A dose limiting toxicity (DLT) is defined as any adverse event or abnormal laboratory value of CTCAE (version 5.0) Grade 3 or higher that occurs within the DLT evaluation period and that is not primarily related to disease, disease progression, intercurrent illness, or concomitant medications with a few exceptions defined in the study protocol. Other clinically significant toxicities may be considered to be DLTs, even if not Grade 3 or higher.

The distribution of adverse events will be done via the analysis of frequencies for treatment emergent Adverse Event (TEAEs) and Serious Adverse Event (TESAEs) and through the monitoring of relevant clinical and laboratory safety parameters.

Dose modifications (dose interruptions and reductions) for 177Lu-DFC413 will be assessed and summarized using descriptive statistics. The number of patients with dose modification and the reasons will be summarized by treatment groups.

Dose intensity for 177Lu-DFC413 will be assessed and summarized using descriptive statistics. Dose intensity is computed as the ratio of actual cumulative dose received and actual duration of exposure.