Kineta has dosed the first patient in Part B of the Phase I/II VISTA-101 clinical trial evaluating KVA12123, along with Merck & Co (MSD)'s anti-PD-1 therapy Keytruda (pembrolizumab), in treating advanced solid tumours.

The dose escalation and dose expansion, multicentre, open-label study will assess the immunogenicity, pharmacokinetics (PK), tolerability, safety, and tumour response of KVA12123, alone and along with pembrolizumab.

Part B is part of the dose escalation study that also includes Part A, and the goal is to determine a recommended Phase II dose (RP2D) for Parts C and D.

Parts C and D will focus on the dose expansion of VISTA-101 as a single-agent and in combination with pembrolizumab.

Part A included six cohorts, which received KVA12123 monotherapy while Part B comprises four cohorts that will receive the combination therapy of KVA12123 and pembrolizumab.

One to six participants in each cohort will receive their respective dosages to characterise the pharmacodynamics, PK, tolerability, safety, and preliminary tumour responses of study interventions.

In preclinical models, through the combination of unique epitope binding and an optimised IgG1 Fc region, KVA12123 demonstrated strong monotherapy tumour growth inhibition, without evidence of cytokine release syndrome in study participants.

It also effectively de-risks the VISTA target and provides a new approach to addressing immune suppression in the tumour microenvironment.

Kineta claims that KVA12123 also has the potential to treat colorectal, head and neck, non-small cell lung, and ovarian cancers, as well as renal cell carcinoma.

Initial combination therapy and additional monotherapy safety and efficacy data are expected in the second quarter of next year.

Kineta CEO Shawn Iadonato said: “We anticipate that the results from the combination arm will further build on the already encouraging initial safety, tolerability, and pharmacokinetic profile of KVA12123 observed in the monotherapy arm.

“We look forward to reporting initial clinical data for the combination treatment next year.”