Inclusion Criteria:
* Signed Informed Consent Form and the subject's ability to follow the Protocol requirements;
* Age: 18 years and older at the signing of the informed consent;
* Histologically confirmed metastatic solid malignant tumors (non-small cell lung cancer, renal cell carcinoma, melanoma), refractory or recurrent after one or more courses of previous therapy and not subject to surgical treatment and radiation therapy. Melanoma - regardless of the presence and success of previous treatment;
* ECOG performance status ≤ 2;
* At least one RESICT 1.1-defined measurable target lesion;
* Completion of the previous drug treatment of the underlying disease (if applicable) at least 28 days before the first administration of GNR-051;
* Resolution or stabilization of toxicity manifestations of previous radiation or chemotherapy.
Exclusion Criteria:
* Prior treatment with anti-CTLA4 and/or anti-PD-1/PD-L1/PD-L2 agents;
* Hypersensitivity to any of the components of GNR-051;
* Progression (growth of previous, appearance of new) metastases in the brain and meninges, identified by CT or MRI, in a period of less than 56 days before the first administration of GNR-051; worsening of neurological symptoms in a patient with metastases in the brain or meninges within a period of less than 28 days before the first administration of GNR-051; or continued treatment of metastases in the brain or meninges with glucocorticosteroids (GCS) for a period of less than 14 days before the first administration of GNR-051 (except for a maintenance daily dose of GCS equivalent to 10 mg of prednisolone);
* Inability to conduct a biopsy according to the protocol;
* Left ventricular ejection fraction (LVEF) \<50% (EchoCG);
* The need to use anticancer drugs, other than the investigated one, for at least 3 months after the first administration of the drug;
* Patients who need radiotherapy or surgical therapy;
* Previous radiotherapy ended \<28 days before the first dose administration;
* Previous stereotactic radiation therapy ended \<14 days before the first dose administration;
* Therapeutic use of radiopharmaceuticals ≤56 days prior to first dose administration;
* Patients who have received another experimental drug (not registered in Russia) within 28 days or 5 half-lives of the experimental drug before the first administration GNR-051;
* Patients who have received vaccines against infectious diseases (eg influenza virus) within 28 days before the first administration of the drug;
* Patients who have received narcotic analgesics \<14 days before the first administration of GNR-051;
* Surgery with general anesthesia \<28 days before the first administration of GNR-051.
* Surgery with regional / epidural anesthesia \<72 hours and / or not all post-anesthetic AEs resolved before the first administration of GNR-051;
* Laboratory parameters:
* Absolute leukocyte count \<2000 / μL;
* Absolute neutrophil count \<1500 / μL;
* Absolute platelet count \<100 × 103 / μL;
* Hemoglobin level \<9.0 g / dL;
* Creatinine\> 2 mg / dL;
* AST\> 2.5 × the upper limit of normal (ULN) in the absence of liver metastases, or\> 5 × ULN with the liver metastases;
* ALT \> 2.5 × ULN in the absence of liver metastases, or\> 5 × ULN with the liver metastases;
* Total bilirubin\> 2 × ULN;
* Systemic autoimmune diseases (including but not limited to SLE, Crohn's disease, ulcerative colitis, systemic scleroderma, inflammatory myopathy, mixed connective tissue disease, overlap syndrome, etc.);
* Concomitant cancer (except for basal or squamous cell carcinoma of the skin, superficial bladder cancer, carcinoma in situ of the cervix, prostate, or breast);
* Patients who need therapy with corticosteroids or other immunosuppressants;
* Systemic therapy with corticosteroids or immunosuppressants for ≤7 days before the first administration GNR-051;
* Any other concomitant condition (e.g., medical condition, mental disorders, alcohol/drug abuse) that constitutes an unacceptable risk to the patient's health during the investigational therapy or prevents a patient from following the Protocol procedures;
* Active HBV/HCV/HIV infection;
* Pregnant or lactating female;
* Patients with reproductive potential who do not agree to practice acceptable methods of birth control throughout the entire trial period, starting from signing the informed consent and up to 6 months after the last dose of GNR-051;
* Simultaneous participation in other clinical trials.
