Osisko Metals Launches Deep Porphyry Exploration Project ("DPEX") and Confirms 852 Metres Averaging 0.95% CuEq at Historic Porphyry Mountain Deposit MONTREAL, Feb. 05, 2026 (GLOBE NEWSWIRE) -- Osisko Metals Incorporated (the "Company" or "Osisko") (TSX: OM; OTCQX: OMZNF; FRANKFURT: 0B51) is pleased to announce initial results from the start of the re-evaluation of the Gaspé Copper Project’s (the "GCP") Porphyry Mountain deposit, discovered in 1994 by mine-site exploration work conducted by Noranda Inc. Osisko’s Deep Porphyry Exploration Project (the "DPEX"), planned for 2026, will include a new deep drill program, re-analysis of historic drill core, and remodelling of historic information designed to outline an NI 43-101 Inferred Mineral Resource Estimate ("MRE") on the Porphyry Mountain Cu-Mo deposit by year end. The DPEX program will be conducted separately from the current resource evaluation work at GCP, to provide preliminary information as to the potential of this deposit. Today’s news release includes re-assaying of core from one historical drill hole (DDH 30-0943) drilled in 2011 by Xstrata in the Porphyry Mountain deposit which is located at depth from the current GCP NI 43-101 MRE (see November 14, 2024 news release), approximately 1100 metres laterally northeast from the centre of the Copper Mountain pit. Re-assayed historical core from DDH 30-0943 returned 852.0 metres averaging 0.70% Cu, 2.92 g/t Ag and 0.062% Mo (0.95% CuEq*) from 998.0 to 1850.0 metres, which confirms previously obtained historical results (see Table 1 below). Many of the historical holes drilled by previous operators that reached the lower portion of the Porphyry Mountain deposit were stopped in mineralization (see Table 1 below), demonstrating that the deposit remains open at depth. Osisko Metals Chief Executive Officer Robert Wares commented: “These very promising results launch our 2026 DPEX resource evaluation program at Porphyry Mountain. Following the anticipated Q1 2026 release of our MRE update on the GCP Copper Mountain deposit, and in addition to the currently planned 2026 expansion drilling on the GCP Needle Mountain and Needle East zones, the DPEX resource evaluation program on Porphyry Mountain will include deep drilling on the deposit and thorough re-assaying of available historical drill core. This should establish its true depth and reveal the full potential of the deposit, with the objective of releasing a maiden Inferred MRE on Porphyry Mountain by the end of 2026. We anticipate that the updated GCP Copper Mountain open pit will reach significant depths near the end of its mine life, and this would potentially allow for future ramp access to the deeper, higher-grade DPEX Porphyry Mountain deposit.” Table 1: Notable historical drilling results from Porphyry Mountain DDH No.YearFrom (m)To (m)Length (m)Cu %Ag g/tMo %CuEq* %Open at depth30-088619941105.11634.6529.50.732.700.0771.03Yes30-089119941144.81738.9594.10.712.890.1161.17Yes30-08991995990.61834.9844.30.572.380.0880.92Yes30-090019951218.01795.9577.90.612.540.0780.91Yes30-090119951080.21729.7649.50.652.520.0620.90Yes30-090219951453.81850.0396.20.472.350.0240.58Yes30-090319951161.91791.9630.00.692.960.0801.01No30-091519961309.12121.5812.40.522.280.0600.75Yes30-091619961211.61710.5498.90.784.320.0531.01Yes30-0920B19971294.51817.2522.70.672.900.1081.10Yes30-092319971190.51887.0696.50.482.440.0370.64Yes30-09432011998.01850.0852.00.652.890.0720.94Yes30-094620111300.51845.0544.50.552.220.0630.80Yes *See explanatory notes below on copper equivalent values and Quality Assurance/Quality Controls. About Porphyry Mountain The Porphyry Mountain deposit was discovered by Noranda in 1994. It is located approximately 1100 metres northeast of the centre of the GCP Copper Mountain pit. The upper limit of the Porphyry Mountain deposit occurs at depths of approximately 1000 to 1200 metres. The porphyry-style stockwork of Cu-Mo veins, hosted by a separate porphyry intrusion at its core (relative to Copper Mountain), forms a subvertical deposit, roughly cylindrical in shape and measuring about 500 metres in diameter, having been defined by historical drilling over a minimum vertical length of 680 metres. Most of the historical holes stopped in mineralization at depths between 1700 to 2100 metres, indicating that the deposit remains open at depth. Both copper and molybdenum average grades are higher compared to the GCP Copper Mountain deposit. All analytical pulps from the historical drill hole (DDH 30-0943) re-assaying program that graded greater than 1% Cu are also currently being analyzed for gold. Explanatory note regarding copper-equivalent grades Copper Equivalent grades are expressed for purposes of simplicity and are calculated taking into account: 1) metal grades; 2) estimated long-term prices of metals: US$4.25/lb copper, $20.00/lb molybdenum, and US$24/oz silver; 3) estimated recoveries of 92%, 70%, and 70% for Cu, Mo, and Ag respectively; and 4) net smelter return v