

What does expert and institutional sentiment suggest about which FcRn blocker may lead the market in coming years?

Institutional analysts see efgartigimod as the current class leader, citing its first-mover advantage, flexible formulations, and expanded indications, including CIDP. However, sentiment is shifting in favor of IMAAVY as data accumulates supporting its sustained efficacy, dosing regularity, and pediatric label. Rozanolixizumab is generally seen as a strong third option for patients seeking subcutaneous administration, especially when corticosteroid avoidance is desired.

Neurologists contacted during EAN 2025 expressed growing interest in nipocalimab’s consistent dosing and extended control without symptom-triggered redosing. Still, many emphasized the need for head-to-head trials or long-term real-world evidence before revising prescribing norms.

What pipeline and lifecycle management strategies are being pursued to extend the FcRn class across autoimmune diseases?

All three companies are pursuing aggressive lifecycle expansions. Argenx is advancing efgartigimod in indications including primary immune thrombocytopenia, pemphigus vulgaris, and multiple sclerosis. UCB is expanding rozanolixizumab into CIDP and lupus.

Johnson & Johnson is taking a broader portfolio approach, exploring nipocalimab in maternal–fetal indications such as fetal and neonatal alloimmune thrombocytopenia (FNAIT), hemolytic disease of the fetus and newborn (HDFN), and rheumatologic indications including Sjögren’s syndrome. With multiple orphan designations and Fast Track status granted by the U.S. FDA, the pipeline may offer significant long-term value.

What’s next for the FcRn class, and how might clinical or market dynamics shift in 2025–2026?

The next 12–18 months are expected to be pivotal for the FcRn inhibitor landscape. Among the most closely watched milestones is the anticipated European Commission decision on Johnson & Johnson’s IMAAVY, following its Marketing Authorisation Application submission to the European Medicines Agency in late 2024. A positive outcome by Q1 2026 would allow IMAAVY to enter the European market as the first FcRn blocker approved for both anti-AChR and anti-MuSK antibody-positive gMG patients aged 12 and above. In parallel, Argenx’s Vyvgart Hytrulo—the subcutaneous version of efgartigimod—is also awaiting regulatory review in Europe, with a decision expected around the same timeframe.

While regulatory clearance is essential, commercial differentiation will likely be shaped by post-marketing performance metrics. Analysts expect payer uptake data, real-world adherence outcomes, and patient-reported experiences to dominate competitive narratives in the absence of direct head-to-head trials. For example, comparative studies tracking duration of IgG suppression, flare rate reduction, and sustained MG-ADL score improvements under routine clinical conditions could offer prescribers more actionable insights than isolated clinical trial endpoints.

Another major dynamic in 2025–2026 will be the ability of FcRn therapies to demonstrate consistent value across different healthcare systems. As national reimbursement agencies in the EU and Asia-Pacific evaluate cost-effectiveness dossiers, pricing strategy, pharmacoeconomic modeling, and health technology assessment outcomes will play a larger role in determining access. Analysts have flagged that countries with single-payer systems may prefer subcutaneous options that allow at-home administration (such as Vyvgart Hytrulo or rozanolixizumab) over infusion-based products like IMAAVY, unless J&J’s real-world data can convincingly show fewer flares or better long-term disease control.

Beyond regulatory and payer trends, FcRn class competition is expected to shift from broad efficacy comparisons to more nuanced differentiators that reflect patient heterogeneity. Factors such as duration of disease at time of initiation, baseline MG-ADL severity, and biomarker-driven treatment response are likely to become focal points. Likewise, cumulative IgG reduction over time—not just acute suppression—may serve as a pharmacodynamic proxy for long-term benefit, particularly in patients with refractory disease.

Pediatric access and adolescent trial expansion are also poised to play a larger role. With IMAAVY already approved for patients aged 12 and above in the U.S., Johnson & Johnson may lead in capturing this underserved segment if EU regulators follow suit. Argenx and UCB are currently trailing in this domain, though ongoing pediatric trials could change the landscape by 2026.

Finally, patient preference—especially regarding the convenience of subcutaneous versus intravenous delivery—will remain a competitive lever. While some patients may prefer fewer hospital visits and at-home care options, others may prioritize treatment predictability, lower dosing frequency, and structured infusion schedules. This divergence makes it likely that no single FcRn agent will dominate universally, but rather that physicians will increasingly tailor choices based on clinical profile, lifestyle compatibility, and reimbursement coverage.

In sum, the 2025–2026 period will be less about proving superiority and more about demonstrating fit: fit for specific patient subtypes, healthcare delivery models, and regulatory environments. As the class matures, subtle strategic decisions around lifecycle management, trial design, and geographic expansion will determine long-term leadership.