This is a first-in-human, open-label, non-randomized, three-part phase 1 trial of INBRX-109, which is a recombinant humanized tetravalent antibody targeting the human death receptor 5 (DR5).

This is an international phase III trial, with a Bayesian design, incorporating two sequential randomisations. It efficiently examines a series of questions that routinely arise in the sequencing of treatment. The study design has evolved from lengthy international consultation that has enabled us to build consensus over which questions arise from current knowledge and practice. It will enable potential randomisation for the majority of patients with inguinal lymph node metastases and will provide data to inform future clinical decisions.

InPACT-neoadjuvant patients are stratified by disease burden as assessed by radiological criteria. Treatment options are then defined according to the disease burden strata. Treatment is allocated by randomisation. Patients may be allocated to one of three initial treatments:

A. standard surgery (ILND); B. neoadjuvant chemotherapy followed by standard surgery (ILND); or C. neoadjuvant chemoradiotherapy followed by standard surgery (ILND).

After ILND, patients are defined as being at low or high risk of recurrence based on histological interpretation of the ILND specimen. Patients at high risk of relapse are eligible for InPACT-pelvis, where they are randomised to either:

P. prophylactic PLND Q. no prophylactic PLND