Endeavour Announces Positive DFS Results for the Assafou Project That Underpins the Next Phase of Organic Growth
NEWS RELEASE – LSE & TSX: EDV
ENDEAVOUR ANNOUNCES POSITIVE DFS RESULTS FOR THE ASSAFOU PROJECT THAT UNDERPINS THE NEXT PHASE OF ORGANIC GROWTH HIGHLIGHTS:
- Definitive Feasibility Study confirms Assafou's potential to become a cornerstone asset for Endeavour
highlighting:
› 320kozpa production at AISC of $1,026/oz over first 8 years.
› 16-year mine life based on P&P reserves of 4.4Moz (77.4Mt at 1.76g/t); M&I resources of 5.0Moz (80.1Mt at 1.93g/t).
› Robust project economics with after-tax NPV(5%) of $2.1bn and 28% IRR at a gold price of $2,500/oz, increasing to $5.1bn and 55% at a gold price of $4,000/oz.
› Upfront capital of $1,061m based on a scalable 5Mtpa design nameplate capacity gravity / CIL processing plant; increased upfront capital reflects changes to site infrastructure, plant optimisations to de-risk ramp-up and to enable seamless plant expansion in the future.
- Significant exploration potential with over 20 highly prospective targets defined:
› Assafou deposit (5.0Moz M&I resource) mineralisation is open along strike and at depth; Pala Trend 3 (0.2Moz maiden M&I resource) satellite located 1km away is mineralised from surface. › Assafou is the first discovery in a highly prospective and underexplored belt.
- Early works launched including long-lead orders, detailed engineering and design, and key tenders.
- Final investment decision targeted before end-2026, with subsequent 24 – 30 month construction.
- Assafou underpins the Group’s sector-leading organic growth outlook to 1.5Moz, at first quartile AISC, by 2030.
Abidjan, 23 April 2026 – Endeavour Mining plc (LSE:EDV, TSX:EDV, OTCQX:EDVMF) (“Endeavour”, the “Group” or the “Company”) is pleased to announce the results of the Definitive Feasibility Study (“DFS”) for the Assafou- Dibibango (“Assafou”) project on the Tanda-Iguela property in Côte d’Ivoire.
Ian Cockerill, Chief Executive Officer, commented: “We are pleased with the results of the Assafou project DFS, which confirms the quality and scale of the asset that will underpin the next phase of Endeavour’s organic growth.
Assafou has the potential to become another cornerstone asset for Endeavour, adding 320koz of production per year at a first quartile AISC of $1,026/oz, over the first eight years of its 16-year mine life. It will be our lowest- cost and longest-life mine, further improving our portfolio quality while bolstering the resilience of the business.
The impressive project economics demonstrate our ability to rapidly generate value through the drill bit. Assafou was discovered for $13 million in 2022 and only four years later has a value of $5.1 billion at aa $4,000/oz gold price. As we continue to de-risk the project and grow its resource base through exploration, we expect to unlock even more value.
Since its discovery, the Assafou M&I resource has grown 470%, to over 5 million ounces, and we are increasingly excited by more than 20 highly prospective satellite targets, in close proximity to the deposit.
Working closely with our supportive in-country stakeholders, we are advancing the project’s mining convention, and we are targeting a final investment decision before the end of the year. Simultaneously, we have launched early works, detailed engineering and design, key tenders and long-lead orders to expedite construction.
As we advance Assafou, we will remain disciplined and prioritise maximising free cash flow from every ounce of gold we produce, ensuring that we continue to deliver sector leading shareholder returns, while we organically grow production to 1.5 million ounces by 2030.”
Table 1: Assafou Project Highlights
| ASSAFOU DFS | STRATEGIC TARGETS |
|---|---|
| P&P Reserve, Moz1 4.4 | >3.0 |
| Mine life, years 16 | >10 |
| Average annual production, kozpa First 8 years 320 Life of mine 257 | >200 |
| AISC, $/oz2 First 8 years 1,026 Life of mine 1,062 | 1st quartile |
| Post-tax NPV $m2 2,059 5%, | n.a. |
| Post-tax IRR, %2 28 | >20 |
1Based on a $1,500/oz reserve price. 2Based on a gold price of $2,500/oz.
The key operational and economic highlights of the Assafou DFS are summarised in Tables 2 and 3 below.
