Patients With Lung Cancer May Benefit From Liquid Biopsy to Identify ALK Mutation

A blood test may help to identify the best treatment option for patients with ALK-positive, advanced non-small cell lung cancer (NSCLC), according to results from the BFAST trial.

Rather than having to get a tumor sample from patients, this test can detect tiny pieces of tumor DNA that shed from cancer cells in the blood, in turn identifying mutations that would make an individual’s cancer suitable for targeted medicines.

“One of the biggest recent changes in treatment of NSCLC has been our ability to identify targetable genetic mutations that drive progression of the disease, but it is a major challenge to get a suitable tumor sample for analysis,” Dr. Shirish Gadgeel, from the Rogel Cancer Center at the University of Michigan, said in a press release issued by the European Society of Medical Oncology (ESMO).

“We showed that liquid biopsy could be used to detect a complex type of driver mutation, called ALK, in patients with NSCLC,” he added. “These then responded at least as well to targeted therapy as in previous studies using conventional biopsy techniques.”

In the phase 2/3 BFAST trial, the researchers analyzed blood-based next generation sequencing (NGS) of actionable genetic alterations among 2,219 patients with stage 3B/4 untreated NSCLC.

Results were obtained in a total of 2,188 patients.

Overall, 119 patients (5.4%) had ALK-positive disease and 87 of the, were enrolled to receive Alecensa (alectinib), an oral drug that blocks the activity of ALK.

After a median follow-up of 12.6 months, Gadgeel and colleagues found approximately one in 20 patients had tumor DNA showing a rearrangement in the ALK gene. In patients treated with Alecensa, more than three-quarters showed no disease progression in the year following treatment: objective response rate was 87.4% and the 12-month duration of response was 75.9%. Moreover, although median progression-free survival (the time from treatment to disease progression) has not been reached yet, 12-month progression-free survival was 78.4%.

The researchers noted that the safety profile of Alecenda was consistent with previous findings.

“Liquid biopsy identified a similar proportion of patients with ALK mutations to that typically seen with traditional biopsy and the results with alectinib compared well with those seen in a pivotal study of this treatment,” Gadgeel concluded.

Dr. Alberto Bardelli, from the Department of Oncology at the University of Turin in Italy, commented on the study, saying that the findings are an important advance to have shown that DNA mutations can be detected in the blood and used to guide ALK inhibitor treatment, which has then been demonstrated to be effective in patients with this mutation.

“It is encouraging to see that increasing numbers of patients with lung cancer can benefit from liquid biopsy to identify their disease mutation instead of tissue samples,” he added. “At present, the technology is quite expensive but as it becomes more widely used, the cost is likely to come down so that testing becomes more affordable and available in daily practice.”