NexGen’s Final Batch of 2025 Assays Return Multiple High-Grade Intercepts Confirming Both Expansion and Continuity of Primary High-Grade Subdomain and Confirmation of New High-Grade Subdomain at Depth

NexGen’s Final Batch of 2025 Assays Return Multiple High-Grade Intercepts

Confirming Both Expansion and Continuity of Primary High-Grade Subdomain and

Confirmation of New High-Grade Subdomain at Depth

Highlights:

• RK-25-239 returns 13.0 m at 5.2% U3O8, including 0.5 m at 30.2% U3O8 confirming expansion

of the growing high-grade subdomain 33 m up dip of RK-25-232 (15.0 m at 15.9% U3O8)

• RK-25-240 returns 10.0 m at 3.95% U3O8, including 0.5 m at 33.3% U3O8 in the down dip

portion of the high-grade subdomain 266 m below RK-25-232

• Assays from RK-25-230 (7.5 m at 5.3% U3O8 including 0.5 m at 35.9% U3O8), RK-25-233 (6.0

m at 2.4% U3O8 including 0.5 m at 23.4% U3O8), RK-25-236 (5.5 m at 2.3% U3O8 including 0.5

m at 13.3% U3O8) confirm continuity of high-grade subdomain; 47 m, 151 m, and 40 m

respectively from RK-25-232

• Confirmed the new high-grade subdomain, at 850 m below surface with RK-25-257

returning 4.5 m at 4.8% U3O8 including 0.5 m at 33.3% U3O8 located 67 m up dip of RK-24-

202 (0.5 m at 6.9% U3O8). Confirms significant growth potential.

Vancouver, BC, May 07, 2026 - NexGen Energy Ltd. ("NexGen" or the "Company") (TSX: NXE) (NYSE:

NXE) (ASX: NXG ) 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 located 3.5 km from the Arrow Deposit. The expansion of the high-grade subdomain is especially

confirmed by RK-25-239 which returned 13.0 m at 5.2% U 3O8, including 0.5 m at 30.2% U 3O8, at 400 m

below surface and RK-25-240 which returned 10.0 m at 3.95% U3O8, including 0.5 m at 33.3% U3O8, at 670

m below surface. B oth of these holes share strong similarities with respect to their overall geological

characteristics which span across 292 m of mineralized dip extent. (Figures 1-3, Table 1).

Results from RK-25-240 emphasize the potential extension of mineralization at depth where the system is

open. Together with these results, the grades from RK -25-230 (Figure 4), RK-25-233, RK-25-236 have

confirmed a strong core zone within the high-grade subdomain which remains open in most directions.

Within the overall mineralized footprint, a new secondary high-grade subdomain is now confirmed by RK-

25-257 (Figures 1 and 5). This hole has several intercepts with the best being 4.5 m at 4.8% U3O8 including

0.5 m at 33.3% U3O8 located 67 m up dip of RK-24-202 (0.5 m at 6.9% 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

(29,241.8 m of the p lanned 42,000 m ) scheduled to recommence the week of May 25, 2026 (see news

release April 22, 2026) . All samples from 2026 drilling to date are submitted to the independent

Saskatchewan Research Council Geoanalytical Laboratory (SRC), with results to follow.

Leigh Curyer, Founder & Chief Executive Officer, commented: “These assay results from 2025 drilling

confirm high- grade mineralization and the expanding scale of PCE . 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. As the Rook I Project enters into major

construction this summer, we continue to advance PCE to ensure that NexGen optimizes its unparalleled

opportunity to become one of the world’s most important mining company in delivering energy fuel for the

current and future generations.”

Figure 1: Interpreted PCE long section (as of April 22, 2026 release) with notable assays collected since discovery and

new results outlined in red ; 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 2: Core photo of assays from RK-25-239 with grades shown as % U3O8

Figure 3: Core photo of assays from RK-25-240 with grades shown as % U3O8

Figure 4: Core photo of assays from RK-25-230 with grades shown as % U3O8

Figure 5: Core photo of assays from RK-25-257 highlighting the new subdomain with grades shown as % U3O8

Table 1: Assays received since December 1, 2025 news release

Drillhole

Unconformity

Depth (m)

SRC Geoanalytical Results

(Cutoff 0.01%)

Hole ID Azimuth Dip

Total

Depth

(m)

From (m) To (m) Width

(m)

U3O8

(wt%)