Table 2: Assafou DFS Summary
OPERATION TYPE
Mine type Open Pit Plant type 5.0Mtpa Gravity / CIL Plant
RESERVES & RESOURCES1
P&P reserves 77.4Mt at 1.76g/t Au for 4.4Moz M&I resources (inclusive of reserves) 80.1Mt at 1.93g/t Au for 5.0Moz Inferred resources 0.9Mt at 2.34g/t Au for 0.1Moz
LIFE OF MINE PRODUCTION
Mine life, years 16 Strip ratio, W:O 6.3 Tonnes processed, Mt 77.4 Grade processed, Au g/t 1.76 Gold contained processed, Moz 4.4 Average recovery rate, % 94 Gold production, Moz 4.1 Average annual production, kozpa 257 Cash costs, $/oz2 952 AISC, $/oz2 1,062
AVERAGE FOR YEARS 1 TO 8
Production, kozpa 320 Cash costs, $/oz 887 AISC, $/oz2 1,026
CAPITAL COST
Upfront capital cost, $m 1,061
ENVIRONMENTAL DATA
GHG Emissions Intensity3, t CO2e/oz 0.59 Energy Intensity, GJ/oz 7.39 1Based on a reserves gold price of $1,500/oz and a resource gold price of $1,900/oz. Reserves and Resources relates to the Assafou Project and are exclusive of Pala Trend 3 Resources. 2Based on a gold price of $2,500/oz. 3GHG Emissions Intensity considers only Scope 1 and 2 emissions.
Table 3: Assafou DFS Project Economics
| Gold Price | ||||||
|---|---|---|---|---|---|---|
| $2,000/oz | $2,500/oz | $3,000/oz | $4,000/oz | |||
| PRE-TAX | ||||||
| NPV , $m 1,625 5% IRR, %1 23 | 2,909 | 4,250 | ||||
| 34 | 45 | |||||
| Payback Period, yr1 | 4.14 | 3.01 | 2.43 | 1.81 | ||
| AFTER-TAX | ||||||
| NPV , $m 5% | 1,074 | 2,059 | 3,077 | 5,113 | ||
| IRR, %1 | 18 | 28 | 37 | |||
| Payback Period, yr1 | 4.97 | 3.52 | 2.73 | 1.95 |
1Payback period and IRR are calculated from the start of commercial production Endeavour expects to file a Technical Report pursuant to National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“the NI 43-101”) in respect of the Assafou DFS within 45 days of this news release.
Overview
The 100% owned Tanda and Iguela exploration permits (“Tanda-Iguela”) are located in the eastern region of Côte d’Ivoire, approximately 280km northeast of Abidjan, adjacent to the Ghana border. The northern permit, Tanda, was added to Endeavour’s portfolio in November 2015 following the combination of La Mancha’s Ivorian assets with Endeavour. Endeavour conducted an initial drilling campaign during 2016 that yielded positive results and quickly identified the southern permit, Iguela, as having a high degree of geological prospectivity. The Iguela permit was awarded to Endeavour in May 2017, through Côte d’Ivoire’s permit application process.
Figure 1: Tanda-Iguela Regional Map
A maiden Indicated resource of 1.1Moz (14.9 at 2.33 g/t Au) was published on 21 November 2022, based on 56,000 metres of drilling, and was subsequently increased to 4.5Moz (70.9 at 1.97 g/t Au) on 29 November 2023, based on an additional 123,000 metres of drilling. Further exploration and advanced grade control drilling at the Assafou deposit and exploration drilling at the Pala Trend 3 satellite deposit resulted in an increase in Measured and Indicated resources to 5.2Moz at 1.91g/t as of 31 December 2025. These resources are based on an additional 99,000 metres of drilling and include maiden Measured resources, reflecting increased resource confidence.
As shown in Figure 2 below, the DFS demonstrates Assafou’s potential to deliver 320kozpa at all-in sustaining cost (“AISC”) of $1,026/oz over the first eight years of operations, with average production of 257kozpa and AISC of $1,062/oz over the 16-year life of mine.
Figure 2: Assafou DFS Production and AISC Profile1
1AISC based on a gold price of $2,500/oz
The DFS production profile is based on the Assafou deposits’ mineral reserves only, with an effective date of 31 December 2025. The DFS production profile excludes mineral resources outside of reserves and excludes the maiden Measured and Indicated mineral resource of 4.7Mt at 1.55g/t for 0.2Moz at the Pala Trend 3 satellite deposit, that was defined following successful exploration drilling during 2025. Furthermore, nearly 70,000 metres of exploration drilling has been completed at nearby satellite deposits, which is expected to contribute to further resource and reserve increases supporting higher levels of production, particularly in years 12 to 16 of the production profile.
Reserves and Resources
The Assafou Project’s 31 December 2025 reserve and resource estimate is shown in Table 4 below. The resource estimate is based on a gold price of $1,900/oz and the reserve estimate is based on a conservative gold price of $1,500/oz.
