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 events (TEAEs) and serious adverse events (TESAEs) and through the monitoring of relevant clinical and laboratory safety parameters.

Dose modifications (dose interruptions and reductions) for \[177Lu\]Lu-NNS309 will be assessed and summarized using descriptive statistics. The number of patients with dose modification will be summarized by treatment groups.

Dose intensity for \[177Lu\]Lu-NNS309 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.