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Lung CancerJune 2021Summary reviewed May 2026

What the CodeBreaK 100 Trial Found — Sotorasib for KRAS G12C Lung Cancer

CodeBreaK 100 tested sotorasib, a daily oral pill targeting a specific cancer mutation called KRAS G12C, in 126 people with advanced non-small cell lung cancer who had previously received chemotherapy and immunotherapy. Tumors shrank in over a third of patients on a once-daily pill.

What the trial was testing

The CodeBreaK 100 enrolled 126 patients with lung cancer. The study was sponsored by Amgen and tracked outcomes across the full group of patients who matched the trial's eligibility profile.

It was initial testing (phase 2). Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.

What the results showed

37% had measurable tumor shrinkage on a once-daily pill.

New England Journal of Medicine · 2021 · NCT03600883

These findings — that had tumor shrinkage on sotorasib in KRAS G12C non-small cell lung cancer — were published in the New England Journal of Medicine and represent the headline result of the study.

Researchers tracked outcomes across 126 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.

What this means for patients

For patients with lung cancer, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.

What you can do now

Sotorasib (Lumakras) is FDA-approved for KRAS G12C-mutated non-small cell lung cancer that has progressed after at least one prior treatment and available now. KRAS G12C testing on tumor tissue determines eligibility. Side effects include diarrhea, nausea, and liver test changes. Ask your oncologist about mutation testing.

Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.