Trial Registered

Peg-Bio starts Phase 1 dose-escalation trial of PA5 in advanced tumors

The China-based trial will test safety and find a recommended dose for a tumor-agnostic asset whose target and mechanism remain unspecified in the registry.

By AppliedXLJuly 14, 2026Trial NCT07702162

Executive Summary

Chongqing Peg-Bio Biopharm opened a Phase 1 trial testing whether its tumor-agnostic candidate can be dosed safely enough to define a path forward, with no efficacy claim yet in play.
The design is built entirely around tolerability and dose-finding, meaning the trial's information value lies in safety and pharmacokinetics rather than a signal of clinical benefit.
The asset enters a tumor field with no trial sharing its target or mechanism class, leaving its competitive position undefined until basic mechanism data emerge.
The sponsor has a clean completion history across its prior programs, a favorable operational baseline for a first-in-human study of this kind.

The trial

The trial, registered as NCT07702162, opened for recruitment on November 14, 2025, and is enrolling adults with advanced or metastatic tumors who have failed, are intolerant to, or have no standard therapy available. It targets 49 patients across two sites in China and carries a primary completion date of February 2, 2027. The design follows a dose-escalation and expansion structure typical of a first-in-human oncology study, evaluating adverse events, dose-limiting toxicity, maximum tolerated dose, and a recommended Phase 2 dose as its four primary measures. NCT07702162

What the endpoints test

None of the trial's primary endpoints measure tumor response or survival. Adverse events are tracked from Cycle 1 Day 1 through Cycle 7 Day 28, dose-limiting toxicity is assessed at the end of Cycle 1, and the recommended Phase 2 dose is determined by Cycle 7 based on both efficacy and safety observed during escalation and expansion. That structure means the trial's near-term information value is entirely about whether PA5 can be dosed at a level patients tolerate, not whether it shrinks tumors. Eligibility requires an ECOG performance status of 0 or 1, life expectancy of at least 12 weeks, and adequate organ and bone marrow function, with prior treatment with ADI-PEG20 or related compounds excluded. NCT07702162

Competitive position

PA5's target and mechanism are not specified in the registry, so no first-in-class claim attaches to it, and none can be denied. Set against the eight actively enrolling advanced--tumor trials Peg-Bio's PA5 program sits alongside, none share its target: Merck's belzutifan (HIF-2α), OncoC4's gotistobart (CLPP), Roche's divarasib and Merck's calderasib (both KRAS G12C), and Bristol-Myers Squibb's BMS-986504 (PRMT5) all work through different mechanisms in the same indication. Two of those, belzutifan and gotistobart, are already in Phase 3 testing overall survival, underscoring that the indication has multiple mechanisms advancing toward late-stage development even as PA5 begins Phase 1.

Sponsor and execution

Chongqing Peg-Bio Biopharm has completed 5 of 5 prior trials with no terminations recorded, and runs 5 more trials currently recruiting across a 10-trial pipeline. That completion history is a favorable baseline for a first-in-human study, though it reflects the sponsor's broader portfolio rather than any prior data on PA5 itself, since this is the company's only registered trial of this asset. The trial has undergone no protocol amendments since registration, a normal state for a study just entering recruitment.

This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.