Vulvar Cancer, Stage IV

The goal of this clinical trial is to evaluate the safety and tolerability of increasing doses of \[177Lu\]Lu-AKIR001, both in relation to tolerable activity of lutetium-177 and the absorbed protein mass dose of AKIR-001 in patients with irresectable or metastatic CD44v6-expressing solid malignancies for whom no reasonable systemic treatment options are be available. The main question it aims to answer is: • What is the toxicity profile of the study drug \[177Lu\]Lu-AKIR001 according to the rate of Dose Limiting Toxicities and (Severe) Adverse Events? Participants will receive one \[177Lu\]Lu-AKIR001 infusion followed by a 6-week safety follow-up period, which can be extended up to 12 weeks. Possible additional infusions of the trial drug, up to a maximum number of four, can be given when clinical benefit is noted and toxicity is deemed acceptable.