Bayer Schering Pharma AG, Germany, announced results from a phase-II trial of regorafenib (BAY 73-4506), a potent oral multi-kinase inhibitor, which demonstrated that treatment with regorafenib resulted in a 31 per cent partial response rate and 50 per cent stabilization rate in patients with metastatic renal cell carcinoma (RCC). These data were presented in an oral session at the joint 15th Congress of the European CanCer Organisation and 34th Congress of the European Society for Medical Oncology (ECCO 15 - 34th ESMO). Preliminary results from this study were presented earlier this year at the 45th American Society of Clinical Oncology (ASCO) Annual Congress, May 29 - June 2, 2009, Orlando, Florida.

"Bayer is committed to researching and developing potential anti-cancer agents like regorafenib, which may eventually help physicians and patients manage this devastating disease," said Kemal Malik, member of the Board of Management of Bayer Schering Pharma AG and head of Global Development. "We look forward to continuing the comprehensive clinical development programme for regorafenib, which we believe could potentially represent a promising new treatment option for various tumour types."

At the time of data analysis, 81 per cent of patients (n=48) in the trial experienced disease stabilization or regression. Specifically, 31 per cent of patients (n=15) experienced a confirmed partial response (PR), according to the Response Evaluation Criteria in Solid Tumours (RECIST), and 50 per cent of patients (n=24) experienced stable disease (SD). The data also showed an estimated median progression-free survival of 8.3 months at the time of protocol-defined end of study. Importantly, the time of data analyses, which occurred on May 31, 2009, was prospectively defined in the protocol as when the last patient was treated for at least six months. At the time of analysis, 25 patients remained on treatment and 80 per cent (12 of 15) of patients who achieved a PR had an ongoing response. Two additional patients who were classified as having SD achieved a confirmed PR past the data analysis date, bringing the total PR to 35 per cent (n=17) of patients. Study data continue to be reviewed.

The most common drug-related adverse events (all grades) were hand-foot skin reaction (HFSR), fatigue, hypertension, mucositis, diarrhoea, alopecia, rash, voice changes, anorexia, nausea, constipation and vomiting.

"This study suggests encouraging activity of regorafenib as a potential first-line treatment option for patients with advanced RCC. These results, coupled with those from phase-I studies in other tumour types, provide rationale for further testing," said lead investigator professor Tim Eisen of Addenbrooke's Hospital at the University of Cambridge, UK. "I am excited about the potential of this compound becoming a potential treatment option for patients and physicians."

Regorafenib (BAY 73-4506) is a potent oral multi-kinase inhibitor with a kinase inhibition profile targeting angiogenic, stromal and oncogenic receptor tyrosine kinases (TK).