FENNEC PHARMACEUTICALS ANNOUNCES PEDMARQSI Ò POSITIVE RECOMMENDATION BY NICE FOR THE PREVENTION OF CISPLATIN-INDUCED HEARING LOSS IN ENGLAND AND WALES ~ PEDMARQSI (anhydrous sodium thiosulfate) is the first and on

PHARMACEUTICALS ANNOUNCES PEDMARQSI POSITIVE

RECOMMENDATION BY NICE FOR THE PREVENTION OF CISPLATIN-INDUCED HEARING LOSS IN ENGLAND AND WALES

PEDMARQSI (anhydrous sodium thiosulfate) is the

first and only treatment available within NHS England and Wales for the prevention of cisplatin-induced ototoxicity (hearing loss) in

children and young people (1 month-17 years of age) ~

~ Data from two open-label, randomized Phase

3 trials, SIOPEL 6 (pivotal) and the Clinical Oncology Group (COG) Protocol ACCL0431, demonstrated an approximate 50% reduction in the

occurrence of cisplatin-induced ototoxicity in patients treated with cisplatin and sodium thiosulfate vs. those treated with cisplatin

~ There is a clear unmet need for the prevention

of hearing loss caused by cisplatin and until now, there have been no preventative pharmacological interventions available, despite the

significant lifelong impact hearing loss has on cancer patients ~

Triangle Park, NC, December 20, 2024 - Fennec Pharmaceuticals

Inc. (NASDAQ:FENC; TSX: FRX), a specialty pharmaceutical company, today announced that Norgine Pharmaceuticals Ltd., a leading European

specialist pharmaceutical company, has received positive final draft guidance from National Institute for Health and Care Excellence (NICE)

recommending PEDMARQSI for

the prevention of cisplatin-induced hearing loss in patients (aged 1 month to 17 years) with localized, non-metastatic, solid tumors.

the first and only approved therapy in the EU and U.K. for the prevention

of ototoxicity, or hearing loss, induced by cisplatin chemotherapy in patients 1 month to <18 years of age with localized, non-metastatic

solid tumors. In March 2024, Fennec entered into an exclusive licensing agreement under which Norgine will commercialize PEDMARQSI in Europe, Australia,

access to PEDMARQSI is

a critical milestone for the cancer community in England and Wales to help reduce the risk of ototoxicity, or permanent hearing loss,

associated with cisplatin treatment," said Jeff

Hackman, chief executive officer and director of Fennec Pharmaceuticals. "We

congratulate Norgine on their collaboration with NICE to reach this important agreement that recognizes the value of ototoxicity intervention

as part of the cancer treatment journey."

the terms of the previously announced exclusive licensing agreement with Norgine, Fennec received approximately $43 million in

an upfront payment and will receive up to approximately $230 million in additional commercial and regulatory milestone payments along

with double-digit tiered royalties on net sales of PEDMARQSI starting

in the mid-teens and growing to the mid-twenties.

About Cisplatin-Induced Ototoxicity

and other platinum compounds are essential chemotherapeutic agents for the treatment of many pediatric malignancies. Unfortunately, platinum-based

therapies can cause ototoxicity, or hearing loss, which is permanent, irreversible, and particularly harmful to the survivors of pediatric

of ototoxicity depends upon the dose and duration of chemotherapy, and many of these children require lifelong hearing aids or cochlear

implants, which can be helpful for some, but do not reverse the hearing loss and can be costly over time.ii Infants and young

children that are affected by ototoxicity at critical stages of development lack speech and language development and literacy, and older

children and adolescents often lack social-emotional development and educational achievement.iii

PEDMARK (sodium thiosulfate

PEDMARK is the first and only

U.S. Food and Drug Administration (FDA) approved therapy indicated to reduce the risk of ototoxicity associated with cisplatin treatment

in pediatric patients with localized, non-metastatic, solid tumors. PEDMARK is also recommended for the Adolescent and Young Adult (AYA)

population by the National Comprehensive Cancer Network as a preventative treatment option to reduce hearing loss associated

with platinum-based chemotherapy in patients with localized, non-metastatic tumors. PEDMARK is a unique formulation of sodium thiosulfate

in single-dose, ready-to-use vials for intravenous use in pediatric patients. PEDMARK is also the first and only therapeutic agent with

proven efficacy and safety data with an established dosing regimen, across two open-label, randomized Phase 3 clinical studies, the Children's

Oncology Group (COG) Protocol ACCL0431 and SIOPEL 6.