Table 4: Assafou Project Reserves and Resources
Tonnage Grade Content On a 100% basis (Mt) (Au g/t) (Au koz)
Assafou Deposit (DFS)
| Proven Reserves | 21.5 | 1.87 | 1,295 |
| Probable Reserves | 55.9 | 1.72 | 3,085 |
| P&P Reserves | 77.4 | 1.76 | 4,379 |
| Measured Resource (incl. reserves) | 20.8 | 2.05 | 1,367 |
| Indicated Resources (incl. reserves) | 59.4 | 1.89 | 3,606 |
| M&I Resources | 80.1 | 1.93 | 4,972 |
| Inferred Resources | 0.9 | 2.34 | 69 |
Pala Trend 3
| Proven Reserves | - | - | - |
| Probable Reserves | - | - | - |
| P&P Reserves | - | - | - |
| Measured Resource (incl. reserves) | - | - | - |
| Indicated Resources (incl. reserves) | 4.7 | 1.55 | 231 |
| M&I Resources | 4.7 | 1.55 | 231 |
| Inferred Resources | 1.0 | 1.68 | 53 |
| T | otal Assafou Project | |||
|---|---|---|---|---|
| P | roven Reserves | 21.5 | 1.87 | 1,295 |
| P | robable Reserves | 55.9 | 1.72 | 3,085 |
| P | &P Reserves | 77.4 | 1.76 | 4,379 |
| M | easured Resource (incl. reserves) | 20.8 | 2.05 | 1,367 |
| In | dicated Resources (incl. reserves) | 64.0 | 1.86 | 3,837 |
| M | &I Resources | 84.8 | 1.91 | 5,203 |
| In | ferred Resources | 1.9 | 2.00 | 122 |
1Mineral Resource Estimate effective 31 December 2025. Mineral Reserve Estimate effective 31 December 2025. Mineral Resource and Reserve Estimates follow the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definitions Standards for Mineral Resources and Reserves and have been completed in accordance with the Standards of Disclosure for Mineral Projects as defined by National Instrument 43-101. Reported tonnage and grade figures have been rounded from raw estimates to reflect the relative accuracy of the estimate. Minor variations may occur during the addition of rounded numbers. Mineral Resources that are not Mineral reserves do not have demonstrated economic viability. Resources were constrained by MII Pit Shell based on a cut-off grade of 0.40g/t at a $1,900/oz gold price. Reserves are based on a cut-off grade of 0.40g/t for oxide, laterite and transitional ore and 0.50g/t for fresh ore and $1,500/oz gold price. Endeavour is not aware of any legal, political, environmental or other risks that could materially affect the potential development of the mineral resources and mineral reserves other than as noted herein.
For technical notes and drilling results from the Assafou drill programme, please see the Technical Notes section below.
Mining Operations
The Assafou deposit mineralisation extends from surface to depths in excess of 300 metres and is amenable to conventional open-pit, drill and blast, mining. The mine planning, resource and cost estimation for the DFS is based on a contract mining operation with a maximum mining capacity of 53.0 Mt per year, that is expected to be achieved 5 months after the commencement of mining. Mining capacity is expected to exceed processing capacity in order to accumulate stockpiles to allow high grade material to be preferentially processed early in the mine plan.
During the pre-commercial production period approximately 49.3 Mt of pre-stripping is expected to support an accelerated production ramp up. The projects and operations teams will review opportunities to reduce the impact of pre-stripping at the Assafou deposit through supplementing the ore feed with near-surface ore from the Pala Trend 3 deposit, located 1km southwest of the Assafou deposit, as well as additional satellite deposits in close proximity to the Assafou deposit.
Ore mining is expected to occur in 15-metre benches and 6.0 x 2.5-metre flitches in fresh rock, while waste is expected to be mined in 5-metre flitches. Smaller excavators will be used for ore loading to decrease dilution.
Diesel excavators and dump trucks will be used for loading and haulage, with a contractor fleet expected to comprise of 300-tonne class face excavators for waste mining, and 150-tonne class excavators for ore mining.
Processing Operations
Ore will be processed via a 5.0 Mtpa gravity / carbon-in-leach (“CIL”) processing plant. Over the life of mine, the plant will be fed with approximately 88% fresh ore and 12% oxide and transitional ore.
The comminution circuit is expected to comprise of two-stage crushing followed by a high-pressure grinding roll and a ball milling circuit. A primary gyratory crusher will crush ore to a coarse crush size, followed by dual secondary cone crushers. A live primary crushed ore stockpile will provide a buffer storage of primary crushed ore, with reclaim to feed the secondary crushing unit. Ore will then be fed through the high-pressure grinding roll circuit that feeds the ball mill. In the event that the secondary crushers or the high-pressure grinding roll circuits are offline, a fines stockpile located after the high-pressure grinding roll circuit will ensure there is feed available for the ball mill. The ball mill will mill the ore to 80% passing 106µm (microns).
The milled ore will pass through a gravity circuit comprising two Knelson concentrators for separation and recovery of coarse free gold, to produce a gravity concentrate for cyanidation and electrowinning that can be smelted to produce gold doré. High gravity recovery of approximately 70% is estimated.
