Exhibit 99.1 FENNEC PHARMACEUTICALS REPORTS FULL YEAR AND FOURTH QUARTER 2023 FINANCIAL RESULTS AND PROVIDES BUSINESS UPDATE ~ Achieved PEDMARK Full-Year 2023 Net Product Sales of $21.3 Million, Including $9.7 Million in Net Product Sales in the Fourth Quarter of 2023 ~ ~ Entered Into Exclusive Licensing Agreement to Commercialize PEDMARQSI™ in Europe, Australia and New Zealand for Approximately $43 Million Upfront and Up to Approximately $230 Million in Additional Commercial and Regulatory Milestones, and ...