Fennec Pharmaceuticals Announces Updated NCCN Clinical Practice Guidelines Recommend PEDMARK (sodium thiosulfate injection) to Reduce the Risk of Cisplatin-Induced Hearing Loss in Pediatric Patients ~ PEDMARK is the Firs

Pharmaceuticals Announces Updated NCCN Clinical Practice Guidelines Recommend PEDMARK (sodium thiosulfate injection) to Reduce the

Risk of Cisplatin-Induced Hearing Loss in Pediatric Patients

PEDMARK is the First and Only FDA-Approved Therapy Indicated to Reduce the Risk of Ototoxicity Associated with Cisplatin in Pediatric

Patients with Localized, Non-metastatic Solid Tumors ~

The 5-year Survival Rate for Childhood Cancers Due to Major Treatment Advances is Now 85 Percent or Higher,1 Underscoring

Need to Mitigate the Profound Impact Hearing Loss Can Have on a Child's Learning and Development ~

TRIANGLE PARK, N.C., Jan. 25, 2023 (GLOBE NEWSWIRE) -- Fennec Pharmaceuticals Inc. (NASDAQ: FENC; TSX: FRX), a commercial stage specialty

pharmaceutical company, today announced that the National Comprehensive Cancer Network (NCCN) has updated its clinical practice

guidelines for Adolescent and Young Adult (AYA) Oncology to include PEDMARK (sodium thiosulfate injection) to help reduce the risk

of ototoxicity (hearing loss) associated with cisplatin use in pediatric patients with localized, non-metastatic solid tumors.

use of cisplatin chemotherapy, an indispensable treatment of choice in many pediatric cancer cases, can be toxic to the ears and frequently

causes permanent and irreversible bilateral hearing loss. In fact, permanent hearing loss occurs in approximately 60 percent of children

treated with cisplatin and can be as high as 90 percent2," said Rosty Raykov, chief executive officer of Fennec Pharmaceuticals.

"We applaud NCCN for not only recognizing the importance of routine monitoring for hearing loss - which can have a profound

impact on children's learning and development at all ages - and also for providing a clear recommendation for the routine

use of PEDMARK, a recently approved FDA therapeutic that may help reduce this unfortunate treatment-related side effect. Moreover, the

FDA has directed that PEDMARK is not substitutable with other sodium thiosulfate products as part of the approved prescribing label.3"

update to the Clinical Guidelines for AYA Oncology follows the U.S. Food and Drug Administration (FDA) approval of PEDMARK in September

2022, which was based upon safety and efficacy data from two pivotal open-label, randomized Phase 3 trials (Clinical Oncology Group [COG]

Protocol ACCL0431 and SIOPEL 6), which compared PEDMARK plus a cisplatin-based regimen to cisplatin-based regimens alone for the reduction

of cisplatin-induced hearing loss in pediatric patients. Fennec Pharmaceuticals commercially launched PEDMARK in the U.S. in October

a parent community, we are enthusiastic about the long-awaited approval of PEDMARK for the treatment of hearing loss associated with

cisplatin. Anytime there is an opportunity to safely increase the long-term quality of life for a young patient, it should be considered

a top priority in both therapeutic and supportive care," said Kimberly Buff, founder & executive director of the non-profit

community organization, Momcology . "With many of our survivors now thankfully living to experience adult lives, we must take

every action possible now to gift them the opportunity for the best future possible."

"Rigorously tested FDA-approved drugs offer parents a blanket of security and peace of mind when they are navigating the many unknowns

after diagnosis, and as parents of children with cancer, we deserve all the security we can get," Bluff added.

goal of the NCCN Guidelines for AYA Oncology is to identify issues specific to the AYA population; recommend interventions unique to

the AYA population; educate physicians regarding the prevalence of cancer in AYAs; discuss long-term consequences; explain considerations

related to the management in AYA patients that aims to improve treatment tolerance, compliance and clinical outcome; and promote participation

Cisplatin-Induced Ototoxicity

Cisplatin 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 cancer.4

incidence 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.5 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.6

thiosulfate injection)

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. It is

a unique formulation of sodium thiosulfate in single-dose, ready-to-use vials for intravenous use in pediatric patients.7 PEDMARK

is also the only therapeutic agent with proven efficacy and safety data with an established dosing paradigm, across two open-label, randomized

Phase 3 clinical studies, the Clinical Oncology Group (COG) Protocol ACCL0431 and SIOPEL 6.

the U.S. 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.

PEDMARK (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.

PEDMARK is contraindicated in patients with history of a severe hypersensitivity to sodium thiosulfate or any of its components.

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.

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.

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.

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

antiemetics prior to each PEDMARK administration. Provide additional antiemetics and supportive care as appropriate.

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.

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 has received

Orphan Drug Designation in the U.S. Fennec has a license agreement with Oregon Health and Science University (OHSU) for exclusive worldwide

license rights to intellectual property directed to sodium thiosulfate and its use for chemoprotection, including the reduction of risk

of ototoxicity induced by platinum chemotherapy, in humans. For more information, please visit www.fennecpharma.com.

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 settings, unforeseen global instability, including political instability, or

instability from an outbreak of pandemic or contagious disease, such as the novel coronavirus (COVID-19), or surrounding the duration

and severity of an outbreak, protection offered by the Company's patents and patent applications may be challenged, invalidated

or circumvented by its competitors, the available market for the Company's products will not be as large as expected, the Company's

products will not be able to penetrate one or more targeted markets, revenues will not be sufficient to fund further development and

clinical studies, our ability to obtain necessary capital when needed on acceptable terms or at all, the Company may not meet its future

capital requirements in different countries and municipalities, and other risks detailed from time to time in the Company's filings

with the Securities and Exchange Commission including its Annual Report on Form 10-K for the year ended December 31, 2021. Fennec disclaims

any obligation to update these forward-looking statements except as required by law.

a more detailed discussion of related risk factors, please refer to our public filings available at www.sec.gov and www.sedar.com.