Osisko Development Reports Third Quarter 2025 Results

Press Release

HIGHLIGHTS

Q3 2025 (at September 30, 2025)

• ~$401.4 million in cash and cash equivalents
• Drawn ~$137.2 million (US$100.0 million) under the US$450 million Appian financing facility executed during the quarter
• Completed private placements for ~$280.4 million (US$203.1 million) in gross proceeds
• Advanced pre-construction activities and underground mine development activities, and announced results of ore sorting and drilling programs at the permitted Cariboo Gold Project
• Sold 877 ounces of gold from the Tintic small-scale heap leach project

Subsequent to Q3 2025

• Completed an additional private placement for ~$82.5 million in gross proceeds
• Released infill drill results from the ongoing program at Cariboo; appointed Scott Smith as VP, Exploration

MONTREAL, Nov. 10, 2025  — Osisko Development Corp. (NYSE: ODV, TSXV: ODV) (“Osisko Development” or the “Company”) reports its financial and operating results for the three months ended September 30, 2025 (“Q3 2025”).

Q3 2025 HIGHLIGHTS

Operating, Financial and Corporate Updates:

• As of September 30, 2025, the Company had approximately $401.4 million in cash and cash equivalents. Approximately $137.2 million (US$100.0 million) was outstanding as of the end of Q3 2025 under the Appian 2025 Financing Facility (as defined herein) following the initial draw.
• $4.4 million in revenues ($0.2 million in Q3 2024) and $3.0 million in cost of sales ($0.1 million in Q3 2024) generated from the sale of 877 gold ounces from the small-scale heap leach project at the Tintic Project by re-treating certain tailings and stockpile material.
• On July 7, 2025, the Company announced results from an ore sorting testing program conducted on a bulk tonnage sample of mineralized material extracted from the Cariboo Gold Project.
• On July 21, 2025, the Company entered into a credit agreement (the “Credit Agreement”) with funds advised by Appian Capital Advisory Limited (“Appian”) with respect to a senior secured project loan credit facility (the “2025 Financing Facility”) totaling US$450 million for the development and construction of the Cariboo Gold Project. The 2025 Financing Facility provides strategic capital and enhanced financial flexibility as the Company advances the Cariboo Gold Project through the next phase of pre-construction and early works milestones toward construction readiness. It is structured in two tranches aligned with the Cariboo Gold Project’s planned development timeline. An initial draw of US$100 million was completed to: (i) undertake a 13,000-meter infill drill campaign to further de-risk project mine planning assumptions; (ii) fund pre-construction and construction activities for the development of the Cariboo Gold Project; (iii) repay the Company’s outstanding US$25 million term loan with National Bank of Canada; and (iv) support the Cariboo Gold Project’s general working capital requirements. Subsequent draws of US$350 million to be drawn in up to four subsequent tranches will be available for a period up to 36 months subject to the satisfaction of certain project milestones and other customary conditions. A copy of the Credit Agreement is available on SEDAR+ (www.sedarplus.ca) under the Company’s issuer profile.
• On August 15, 2025, the Company completed private placements for aggregate gross proceeds of US$203.1 million. This consisted of a “bought deal” brokered private placement of 58,560,000 units of the Company at a price of US$2.05 per unit for aggregate gross proceeds of US$120.0 million, which was announced on July 31, 2025, and a non-brokered private placement of 40,505,330 units at a price of US$2.05 for aggregate gross proceeds of approximately US$83.0 million. The non-brokered offering included an approximate US$75 million subscription by Double Zero Capital LP, a Delaware investment firm, representing approximately 15.4% of the issued and outstanding common shares of the Company immediately following the closing of the offering, on a non-diluted basis. Each unit consisted of one common share and one-half of one common share purchase warrant of the Company. Each whole warrant entitles the holder to acquire one Common Share at an exercise price of US$2.56 for a period of 24 months following the closing date. At any time following the 15-month anniversary of the closing date, if the closing price of the common shares exceeds the exercise price for 20 or more consecutive trading days, the Company may, within 10 days following such occurrence, deliver a notice to the holders thereof accelerating the expiry date of the warrants to a date that is 30 days after the date of such notice.
• On August 20, 2025, the Company granted 58,824 deferred share units of the Company to Ms. Susan Craig, an independent director, in connection with her appointment to the Company’s board of directors announced on June 16, 2025.
• On September 8, 2025, the Company announced results from its infill and exploration diamond drilling and development sampling campaigns conducted from November 2024 through early August 2025 in the Lowhee Zone within the Cariboo Gold Project. The program consisted of approximately 6,471 meters of underground infill drilling and approximately 398 meters of chip and rock saw channel sampling.

