US-based OncoMed Pharmaceuticals has started dosing patients in its randomised, placebo-controlled Phase II portion of its PINNACLE clinical trial of anti-Notch2/3 cancer stem cell antibody, tarextumab (OMP-59R5), to treat small cell lung cancer (SCLC).
Currently, tarextumab is being evaluated in combination with chemotherapy in patients with previously untreated, extensive stage SCLC.
The randomised Phase II trial will compare progression-free survival (PFS) outcomes for patients treated with tarextumab administered at 15mg/kg every three weeks in combination with etoposide and cisplatin or carboplatin versus patients who receive chemotherapy alone.
In addition, PFS will be evaluated using a predictive biomarker for high tumour Notch3 expression.
According to the company's scientists, high tumour Notch3 expression is estimated to occur in about 60% of SCLC patients.
The trial's secondary endpoints include overall survival, overall response rate, pharmacokinetics, safety and other biomarkers.
Around 130 patients are expected to be enrolled in the PINNACLE trial, which is being conducted at about 40 sites in the US.
OncoMed chief medical officer Dr Jakob Dupont said: "Based on the manageable safety profile and the early response data observed in the Phase Ib portion of the PINNACLE study, we are excited to advance tarextumab into the randomised Phase II portion of this clinical trial."
The company has completed enrolment in the Phase Ib portion of the PINNACLE trial, which was designed to establish a maximum-tolerated dose for tarextumab when administered in combination with etoposide and cisplatin or carboplatin.
According to the company, tarextumab was well tolerated in combination with etoposide and cisplatin.
OncoMed chairman and chief executive officer Paul Hastings said: "This is the second of four randomised Phase II programmes expected to begin by late 2014 or early 2015.
"In addition to tarextumab in SCLC and pancreatic cancer, which are both now under way, we are very close to enrolling patients in randomised studies of our anti-DLL4 antibody, demcizumab, in pancreatic and non-small cell lung cancer.
"Our aim is to have multiple randomised Phase II data results between now and by the end of 2016."