Coarse feed is returned to the ball mill while screened cyclone overflow is passed via the leach feed thickener to a CIL circuit containing one pre-leach tank and six CIL tanks, in series, for leaching and absorption. Leach residence time will be approximately 36 hours. Following leaching and absorption, gold will be recovered from activated carbon by elution, electrowinning, and gold smelting to produce gold doré.
Extensive multiphase metallurgical test work has demonstrated that ore from the Assafou deposit contains freemilling gold, with a high proportion of gravity recoverable gold, that is amenable to cyanidation. The majority of the remaining gold has a high leach extraction potential resulting in an overall gold recovery rate of 94% over the life of mine.
Operating Cost Summary
Mining operating costs, which are based on Q3-2025 estimates, were prepared by Endeavour, are based on a contractor mining model. Process operating cost estimates were prepared by Lycopodium Minerals Canada Ltd (Lycopodium), who have successfully supported Endeavour through five engineering and construction projects in West Africa over the last twelve years. General and Administration (“G&A”) cost estimates were also prepared by Endeavour, as summarised in the table below.
Table 5: Assafou Project Life of Mine Operating Unit Costs (-10/+15%)
UNIT COSTS (US$)
Open Pit Mining and Rehandling $4.11/t mined Processing $14.38/t processed G&A $4.48/t processed Based on Q3-2025 estimates that exclude escalation.
Operating costs have been based on a delivered diesel price of $1.13 per litre and are in line with current local pricing and, therefore do not reflect any potential pricing impact from current hostilities in the Middle East. Power will be sourced from the grid supplying 90kV to site via a ring main system providing power from two different parts of the power grid to increase reliability with an assumed grid availability of 90% and power costs estimated at $0.13/kWh.
Capital Cost and Infrastructure Summary
The project upfront capital cost, which is based on Q3-2025 estimates, was compiled by Lycopodium with input from Knight Piésold Pty Ltd (Knight Piésold) on the tailings storage facility (“TSF”), water infrastructure, site access roads and airstrip, SRK Consulting (UK) Ltd (SRK) for mining cost models and contractor rates, Digby Wells Environmental Holding Ltd (Digby Wells) for RAP costs, compensation and closure costs, Cabinet Enval SARL (ENVAL) for environmental assessments, and from ECG Engineering Pty Ltd (ECG Engineering) on the power infrastructure. Endeavour has provided project specific estimates for mine establishment, facilities, power and owner’s costs.
The initial capital cost is summarized in the table below.
Table 6: Assafou Project Upfront Capital Cost Estimate Summary (-10/+15%)
| CAPITAL COSTS (US$M) | |
| Pre-production Mining | 111.4 155.8 30.9 250.2 65.4 215.7 50.7 |
| Processing Plant Costs | |
| Reagents and Plant Services | |
| Site Infrastructure | |
| Contractor Distributables | |
| Owner Project and Operations Costs | |
| Management Costs | |
| Subtotal | 880.1 76.3 85.4 18.8 |
| Pre-production Working Capital | |
| Contingency | |
| Taxes and Duties |
Total Upfront Capital Cost 1060.6
Based on Q3-2025 estimates that exclude escalation.
The Assafou project capital cost estimate assumes a contractor mining model, selected due to the additional fleet flexibility that can accommodate the pre-production mining ramp-up and the potential incorporation of satellite deposits into the mine plan.
The Assafou project benefits from good surrounding infrastructure, including access to the 90kV ring main power supply, which will be diverted via a new 12km transmission line, and access to the A1 national road, which will be diverted via an assumed 55km extension around the operation. In addition, backup power comprised of 28 containerised diesel generators with prime output of 28.0MW has been included in the upfront capital costs. Furthermore, land provision within the existing mine perimeter for a potential 31.5MW solar power plant has been provided. The airstrip will be built 10km from the site’s permanent accommodation. Resettlement of two villages, within close proximity to the project, is required and is included in the upfront capital cost estimate. The tailings storage facility (“TSF”) is expected to be a High-Density Polyethylene (“HDPE“) lined cross-valley storage facility, utilising the natural topography of the project area, that will be formed by multi-zoned earth fill embankments, with a total footprint area (including the basin area) of approximately 239ha for the stage 1 TSF to 265ha for the final TSF. TSF construction will benefit from the high availability of fresh waste rock from the mining pre-stripping activities. The TSF is designed to a life-of-mine capacity accommodating a total of 72.0Mt of tailings. The Stage 1 TSF is designed for 7.5Mt, approximately 18 months storage capacity, and subsequently, downstream raise construction will be used to progressively increase capacity.
Estimated resettlement disbursements and related costs are included in the Owner Project and Operations Costs. These estimates are based on a combination of legislated compensation mechanisms and historic precedents of similar costs. Final costs are subject to negotiation and agreement between various stakeholders, including the State of Côte d’Ivoire and local communities.
Figure 3 below highlights the proposed site and infrastructure layout.
