YM BioSciences announces results of nimotuzumab Phase II study on DIPG

YM BioSciences Inc. (NYSE Amex: YMI, TSX: YM) today announced that preliminary results of a Phase II study evaluating the safety and efficacy of nimotuzumab in pediatric patients with recurrent diffuse intrinsic pontine glioma (DIPG) were reported at the 43rd Congress of the International Society of Paediatric Oncology (SIOP) conference being held in Auckland, New Zealand.

"Nimotuzumab is an anti-EGFR antibody that has shown promising activity in a previous Phase II study in patients with recurrent/refractory DIPG, a particularly severe, inoperable form of cancer for which there are currently no lifesaving effective treatments," said Dr. Ute Bartels at The Hospital for Sick Children in Toronto, Canada. "In the study we conducted, nimotuzumab was found to be safe and well tolerated. In this very challenging disease, a small subset of patients showed prolonged survival and benefit from nimotuzumab."

The study was a Phase II, open-label, single-arm, multi-center study conducted at multiple sites in the US, Canada, and Israel. It was designed to evaluate the efficacy and safety of nimotuzumab in patients aged three to 18 years of age with clinically and radiologically confirmed recurrent diffuse intrinsic pontine glioma (DIPG) following one previous regimen for their disease. All had received prior radiotherapy and 25 had received chemotherapy. Nimotuzumab (150 mg/m2) was administered intravenously once weekly from week one to seven and once every two weeks from week eight to 18. Patients with Partial Response (PR) or Stable Disease (SD) were allowed to continue nimotuzumab.

Of 46 patients enrolled, 44 received at least one dose of nimotuzumab. Nineteen patients (43.2%) completed the induction phase, five patients (11.4%) completed the consolidation phase, and three patients (6.8%) continued to receive nimotuzumab after completing the consolidation phase. Seven patients (15.9%) died due to disease progression. Treatment with nimotuzumab was well tolerated with most adverse events reported as mild or moderate in severity. The majority of Adverse Events (AEs) were associated with CNS disorders and not related to study drug. The most commonly reported events related to study drug were rash and lymphopenia occurring in 9.1% and 6.8% of patients respectively. Study drug discontinuation was reported in four patients overall due to AEs. Only one patient experienced serious Adverse Events (Grade 5 intracranial tumor hemorrhage and tumor necrosis), assessed as possibly related to nimotuzumab.

No Complete Responses (CR) were observed. At week 8, a PR was reported in two patients, SD in six patients and Progressive Disease (PD) in 11 patients who were evaluable for response, resulting in a Clinical Benefit Rate (CR+PR+SD) of 18.2%.  At week 18, one patient continued to have a PR and three patients continued with SD, giving an Overall Response Rate of 2.3%. The Median Duration of Response, Time to Progression, and Overall Survival were 2.1 months, 1.7 months and 3.2 months respectively.

Nimotuzumab is designated an Orphan Drug for adult and pediatric glioma by the FDA as well as the EMEA for Europe.