Clinical-stage firm OncoMed Pharmaceuticals has enrolled the first patient in its anti-RSPO3 antibody (OMP-131R10) Phase Ia / Ib clinical trial.
Anti-RSPO3 is claimed to be the first drug in its class to target the R-spondin-LGR pathway, a cancer stem cell pathway identified by researchers of OncoMed.
The company is currently enrolling patients with advanced refractory solid tumours in the open-label study, which is designed to assess the safety, pharmacokinetics, pharmacodynamics, and initial evidence of efficacy of the anti-RSPO3 antibody.
OncoMed Pharmaceuticals chief medical officer Dr Jakob Dupont said: "In this trial, we look forward to establishing a suitable dose and exploring this antibody's safety and initial efficacy.
"In addition, studies using our human tumour xenograft models have demonstrated a strong correlation between activity and RSPO3 biomarkers as well as potent activity in the colorectal cancer setting, which we will examine in the second part of this comprehensive Phase Ia / Ib trial."
In the study, patients will be provided with escalating doses of anti-RSPO3 until disease progression.
Biomarker-selected patients will be enrolled in a Phase Ia expansion arm to obtain additional preliminary information on possible anti-tumour activity, once a single-agent dose is being identified.
In the Phase Ib portion of the study, anti-RSPO3 will also be evaluated in second-line colorectal cancer patients in combination with the chemotherapeutic standard of care in metastatic colon cancer called Folfiri (folinic acid, fluorouracil and irinotecan).
According to the firm, the study is being carried out at five states in the US.
In preclinical studies, anti-RSPO3 antibody showed stronger in vivo anti-tumour efficacy as a single agent and in combination with standard of care across a range of solid tumours, including colon, lung, ovarian, and pancreatic cancers, said OncoMed.
The anti-RSPO3 antibody is the third drug being tested, under OncoMed's collaboration with Celgene.