Cariboo Gold Project – British Columbia, Canada (100%-owned)

• Infill Drilling Program. During August 2025, the Company commenced a 13,000-metre infill drill program within the Lowhee Zone, being undertaken as part of the Appian 2025 Financing Facility obligations, from existing underground development infrastructure completed to date.
  • The infill program is expected to provide a comprehensive data set that will inform resource modeling, mine planning and production stope design procedures and parameters. It will also support the development of a systematic approach to infill drilling for the underground mining operation.
  • Subsequent to Q3 2025, the Company released 2,279 meters of underground infill drilling results (refer to Subsequent to Q3 2025) from this program.
  • To date, an aggregate total of approximately 6,900 meters of drilling has been completed, representing approximately 51% of the total planned drill meters. Full assays are pending along with completion of associated quality assurance and quality control reviews. The Company expects to complete the infill drilling program in the first quarter of 2026.
• Pre-Construction Activities. The Company continues to advance pre-construction activities, including certain surface infrastructure and underground development.
  • These include, among others, the upgrade of the Bonanza Ledge water treatment plant, construction of the waste rock storage facility and the sediment control pond, expansion of the Ballarat camp, ongoing underground development, the underground infill drilling program and related detailed engineering work.
  • To date, approximately 1.9 kilometers of underground development has been completed from the existing Cow Portal into the Cariboo Gold Project’s Lowhee Zone and along the main access ramp towards the Cow Mountain Zone up to the Lowhee fault (see Figure 1).

Figure 1: Cariboo Gold Project long section and underground development progress.

Figure 2: Waste rock storage facility (WRSF) excavation and BL water treatment plant under construction.

Figure 3: Sediment control pond (SCP) stripping in progress.

Figure 4: Existing Ballarat camp.

Figure 5: Lowhee Zone underground infill drill rig stations currently in use.

Figure 6: Main decline ramp from Cow portal (5.4 meters wide x 5.8 meters high).

UPCOMING MILESTONES – CARIBOO GOLD PROJECT

Key Project Milestones(1)		Expected Timing of Completion		Anticipated Remaining Costs*
CGP Underground Development		Q4 2025		$7.9 million
Bonanza Ledge – Construction		Q4 2025		$0.7 million
Bonanza Ledge Water Treatment Upgrade		Q4 2025		$4.3 million
Underground Infill Drilling		Q1 2026		$2.6 million
Ballarat Camp Expansion		Q1 2026		$7.0 million
Waste Rock Storage Facility Construction		Q2 2026		$9.0 million
Detailed Engineering		Q4 2026		$6.6 million

__________________________
*As of September 30, 2025

Note:
(1)	The expenditures disclosed in this table include amounts approved by the Board of Directors up until the end of December 2025. Additional expenditures will be required to complete certain of the milestones and are subject to approval by the Board of Directors.

Tintic Project – Utah, U.S.A. (100%-owned)

• Small-Scale Heap Leach Project. In the first quarter of 2025, a small-scale heap leach project was undertaken to re-treat certain tailings and stockpile material. As a result, a total of 877 gold ounces were sold in Q3 2025, with small-scale operations anticipated to continue into the fourth quarter of 2025. While management continues to evaluate options for the next steps at the Tintic Project, it is expected that limited activities will occur beyond care and maintenance.

San Antonio Gold Project – Sonora State, Mexico (100%-owned)

• The San Antonio Gold Project remains in care and maintenance and the Board of Directors of the Company has authorized a strategic review. The approval process for mining permits appears to be gaining traction, specifically for open-pit mining in the country, and the Company intends to re-submit its two permit applications in the foreseeable future.

