NexGen Announces New Significant High Grade Assay Results at Patterson Corridor East

The news release on November 12, 2025, announces significant high-grade assay results from the Patterson Corridor East (PCE) discovery on the Rook I property. Key highlights include: - Hole RK-25-254 intersected 10.5 meters grading 11.3% U3O8. - Hole RK-25-244 intersected 17.0 meters grading 7.63% U3O8. - Other holes (RK-25-231, RK-25-241, RK-25-234) demonstrate strong continuity and the potential for new high-grade shoots within the system. - The results provide assay confirmation for the "off-scale" radioactivity previously reported via spectrometer readings on August 28, 2025. - The mineralized footprint is currently defined as being 600 meters along strike and having a 600-meter vertical extent, containing a high-grade subdomain of 210 meters strike and 335 meters vertical extent. - Management states that the exploration approach and results are of the same calibre as those that defined the world-class Arrow deposit.

The assay results are highly material and positive for NexGen. The key impact is the significant de-risking of the Patterson Corridor East (PCE) discovery and the validation of the company's exploration methodology.

NexGen Energy is a Canadian uranium company focused on the development of its 100%-owned Rook I Project in the Athabasca Basin, Saskatchewan. The project hosts the Arrow Deposit, which is one of the largest and highest-grade undeveloped uranium deposits in the world. The project is in the final stages of a multi-year environmental and permitting process, with a final decision expected in H1 2026. In addition to the development-stage Arrow deposit, the company is aggressively exploring the Patterson Corridor East (PCE) discovery on the same property, which is showing characteristics of a second world-class deposit.