Immune Resistance Interrogation Study

Inclusion Criteria: * Patients with a histological or cytological diagnosis of solid malignancies, with at least one tumor lesion amenable to core needle biopsy and consent to such a procedure. * Patients must have progressed on immunotherapy (defined as anti-PD1/PD-L1 antibodies given as monotherapy or as part of a combination therapy) as their most recent line of therapy. Patients will be classified into two groups: 1) those who benefitted from immunotherapy with either complete response (CR), partial response (PR) or prolonged stable disease (SD) lasting at least 6 months with subsequent progression or who had disease progression after at least 12 weeks from the last dose of immunotherapy in the adjuvant setting (i.e. acquired resistance), 2) those whose disease is primary refractory to immunotherapy with disease progression at their first on-treatment imaging, those who benefitted from immunotherapy with stable disease (SD) but progressed in \<6 months or those that had progressive disease earlier than 12 weeks from the last dose of immunotherapy in the adjuvant setting. * Patients must be of good performance status, ECOG 0-1, for subsequent anticancer therapy, with either standard treatment or within the context of a clinical trial. * Patients must be ≥ 18 years old. * Patients must have provided voluntary written informed consent. Exclusion Criteria: * Any condition that could interfere with a patient's ability to provide informed consent such as dementia or severe cognitive impairment. * Any contraindication to undergoing venipuncture. * Any condition that, in the opinion of the Investigator, would interfere with patient safety, or evaluation of the collected specimens and interpretation of study results.