Age Does not Affect the Efficacy of Antibody Drug Conjugates, But is Associated with High-Grade Adverse Events in Patients with Cancer Enrolled in Early Phase Clinical Trials.

BACKGROUND

Data on the use of antibody drug conjugates (ADCs) in older patients are scarce.

OBJECTIVE

The objective was to study the safety and efficacy of ADCs used in early phase clinical trials in patients aged ≥ 65 years compared with younger patients.

PATIENTS AND METHODS

All patients enrolled in early phase clinical trials (phase I or II) of ADCs for solid tumors in our institution between November 2014 and May 2023 were included in this retrospective monocentric study. Safety and efficacy were compared between patients ≥ 65 and < 65 years old (y.o).

RESULTS

A total of 136 patients were included in our study, with 43 (31.6%) patients aged ≥ 65 y.o. In comparison with the younger population, patients aged 65 years or older had similar demographic characteristics. Older patients experienced the same rate of all-grade adverse events (95.3 versus 97.8%) and all-grade related adverse events (65.1 versus 66.7%) but more high-grade adverse events (41.9 versus 30.1%) than younger patients. In the univariate analysis, we identified age, taken as a continuous variable, as associated with high-grade adverse event (p = 0.047). No statistically significant difference was found between older and younger patients in terms of disease control rate (65 versus 54%), median progression-free survival (2.76 months [95% confidence interval, 95% CI 1.64-3.75] compared with 2.56 [95% CI 1.81-2.79], p = 0.34), or median overall survival (6.57 months [95% CI 4.01-13.01] compared to 7.89 [95% CI 6.83-9.36], p = 0.65).

CONCLUSIONS

In our cohort, ADC therapy provided comparable survival benefits for the older patients but with a higher risk of high-grade adverse event.