Figure 3: Assafou Project Schematic Site Layout
Ownership, Permitting, Taxes and Royalties
Endeavour acquired the Tanda exploration permit in 2015, subsequently acquiring the Iguela exploration permit, which contains the Assafou project, in 2017. The exploitation permit for the Assafou project was granted in February 2026. Once the new project company is fully incorporated with the State of Côte d’Ivoire as a shareholder in accordance with Ivorian law, the exploitation permit will be transferred to that company. The current Mining Code envisages a State free carried interest of 10%.
A corporate tax rate of 25% of gross profit, a royalty rate of 8.0% above a gold price of $2,000/oz and a local development fund contribution of 0.5% of gold sales were applied in the DFS. Gold royalties in Côte d’Ivoire are based on a sliding scale with the gold price and vary between 5.0% and 8.0%. A transport and refining charge of $4/oz Au was also applied.
The Mining Code in Côte d’Ivoire is currently under review, and if the proposed new Mining Code, is passed into law before the Assafou mining convention is granted, then the level of State participation and the fiscal terms applicable to the Assafou project may reflect those of the new Mining Code.
Timetable, Early Works and Project Construction
A 24 to 30 month construction period is projected following the final investment decision, which is targeted before the end of 2026. The final investment decision and the construction period do not reflect any potential impact from current hostilities in the Middle East.
As shown below in Figure 4, commencement of procurement for long-lead items, detailed engineering and design, and the EPCM, power and earthworks tenders are already underway.
Figure 4: Assafou Project Early Works Work Stream Q2-2026 Q3-2026 Q4-2026 Q1-2027 Q2-2027 Q3-2027 Q4-2027 Q1-2028 Early Works
EPCM Award Detailed Design & Engineering Order & Procure Long Lead Items Relocation Action Plan
Project Approvals
Mining Convention Approval Final Investment Decision
For FY-2026, growth capital guidance of between $50 – 100 million is expected to be incurred prior to the approval of the final investment decision. The remaining $961 – 1,011 million of the $1,061 million upfront capital is expected to be incurred after the final investment decision.
Following the final investment decision, construction is expected to start, initially prioritising the resettlement, which is on the critical path, and the site infrastructure and earth works. Subsequently tailings and water dam construction, then power supply and process plant construction will commence.
The critical path includes the resettlement, mining pre-stripping and process ore commissioning. The resettlement is required to commence mining pre-stripping. Mining pre-stripping is expected to start approximately five quarters after the final investment decision, in order to provide access to thick, high-grade zones of the ore body early, and support a short processing plant and production ramp-up.
Figure 5: Assafou Project Construction Work Stream Q-1 Q-2 Q-3 Q-4 Q-5 Q-6 Q-7 Q-8 Q-9 Q-10 Q-11 Final Investment Decision Tailings Dam & Water Dams Earthworks
Tailings Dam Water Storage and Harvest Dam
Construction
Power Supply Construction Resettlement* National Road Diversion Site Infrastructure Earth Works & Concrete Works Mining pre-stripping* Process Plant Construction Process Plant Commissioning*
First Gold
- Critical path items.
Next steps
- Q2-2026: Procurement of long-lead items has been launched.
- Q2-2026: Detailed engineering and design is underway.
- Q2-2026: EPCM, power and earthworks tender reviews are advancing towards finalisation.
- Q2-2026: Development of the relocation action plan is underway to support the resettlement.
- Q3-2026: Expected completion of mining convention negotiations.
- End-2026: Final investment decision is targeted before the end of 2026.
2026 DFS vs 2024 PFS
The key changes between the Assafou PFS news release published on 11 December 2024 and the Assafou DFS news release published on 23 April 2026 are highlighted in table 7 below. These include the increase in resource and reserve endowment following successful exploration, the increase in processing unit costs reflecting current costs assumptions across the portfolio, and the increase in upfront capital resulting from scope changes to infrastructure as well as plant optimisations, scalability and ramp-up de-risking.
