GlobeNewswire Inc | Jun 22, 2021 06:00AM EDT

June 22, 2021

~ Prescription Drug User Fee Act (PDUFA) Target Action Date Set for November 27, 2021 00EF

~ NDA Resubmission for PEDMARK for the Prevention of Cisplatin-Induced Ototoxicity for Pediatric Patients with Localized, Non-Metastatic Solid Tumors ~~W0:

~ If Approved by the FDA, PEDMARK Stands to Be the First Therapy for the Prevention of Cisplatin-Induced Hearing Loss in Children ~~W0:

RESEARCH TRIANGLE PARK, N.C., June 22, 2021 (GLOBE NEWSWIRE) -- Fennec Pharmaceuticals Inc. (NASDAQ: FENC; TSX: FRX), a specialty pharmaceutical company, today announced that theU.S. Food and Drug Administration (FDA) has accepted for filing the resubmission of its New Drug Application (NDA) for PEDMARK(a unique formulation of sodium thiosulfate) for the prevention of ototoxicity induced by cisplatin chemotherapy in patients one month to < 18 years of age with localized, non-metastatic, solid tumors. The Prescription Drug User Fee Act (PDUFA) target action date has been set for November 27, 2021.

We are pleased that the FDA has accepted our PEDMARKresubmission, said Rosty Raykov, chief executive officer of Fennec Pharmaceuticals, Inc. We look forward to working closely with the FDA through the review process. We are committed to bringing this treatment to children receiving cisplatin chemotherapy, an area of high unmet medical need. If approved, PEDMARK stands to be the first FDA approved therapy to reduce the risk of cisplatin induced ototoxicity in pediatric patients.

PEDMARK has been granted both Fast Track Designation and Breakthrough Therapy Designation by the FDA.The Complete Response Letter (CRL) received on August 10, 2020, referred to deficiencies with the facility of the drug product manufacturer; no clinical safety or efficacy issues were identified and there was no requirement for further clinical data.

About PEDMARK

Cisplatin and other platinum compounds are essential chemotherapeutic agents for many pediatric malignancies. Unfortunately, platinum-based therapies cause ototoxicity, or hearing loss, which is permanent, irreversible, and particularly harmful to the survivors of pediatric cancer.

In the U.S. andEurope,it is estimated that, annually, over 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.

PEDMARK has been studied by co-operative groups in two Phase 3 clinical studies of survival and reduction of ototoxicity, The Clinical Oncology Group Protocol 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.The Marketing Authorization Application (MAA) for sodium thiosulfate (tradename PEDMARQSI) is currently under evaluation by theEuropean Medicines Agency(EMA). PEDMARKreceived Breakthrough Therapy and Fast Track Designation from the FDA inMarch 2018.

About Fennec PharmaceuticalsFennec Pharmaceuticals Inc. is a specialty pharmaceutical company focused on the development of PEDMARK for the prevention of platinum-induced ototoxicity in pediatric patients. Further, PEDMARK has received Orphan Drug Designation in the U.S. for this potential use. Fennec has a license agreement withOregon Health and Science University(OHSU) for exclusive worldwide license rights to intellectual property directed to sodium thiosulfate and its use for chemoprotection, including the prevention of ototoxicity induced by platinum chemotherapy, in humans. For more information, please visit www.fennecpharma.com

Forward Looking StatementsExcept 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 the Companys expectations regarding its interactions and communications with the FDA, including the Companys expectations and goals respecting the NDA resubmission for PEDMARK. Obtaining Fast Track Designation and Breakthrough Therapy Designation by the FDA is no guarantee that the FDA will approve the NDA resubmission of PEDMARK. Forward-looking statements are subject to certain risks and uncertainties inherent in the Companys business that could cause actual results to vary, including the risk that unforeseen factors may result in delays in or failure to obtain FDA approval of PEDMARK, the risks and uncertainties relating to the Companys reliance on third party manufacturing, the risks that the Companys NDA resubmission does not adequately address the concerns identified in the CRL previously provided by the FDA, the risk that the NDA resubmission to the FDA will not be satisfactory, 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 Companys patents and patent applications may be challenged, invalidated or circumvented by its competitors, the available market for the Companys products will not be as large as expected, the Companys products will not be able to penetrate one or more targeted markets, revenues will not be sufficient to fund further development and clinical studies, the Company may not meet its future capital requirements in different countries and municipalities, and other risks detailed from time to time in the Companys filings with theSecurities and Exchange Commissionincluding its Annual Report on Form 10-K for the year endedDecember 31, 2020. Fennec disclaims any obligation to update these forward-looking statements except as required by law.

For a more detailed discussion of related risk factors, please refer to our public filings available atwww.sec.govandwww.sedar.com.

For further information, please contact:

Investors:Robert AndradeChief Financial OfficerFennec Pharmaceuticals Inc.(919) 246-5299

Media:Elixir Health Public RelationsLindsay Rocco(862) 596-1304lrocco@elixirhealthpr.com