RK-25-210c1 310 -70 894.0 - 794 794.5 0.5 0.01

801.5 803.5 2 1.00

incl. 801.5 802.5 1 1.92

804 807 3 0.04

811 812 1 0.09

812.5 814 1.5 0.15

814.5 815 0.5 0.03

817.5 818 0.5 0.07

819.5 820.5 1 0.13

821 822 1 0.48

824.5 825 0.5 0.08

RK-25-210c2 310 -70 909.0 - 811.5 813.5 2 0.14

814 815 1 0.13

816.5 817.5 1 0.06

818 818.5 0.5 0.01

819 819.5 0.5 0.03

821.5 825 3.5 0.61

incl. 822 822.5 0.5 2.97

841 842 1 0.05

852.5 853 0.5 0.03

868.5 869 0.5 0.03

887.5 888.5 1 0.01

RK-25-229 350 -70 681.4 113.2 570.5 572 1.5 0.04

573 574 1 0.02

574.5 575 0.5 0.01

576.5 579 2.5 0.04

582 582.5 0.5 0.02

604 604.5 0.5 0.03

606.5 608 1.5 0.57

incl. 606.5 607 0.5 1.62

623 623.5 0.5 0.15

636.5 637 0.5 0.24

RK-25-230 330 -70 598 112.5 441.5 444 2.5 0.20

446.5 449 2.5 0.06

450 451.5 1.5 0.01

452.5 453 0.5 0.02

456 456.5 0.5 0.02

457 459 2 0.03

459.5 460 0.5 0.02

462.5 463.5 1 0.01

467 468 1 0.02

469 469.5 0.5 0.02

471.5 472 0.5 0.01

473 474 1 0.01

475 490.5 15.5 0.25

492.5 500 7.5 5.32

incl. 493 493.5 0.5 35.9

incl. 498.5 499 0.5 27.4

511 511.5 0.5 0.02

512 513 1 0.03

513.5 514 0.5 0.03

517.5 519.5 2 0.04

520 521.5 1.5 0.05

525 526.5 1.5 0.02

532 533.5 1.5 0.01

537.5 538.5 1 0.06

539.5 540 0.5 0.05

588.5 589 0.5 0.02

RK-25-233 330 -70 694 109.7 539 540 1 0.03

555.5 558 2.5 0.02

558.5 559 0.5 0.02

560.5 568.5 8 0.04

569 570.5 1.5 0.02

571 572 1 0.11

572.5 573 0.5 0.03

574.5 575.5 1 0.02

576 582 6 2.42

incl. 578 580 2 6.98

incl. 578.5 579 0.5 23.4

582.5 589.5 7 1.59

incl. 586 588 2 4.70

590 596 6 0.08

602 602.5 0.5 0.04

603.5 609.5 6 0.53

incl. 604 605 1 2.35

624.5 625.5 1 0.11

628 628.5 0.5 0.06

629.5 630.5 1 0.04

633 633.5 0.5 0.02

634 636 2 0.36

incl. 635.5 636 0.5 1.04

RK-25-235 270 -70 858 105.5 No significant intersections

RK-25-236 267 -65 541 129 376.5 380 3.5 0.04

380.5 382 1.5 0.29

393.5 394 0.5 0.02

395 397.5 2.5 0.07

401 403 2 0.44

411 414 3 0.03

414.5 415 0.5 0.03

425.5 426 0.5 0.02

427 430 3 0.03

431 431.5 0.5 0.01

433 433.5 0.5 0.01

440 440.5 0.5 0.03

441.5 442.5 1 0.01

445 445.5 0.5 0.02

447 447.5 0.5 0.01

457.5 460.5 3 0.07

461.5 462.5 1 0.09

464 464.5 0.5 0.01

465 470.5 5.5 2.34

incl. 467.5 468.5 1 10.7

incl. 467.5 468 0.5 13.3

475.5 477 1.5 0.02

477.5 479 1.5 0.05

516 517.5 1.5 0.02

RK-25-239 278 -68 594 123.4 364.5 366 1.5 0.02

367.5 368.5 1 0.02

390.5 392.5 2 0.06

393 397 4 0.06

397.5 399 1.5 0.06

400.5 401 0.5 0.03

402 402.5 0.5 0.01

407 410.5 3.5 0.41

incl. 407.5 408 0.5 1.54

411 411.5 0.5 0.01

414 415 1 0.08

416.5 417 0.5 0.01

417.5 418.5 1 0.01

419 420.5 1.5 0.04

421 421.5 0.5 0.04

422.5 423 0.5 0.02

424.5 425 0.5 0.01

426 426.5 0.5 0.01

429 429.5 0.5 0.02

430 431.5 1.5 0.03

433 446 13 5.21

incl. 438 441.5 3.5 14.4

incl. 441 441.5 0.5 30.2

448 449 1 0.01

449.5 450.5 1 0.06

451 452.5 1.5 0.15

454.5 455 0.5 0.01

456.5 457 0.5 0.05

463.5 464.5 1 0.01

466.5 467.5 1 0.02

468.5 469 0.5 0.01

469.5 470 0.5 0.02

471 473.5 2.5 0.40

incl. 472 472.5 0.5 1.28

476 477 1 0.02

478 479.5 1.5 0.30

482.5 483 0.5 0.03

484 485 1 0.04

486.5 488 1.5 0.42

490.5 491.5 1 4.58

494.5 495 0.5 0.01

497.5 500 2.5 0.10

501 501.5 0.5 0.02

502 503 1 0.02

503.5 504.5 1 2.69

505 506 1 0.04

507.5 508.5 1 0.78

incl. 508 508.5 0.5 1.32

509.5 510 0.5 0.02

514.5 515 0.5 0.08

518 520 2 0.06

RK-25-240 270 -70 893 106.1 653.5 654.5 1 0.02

659 659.5 0.5 0.01

660 669.5 9.5 0.76

incl. 664 665 1 1.99

incl. 665.5 666 0.5 6.40

incl. 668 668.5 0.5 2.10

670 671 1 0.40

671.5 672.5 1 0.13

673 674 1 1.00

675 679.5 4.5 0.27

incl. 675 675.5 0.5 1.21

680 683 3 0.09

683.5 693.5 10 3.95

incl. 685 686 1 32.7

694.5 704 9.5 0.08

705.5 707 1.5 0.08

714.5 715 0.5 0.85

717.5 718 0.5 0.07

718.5 719 0.5 0.02

726.5 727 0.5 0.02