1.DESCRIPTION OF BUSINESS

Business Description

ProMIS Neurosciences Inc. (the “Company” or “ProMIS”) is applying our patented technology platform to build a portfolio of antibody therapies, therapeutic vaccines, and other antibody-based therapies in neurodegenerative diseases and other protein-misfolding diseases, with a focus on Alzheimer’s disease (AD), multiple system atrophy (MSA), and amyotrophic lateral sclerosis (ALS). We believe these diseases share a common biologic cause — misfolded versions of proteins, that otherwise perform a normal function, becoming toxic and killing neurons, resulting in disease. ProMIS’ technology platform enables drug discovery through a combination of protein biology, physics and supercomputing. We believe this platform provides a potential advantage in selectively targeting the toxic misfolded proteins with therapeutics or detecting them with diagnostics.

We are developing a pipeline of antibodies aimed at selectively targeting misfolded toxic forms of proteins that drive neurodegenerative diseases without interfering with the essential functions of the same properly folded proteins. Our product candidates are PMN310, PMN442, and PMN267. Our lead product candidate is PMN310, a monoclonal antibody designed to treat AD by selectively targeting toxic, misfolded oligomers of amyloid-beta. In light of research suggesting that misfolded toxic a-syn is a primary driver of disease in synucleinopathies, our second lead product candidate, PMN442, shows robust binding to pathogenic a-syn oligomers and seeding fibrils in preclinical in vivo studies, with negligible binding to a-syn monomers and physiologic tetramers which are required for normal neuronal function. PMN267 is our third lead product candidate, which has been shown in preclinical in vivo studies to selectively recognize misfolded, cytoplasmic TDP-43 aggregates without interacting with normal TDP-43. Misfolded TDP-43 is believed to play an important role in the development of ALS.

The Company was incorporated on January 23, 2004 under the Canada Business Corporations Act and is located at 1920 Yonge Street, Toronto, Ontario. The Company’s Common Shares are traded on the Toronto Stock Exchange (“TSX”) and on the Nasdaq Capital Market (“Nasdaq”) under the symbol PMN. The Company has a wholly-owned U.S. subsidiary, ProMIS Neurosciences (US) Inc. (“ProMIS USA”), which was incorporated in January 2016 in the State of Delaware. As of December 31, 2022, ProMIS USA has had no material activity and has no material financial impact on the Company’s consolidated financial statements.

The success of the Company is dependent on obtaining the necessary regulatory approvals of its product candidates, marketing its products and achieving profitable operations. The continuation of the research and development activities and the commercialization of its products, if approved, are dependent on the Company’s ability to successfully complete these activities and to obtain additional financing through a combination of financing activities and operations. It is not possible to predict either the outcome of future research and development or commercialization programs, or the Company’s ability to fund these programs.

Liquidity Risk

The accompanying consolidated financial statements were prepared on a going concern basis, which assumes that the Company will continue its operations for the foreseeable future and will be able to realize its assets and discharge its liabilities in the normal course of business. To date, the Company has not generated revenues from its activities. The Company had a net loss of $18,062,263 for the year ended December 31, 2022 and an accumulated deficit of $80,253,464 as of December 31, 2022 and negative cash flows from operations. Management believes these conditions raise substantial doubt about the Company’s ability to continue as a going concern within the next twelve months from the date these consolidated financial statements are issued. The

Company will require additional funding to conduct future clinical activities. The Company will seek additional funding through public and private financings, debt financings, collaboration agreements, strategic alliances and licensing agreements. Although the Company has been successful in raising capital in the past, there is no assurance of success in obtaining such additional financing on terms acceptable to us, if at all, and there is no assurance that the Company will be able to enter into collaborations or other arrangements. If the Company is unable to obtain funding, it could force delays, reduce or eliminate research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect future business prospects, and the ability to continue operations.

The Company may continue to incur net losses for at least the next several years as the Company advances its product candidates. The Company is actively pursuing additional financing to further develop certain of the Company’s scientific initiatives, but there is no assurance these initiatives will be successful, timely or sufficient.