Mr. Peter Puccetti reports

COSCIENS COMPLETES SECOND TRANCHE OF CONVERTIBLE DEBENTURE OFFERING

Cosciens Biopharma Inc., further to the news release dated Sept. 10, 2026, has closed the second tranche of a non-brokered private placement of 15 per cent unsecured convertible debentures.

In the second tranche of the offering, the company issued additional unsecured convertible debentures in an aggregate principal amount of $4,375,000 (U.S.), for an aggregate principal amount, together with the first closing, of $10,706,250 (U.S.). The terms of the offering contemplate the issuance of an aggregate principal amount of debentures up to $20-million (U.S.), and the company anticipates closing one or more additional tranches in the coming weeks. Completion of additional tranches is subject to customary closing conditions and there can be no assurance that additional tranches will be completed.

As previously disclosed, pursuant to the rules and policies of the Toronto Stock Exchange, the conversion rights and certain related terms of the debentures require shareholder approval. The company has agreed to call a meeting of shareholders within six months to seek the necessary approvals. Additional details will be provided in a forthcoming management information circular, which, once filed, will be available on SEDAR+.

In connection with the second tranche, the company agreed to pay finders' fees on certain subscriptions, which finders' fees may be satisfied in cash or through the issuance of debentures. Total finder's fees for the second tranche amounted to $35,000 (U.S.) aggregate principal amount of debentures and $100,000 (U.S.) in cash. Any debentures issued as finders' fees are counted toward the aggregate principal amount outstanding and the maximum of $20-million (U.S.).

The debentures (and common shares issuable upon conversion of the debentures) are subject to a four-month hold period under Canadian securities laws.

About Cosciens Biopharma Inc.

Cosciens Biopharma is a holding company operating through its subsidiaries, including Ceapro Inc. and Nualtis.

Ceapro is focused on the development and commercialization of natural, plant-based active ingredients derived from oats and other renewable plant resources, using proprietary manufacturing and extraction technologies. Ceapro's primary active ingredient business activities relate to the development and commercialization of natural products for the personal care, cosmetic, human and animal health industries.

Nualtis is a specialty pharmaceutical technology business focused primarily on proprietary oral thin-film drug delivery technologies. Its business model includes pharmaceutical formulation development, analytical and regulatory support services, contract development and manufacturing activities, partner-sponsored development programs, and commercial product manufacturing.

The company's common shares are listed on the Toronto Stock Exchange under the symbol CSCI, and are listed and posted for trading on the OTCQB Venture Market under the symbol CSCIF.

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