Testing a new antibody treatment for advanced solid tumors

Plain-English translation of NCT03526835 on ClinicalTrials.gov ↗ · Source last updated July 2026 · Translation generated July 2026 · How we translate trials

Phase 1/2 — A combined trial that checks safety and dosing while also starting to look at whether the treatment works.

This is one of the first times this treatment has been tested in people.

What is this trial?

This trial is testing a new drug called petosemtamab (), which is a type of antibody designed to fight advanced cancers that depend on EGFR signaling to grow. Researchers want to find the right dose and understand how well this medication works, either given by itself or combined with other cancer treatments. The trial includes patients with several types of advanced solid tumors, including colorectal, head and neck, gastric, and lung cancers.

Many patients with advanced cancers don't respond well to existing treatments, or they develop resistance over time. This medication targets a specific pathway that helps cancer cells grow, offering hope for patients who have limited options left.

Do you qualify?

You likely qualify if…

you have been diagnosed with an advanced or metastatic solid tumor (cancer that has spread) that cannot be treated with surgery aimed at cure
you have measurable disease that can be seen on imaging scans
you are in good enough health to tolerate the treatment (ECOG performance status of 0 or 1)
your heart function is normal or near-normal (left ventricular ejection fraction ≥50%)
your organs are functioning well enough to safely receive the medication
you are expected to live at least 12 weeks, in your doctor's judgment

You likely don't qualify if…

you have a type of cancer with specific genetic mutations (KRAS, NRAS, BRAF mutations, or HER2 amplification) that would make you ineligible for certain parts of the study
you have already received certain types of treatments (such as EGFR inhibitors) that would exclude you from specific study cohorts
you have microsatellite instability (MSI) or mismatch repair deficiency in your tumor (for certain cohorts)
your heart function is significantly reduced
you have severe organ dysfunction that would make treatment unsafe

What participation looks like

You would receive intravenous infusions of the medication every 2 weeks (on Day 1 and Day 15 of each 28-day cycle) at a hospital or treatment center. Depending on which part of the trial you join, you might receive the medication alone or combined with other treatments like chemotherapy or immunotherapy. You would have regular visits for blood tests, imaging scans, and physical exams to check how you are responding and to watch for any side effects. The trial is still recruiting patients for certain cancer types and treatment combinations.

AI-generated summary from trial data · Jul 18, 2026 · Not medical advice

Testing a new antibody treatment for advanced solid tumors

What is this trial?

Do you qualify?

What participation looks like

Trial locations