A health expert stressed the importance of introducing more accurate diagnostic tests to identify KRAS G12C mutated non-small cell lung cancer (NSCLC) patients that can receive treatment with Amgen's Lumakras.

Lumakras is the first KRAS targeted therapy developed 40 years after researchers discovered KRAS as an oncogene. In addition, it is the first-in-class KRAS G12C inhibitor.

KRAS mutations vary according to the mutation type and location. Among them, KRAS G12C is a single-point mutation with a glycine-to cysteine substitution at codon 12, and it accounts for 44 percent of all KRAS mutations.

NSCLC patients with KRAS G12C mutation usually have resistance to existing therapy, showing lower survival rates in surgery or chemotherapy compared to other types of cancer patients.

"To identify NSCLC patients who can receive Lumakras targeted therapy in the future, I think that it will be important for the medical community to actively introduce diagnostic tests, such as polymerase chain reaction and next-generation sequencing, to detect KRAS G12C mutations," said professor Ahn Myung-ju of the Department of Hematology-Oncology at Samsung Medical Center during a press conference held by Amgen Korea Wednesday.

Professor Ahn stressed the need for such expanded diagnostic tests because a new treatment option for KRAS G12C mutation NSCLC was something that both the medical community and patients had waited for a long time.

"Most of the patients with KRAS G12C mutated NSCLC had an average progression-free survival (PFS) of only about four months despite chemotherapy and immunotherapy," Ahn said. "Also, unlike other mutations, KRAS G12C was a field where a targeted therapeutic agent was absent."

In the phase 1 and 2 CodeBreak 100 trial, which was the basis for Lumakras's approval, the drug showed an objective response rate of 37.1 percent, a progression-free period of 6.8 months, and a response rate of 37.1 percent, despite the fact that 81 percent of the patients in the trial had previously received intensive treatment such as immunotherapy and platinum-based anti-inflammatory chemotherapy, she added.

Ahn also stressed that the duration of response was 11.1 months, and the median overall survival period was 12.5 months, showing a very encouraging treatment effect.

"The treatment's side effects were also mild," Ahn said. "Therefore, the approval of Lumakras, the first targeted treatment for KRAS G12C mutated NSCLC, is a drug that both patients and clinical sites have been waiting for, and to use the drug effects in the field diagnostic testing to find patients eligible for the treatment is key."

During the press conference, Amgen Korea officials agreed with Ahn and said they would implement various measures to increase the accessibility of Lumakras, including receiving reimbursement for the drug and invigorating diagnostic tests to select KRAS mutation NSCLC patients.

"To increase patients' access to Lumakras, we will continue to discuss with phyicians and health authorities to conduct KRAS diagnostic tests more aggressively and win reimbursement," Amgen Korea Oncology Business Unit Head Kim Mi-seung said.