OncoResponse, a US-based clinical-stage biotech company, announced on Thursday the outcome of the Phase one trial of OR502, a novel, humanised anti-leukocyte immunoglobulin like receptor B2 (LILRB2) antibody that rescues innate and adaptive immune responses from LILRB2 mediated immune suppression.

The Phase one study was designed to assess the safety, tolerability, and preliminary anti-tumour activity of OR502 administered as a monotherapy and in combination with anti-PD-1 in patients with advanced solid tumours. It was an open-label, multicentre, first-in-human dose-escalation and expansion study, to assess the safety, tolerability, and preliminary anti-tumour activity of OR502, a fully human IgG1 antibody that binds specifically to LILRB2. The product is to be administered as a monotherapy and in combination with anti-PD-1, cemiplimab, patients with advanced solid tumours.

Clifford Stocks, OncoResponse chief executive officer, said: "We are pleased that OR502 has demonstrated an excellent safety profile and compelling early efficacy signals. OR502 was well tolerated up to the highest dose level with no DLTs, SAEs or Grade greater than or equal to 3 treatment-related AEs. The study showed promising early efficacy signals in monotherapy, including 2 PR and 9 SD (N=17) for a disease control rate of 65 percent. We are excited to conduct the next phase of clinical studies, which will evaluate OR502 in two mini-cohorts of patients, including cutaneous melanoma and NSCLC. Completing this Phase 1 study reflects our ongoing commitment to develop impactful treatments to improve outcomes for cancer patients."