AMBIGUOUS RESULTS

Kairos reports no severe toxicity in 13 patients on carotuximab-osimertinib combo

The Phase 1 trial's primary endpoint is dose-limiting toxicity, and safety data so far do not report efficacy on the resistance-reversal thesis the company is pitching.

By AppliedXLJuly 15, 2026Trial NCT05401110

Executive Summary

Kairos Pharma disclosed that no severe adverse events have occurred among patients treated so far in its Phase 1 trial combining carotuximab with osimertinib in EGFR-mutated lung cancer, a safety update rather than an efficacy result.
The study is designed to find a tolerable combination dose by tracking toxicity, not tumor shrinkage, so a favorable safety signal advances dose selection without yet addressing whether the drug reverses resistance to the standard therapy it is paired with.
The company's public framing leans on the size of the EGFR-mutated lung cancer market and characterizes the safety data as a milestone toward resensitizing resistant tumors, an efficacy claim the disclosed data do not yet support.
The trial has moved through a status reversal and a primary completion date change since 2022, and enrollment sits at 13 of an anticipated 60 patients, so the readout that will actually test the drug's efficacy thesis remains ahead.

The disclosure

Kairos Pharma, Ltd. said on July 15, 2026, that interim data from its Phase 1 trial of carotuximab (ENV-105) combined with osimertinib showed no Grade 3 or higher adverse events across 13 treated patients with advanced, EGFR-mutated non-small cell lung cancer. The trial, registered as NCT05401110, is sponsored by Cedars-Sinai Medical Center with Enviro Therapeutics as a collaborator, and its registered primary outcome measure is the number of adverse events and dose-limiting toxicities needed to establish a Recommended Phase 2 Dose for the combination. The company's own statement frames the finding as support for "continued progression toward an early efficacy readout," language that describes a future disclosure rather than the one made now. Kairos+1

The stake

Osimertinib is the standard first-line therapy for EGFR-mutated non-small cell lung cancer, and resistance to it eventually develops in nearly all patients, leaving them with limited options, according to Kairos Pharma's disclosure. The company's scientific rationale holds that CD105, a protein target also known as endoglin, becomes elevated in osimertinib-resistant tumors and that blocking it with carotuximab could restore sensitivity to the drug. That is a mechanistic hypothesis the current safety data do not test: the trial's design measures toxicity and dose-limiting events, not tumor response or progression-free survival. Kairos+1

Reading the safety signal

Chief Executive Officer John Yu framed the update as confirming "this clean safety profile now confirmed across 13 patients" toward a goal of changing the post-progression treatment paradigm. Chief Science Officer Neil Bhowmick added that the drug "continues to be extremely well tolerated, now across two very different indications," pointing to a separate Phase 2 prostate cancer trial the disclosure says produced a median progression-free survival exceeding 13 months. Those statements describe tolerability and a separate program's result; neither substitutes for tumor-response or resistance-reversal data from this NSCLC cohort, which the disclosure does not report. Kairos

Trial mechanics

NCT05401110 targets enrollment of 60 patients on an anticipated basis and has enrolled 13 to date, with a primary completion date of January 1, 2025, that was pushed back from an original October 2024 target in a November 2022 amendment. The trial's recruiting status reversed briefly to "Not yet recruiting" in mid-2023 before returning to "Recruiting" three months later, and the record shows no update since April 2024. First patient dosing was reported in January 2024, and Kairos presented initial Phase 1 data at the World Lung Cancer Conference in September 2025, so the trial has generated a steady disclosure cadence even as it has not yet posted efficacy results. NCT05401110

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.