CHRYSALIS External Control Analysis Sheds Light on Real-World Treatments, Outcomes in NSCLC

Amivantamab “presents a promising targeted treatment option” for patients with advanced non-small cell lung cancer (NSCLC) who also have EGFR exon 20 insertions (ex20ins), according to a recent study that analyzed and compared the results of the CHRYSALIS study with real-world patient outcomes in Taiwan.

The study, published in ESMO Annals of Oncology and sponsored by Johnson & Johnson Innovative Medicine, was conducted by a team of researchers in Taiwan at the National Taiwan University Hospital. Their objective was to compare the effectiveness of amivantamab, as demonstrated by the CHRYSALIS study, with the platinum-doublet chemotherapy regimen received by real-world patients with NSCLC and EGFR ex20ins.

It was important to conduct the real-world study and compare amivantamab with systemic anti-cancer therapy in Taiwan because of the treatment challenges, clinical burden, and advanced stage of disease faced by this patient population.

To conduct the comparison, the investigators selected eligible patients who met CHRYSALIS criteria to create an external control group. According to the study authors, the external control dataset used for indirect comparison “includes each line of post-platinum-based chemotherapy treatment.”

To adjust the analysis for differences in patient characteristics at baseline, the researchers utilized the propensity score average treatment effects on the treatment method. The outcomes that were measured included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS), which were compared using weighting generalized estimating equations and weighting Cox proportional hazards regression, respectively.

In comparison to real-world patients in Taiwan, patients treated with amivantamab in the CHRYSALIS study were found to have “significantly improved OS” at a median of 23.1 months versus 7.5 months (95% CI, 0.23-0.66), respectively. PFS also improved more among patients treated with amivantamab versus patients treated in Taiwan, at a median of 6.9 months versus 2.3 months (95% CI, 0.24-0.56), respectively.

In addition, ORR was found to be an improved outcome, measuring at 36.8% among patients who received amivantamab versus 3% among real-world patients evaluated in Taiwan (95% CI, 7.25-59.06). Ultimately, a total of 158 patients were evaluated as part of the study, 114 from the CHRYSALIS study and 44 from the external control group.

Notably, while patients who received amivantamab scored higher across all measured outcomes, the study results showed that smoking history was comparatively lower among the real-world patients evaluated in Taiwan (13.6%) compared to those who were part of CHRYSALIS (43%).

In reflecting on the results, the investigators noted that, although a “lack of effective treatments” in Taiwan contributes to the clinical burden faced by this population, the implementation of amivantamab presents a potentially effective and more individualized treatment option for this patient population.

Source: ESMO Annals of Oncology