Table 7: Assafou Project DFS vs PFS Highlights
| DFS PFS | DFS VS PFS |
|---|---|
| PLANT TYPE, SIZE & CAPEX Plant type Gravity / CIL Gravity / CIL Mill capacity, Mtpa 5.0 5.0 RESERVES & RESOURCES4 P&P Reserves, koz 4,379 4,115 M&I Resources, koz 4,972 4,604 Inferred Resources, koz 69 208 LIFE OF MINE PRODUCTION Mine life, years 16 15 Strip ratio, W:O 6.3 5.9 Tonnes processed, Mt 77.4 72.8 Grade processed, Au g/t 1.76 1.76 Gold contained processed, Moz 4.4 4.1 Average recovery rate, % 94 94 Gold production, Moz 4.1 3.9 CAPITAL AND OPERATING COSTS Upfront capital cost, $m 1,061 734 Open Pit Mining & Rehandling, $/t mined 4.11 4.08 Processing, $/t processed 14.38 12.25 G&A, $/t processed 4.48 4.10 AVERAGE FOR YEARS 1 TO 8 Average annual production, kozpa 320 327 Cash costs, $/oz1 887 854 AISC, $/oz1 1,026 949 ENVIRONMENTAL DATA GHG Emissions Intensity2, t CO2e/oz 0.59 0.55 Energy Intensity, GJ/oz 7.39 7.23 ECONOMICS (BASED ON $2,500/oz) Pre-Tax Returns NPV $m 2,909 3,408 5%, IRR, % 34 48 Payback, years3 3.0 2.4 After-Tax Returns NPV $m 2,059 2,485 5%, IRR, % 28 40 Payback, years3 3.5 2.7 | |
| − | |
| +6% | |
| +8% | |
| (67)% | |
| +7% | |
| +7% | |
| +6% | |
| − | |
| +6% | |
| − | |
| +5% | |
| +45% | |
| +1% | |
| +17% | |
| +9% | |
| (2)% | |
| +4% | |
| +8% | |
| +7% | |
| +2% | |
| (15)% | |
| (29)% | |
| 25% | |
| (17)% | |
| (30)% | |
| 30% |
1 AISC and cash costs based on a gold price of $2,500/oz. Sliding scale royalty rates from $2,000/oz have increased from 6% per the PFS to 8% in the DFS. 2GHG Emissions Intensity calculated as Scope 1 and 2 emissions. 3 Payback period calculated starting from start of commercial production. 4 Based on a reserves gold price of $1,500/oz and a resource gold price of $1,900/oz. Reserves and Resources relates to the Assafou Project and are exclusive of Pala Trend 3 Resources.
Table 8 demonstrates a significant uplift in resource and reserve size and confidence within the Assafou deposit. P&P reserves at the Assafou deposit increased by 6% while M&I resources increased by 8%, following 99,000 metres of additional drilling both within, and outside of, the Assafou pit shell, subsequent to the completion of the PFS.
This additional drilling also supported improved reserve and resource confidence, which is reflected by the addition of maiden Proven reserves of 21.5Mt at 1.87g/t for 1.3Moz alongside maiden Measured resources of 20.8Mt at 2.05g/t for 1.4Moz, which cover 40% of the first five years of the mine plan. This improvement is underpinned by closer spaced drilling at 20 x 25 metre spacing, compared to previous drilling at 33 x 40 metre spacing and 100 x 80 metre spacing that supported the PFS and the maiden resources respectively. The increased reserve and resource confidence supports de-risking of the ramp up and the first five years of the mine plan.
Table 8: Assafou Project Mineral Reserves and Resources1
| 31 December 20252 | 31 December 20243 | VARIANCE | |||||
|---|---|---|---|---|---|---|---|
| On a 100% basis. M&I Resources | Tonnage | Grade | Content | Tonnage | Grade | Content | Au Content |
| shown inclusive of Reserves. | (Mt) | (Au g/t) | (Au koz) | (Mt) | (Au g/t) | (Au koz) | (Au koz) |
| Proven Reserves | 21.5 | 1.87 | 1,295 | - | - | - | +1,295 |
| Probable Reserves | 55.9 | 1.72 | 3,085 | 72.8 | 1.76 | 4,115 | -1,030 |
| P&P Reserves | 77.4 | 1.76 | 4,379 | 72.8 | 1.76 | 4,115 | +264 |
Measured Resource (incl.
20.8 2.05 1,367 - - - +1,367 reserves)
Indicated Resources (incl.
59.4 1.89 3,606 73.6 1.95 4,604 -998 reserves)
M&I Resources (incl. reserves) 80.1 1.93 4,972 73.6 1.95 4,604 +368
Inferred Resources 0.9 2.34 69 3.3 1.97 208 -139 1Excludes maiden Mineral resource Estimate for the Pala Trend 3 deposit, which is excluded from the DFS mine plan. 2Mineral resource Estimate effective 31 December 2025. Mineral Reserve Estimate effective 31 December 2025. Mineral Resource and Reserve Estimates follow the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definitions Standards for Mineral Resources and Reserves and have been completed in accordance with the Standards of Disclosure for Mineral Projects as defined by National Instrument 43-101. Reported tonnage and grade figures have been rounded from raw estimates to reflect the relative accuracy of the estimate. Minor variations may occur during the addition of rounded numbers. Mineral resources that are not Mineral Reserves do not have demonstrated economic viability. Resources were constrained by MII Pit Shell based on a cut-off grade of 0.40g/t at a $1,900/oz gold price. Reserves are based on a cut-off grade of 0.40g/t for oxide, laterite and transitional ore and 0.50g/t for fresh ore and $1,500/oz gold price. 3Mineral resource estimate effective 31 December 2024. Mineral reserve estimate effective 31 December 2024. Mineral resource and reserve estimates follow the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definitions Standards for Mineral Resources and Reserves and have been completed in accordance with the Standards of Disclosure for Mineral Projects as defined by National Instrument 43-101. Reported tonnage and grade figures have been rounded from raw estimates to reflect the relative accuracy of the estimate. Minor variations may occur during the addition of rounded numbers. Mineral Resources that are not mineral reserves do not have demonstrated economic viability. Resources were constrained by MII Pit Shell based on a cut-off grade of 0.5g/t at a $1,900/oz gold price. Reserves are based on a cut-off grade of 0.40g/t for oxide ore and 0.50g/t for fresh ore and $1,500/oz gold price. Endeavour is not aware of any legal, political, environmental or other risks that could materially affect the potential development of the mineral resources and mineral reserves other than as noted herein.
