First-In-Human Study of STX-721/PFL-721 in Participants With Locally Advanced or Metastatic Non-Small Cell Lung Cancer Harboring EGFR or HER2 Exon 20 Insertion Mutations

This clinical trial is studying an experimental drug called STX-721 for people with advanced non-small cell lung cancer. The study focuses specifically on patients whose cancer has a rare genetic change known as an EGFR or HER2 "exon 20 insertion" mutation. STX-721 is a targeted therapy designed to block the activity of these specific proteins, which may help slow or stop the growth of cancer cells while causing less damage to healthy cells.

To be eligible, you must have stage 3 or 4 lung cancer that cannot be treated with surgery or curative radiation. Depending on which part of the study you join, you may need to have already tried and progressed on standard treatments, such as platinum-based chemotherapy. You will also need to provide a recent or stored tumor sample so doctors can confirm your mutation type. This trial is generally for patients who are still physically active and do not have symptomatic brain or spinal metastases.

Participation involves taking the study drug orally, likely on a daily schedule. You will undergo regular scans and check-ups to see how the drug is working and monitor for side effects. Before enrolling, you should talk with your doctor about your prior treatments and any recent genetic testing results. You may also want to discuss how this experimental drug differs from currently approved treatments for exon 20 mutations and what the schedule of clinic visits will look like for you.