Biotechnology company Atreca has dosed the first patient in a Phase Ib clinical trial evaluating monoclonal antibody ATRC-101 for the treatment of select solid tumour cancers.

Patients with colorectal, ovarian, non-small cell lung and breast cancers and acral melanoma will be enrolled for the first-in-human open-label, dose-escalation, monotherapy trial with an adaptive 3+3 design.

The company evaluated tumour tissue samples in each of these cancer types and found that more than 50% were positive for the antigenic target of ATRC-101.

Atreca CEO John Orwin said: “Dosing of the first patient in our Phase Ib study of ATRC-101 is an important milestone marking our transition to a clinical-stage company.

“ATRC-101 has demonstrated potent single-agent anti-tumour activity in multiple preclinical solid tumour models and we believe, through both its novel target and mechanism of action, that this antibody represents an exciting potential new approach in oncology.”

The trial aims to characterise ATRC-101’s safety and determine a recommended dose for future studies.

Potential biomarkers and initial signals of clinical activity of ATRC-101 will be evaluated as part of the trial.

Once safety is confirmed, Atreca plans to test the drug as a single agent and in combination with checkpoint inhibitors and select chemotherapeutics.

The company plans to release the initial data from this study in the second half of this year.

ATRC-101 is derived from a human antibody identified in a cancer patient through Atreca’s drug discovery platform.

The drug targets a ribonucleoprotein (RNP) complex and is believed to function through the Driver Antigen Engagement mechanism.

Last December, Atreca secured clearance from the US Food and Drug Administration (FDA) for its investigational new drug (IND) application for ATRC-101.