Mr. Mark Smith reports

NIOCORP TO COMBINE WITH NASDAQ-LISTED GXII TO ACCESS ADDITIONAL CAPITAL FOR THE ELK CREEK CRITICAL MINERALS PROJECT

Niocorp Developments Ltd. and GX Acquisition Corp. II (GXII) have signed a definitive agreement for a proposed business combination between the two companies. Under the business combination agreement, Niocorp will acquire GXII, a United States-based special purpose acquisition company, and intends to be listed on the Nasdaq Stock Exchange soon after the acquisition closes, which is expected in the first quarter of 2023. Niocorp shares will also continue to be traded on the Toronto Stock Exchange. The proposed transaction (as defined below) values the combined entity at an estimated enterprise value of $313.5-million. All amounts are in U.S. dollars, unless indicated otherwise.

Assuming no redemptions by GXII public shareholders, upon deal close, the combined operating entity could have access to as much as $285-million in net cash (after paying transaction expenses) from the GXII trust account to continue advancing the Elk Creek critical minerals project. Final proceeds will depend upon redemption rates of current GXII shareholders at the consummation of the proposed transaction.

Additionally, Niocorp announced the signing of non-binding letters of intent (LOIs) for two separate financing packages with Yorkville Advisors Global LP. Subject to entering into definitive agreements, these financings could provide the company with access to up to an additional $81-million to help advance the Elk Creek project. The financings contemplated by the LOIs include $16-million in convertible debentures that are expected to be financed at the closing of the business combination, and, subject to certain limitations, can be repaid by Niocorp in either cash or Niocorp common shares, and a standby equity purchase facility pursuant to which Niocorp will have the ability to require Yorkville, subject to the conditions set out in the definitive agreements, to purchase up to $65-million of its common shares.

Niocorp chief executive officer and executive chairman Mark A. Smith said: "This business combination with GXII, and the two additional financing packages, have the potential to significantly accelerate our efforts to obtain the required project financing and to ultimately bring the Elk Creek project to construction and eventual commercial operation. Our goal is to rapidly build secure and reliable U.S. supply chains of the critical minerals that multiple industries need to help us build a more sustainable and less carbon-intensive future and for other critical domestic uses. Once completed, these transactions have the potential to put Niocorp on the fast-track to obtain the required project financing to deliver on that promise, and to do so in an environmentally smart manner."

Dean C. Kehler, co-chairman and CEO of GXII, said: "Niocorp's Elk Creek project is the highest-grade niobium deposit under development in North America, and the second-largest indicated rare earth resource in the U.S. Critical minerals such as niobium and scandium, and magnetic rare earth elements, can accelerate the world's transition to a lower-carbon economy. We believe Niocorp is well positioned to be a reliable, U.S.-based supplier that will produce these products on a sustainable basis. We are pleased that GXII shareholders will have the opportunity to invest in Niocorp's Elk Creek project and help accelerate the transition to a greener world."

Niocorp's Elk Creek project

Subject to receipt of necessary project financing, Niocorp intends to launch construction of its Elk Creek project, a pure-play critical minerals project with the highest-grade niobium resource in North America and the second-largest indicated rare earth resource in the U.S.

Located in southeastern Nebraska, the project is positioned to become a significant U.S. miner and producer of niobium, scandium and titanium. Additionally, Niocorp is currently conducting technical and economic analyses of the potential addition to the planned product suite of several magnetic rare earth oxides, which are forecast to experience large supply shortages because of sharply rising demand. The project is located on all-private land that Niocorp either owns or has option to purchase agreements in place with local landowners to acquire. Niocorp has secured all federal, state and local permits necessary to proceed to construction once sufficient project financing is secured. In addition, the project will be required to obtain a series of permits for operations from federal, state and local agencies.

The project has also completed a June, 2022, feasibility study, as summarized by Niocorp's 2022 National Instrument 43-101 Elk Creek technical report and Niocorp's S-K 1300 Elk Creek technical report summary, which shows a $2.8-billion net present value (NPV) and a 29.2-per-cent internal rate of return (IRR), both on a pretax basis, and an estimated $403-million in averaged annual EBITDA (earnings before interest, taxes, depreciation and amortization) generated. These figures do not include impacts from the possible addition of magnetic rare earth oxide products to Niocorp's planned product suite, as Niocorp is currently conducting technical and economic analyses with respect thereto.

The project also enjoys very strong local support in Nebraska and is projected to create approximately 450 permanent full-time jobs, more than 1,200 contract construction jobs over its three-plus-year construction period, and an estimated 2,100 indirect jobs created or supported. It is also projected to generate $1.1-billion in employee payroll, $298-million in new tax revenue to state and local governmental units, and $148-million in royalty payments to local landowners over the life of the mine. Niocorp has contracted with the State of Nebraska for tax benefits over the first 10 years of operations that are potentially worth in excess of $200-million.

Niocorp has succeeded in placing 75 per cent of its planned production of ferroniobium over the first 10 years of operations under enforceable sales contracts and has also placed 10 per cent of its planned scandium production under an enforceable sales contract. The scandium contract is thought to be the largest such commercial sales agreement for scandium ever executed.

