LiBRA Study

This post is a reflection on the LiBRA Study.

The title of the study is

Liquid Biopsy Monitoring in BRAF V600E–Mutated Patients With Non–Small Cell Lung Cancer Treated With Dabrafenib Plus Trametinib: The Prospective, Multicenter LiBRA Study (GOIRC-03-2020)

Baseline population was the following. This is a reasonable population for such a study, but sample size is small.

Next, consort diagram shows retention in study was relatively good. Only 4 patients missed ctDNA draws and there were about 9 follow up timepoints. Interestingly, only t0 and t1 results are shared.

Shedding status via ctDNA was measured over time and expressed in several different figures. The below figures show that of the 24 positive ctDNA patients at t0, 17 (81%) cleared ctDNA after 1 timepoint from treatment.

Patients who were positive at t0 and cleared ctDNA at t1 had improved PFS and OS.

Of the total population (regardless of t0 result), patients who had negative ctDNA at t1 had improved PFS and OS.

Reflecting on the above, a particularly interesting result is the high number of patients progressing or dying with negative ctDNA results. Figure 1A 3rd panel shows 10/21 patients (48%) with negative ddPCR ctDNA who developed progression of disease. Similarly, 11/21 (52%) were negative by ctDNA NGS who devloped PD. Later, it can be seen that of total population, there were 31 patients with negative ctDNA at t1. It’s not stated the total number of deaths, but it appears approximately 30% of this population.

We can see some more detail below. There are at least 4 patients with only t0 negative ctDNA result that die. There are also 8 patients who have t1 negative ctDNA that die.

To be continued.