• SIOPEL 6 oral presentation for hearing protection in standard risk hepatoblastoma on June 5 at ASCO 2016

Research Triangle Park, NC, April 20, 2016 – Fennec Pharmaceuticals Inc. (TSX: FRX, OTCQB: FENCF) (the “Company” or “Fennec”), a specialty pharmaceutical company focused on the development of Sodium Thiosulfate (STS) for the prevention of platinum-induced chemotherapy ototoxicity in pediatric patients, announced today that interim results from “SIOPEL 6: A multi-centre open label randomised phase III trial of the efficacy of sodium thiosulfate (STS) in reducing ototoxicity in patients receiving cisplatin (Cis) monotherapy for standard risk hepatoblastoma (SR-HB)” has been accepted for an oral presentation at the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois.

Penelope Brock, MD, PhD, FRCPCH, International Chair of SIOPEL will present “Two year results of clinical efficacy of cisplatin in combination with sodium thiosulfate (STS) vs cisplatin alone in a randomized phase III trial for standard risk hepatoblastoma (SR-HB): SIOPEL 6,” in an oral presentation on June 5, 2016 at ASCO.

About SIOPEL 6

SIOPEL 6 is a multi-centre open label randomized phase III study evaluating the efficacy of STS in reducing ototoxicity in patients receiving cisplatin monotherapy for SR-HB. The study is closed to recruitment and all protocol pre-specified IDMC safety reviews have been completed.

From the beginning of 2007 to the end 2014, 45 sites from 11 countries enrolled 109 evaluable patients. Newly diagnosed patients with SR-HB were treated with weekly cycles of cisplatin every two weeks including 4 chemotherapy courses before primary tumor resection and 2 courses after surgery. Patients were randomized to cisplatin alone or cisplatin and STS. cisplatin of 80 mg/m² was administered i.v. over 6 hrs. STS was administered i.v. exactly 6 hrs after stop of cisplatin over 15 minutes at 20 g/m². Tumor response was assessed after 2 and 4 cycles pre-operative with serum AFP and liver imaging. In case of progression after 2 cycles, STS was stopped and doxorubicin 60 mg/m2 continuous infusion over 48 hrs added. The primary endpoint is centrally reviewed absolute hearing threshold, at the age of ≥ 3.5 yrs, by pure tone audiometry. The trial has 80% power to detect a reduction in hearing loss defined as Brock grade ≥ 1 from 60% of patients with cisplatin to 35% with cisplatin +STS.

About Sodium Thiosulfate (STS)

Cisplatin and other platinum compounds are essential chemotherapeutic components for many pediatric malignancies.  Unfortunately, platinum-based therapies cause hearing loss or ototoxicity in many patients, and are particularly harmful to the survivors of pediatric cancer.

In the U.S. and Europe there is estimated that 10,000 children are diagnosed with local cancers that may receive platinum based chemotherapy.   Localized cancers have overall survival rates of greater than 80%, further emphasizing the importance of quality of life after treatment. The incidence of hearing loss in these children depends upon the dose and duration of chemotherapy, but it affects at least 60% of the patients.  Many of these children require lifelong hearing aids and technically difficult and sub-optimal cochlear (inner ear) implants that have been shown to provide some marginal benefit. Post platinum exposure, infants and young children at critical stages of development lack speech language development and literacy, and older children and adolescents lack social-emotional development and educational achievement.

STS has been studied by cooperative groups in two Phase 3 clinical studies of reduction of ototoxicity, The Clinical Oncology Group Protocol ACCL0431 and SIOPEL 6. Both studies are closed to recruitment. The COG ACCL0431 protocol enrolled one of five childhood cancers typically treated with intensive cisplatin therapy for localized and disseminated disease, including newly diagnosed hepatoblastoma, germ cell tumor, osteosarcoma, neuroblastoma, and medulloblastoma.  SIOPEL 6 enrolled only hepatoblastoma patients with localized tumors.

About Fennec Pharmaceuticals

Fennec Pharmaceuticals, Inc. is a specialty pharmaceutical company focused on the development of Sodium Thiosulfate (STS) for the prevention of platinum-induced chemotherapy ototoxicity in pediatric patients. STS has received Orphan Drug Designation in the US in this setting. For more information, please visit www.fennecpharma.com.

Forward-Looking Statement Disclaimer

Except for historical information described in this press release, all other statements are forward-looking, including statements or assumptions about the size, timing and completion of the proposed private placement, regulatory approvals, anticipated use of proceeds and any other statements regarding the Company’s objectives (and strategies to achieve such objectives), future expectations, beliefs, goals or prospects. Forward-looking statements are subject to certain risks and uncertainties inherent in the Company’s business that could cause actual results to vary, including such risks that regulatory and guideline developments may change; that scientific data may not be sufficient to meet regulatory standards or receipt of required regulatory clearances or approvals; that clinical results may not be replicated in actual patient settings; that protection offered by the Company’s patents and patent applications may be challenged, invalidated or circumvented by its competitors; that the available market for the Company’s products will not be as large as expected; that the Company’s products will not be able to penetrate one or more targeted markets; that revenues will not be sufficient to fund further development and clinical studies; that 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, 2015. Fennec Pharmaceuticals Inc. 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 at www.sec.gov and www.sedar.com.

For further information, please contact:

Rosty Raykov

Chief Executive Officer

Fennec Pharmaceuticals Inc.

T: (919) 636-5144