The updated mineral resource estimate for the Assafou deposit, based on a gold price of $1,900/oz is robust, given its high-grade, thickness and continuity, as demonstrated by the sensitivity analysis presented in Table 9.
Table 9: Assafou Deposit Mineral Resource Estimate Sensitivity1
| Tonnage | Grade | Content | ||||
|---|---|---|---|---|---|---|
| Measured Resource | (Mt) | (Au g/t) | (Au koz) | |||
| Based on a gold price of $1500/oz | 20.2 | 2.05 | 1,334 | |||
| Based on a gold price of $1900/oz | 20.8 | 2.05 | 1,367 | |||
| Based on a gold price of $2000/oz | 20.8 | 2.05 | 1,370 | |||
| Based on a gold price of $2100/oz | 20.9 | 2.04 | 1,372 | |||
| Based on a gold price of $2500/oz | 20.9 | 2.04 | 1,375 | |||
| Based on a gold price of $3000/oz | 21.0 | 2.04 | 1,382 | |||
| Indicated Resource | ||||||
| Based on a gold price of $1500/oz | 54.0 | 1.92 | 3,328 | |||
| Based on a gold price of $1900/oz | 59.4 | 1.89 | 3,606 | |||
| Based on a gold price of $2000/oz | 60.1 | 1.88 | 3,635 | |||
| Based on a gold price of $2100/oz | 60.3 | 1.88 | 3,645 | |||
| Based on a gold price of $2500/oz | 62.3 | 1.87 | 3,738 | |||
| Based on a gold price of $3000/oz | 63.3 | 1.86 | 3,777 | |||
| Inferred Resource | ||||||
| Based on a gold price of $1500/oz | 0.6 | 2.46 | 46 | |||
| Based on a gold price of $1900/oz | 0.9 | 2.34 | 69 | |||
| Based on a gold price of $2000/oz | 1.0 | 2.28 | 72 | |||
| Based on a gold price of $2100/oz | 1.0 | 2.25 | 74 | |||
| Based on a gold price of $2500/oz | 1.4 | 2.20 | 97 | |||
| Based on a gold price of $3000/oz | 1.7 | 2.14 | 115 |
1Mineral resource estimate effective 31 December 2025. Mineral reserve estimate effective 31 December 2025. Mineral resource and reserve Estimates follow the Canadian Institute of Mining, Metallurgy and Petroleum (“CIM”) Definitions Standards for Mineral Resources and Reserves and have been completed in accordance with the Standards of Disclosure for Mineral Projects as defined by National Instrument 43-101. Reported tonnage and grade figures have been rounded from raw estimates to reflect the relative accuracy of the estimate. Minor variations may occur during the addition of rounded numbers. Mineral resources that are not mineral reserves do not have demonstrated economic viability. Resources were constrained by MII Pit Shell based on a cut-off grade of 0.40g/t at a $1,900/oz gold price. Reserves are based on a cut-off grade of 0.40g/t for oxide, laterite and transitional ore and 0.50g/t for fresh ore and $1,500/oz gold price.
As illustrated in the figure 6 below, Assafou’s mine life has been extended by approximately one year due to the increase in P&P reserves, while its average annual production and cost profile remain similar to the PFS.
Figure 6: Assafou Project DFS vs PFS Production Profile1
1AISC based on a gold price of $2,500/oz
The upfront capital cost for the project has increased from $734 million in the PFS to $1,061 million in the DFS. As shown in table 10 below, the increase in upfront capital is related to scope changes to infrastructure as well as plant optimisations, scalability and ramp-up de-risking.
Table 10: Assafou Project PFS - DFS Capital Cost Changes Capital cost changes PFS vs DFS Rationale
Site infrastructure: +$130.3m • Improved backup power in the DFS incorporating containerised • Improved backup power is engineered and capable of diesel generators with a more robust design comprised of 28 supporting the full load requirements in the event that there generators with prime output of 28.0MW. are any outages or capacity constraints on the grid.
- Increase in length of the national highway diversion from the • The increased diversion length to the East of the Assafou original 22km in the PFS to an assumed 55km in the DFS. project is fully aligned with the updated infrastructure layout and supports current Government and local community preferences.
