Once considered “undruggable,” KRAS mutations were a thorn in researcher’s sides-until now. On May 28, 2021, the first KRAS G12C targeted therapy was approved (Sotorasib), opening up another line of therapy for 1 in 8 non-small cell lung cancer patients who are impacted by this biomarker. Now lung cancer patients who have KRAS G12C, can go on a targeted pill if their cancer grows after they have been on chemotherapy, immunotherapy or a combination.
When tumor tissue is looked at under a microscope, physicians can see what type of cancer it is. But physicians can also look for changes in the DNA of the tumor that might be causing the tumor to grow. In lung cancer, these are changes that happen over time, not changes that are inherited. Sometimes these changes are called biomarkers or molecular markers.
The KRAS mutation is one of those biomarkers. The KRAS mutation is an error in a protein in normal cells. Normally KRAS serves as an information hub for signals in the cell that lead to cell growth. When there is a mutation in KRAS, it signals too much and cells grow without being told to, which causes cancer. There are several types of KRAS mutations. About 13% of non-small cell lung cancer patients have KRAS G12C, making it one of the most common lung cancer biomarkers.
Since KRAS was discovered in lung cancer in 1984, researchers have been unable to find a targeted therapy, a pill that can address what is driving the cancer cell to grow. There have been a large number of targeted therapies approved in lung cancer for a variety of other biomarkers, including biomarkers that appear less commonly than KRAS does in lung cancer patients.
But this new drug doesn’t do any good sitting on a shelf. Advanced non-small cell adenocarcinoma lung cancer patients need to be tested for a wide range of biomarkers that have approved therapies or emerging therapies. This is sometimes called comprehensive biomarker testing.
Patients should also talk to their doctor about clinical trials. Before the new KRAS drug became approved, it was studied in a clinical trial, like all cancer drugs. Clinical trials are highly monitored and many of the trials testing emerging targeted therapies are now being structured as “single arm,” meaning all the patients in the trial get the new drug being tested. However, if that is not the case, the clinical trial will be structured so participants receive the highest standard of care known at the time or the new drug, meaning trial participants will never get a placebo or sugar pill. Like biomarker testing, clinical trials should be discussed with your physician as soon as possible.
Sotorasib was the fourth lung cancer drug approved in 2021, and there will likely be many others. For patients with KRAS G12C, this marks a turning point in their treatment options that will hopefully open doors for even more KRAS targeted therapies.
The American Lung Association recently released new videos helping explain KRAS and giving advice for newly diagnosed KRAS-positive lung cancer patients. Visit Lung.org/kras to learn more.
Blog last updated: August 25, 2023