SUBSEQUENT TO Q3 2025

• On October 6, 2025, the Company announced new infill drilling results from its ongoing 13,000-meter program on 10-meter drill spacing that commenced in August 2025 in the Lowhee Zone of the Cariboo Gold Project. The first three fans of this program consisted of approximately 2,279 meters of underground infill drilling, representing approximately 17.5% of the total planned drill meters.
• On October 27, 2025, the Company announced the filing of an early warning report regarding Falco Resources Ltd. (“Falco”) wherein the Company acquired, indirectly through its wholly-owned subsidiary, Barkerville Gold Mines Ltd., 6,250,000 units of Falco at a price of $0.32 per unit for an aggregate purchase price of $2.0 million in connection with a “bought deal” private placement of 41,005,000 units completed by Falco. Each unit consisted of one common share of Falco and one-half of one common share purchase warrant of Falco. As a result of and immediately following completion of the private placement, the Company owned or controlled, indirectly through its wholly-owned subsidiary, an aggregate of 54,925,240 common shares and 4,915,000 warrants, representing approximately 15.9% of the issued and outstanding common shares on a basic non-diluted basis.
• On October 29, 2025, the Company completed a private placement offering of 15,409,798 common shares of the Company for aggregate gross proceeds of approximately $82.5 million comprised of the following issuances:
  • 2,990,000 common shares that will qualify as “flow-through shares” (“FT Shares”) within the meaning of subsection 66(15) of the Income Tax Act (Canada) (the “Tax Act”) at a price of $6.69 per FT Share for gross proceeds of approximately $20.0 million;
  • 1,444,000 common shares to certain eligible British Columbia resident subscribers (the “BC FT Shares”, and together with the FT Shares, the “Flow-Through Shares”) that will qualify as “flow-through shares” within the meaning of subsection 66(15) of the Tax Act at a price of $6.93 per BC FT Share for gross proceeds of approximately $10.0 million; and
  • 10,975,798 common shares at a price of $4.78 per common share for gross proceeds of approximately $52.5 million.
• On November 3, 2025, the Company announced the appointment of Mr. Scott Smith as Vice President, Exploration.

Consolidated Financial Statements

The Company’s unaudited condensed interim consolidated financial statements (the “Financial Statements”) and related management’s discussion and analysis (“MD&A”) for the three months ended September 30, 2025 have been filed with Canadian securities regulatory authorities and the U.S. Securities and Exchange Commission. These filings are available on the Company’s website at www.osiskodev.com, on SEDAR+ (www.sedarplus.ca) and on EDGAR (www.sec.gov) under Osisko Development’s issuer profile.

Qualified Persons

The scientific and technical information contained in this news release has been reviewed and approved by Victor Gauthier, ing., P.Eng., Manager – Technical Services of Osisko Development, and Eryn Doyle, P.Geo., Senior Exploration Manager of Osisko Development, each of whom is considered to be a “qualified person” within the meaning of National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”).

Technical Reports

Information relating to the Cariboo Gold Project and the 2025 Feasibility Study on the Cariboo Gold Project is supported by the technical report titled “NI 43-101 Technical Report, Feasibility Study for the Cariboo Gold Project, District of Wells, British Columbia, Canada” and dated June 11, 2025 (with an effective date of April 25, 2025) (the “Cariboo Technical Report”).

Information relating to the Tintic Project and the current mineral resource estimate for the Trixie deposit (the “2024 Trixie MRE”) is supported by the technical report titled “NI 43-101 Technical Report, Mineral Resource Estimate for the Trixie Deposit, Tintic Project, Utah, United States of America” and dated April 25, 2024 (with an effective date of March 14, 2024) (the “Tintic Technical Report”).

Information relating to San Antonio Gold Project is supported by the technical report titled “NI 43-101 Technical Report for the 2022 Mineral Resource Estimate on the San Antonio Project, Sonora, Mexico” and dated July 12, 2022 (with an effective date of June 24, 2022) (the “San Antonio Technical Report” and collectively with the Tintic Technical Report and the Cariboo Technical Report, the “Technical Reports”).

For readers to fully understand the information in the Technical Reports, reference should be made to the full text of the Technical Reports in their entirety, including all assumptions, parameters, qualifications, limitations and methods therein. The Technical Reports are intended to be read as a whole, and sections should not be read or relied upon out of context. The Technical Reports were prepared in accordance with NI 43-101 and are available electronically on SEDAR+ (www.sedarplus.ca) and on EDGAR (www.sec.gov) under Osisko Development’s issuer profile and on the Company’s website at www.osiskodev.com.

ABOUT OSISKO DEVELOPMENT CORP.

Osisko Development Corp. is a continental North American gold development company focused on past-producing mining camps located in mining friendly jurisdictions with district scale potential. The Company’s objective is to become an intermediate gold producer by advancing its flagship permitted 100%-owned Cariboo Gold Project, located in central B.C., Canada. Its project pipeline is complemented by the Tintic Project in the historic East Tintic mining district in Utah, U.S.A., and the San Antonio Gold Project in Sonora, Mexico—brownfield properties with significant exploration potential, extensive historical mining data, access to existing infrastructure and skilled labour. The Company’s strategy is to develop attractive, long-life, socially and environmentally responsible mining assets, while minimizing exposure to development risk and growing mineral resources.

For further information, visit our website at www.osiskodev.com or contact:

Sean Roosen	Philip Rabenok
Chairman and CEO	Vice President, Investor Relations
Email:sroosen@osiskodev.com	Email:prabenok@osiskodev.com
Tel: +1 (514) 940-0685	Tel: +1 (437) 423-3644

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