For several years stage 4 adenocarcinoma non-small cell (aNSCLC) lung cancer treatment has been dictated by the genetic mutation, called biomarkers, of the patient. A patient’s treatment was seen as either chemotherapy, immunotherapy (or some sort of combination of the two), or a personalized targeted therapy. In the early stages of targeted therapy in aNSCLC, only a few biomarkers had FDA approved targeted therapies. Unfortunately, KRAS was not one of them. KRAS is the most common genetic mutation in aNSCLC and has several different subtypes of specific mutations. The most common of those subtypes is KRAS G12C, making up 40% of all KRAS mutations in aNSCLC and 13% of all aNSCLC mutations in general. For comparison, all types of EGFR mutations make up 14% of aNSCLC mutations.

Originally, as Dr. Liu, Associate Professor of Medicine, Director of Thoracic Oncology and Director of Developmental Therapeutics at Georgetown Lombardy Comprehensive Cancer Center pointed out at our June 15th Living Room on biomarker testing, “our treatments for KRAS have been immunotherapy and chemotherapy and that’s it.” This means more than one third of aNSCLC patients with an identified mutation did not have any targeted treatment options. However, scientists were hard at work to develop drugs to target KRAS. This process is much harder than it was for EGFR, ALK, and many other biomarkers because of how difficult it is to directly affect the KRAS gene in a patient’s tumor cells.

Despite the difficulty, drugs targeting the G12C variant of KRAS went into clinical trials and one received approval in May of 2021. This new approval breathed fresh air into the treatment landscape for thousands of patients in the US. One such patient is Cecily Hatchitt of Merlin, Oregon. Cecily describes the advent of KRAS G12C drugs as a personal letter. “It’s like a personal email to you. It’s intended just for me with G12C and anybody else who might have G12C.”

Instead of receiving general treatments like the chemotherapy and immunotherapy that Dr. Liu described, Cecily and other patients like her now get a drug designed exactly for their type of lung cancer. One of Cecily’s highlights about now being on a targeted therapy is that she can travel. “I am no longer tied down to a clinic with infusions because this therapy is actually a pill that I can take.”

As with any other targeted therapy, the only way to receive a KRAS G12C drug is to have biomarker testing and identify that you have the correct mutation. The best type of test to receive is a comprehensive biomarker test because as Dr. Liu also shared at the Living Room, “knowing KRAS positive is not enough, like in EGFR you need the details, you need the specific mutation. And if you’re doing a test like PCR, that’s not going to tell you whether it’s a C or a D. So you need to know exactly what type of test you’re doing.” For patients to receive the best treatment possible, everyone should receive comprehensive testing. Regardless of their age, smoking history, or racial background. In addition to possibly identifying a targetable mutation and receiving targeted therapy, comprehensive biomarker tests allow for patients to be eligible for cutting edge clinical trials and continue striving for personalized and precision medicine.