- Addition of a 10km 33kV power line connecting the Iguela, • The additional power line ensures power supply is maintained Assafo, Dibibango and Broukro villages to the grid following to local villages and infrastructure following the relocation and mine development. mine development.
- Addition of digital optimisations have been included in the • Digitalisation opportunities are expected to drive life of mine upfront capital. operating costs savings and improved productivity.
Owner project and operations • Owners costs have been increased to account for continued • Retaining the in-house projects team as well as key consultants costs: +$91.3m support from the in-house projects team following the and contractors on site and associated costs, following completion of commissioning through to the completion of the commissioning for the processing plant ramp up, helps de-risk processing plant ramp-up. the ramp up and the first year of production.
Processing plant costs: +$49.5m • Modifications in processing plant flow sheet based on learnings • Flow sheet optimisation is expected to improve processing from Lafigué ramp-up, including optimising conveyors, plant performance and build in additional redundancy, increased crushed ore screens and replacement of the crushed minimising downtime. The addition of the stockpile after the ore stockpile, subsequent to the secondary crushing circuit HPGR allows milling activity to continue in the event the with a stockpile after the -HPGR. crushing or HPGR circuit is down for maintenance or repair.
- Increase in secondary crusher capacity from two Metso • Larger secondary crushers provide capacity to increase throughput beyond processing plant nameplate and ensure 3.0mtpa capacity HP6 secondary crushers in the PFS to two that the processing plant can operate at nameplate capacity in Metso 5.0mtpa capacity HP900 secondary crushers in the DFS.
the event that one of the secondary crushers is down for repair or maintenance.
Pre-production mining and pre- • Optimisation of the mine plan following 99,000 metres of • Advanced grade control drilling covering the first 18 months of production working capital: additional advanced grade control drilling. production to de-risk the operational ramp-up.
+$37.7m • Mine plan optimisation also resulted in earlier mobilisation of • Supports access to a higher-grade zone of the ore body earlier the mining contractor and 35% increased pre-production waste in the mine plan helping to de-risk the mining ramp up.
stripping.
Contractor distributables: • Alignment of construction distributables to reflect changes to • Improves confidence in growth capital expenditure budget by +$20.5m direct capital costs. updating earthwork, concrete, steel and other construction distributable rates.
Management costs: -$2.8m • Finalisation of EPCM management costs. • Finalisation of EPCM and owners cost scope.
- Savings associated with sterilisation drilling. • Completion of sterilisation drilling earlier than initially planned resulted in upfront capital savings.
Geology
Mineralisation at the Assafou deposit is both hosted in quartz veins and disseminated within the Tarkwaian Sandstones. The deposit appears to be monometallic, with no potentially deleterious elements associated with the gold. Mineralisation starts at surface and extends to depths of more than 300 metres. It is continuous along strike, following a prominent northwest-trending structure that separates the Tarkwaian Sandstones from the mafic Birimian Basement rocks. The deposit comprises a thick main (up to 100 metres), flat-lying, continuous lens, overlain by a series of stacked lenses dipping at a low angle to the northeast.
High grade mineralisation and the thickest mineralised intercepts are located adjacent to the structural contact between the mafic Birimian Basement rocks and the Tarkwaian Sandstones along the northeast boundary of the Assafou deposit.
Assafou Exploration
The Assafou deposit was discovered in 2022 with the maiden Indicated resource of 14.9Mt at 2.33g/t containing 1.1Moz and an Inferred resource of 32.9Mt at 1.80g/t containing 1.9Moz defined on 31 October 2022, based on 56,000 metres of drilling.
Subsequently, an updated Indicated resource of 70.9Mt at 1.97g/t containing 4.5Moz and an Inferred resource of 2.9Mt at 1.91g/t containing 0.2Moz was defined on 14 November 2023, based on 123,000 metres of drilling.
In 2025, the mineral resource estimate was updated, with a Measured and Indicated resource of 84.8Mt at 1.91g/t for 5.2Moz and an Inferred resource of 1.9Mt at 1.95g/t containing 0.1Moz, based on 99,000 metres of drilling. This includes the maiden Mineral Resource estimate at Pala Trend 3.
Mineralisation at Assafou remains open along strike along the 20km long structural corridor extending from Koumenagaré in the northwest to Kongojdan in the southeast, as well as at depth where mineralisation has been identified below the current resource pit shell, and within the basement mafic Birimian volcanic rocks.
Figure 7 below highlights the additional drilling at the Assafou deposit that supports the increased reserve and resource size and confidence in the DFS. Infill and advanced grade control drilling on the Assafou deposit was completed during 2025 and reconfirmed the existing resource model, providing increased confidence in the initial phases of ore mining at the deposit. Resource definition drilling was completed at the Pala Trend 3 target located approximately 1 kilometre west of the Assafou deposit defining maiden resources.
Figure 7: Assafou Deposit Map