Inclusion Criteria:
1. Be willing and able to provide written informed consent for the trial.
2. Be ≥ 18 years of age on day of signing informed consent.
3. Cytologically or histologically confirmed resectable stage IIIB, IIIC, IIID, or IV melanoma of cutaneous or unknown primary origin with one or more macroscopic lymph node metastases (clinically detectable), that can be biopsied and a maximum of 3 additional resectable in-transit metastases. A concurrent resectable primary melanoma is allowed. Clinical detectable lymph nodes are defined as either a palpable node ora non-palpable but enlarged lymph node according to RECISTv1.1 (at least 15 mm in short axis).
1. Note: Patients with ocular melanoma are not eligible.
2. Note: The determination of resectable disease is at the discretion of the principal investigator and surgeon.
3. Note: Patients with BRAF V600E or V600K mutations are eligible.
4. At least one measurable lesion per RECIST v1.1; the injected lesion may also serve as the target lesion.
5. Anti-PD-1 therapy naïve, or if previously treated with immunotherapy, recurrence occurred at least 12 weeks after the last dose of therapy.
6. Females of childbearing potential must have a negative beta-human chorionic gonadotropin (β- hCG) test during screening, and a negative urine pregnancy test on days of treatment with RP2 and/or nivolumab. Female subjects are considered to be of childbearing potential unless one of the following criteria is met:
a. Permanent sterilization (hysterectomy, bilateral salpingectomy, or bilateral oophorectomy) or documented postmenopausal status (defined as 12 months of amenorrhea in a woman \> 45 years-of-age in the absence of other biological or physiological causes). Note: Documentation may include review of medical records, medical examination, or medical history interview by study site staff.
7. Sexually active fertile subjects and their partners must agree to use highly effective methods of contraception prior to study entry, during the course of the study, and for 90 days after the last dose of RP2 alone or 5 months after the last dose of nivolumab. An additional contraceptive method, such as a barrier method (e.g., condom), is required. In addition, men must agree not to donate sperm and women must agree not to donate eggs (ova, oocyte) for the purpose of reproduction during these same periods.
a. Note: Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the subject.
8. Have a performance status of 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) Performance Scale.
9. Demonstrate adequate organ function. All screening labs should be performed within 28 days of treatment initiation. Baseline labs may be used as screening -
Exclusion Criteria:
1. Prior treatment with an oncolytic virus therapy.
2. Active significant herpetic infections or prior complications of HSV-1 infection (e.g., herpetic keratitis or encephalitis).
3. Immunodeficiency or use of systemic corticosteroids exceeding 10 mg of prednisone daily (or equivalent). Steroids for physiologic repletion (for example hydrocortisone for adrenal insufficiency) are permitted.
4. Has acute or chronic active hepatitis B and C virus infection or known history of untreated hepatitis B (defined as hepatitis B surface antigen \[HBsAg\] reactive) or known active hepatitis C virus (HCV) (defined as HCV RNA \[qualitative\]) or HIV infection (see note).
1. Note: No testing for Hepatitis B, Hepatitis C, or HIV is required unless mandated by local health authority or clinically indicated.
2. Note: Participants with a history of HIV infection are considered eligible if CD4+ T cell counts are ≥ 350 cells/µL and the patient has had no opportunistic infections in the last 12 months.
5. Had systemic infection requiring IV antibiotics or other serious infection within 14 days prior to dosing.
6. Major surgery ≤ 1 week prior to starting study drug. Note: Patients who undergo major surgery must adequately recover prior to starting study treatment.
7. Is currently participating in or has participated in a study of an investigational agent or has used an investigational device within four weeks prior to the first dose of study treatment.
8. History of documented allergic reactions or acute hypersensitivity reactions attributed to RP2 or any of its excipients.
9. Has received a live vaccine within 30 days prior to the first dose of study drug. Examples of live vaccines include, but are not limited to measles, mumps, rubella, varicella/zoster (chicken pox), yellow fever, rabies, Bacille Calmette-Guérin (BCG), and typhoid vaccine. Seasonal influenza vaccines for injection are generally killed virus vaccines and are allowed, however, intranasal influenza vaccines (e.g., FluMist®) are live attenuated vaccines and are not allowed.
a. Note: Available COVID-19 vaccines do not contain live virus.
10. Has a history or current evidence of any condition, therapy, or laboratory abnormality that:
1. Will be unfavorable for the administration of study drug
2. Will affect the explanation of drug toxicity or AEs
3. Will interfere with the patient's participation for the full duration of the study
4. In the opinion of the treating Investigator, deems participation not in the best interest of the patient
11. Has serious or uncontrolled medical disorders that do not make it in the best interest of the patient to participate, in the opinion of the treating Investigator.
12. Has known psychiatric, alcohol abuse, or substance abuse disorders that would in the opinion of the treating investigator interfere with cooperating with the requirements of the study.
13. Is a person deprived of their liberty by a judicial or administrative decision, or an adult person subject to a legal protection measure.
14. Is a solid organ transplant recipient.
15. Patients with tumors that are located near critical structures, such as the carotid artery or portal vein, or scalp lesions presenting with moderate to extensive bone erosion and tumors that may have invaded the heart, great vessels, or other critical structures will not be eligible because these areas should not be injected. Injection through an ulcerated area of a lesion should be avoided.
16. Known additional malignancy that is progressing or requires active treatment (patients with definitively treated malignancies and low risk of recurrence, or patients with low risk of progression (such as indolent lymphomas) may be eligible after discussion with the PI).
17. Active or untreated central nervous system (CNS) metastases.
18. Active autoimmune disease requiring systemic therapy within the past 2 years, not including endocrinopathies or vitiligo.
19. History of non-infectious pneumonitis or interstitial lung disease.
20. Clinically significant hemoptysis or tumor-associated bleeding within 2 weeks prior to study treatment initiation.
21. Clinically significant cardiovascular disease (i.e., including myocarditis or congestive heart failure (defined as New York Heart Association Functional Classification III or IV), or unstable angina, serious uncontrolled cardiac arrhythmia, cerebral vascular accident, or myocardial infarction within 6 months of treatment.).
22. Use of anti-coagulation medication that cannot be held, at the discretion of the treating investigator, for the baseline biopsy and for surgical resection.
