Final 2025 Assays Return Multiple High-Grade Intercepts

• Expansion and continuity of high-grade subdomain confirmed • New high-grade subdomain discovered at depth • Significant growth potential remains at PCE

NexGen Energy Ltd. announces the final receipt of 2025 assay results that highlight the expansion and continuity of the high-grade subdomain at the Company's 100% owned Patterson Corridor East (PCE) discovery. The expansion of the high-grade subdomain is confirmed by RK-25-239 which returned 13.0 m at 5.2% U3O8, including 0.5 m at 30.2% U3O8, and RK-25-240 which returned 10.0 m at 3.95% U3O8, including 0.5 m at 33.3% U3O8. These results, along with grades from other holes, have confirmed a strong core zone within the high-grade subdomain which remains open in most directions. Additionally, a new secondary high-grade subdomain has been confirmed by RK-25-257, which intersected 4.5 m at 4.8% U3O8 including 0.5 m at 33.3% U3O8. This new subdomain has high prospectivity for continued growth and is open in most directions. Exploration drilling in 2026 has already driven further growth at PCE, with the majority of the campaign scheduled to recommence in late May 2026.

The combination of high-grades, continuity, scale and geotechnical characteristics continue to highlight the similarities between PCE and the mighty Arrow Deposit. The opening up of a new high-grade subdomain emphasizes significant growth potential remains at PCE. With the structural supply deficit in the market widening, and the impacts of the industry wide underinvestment in the uranium supply chain for a generation, the urgency of finding and bringing online new, reliable uranium supply has never been greater.