Cardiol Therapeutics Files US$150 Million Preliminary Base Shelf Prospectus Including Additional Disclosure Following Review by Staff of the Ontario Securities Commission

Cardiol Therapeutics Inc. (NASDAQ: CRDL) (TSX: CRDL) ("Cardiol" or the "Company"), a late-stage life sciences company advancing anti-inflammatory and anti-fibrotic therapies for heart disease, today announced that it has filed a preliminary short form base shelf prospectus (the "Shelf Prospectus") with the securities regulatory authorities in each of the provinces and territories of Canada, together with a corresponding registration statement on Form F-10 (the "Registration Statement") with the United States Securities and Exchange Commission (the "SEC") under the U.S./Canada Multijurisdictional Disclosure System.

No securities are being offered in connection with this announcement. The filing of the Shelf Prospectus does not obligate the Company to undertake an offering, and there can be no assurance that any securities will be offered or sold thereunder. Once a receipt has been issued for the final short form base shelf prospectus and the Registration Statement has become effective, the filings will permit Cardiol to offer and sell, from time to time during the 25-month period the final short form base shelf prospectus remains effective, Class A common shares, debt securities, warrants, subscription receipts, units, or any combination of such securities, having an aggregate initial offering price of up to US$150 million, or the equivalent in other currencies.

Copies of the Shelf Prospectus are available under the Company's respective profiles on SEDAR+ at www.sedarplus.ca and EDGAR at www.sec.gov, and are available on the Company's website at www.cardiolrx.com.

In connection with a review by staff of the Ontario Securities Commission (the "OSC"), and at the request of OSC staff, the Shelf Prospectus includes additional disclosure that supplements the Company's management's discussion and analysis for the year ended December 31, 2025, and for the three and six months ended June 30, 2026. No previously filed financial statement has been restated or amended, and there is no change to the Company's reported research and development or general and administrative expenses, net loss, cash flows, cash position, or financial position for any period.

The additional disclosure provides additional information regarding: tabular and narrative disclosure setting out, for the Company's research and development programs, the original and updated target completion dates, the original estimated cost of the current stage of development, cumulative external program expenditures incurred to date, and estimated remaining costs to completion, together with explanatory notes describing program status, anticipated next steps, and the basis on which the estimates were prepared; the allocation of external research and development expenditures among those programs for each comparative period presented, together with narrative explaining the ordinary course development activities underlying period-over-period changes; the disaggregation of the components of the Company's general and administrative expenses, together with additional narrative outlining the specific factors and circumstanc...