ALX Oncology Doses First Patient in Phase 1 Trial for ALX2004: A Potential Breakthrough in EGFR-Targeted ADCs.

ALX Oncology has dosed its first patient in a Phase 1 clinical trial for ALX2004, a potential EGFR-targeted ADC for solid tumors. The trial aims to evaluate the drug's safety and efficacy. CEO Jason Letttmann stated that the trial represents a significant step forward in EGFR-targeted ADC development, with initial safety data expected in H1 2026.

ALX Oncology Holdings Inc. (Nasdaq: ALXO) has dosed its first patient in a Phase 1 clinical trial for ALX2004, a potential best- and first-in-class epidermal growth factor receptor (EGFR) antibody-drug conjugate (ADC) designed to treat EGFR-expressing solid tumors. The trial, designated as NCT07085091, aims to evaluate the safety and efficacy of ALX2004 in participants with advanced or metastatic EGFR-expressing solid tumors.

The Phase 1 clinical trial is a first-in-human, open-label, multicenter study consisting of a Phase 1a dose escalation portion followed by dose exploration and a Phase 1b dose expansion. The dose escalation portion will enroll patients with previously treated advanced or metastatic non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), esophageal squamous cell carcinoma (ESCC), and colorectal cancer (CRC). The study will also explore and expand on these tumor types in subsequent phases.

ALX2004 is uniquely designed by ALX Oncology's protein engineers, utilizing the company's proprietary topoisomerase I inhibitor (Top1i) payload and linker payload platform. The ADC is optimized to maximize the therapeutic window by reducing toxicity, featuring an affinity-tuned EGFR antibody with a distinct binding epitope and a proprietary Top1i payload engineered for enhanced bystander effect and improved linker stability.

Preclinical data support ALX2004's differentiated linker-payload construct, which has demonstrated superior stability and dose-dependent activity compared to other ADCs in its class. The drug has shown potent activity across various tumors, EGFR expression levels, and mutations, with no EGFR-related skin toxicity or payload-related interstitial lung disease observed at clinically relevant doses.

CEO Jason Lettmann emphasized the significance of this milestone in ALX Oncology's mission to develop a pipeline of best-in-class drugs. "Dosing of the first patient in the Phase 1 trial is an important milestone in ALX Oncology’s mission to develop a pipeline of best-in-class drugs; ALX2004 is our first ADC and treating our first patient with this drug is a significant step forward in fulfilling the potential of EGFR-targeted ADCs," Lettmann stated. Initial safety data from the trial is anticipated in the first half of 2026.

ALX Oncology is a clinical-stage biotechnology company focused on developing novel therapies to treat cancer and extend patients' lives. Its lead therapeutic candidate, evorpacept, is currently being evaluated across multiple ongoing clinical trials. ALX2004, the company's second pipeline candidate, is a novel EGFR-targeted ADC with a differentiated mechanism of action, entering the clinic in a Phase 1 trial in August 2025.

References:
[1] https://ir.alxoncology.com/news-releases/news-release-details/alx-oncology-doses-first-patient-phase-1-dose-escalation-trial
[2] https://drug-dev.com/alx-oncology-doses-first-patient-in-phase-1-dose-escalation-trial-evaluating-adc-alx2004-for-the-treatment-of-egfr-expressing-solid-tumors/