Strategic Astellas Collaboration Closed
Entered and closed a global collaboration and licensing agreement with Astellas for VIR-5500 valued up to $1.7 billion; Vir received $75 million equity at closing and will receive a $240 million upfront payment within 30 days (total $315 million in proceeds), is eligible for up to $1.37 billion in additional milestones, and will share U.S. commercial profit 50/50.
Material Capital Raises and Balance Sheet Strength
Completed a follow-on equity offering that generated approximately $172.5 million gross; ended Q1 2026 with ~$809.3 million in cash, cash equivalents and investments (excluding the $315M Astellas proceeds received after quarter-end); management expects cash runway into 2028.
VIR-5500 Phase 1 Safety and Early Efficacy
Phase 1 data for VIR-5500 showed favorable safety with no dose-limiting toxicities and mostly Grade 1 cytokine release syndrome at ≥3,000 µg/kg with no observed Grade 3 CRS at that dose; observed deep PSA and RECIST responses with sustained responses up to 27 weeks and case-level durability of 8–12 months, including a complete response in a patient who relapsed after actinium-based PSMA RLT.
Operational Progress in VIR-5500 Development
Dosed first patient in the Phase 1 expansion cohorts (monotherapy) and continuing dose escalation in combination with enzalutamide for early-line mCRPC; plan to initiate registrational Phase 3 program in 2027 pending data.
PROXTEN Platform Expansion and Pipeline Optionality
Advancing multiple PROXTEN-masked T cell engagers: VIR-5818 (HER2) is signal-seeking with planned preliminary response data in 2026, VIR-5525 (EGFR) enrollment progressing, plus seven preclinical PROXTEN assets to broaden pipeline optionality.
Compelling Hepatitis Delta (HDV) Phase 2 SOLSTICE Results
Tobevibart plus elebsiran combination showed strong viral suppression: 88% of evaluable participants achieved undetectable HDV RNA (TND) at Week 96 versus 46% on tobevibart monotherapy; rapid effect with 41% TND by Week 24 and 66% TND reported at Week 48 in pooled comments; combination was well tolerated with no Grade ≥3 treatment-related AEs and no discontinuations.
Regulatory Recognition and Clinical Program Momentum in HDV
Hepatitis delta regimen has FDA Breakthrough Therapy and Fast Track designations and EMA PRIME and orphan drug designation; ECLIPSE 1 enrollment complete (~120 randomized 2:1) with topline expected in Q4 2026, ECLIPSE 2 (~150) and ECLIPSE 3 (~100) on track to generate additional pivotal/registrational data.
Commercial Partnerships to Support Global Reach
Established commercialization partner Norgine with exclusive license across Europe, Australia and New Zealand for HDV; Astellas partnership adds global prostate cancer reach and shared development/commercial capabilities.
Year-over-Year Operating Expense Improvement
Total operating expenses for Q1 2026 were $132.3 million, a decrease of $10.3 million (≈7.2%) versus Q1 2025, driven by lower R&D and slightly lower SG&A.