RTX-321 Monotherapy in Patients With HPV 16+ Tumors

Inclusion Criteria: * Signed written informed consent obtained prior to study procedures Patients ≥18 years with an ECOG 0 or 1 * Histologically confirmed diagnosis by the local laboratory of persistent, recurrent, or metastatic, unresectable cervical cancer (squamous, adeno, or adenosquamous histology), HNSCC, or squamous cell cancer of the anal canal that is not amenable to curative therapy. * All patients must have experienced disease progression following platinum-based or mitomycin C-based chemotherapy administered in the persistent, recurrent, or metastatic setting. * All patients with programmed death-ligand 1 (PD-L1) positive cervical cancer and those with HNSCC must have received or have been determined to be ineligible for immunotherapy with a PD-1 or PD-L1 inhibitor. * All patients with cervical cancer will have received or have been determined to be ineligible for bevacizumab. * Confirmation of HLA-A\*02:01 positive status by central testing. * In patients with cervical cancer or HNSCC, confirmation of HPV 16 within the tumor either from historical pathology result (using an FDA-approved HPV testing method, patients with cervical cancer only) or based on central laboratory analysis of a tumor sample. Patients with anal cancer will not be required to have prospective determination of HPV 16 positive status prior to enrollment. * Disease must be measurable per Response Evaluation Criteria * The shorter of 28 days or 5 half-lives must have elapsed since the completion of prior therapy, before initiation of study treatment. * Adequate Organ Function as Defined by the protocol: * AST and ALT ≤3 × the upper limit of normal (ULN) * Except in documented cases of Gilbert syndrome, total bilirubin ≤1.5 × ULN * Serum albumin ≥2.5 g/dL * Serum or plasma creatinine ≤1.5 × ULN and/or glomerular filtration rate ≥50 mL/min/1.73 calculated by the Cockcroft-Gault formula * Absolute neutrophil count ≥1 × 103/μL, without myeloid growth factor support for ≥1 week * Platelet count ≥100 × 103/μL, without platelet transfusion for ≥1 week * Hemoglobin ≥9 g/dL, without red blood cell transfusion for ≥2 weeks Exclusion Criteria: * Patient has central nervous system (CNS) involvement. If the patient fulfills the following 3 criteria, she/he is eligible for the trial after consultation with the Sponsor Medical Monitor. * Completed prior therapy for CNS metastases (radiation and/or surgery) * CNS tumor(s) is clinically stable at the time of enrollment * Patient does not require corticosteroid or antiepileptic therapy for management of CNS metastases * Known hypersensitivity to any component of study treatment or excipients. * Positive antibody screen using institution's standard type and screen test. * Clinically significant, active and uncontrolled infection, including human immunodeficiency virus (HIV), Hepatitis B virus (HBV), or Hepatitis C virus (HCV).