Fennec presents positive interim results from phase III trial of sodium thiosulphate at ASCO 2015

Fennec Pharmaceuticals, Inc. (TSX: FRX, OTCQB: FENCF), announced the presentation of positive interim results from a poster presented today entitled, "Anti-tumor efficacy in SIOPEL6: A multi-centre open label randomised phase III trial of the efficacy of sodium thiosulphate (STS) in reducing ototoxicity in patients receiving cisplatin (Cis) monotherapy for standard risk hepatoblastoma (SR-HB)." The data was presented at the American Society of Clinical Oncology (ASCO) 2015 Annual Meeting in Chicago.

"I am excited to be sharing very encouraging safety data on the impact of STS in children with standard risk hepatoblastoma at ASCO," said Dr. Penelope Brock, MD, PhD, FRCPCH, International Chair of SIOPEL. "STS is very well tolerated. We are especially encouraged to see the safety after six courses of Cisplatin with the addition of STS."

"Our company's mission is to serve an unmet medical need for patients treated with cisplatin chemotherapy by improving the quality of life through the reduction of hearing loss," said Rosty Raykov, Chief Executive Officer. "We are very pleased with the interim safety results presented at ASCO especially the conclusion, that, to date, STS as a chemoprotectant appears to have no adverse effect on the efficacy of cisplatin. We look forward to the data from the audiological results from the trial."

SIOPEL6 is a multi-centre open label randomized phase 3 study evaluating the efficacy of STS in reducing ototoxicity in patients receiving Cis monotherapy for SR-HB. The study is closed to recruitment and all protocol pre-specified IDMC safety reviews are now complete.

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 Cis every two weeks including 4 chemotherapy courses before primary tumor resection and 2 courses after surgery. Patients were randomized to Cis alone or Cis and STS. Cis of 80 mg/m² was administered i.v. over 6 hrs. STS was administered i.v. exactly 6 hrs after stop of Cis 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 Cis to 35% with Cis+STS.

The efficacy results indicate that it is safe to treat SR-HB with six cycles of Cis monotherapy with the addition of the chemoprotectant STS. Efficacy results at the end treatment for the 109 evaluable patients (52 Cis, 57 Cis+STS) were complete response/partial response/progressive disease for Cis: 85%/6%/4% and for CIS+STS: 91%/7%/0%.