and Europe, it is estimated that, annually, more than 10,000 children may receive platinum-based chemotherapy. The incidence of ototoxicity

depends upon the dose and duration of chemotherapy, and many of these children require lifelong hearing aids. There is currently no established

preventive agent for this hearing loss and only expensive, technically difficult, and sub-optimal cochlear (inner ear) implants have been

shown to provide some benefit. Infants and young children that suffer ototoxicity at critical stages of development lack speech language

development and literacy, and older children and adolescents lack social-emotional development and educational achievement.

has been studied by co-operative groups in two Phase 3 clinical studies of survival and reduction of ototoxicity, COG ACCL0431 and SIOPEL

6. Both studies have been completed. The COG ACCL0431 protocol enrolled childhood cancers typically treated with intensive cisplatin therapy

for localized and disseminated disease, including newly diagnosed hepatoblastoma, germ cell tumor, osteosarcoma, neuroblastoma, medulloblastoma,

and other solid tumors. SIOPEL 6 enrolled only hepatoblastoma patients with localized tumors.

(sodium thiosulfate injection) is indicated to reduce the risk of ototoxicity associated with cisplatin in pediatric patients 1 month

of age and older with localized, non-metastatic solid tumors.

The safety and efficacy of PEDMARK have not been

established when administered following cisplatin infusions longer than 6 hours. PEDMARK may not reduce the risk of ototoxicity when administered

following longer cisplatin infusions, because irreversible ototoxicity may have already occurred.

Important Safety Information

PEDMARK is contraindicated in patients with history

of a severe hypersensitivity to sodium thiosulfate or any of its components.

Hypersensitivity reactions occurred in 8% to 13%

of patients in clinical trials. Monitor patients for hypersensitivity reactions. Immediately discontinue PEDMARK and institute appropriate

care if a hypersensitivity reaction occurs. Administer antihistamines or glucocorticoids (if appropriate) before each subsequent administration

of PEDMARK. PEDMARK may contain sodium sulfite; patients with sulfite sensitivity may have hypersensitivity reactions, including anaphylactic

symptoms and life-threatening or severe asthma episodes. Sulfite sensitivity is seen more frequently in people with asthma.

PEDMARK is not indicated for use in pediatric

patients less than 1 month of age due to the increased risk of hypernatremia or in pediatric patients with metastatic cancers.

Hypernatremia occurred in 12% to 26% of patients

in clinical trials, including a single Grade 3 case. Hypokalemia occurred in 15% to 27% of patients in clinical trials, with Grade 3 or

4 occurring in 9% to 27% of patients. Monitor serum sodium and potassium levels at baseline and as clinically indicated. Withhold PEDMARK

in patients with baseline serum sodium greater than 145 mmol/L.

Monitor for signs and symptoms of hypernatremia

and hypokalemia more closely if the glomerular filtration rate (GFR) falls below 60 mL/min/1.73m2.

Administer antiemetics prior to each PEDMARK administration.

Provide additional antiemetics and supportive care as appropriate.

The most common adverse reactions ( 25%

with difference between arms of >5% compared to cisplatin alone) in SIOPEL 6 were vomiting, nausea, decreased hemoglobin, and hypernatremia.

The most common adverse reaction ( 25% with difference between arms of >5% compared to cisplatin alone) in COG ACCL0431 was hypokalemia.

Please see full Prescribing Information for PEDMARK

at: www.PEDMARK.com.

Pharmaceuticals Inc. is a specialty pharmaceutical company focused on the development and commercialization of PEDMARK

to reduce the risk of platinum-induced ototoxicity in pediatric patients. Further, PEDMARK received FDA approval in September 2022 and

European Commission approval in June 2023 and U.K. approval in October 2023 under the brand name PEDMARQSI .

PEDMARK has received Orphan Drug Exclusivity in the U.S. and PEDMARQSI has received Pediatric Use Marketing Authorization in Europe which

includes eight years plus two years of data and market protection. For more information, please visit www.fennecpharma.com.

Forward Looking Statements

Except for historical information

described in this press release, all other statements are forward-looking. Words such as "believe,"

"anticipate," "plan," "expect," "estimate," "intend," "may,"

"will," or the negative of those terms, and similar expressions, are intended to identify forward-looking statements.

These forward-looking statements include statements about our business strategy, timeline and other goals, plans and prospects,

including our commercialization plans respecting PEDMARK , the market opportunity for and market impact of

PEDMARK , its potential impact on patients and anticipated benefits associated with its use, and potential access to

further funding after the date of this release. Forward-looking statements are subject to certain risks and uncertainties inherent

in the Company's business that could cause actual results to vary, including the risks and uncertainties that regulatory and

guideline developments may change, scientific data and/or manufacturing capabilities may not be sufficient to meet regulatory

standards or receipt of required regulatory clearances or approvals, clinical results may not be replicated in actual patient