The project is also strongly focused on environmental, social and governance values and is already aligned with the Equator Principles ESG framework.

Board of directors recommendations

The business combination agreement has been approved by the board of directors of each of Niocorp and GXII. Each of the board of directors of Niocorp and the board of directors of GXII recommends that Niocorp shareholders and GX stockholders, respectively, vote in favour of the business combination.

GenCap Mining Advisory Ltd. has provided a fairness opinion to the board of directors of Niocorp stating that, as of the date of such opinion, and based upon and subject to the assumptions, limitations and qualifications stated in such opinion, the transaction, defined below, is fair from a financial point of view to Niocorp shareholders.

Scalar LLC has provided a fairness opinion to the board of directors of GXII stating that, as of the date of such opinion, and based upon and subject to the assumptions, limitations and qualifications stated in such opinion, the consideration to be received by the holders of GXII's Class A common stock is fair from a financial point of view to such shareholders.

The directors and management of both Niocorp and GXII have entered into agreements pursuant to which they have committed to vote their respective shares in favour of the business combination.

The Niocorp-GXII business combination agreement

Under the terms of the business combination agreement with GXII, GXII will merge with and into a wholly owned subsidiary of Niocorp, with GXII surviving the merger as a subsidiary of Niocorp. Niocorp, as the parent company of the merged entity, will issue common shares to the public shareholders of GXII, with the sponsor shareholders receiving shares in GXII that are exchangeable into common shares of Niocorp. The business combination agreement contemplates that Niocorp will undertake a reverse stock split at the time of close so as to effectuate an expected uplisting to the Nasdaq Stock Market. The transactions contemplated by the business combination agreement and the ancillary agreements thereto are referred to, collectively, as the transaction.

The business combination agreement contains covenants in respect of non-solicitation of alternative acquisition proposals, a right to match any superior proposals for GXII and a termination fee payable to GXII in certain circumstances.

The proposed business combination is expected to close in the first quarter of 2023, subject to effectiveness of the registration statement on Form S-4 that Niocorp expects to file, the satisfaction of customary closing conditions, including certain governmental approvals, the approval of the Toronto Stock Exchange, and the approval of certain elements of the proposed transaction by a majority of shareholders of GXII and a majority of Niocorp shareholders voting to approve such elements. The proposed additional financings will also be subject to the approval of the TSX.

Postclosing, the Niocorp board will include two directors from GXII.

Additional information may be found in the current reports on Form 8-K being filed by Niocorp and GXII with the U.S. Securities and Exchange Commission (SEC) and the applicable Canadian securities regulatory authorities in connection with the announcement of the proposed transaction.

Niocorp intends to use the proceeds from the proposed transaction and the contemplated financings to advance its efforts to launch construction of the Elk Creek project and move it to commercial operation.

Advisers

SWI Partners Ltd. is serving as an adviser to Niocorp. Jones Day is serving as legal counsel to Niocorp in the U.S. and Blake, Cassels and Graydon LLP is serving as legal counsel to Niocorp in Canada. Niocorp has engaged GenCap Mining Advisory Ltd. as its financial adviser.

Cantor Fitzgerald & Co. is serving as lead capital markets adviser and BTIG LLC is serving as a capital markets adviser to GXII. Skadden, Arps, Slate, Meagher & Flom LLP is serving as legal counsel to GXII in the U.S. and Stikeman Elliott LLP is serving as legal counsel to GXII in Canada. DLA Piper LLP (U.S.) is serving as legal counsel to Cantor Fitzgerald & Co.

About Niocorp Developments Ltd.

Niocorp is developing a critical minerals project in southeast Nebraska that will produce niobium, scandium and titanium. The company also is evaluating the potential to produce several rare earths from the project. Niobium is used to produce specialty alloys as well as high-strength, low-alloy (HSLA) steel, which is a lighter, stronger steel used in automotive, structural and pipeline applications. Scandium is a specialty metal that can be combined with aluminum to make alloys with increased strength and improved corrosion resistance. Scandium is also a critical component of advanced solid oxide fuel cells. Titanium is used in various lightweight alloys and is a key component of pigments used in paper, paint and plastics, and is also used for aerospace applications, armour and medical implants. Magnetic rare earths, such as neodymium, praseodymium, terbium and dysprosium, are critical to the making of neodymium-iron-boron (NdFeB) magnets, which are used across a wide variety of defence and civilian applications.

Qualified persons

All technical and scientific information included in this press release derived from the June, 2022, feasibility study respecting Niocorp's mineral resources has been reviewed and approved by Matthew Batty, PGeo, owner, Understood Mineral Resources Ltd., and all such information respecting Niocorp's mineral reserves has been reviewed and approved by Richard Jundis, PEng, director of mining, Optimize Group. Each of Mr. Batty and Mr. Jundis and their respective firms are independent consultants that provide consulting services to Niocorp. All other technical and scientific information included in this press release has been reviewed and approved by Scott Honan, MSc, SME-RM, Niocorp's chief operating officer. Each of Mr. Batty, Mr. Jundis and Mr. Honan is a qualified person as such term is defined in NI 43-101.

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