In Situ, Autologous Therapeutic Vaccination Against Solid Cancers With Intratumoral Hiltonol®

Inclusion Criteria: 1)1) Histologically confirmed diagnosis of one of the following: 1. Melanoma 2. Squamous head and neck cancer 3. Sarcoma 4. Non-Melanoma skin cancers 2) Sarcoma Patients must be 14 years of age or older. All other patients must be 18 years of age or older. 3\) Unresectable disease. Patients with resectable disease may be enrolled after having refused surgery after a documented consultation with a surgeon. 4\) Radiographic or visually measurable disease based on Response Evaluation Criteria In Solid Tumors, Version 1.1 criteria. 5\) At least one accessible primary or metastatic tumor site that can be readily injected IT with poly-ICLC with or without ultrasound guidance. This lesion can be superficial cutaneous, subcutaneous, or within a readily accessible location, including a lymph node, and must measure ≥ 15mm short axis for target. 6\) Patients who have received at least 8 weeks of aPD1 or aPDL1 immunotherapy and who have either progressive disease, stable disease or partial response based on RECIST 1.1 criteria are elegible for participation as separate cohorts B or C, with continuation of the aPD1 or aPDL1 therapy at their physician's discretion. 7\) ECOG performance status of ≤ 2. 8) Acceptable hematologic, renal and liver function as follows: A) Absolute neutrophil count \> 1000/mm3 B) Platelets \> 50,000/mm3, C) Creatinine ≤ 2.5 mg/dl, D) Total bilirubin ≤ 1.5 mg/dl, E) Transaminases ≤ 2 times above the upper limits of the institutional normal. F) INR\<2 if off of anticoagulation. Patients on anticoagulation therapy with an INR\>2 may be enrolled at the discretion of the investigator if they have not had any episodes of severe hemorrhage and if the site to be injected is not located in the oropharynx or another area where achieving homeostasis would be complicated by local anatomy. 9\) Patients must be able to provide informed consent. 10) Patients with the potential for pregnancy or impregnating their partner must agree to follow acceptable birth control methods to avoid conception. Contraception must be continued for at least 2 months following the last dose of poly-ICLC. Women of childbearing potential must have a negative pregnancy test. While animal reproductive studies have been negative, the simulated viral infection and anti-proliferative activity of this experimental drug may theoretically affect the developing fetus or nursing infant. Cohort Specific Inclusion Criteria (see § 11.6 Evaluation of Best Overall Response (BOR) Cohort A) 11) Patients who are not receiving an anti-PD-1 or anti-PD-L1 agent, Cohort B 12) Patients who have received at least 8 weeks of aPD1 or aPDL1 immunotherapy. 13) Patients have progressive disease based on RECIST 1.1 criteria. Cohort C) 14) Patients who have received at least 8 weeks of aPD1 or aPDL1 immunotherapy. 15) Patients have stable disease or a partial response based on RECIST 1.1 criteria. 4.2 Exclusion Criteria Patients with any of the following are ineligible for this research study: 1. Serious concurrent infection or medical illness, which would jeopardize the ability of the patient to receive the treatment outlined in this protocol with reasonable safety. 2. Bulky intracranial metastatic disease with shift of midline structures or progressive brain metastasis such that ongoing therapy for these brain metastasis is required at the time of enrollment. 3. In the opinion of the local PI: Head and neck cancer patients with airway tumor recurrence that may compromise breathing or swallowing if inflammation or edema is transiently aggravated by Hiltonol® injection. Head and neck cancer patients with tumor invading major blood vessels for whom there may be a risk of blockage or bleeding if inflammation or edema is transiently increased by Hiltonol® injections. 4. AIDS defined as a CD4 count less than 200 in the context of HIV sero-positivity or chronically is taking immunosuppressive medication such as steroids or transplant related medications. 5. Life expectancy of less than 6 months in the judgment of the study physician. 6. Persistent toxicity from recent therapy that has not sufficiently resolved in the judgment of the study physician. 7. History of active cancer vaccine immunotherapy in the previous month. Patients who have received at least 8 weeks of aPD1 or aPDL1 immunotherapy and who have either progressive disease, stable disease or partial response based on RECIST 1.1 criteria are elegible for participation and continuation of the aPD1 or aPDL1 therapy at their physician's discretion.