Sobi North America is spotlighting 15 presentations at ACR Convergence 2025, featuring new Phase 3 analyses for its investigational nanoencapsulated sirolimus plus pegadricase regimen in uncontrolled gout (NASP, formerly SEL-212), pooled efficacy and pharmacodynamic data for Gamifant (emapalumab) in macrophage activation syndrome in Still’s disease, and the first randomized, double-blind, placebo-controlled pharmacotherapy trial design in VEXAS syndrome with pacritinib (Vonjo). The NASP biologics license application was accepted in September with a PDUFA target action date of June 27, 2026.
The throughline is strategic: Sobi is stitching together a rare immuno-inflammation portfolio that spans refractory gout, hyperinflammatory crises, and hematoinflammatory syndromes. The question is whether strong signals across trials and mechanistic biomarkers can be translated into payer-recognized value in infusion-centric, high-cost conditions where comparators, care pathways, and real-world adherence will determine market traction.
For uncontrolled gout, NASP’s post hoc Phase 3 readouts aim squarely at Krystexxa’s incumbency. Immediate and sustained serum uric acid suppression to at or below 2.0 mg/dL, median SUA reductions of 97–98% at 24 weeks, roughly twofold drops in tender and swollen joints, and quality-of-life gains build a clinically coherent story. Critically, flares fell over time on NASP, with weeks 13–24 showing 2.3- and 5.7-fold fewer flares on high- and low-dose regimens versus placebo, and tophus resolution reached 31–48% versus 5% on placebo at week 24. The commercial implication is clear: a monthly infusion that pairs uricase with tolerogenic sirolimus to mitigate anti-drug antibodies could challenge a market dominated by an immunomodulator-augmented uricase strategy. Payers will look for durable flare reduction, tophus outcomes, steroid sparing, and health utility improvements to justify premium positioning, while clinicians will weigh immunosuppression management, infusion logistics, and switching dynamics from established uricase regimens, including those now under Amgen’s stewardship.
In Still’s disease–associated MAS, new pooled analyses reinforce Gamifant’s expansion into rheumatology following its June 2025 U.S. approval. Consistent responses across diverse MAS presentations and pronounced reductions in interferon-γ activity markers such as CXCL9 and ferritin strengthen the mechanistic rationale for targeting the pathway upstream of IL-1 and IL-6. For Medical Affairs, the work now shifts to accelerating recognition of MAS in emergency and inpatient settings, operationalizing biomarker-driven treatment algorithms, and generating real-world evidence around time-to-therapy, ICU utilization, and glucocorticoid tapering. Payers will expect demonstration of avoided organ support and shortened hospital stays to balance the cost of specialty biologics in acute care.
Pacritinib’s entry into VEXAS via the first randomized, placebo-controlled pharmacotherapy study, alongside consensus development of flare definitions and a disease activity index, represents foundational infrastructure for a registrational path in an ultra-rare, late-onset autoinflammatory syndrome. The strategy echoes a broader industry pattern: build the disease model, codify endpoints, then prosecute targeted assets from adjacent franchises. For Sobi, the CTI acquisition that brought pacritinib now offers optionality across immunohematology, provided clinical signals translate into payer-ready outcomes and companion diagnostic workflows for UBA1 mutation testing are standardized.
The next 12–18 months will test whether Sobi can convert compelling trial metrics into access wins across three very different care settings: outpatient infusion for chronic gout, acute inpatient management for MAS, and specialty hematology clinics for VEXAS. The decisive variable may be evidence that bridges biomarker change to hard utilization outcomes. If NASP clears its 2026 PDUFA with robust postmarketing plans and if Gamifant and pacritinib generate practice-changing real-world data, Sobi could emerge as a consolidator in rare immunology. If not, scale players with deeper access muscle may set the terms.
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.
