ProMIS Neurosciences Lead Product Candidate for Alzheimer's Disease Shows Potential for Improved Therapeutic Potency versus Other Amyloid Beta-Directed Antibodies

Humanized PMN310 and Aducanumab Show Similar Ability to Cross the Blood Brain Barrier in Aged Mice.

TORONTO and CAMBRIDGE, MA, March 6, 2018 /PRNewswire/ – ProMIS Neurosciences, Inc., a biotechnology company focused on the discovery and development of precision treatments for neurodegenerative diseases, today announced that its lead product candidate for Alzheimer’s disease (AD), PMN310, showed similar ability to cross the blood brain barrier and penetrate the central nervous system (CNS) compared to aducanumab (Biogen).

Commenting on these results, ProMIS President and CEO, Dr. Elliot Goldstein, stated: “Our latest data lend further support to the potential best in class profile of PMN310. We previously reported greater selectivity and binding of humanized PMN310 for toxic, amyloid beta (Aβ) oligomers in direct comparison to other amyloid beta-directed antibodies, including aducanumab.” Goldstein continued, “In addition, PMN310 has shown lack of binding to plaque in and around blood vessels in the brain, thereby supporting the potential for lower risk of brain swelling and the possibility of higher dosing and greater therapeutic potency with PMN310 compared to aducanumab.”

Aged mice were studied to assess and compare the ability of humanized PMN310 (huPMN310) and aducanumab to cross the blood brain barrier (BBB) and penetrate the CNS. Identical doses of huPMN310 and aducanumab were administered to mice systemically (outside the CNS) and the levels of antibodies present in the blood circulation and in the brain were measured after 24 hours. The results showed equivalent concentrations of huPMN310 and aducanumab in the circulation and in the brain indicating that the two antibodies possess a similar degree of CNS penetrance. The results obtained with aducanumab were in line with those previously reported in the literature (Sevigny et al, Nature 2016)

About ProMIS Neurosciences, Inc.

ProMIS Neurosciences is a development stage biotechnology company focused on discovering and developing precision medicine therapeutics to treat neurodegenerative diseases, in particular Alzheimer’s disease (AD) and amyotrophic lateral sclerosis (ALS). The Company’s proprietary target discovery engine is based on the use of two complementary techniques. The Company applies its thermodynamic, computational discovery platform—ProMIS™ and Collective Coordinates — to predict novel targets known as Disease Specific Epitopes (DSEs) on the molecular surface of misfolded proteins. Using this unique precision medicine approach, the Company is developing novel antibody therapeutics and specific companion diagnostics for AD and ALS. ProMIS is headquartered in Toronto, Ontario, with offices in Cambridge, Massachusetts. ProMIS is listed on the Toronto Stock Exchange under the symbol PMN.TO, and on the OTCQB Venture Market under the symbol ARFXF.

For further information please consult the Company’s website at: www.promisneurosciences.com

This announcement contains “forward-looking statements” within the meaning of applicable securities laws. Forward-looking statements are statements that are not historical facts; they are generally, but not always, identified by the words “expects”, “plans”, “anticipates”, believes”, “intends”, “estimates”, “projects”, “aims”, “potential”, “goal”, “objective”, “prospective”, and similar expressions, or that events or conditions “will”, “would”, “may”, “can”, “possibly”, “could” or “should” occur. Forward-looking statements are based on the beliefs, estimates and opinions of the Company’s management on the date the statements are made and they involve a number of risks and uncertainties. Consequently, there can be no assurances that such statements will prove to be accurate and actual results and future events could differ materially from those anticipated in such statements. Except as required by the securities disclosure laws and regulations applicable to the Company, the Company undertakes no obligation to update these forward-looking statements if management’s beliefs, estimates or opinions, or other factors, should change.

Neither the TSX nor the OTCQB has approved or disapproved of the contents of this press release.

SOURCE ProMIS Neurosciences Inc.

CONTACT: For media inquiries, please contact: David Schull, RussoPartners/LLC, David.Schull@russopartnersllc.com, Tel. 858 717-2310; For Investor Relations please contact: Alpine Equity Advisors, Nicholas Rigopulos, President, nick@alpineequityadv.com, Tel. 617 901-0785, Dr. Elliot Goldstein, President and Chief Executive Officer, ProMIS Neurosciences Inc., Tel. 415 341-5783, Elliot.goldstein@promisneurosciences.com