To be eligible to cohort 1 [stable disease], the initial evidence of SD is to be confirmed by a second assessment, no less than 4 weeks from the date of the first documented SD. To be eligible to cohorts 2 and 3 [primary and secondary refractory patients], patients must meet all the following criteria:~Evidence of clinical benefit according to investigator assessment. The assessment of clinical benefit should be balanced by clinical judgment as to whether the patient is clinically deteriorating and unlikely to receive any benefit from continued anti-PD-1/PD-L1 treatment.~Absence of symptoms and signs (including laboratory values, such as new or worsening hypercalcemia) indicating unequivocal progression of disease,~Absence of decline in ECOG PS that can be attributed to disease progression,~Absence of tumor progression at critical anatomical sites (e.g., leptomeningeal disease) that cannot be managed by protocol-allowed medical interventions.~No ongoing clinically significant AE related to anti-PD-1/PD-L1.~During this study:~All patients will receive NP137 (14 mg/kg, IV, Q3W) as add-on treatment to their standard anti-PD1 or anti-PDL1 treatment administered.~To facilitate the study treatments administration and to not over burden patients, the study drug NP137 which is administered every 3 weeks (Q3W) will be associated to standard PD-1/PD-L1 therapies for which dosing are administered every 3 weeks or every 6 weeks (Q3W or Q6W). A treatment delay of up to 3 days is allowed before the start of a new cycle.
This study is a multicenter, open-label, proof-of-concept study aiming to assess the clinical and biological impact of NP137 when added to standard PD-1/PD-L1 blockade therapy in 3 independent cohorts of advanced or metastatic solid tumors with various sensitivity to anti-PD-1/PD-L1:~Cohort 1 [Stable Disease]: Patients with a radiological documentation of SD according to RECIST V1.1 criteria following at least 12 weeks under standard anti PD-1/PD-L1 therapy. The initial evidence of SD is to be confirmed by a second assessment, no less than 4 weeks from the date of the first documented SD.~Cohort 2 [primary refractory]: Patients with documented radiological PD according to RECIST V1.1 but with clinical benefit under anti PD-1/PD-L1 standard therapy.~Cohort 3 [secondary refractory]: Patients with documented radiological PD following an initial Objective Response according to RECIST V1.1, with clinical benefit under standard anti-PD-1/PD-L1.