PCE Expansion:

• Vertical extent of high-grade subdomain has increased by 23% from 335 m to 412 m with 210 m of strike length.
• Additional expansion of the mineralized footprint to 700 m vertical extent (from 600 m) and to 620 m strike length (from 600 m).
• Additional high-grade subdomain building at 850 m below surface, extending high-grade in this portion of the mineralization and opening it to further growth.
• 2026 Drilling Program Commencement:
• 42,000 meters ("m") of diamond drilling at PCE in 2026 to be largest program conducted at the discovery to date building on the highly successful 2025 growth and results.
• Inaugural drilling at NexGen's 100% owned SW3 property with 3,500 m to advance high-priority targets.

Vancouver, British Columbia--(Newsfile Corp. - January 15, 2026) - NexGen Energy Ltd. (TSX: NXE) (NYSE: NXE) (ASX: NXG) ("NexGen" or the "Company") is pleased to announce the concluding holes of the 2025 PCE program and the commencement of the 2026 Exploration Program.

2025 PCE

Final drill holes of the 2025 PCE program delivered continued expansion of mineralization with high-grade growth and assessment of extents advancing significantly since the Company's last scintillometer report (see news release dated August 28, 2025). The primary high-grade subdomain grew to 412 m in vertical extent (increase of 77 m) and a strike length of 210 m. An additional high-grade subdomain is developing with hole RK-25-257 intersecting local off-scale (>61,000 cps) at the base of the currently outlined mineralized footprint, indicating significant expansion potential at depth (Figures 1-4, Table 1).

The overall mineralized footprint expanded to 620 m (increase of 20 m) of strike length and 700 m (increase of 100 m) of vertical extent, remaining open in most directions. Step out testing has provided critical information regarding extents of the system and opportunities for continued growth.

Internal continuity within the subdomain was most recently highlighted by RK-25-271 with 5.8 m of cumulative high-grade (>10,000 cps) and 0.8 m of off-scale (>61,000 cps) that increases the mineralized zone in the lower half of this subdomain (Figure 3, Table 1). Hole RK-25-271 is located 65 m down-dip from hole RK-25-256 (see news release dated December 1, 2025) which returned 5.5 m at 21.4% U₃O₈, including 2.5 m at 46.1% U₃O₈ and 0.5 m at 74.8% U₃O₈.

The 2025 drilling program successfully completed 35,366.2 m, the largest reported in the Athabasca Basin in 2025. Since discovery (see news release date March 11, 2024), 102 drillholes totalling 69,042.2 m have been completed (Figure 1). A dual focused approach was taken in 2025 to both grow and define multiple high-grade subdomains as well as expand the overall mineralized footprint. To date, 67 of the 102 drill holes are mineralized, including 45 intersecting high-grade (>10,000 cps) and 17 intersecting off-scale (>61,000 cps).

Figure 1: Interpreted model of mineralization at PCE (as of this release); new holes emphasized by larger diameter pierce points and bold labels; view is a long section that looks perpendicular to the primary mineralized plane; total mineralized footprint in orange and the high-grade subdomains in red; drillholes with pending assays are underlined, 32% of 2025 drillholes have fully received results (as of this release).

Figure 2: Comparison of mineralization at PCE over time with the model evolving based on new geological data; dimensions are measured from confirmed mineralized intercepts along strike and vertical extent; view is a long section that looks perpendicular to the primary mineralized plane; total mineralized footprint in orange and the high-grade subdomains in red.

Figure 3: Core photo from RK-25-271 displays mineralization from 624.7 to 640.6 m down hole with abundant high-grade and several instances of off-scale in competent basement rock; yellow outlines >1,000 cps, red outlines >10,000 cps, >61,000 cps outlined in purple.

Figure 4: Representative geological cross-section through high-grade subdomain looking northeast with confirmed dip extent of 450 m and width up to 135 m; uranium mineralization shown as red overlay; interpretation of features extending beyond drillholes aided by drilling information outside of cross-section width (25 m).

2026 Exploration Program Commencement

Advancement of PCE mineralization with 42,000 m of drilling (Figure 5):

Drilling activity will primarily focus on high-grade growth and the continued expansion of the mineralized footprint. At least eight (8), 200 m spaced tests will also investigate for repetition of basement-hosted mineralization within the same hydrothermal system approximately 600 m southeast of the PCE discovery.

Figure 5: Map of PCE with ground gravity in background, target areas are hosted within gravity low denoted by blue colours, interpreted faults are shown as black dashed lines; primary focus in the immediate vicinity of PCE mineralization with additional secondary investigation of local system.

Regional drilling of 3,500 m at SW3 (Figure 6):

An inaugural, drill program will take place on the SW3 land package with regional greenfield testing of highly prospective target areas. This marks the first drilling on any SW3 mineral claims by NexGen and an exciting step in the direct investigation of geophysical anomalies identified. The SW3 package is one of the three core packages NexGen owns 100% of in the southwest Athabasca Basin and is situated 20 km southeast of the SW2 package which hosts the Rook I Project.

Figure 6: Map of SW3 with inset of overall NexGen land packages; 3,500 m will investigate highest priority target areas, outlined in red, in this greenfield setting.

Leigh Curyer, Chief Executive Officer, commented: "We are extremely pleased with the 2025 outcomes from the 2025 drill program at PCE that delivered on our dual-purpose objectives of expanding the overall mineralized footprint and expand the high-grade subdomain within it. These results systematically outline mineralization that continues to deliver growth and strong continuity, characteristics synonymous with Arrow deposit 3.5 km west. The 2025 drill program has rapidly advanced this new discovery, while underscoring the tremendous prospectivity of NexGen's 100% owned dominant land holdings which is driving the expanded activity in 2026. The 2026 program is designed to continue the dual track focus at PCE and in parallel, test for a repetition of PCE within the same system. In addition, drilling for the first time at our SW3 property is a reflection of the south western section of the Athabasca Basin world class prospectivity.

At a pivotal moment for global energy security, nuclear power is being recognized as an indispensable pillar for reliable, clean, cost efficient energy. The NexGen team is laser focused on concluding the final Federal permitting and licensing for the Rook I Project and immediately advancing through construction into production whilst simultaneously advancing the exciting PCE discovery and other high priority targets."

Jason Craven, Vice President, Exploration, commented: "Last year's highly transitional and successful program positions NexGen to enter 2026 with an even deeper understanding of this broad and growing high-grade system. A multitude of targets remain to be tested as we continue to systematically advance PCE with a dual priority track of expanding both the high-grade subdomains as well as the overall mineralized system. The comprehensive 2026 program strategically positions all three land packages on an exciting path toward expansion of PCE as well as additional discoveries as NexGen works to sustainably supply the world with uranium in the face of mounting and persistent deficits."

Table 1: Spectrometer results since August 28, 2025 release