Study of RP3 Monotherapy and RP3 in Combination With Nivolumab in Patients With Solid Tumours

Inclusion Criteria:

* Patients with advanced or metastatic non-neurological solid tumors, who have progressed on standard therapy or cannot tolerate standard therapy, or for whom there is no standard therapy preferred to enrollment in a clinical study
* All patients must consent to provide archival tumor biopsy samples within 12 months, or a fresh tumor biopsy is needed. Patients must also consent to provide on treatment biopsies as per protocol
* At least one measurable tumor ≥ 1 cm in longest diameter (or shortest diameter for lymph nodes)
* At least one injectable tumor ≥ 1 cm in longest diameter or injectable tumors which in aggregate are ≥ 1 cm in longest diameter (or shortest diameter for lymph nodes
* Have an Eastern Cooperative Oncology Group (ECOG) performance status 0-1

Note: Predefined inclusion criteria may apply for each additional expansion cohort.

Exclusion Criteria:

* Prior treatment with an oncolytic virus therapy
* History of viral infections according to the protocol
* Systemic infection requiring intravenous (IV) antibiotics
* Active significant herpetic infections or prior complications of HSV-1 infection (e.g., herpetic keratitis or encephalitis)
* Requires intermittent or chronic use of systemic antivirals

  a. Hepatocellular carcinoma patients with a diagnosis of hepatitis B must be off antiviral therapy for at least 4 weeks prior to enrollment . Hepatocellular carcinoma patients with a history of or ongoing hepatitis C infection must have completed treatment for hepatitis C at least 1 month prior to study enrollment and hepatitis
* History of interstitial lung disease
* Has a history of (non-infectious) pneumonitis that required steroids or has current pneumonitis

Additional Exclusion Criteria for Patients Enrolled in Part 2 (Expansion Cohorts):

* History of life-threatening toxicity related to prior immune treatment or any other antibody or drug specifically targeting T-cell co-stimulation or immune checkpoint pathways
* Treatment with botanical preparations within 2 weeks prior to treatment.
* Active, known, or suspected autoimmune disease requiring systemic treatment.
* History of interstitial lung disease.
* Severe hypersensitivity to another monoclonal antibody.
* Has received prior radiotherapy within 2 weeks of start of study treatment.
* Has received a live vaccine within 28 days prior to the first dose of study treatment.
* History of (non-infectious) pneumonitis that required steroids or has current pneumonitis.
* History of myocarditis or congestive heart failure within 6 months of screening.
* Has a serious or uncontrolled medical disorder.
* Has a QT interval corrected for heart rate using Fridericia's formula (QTcF) \> 480 msec, except for right bundle branch block.