A Clinical Study of the Pharmacokinetics and Safety of BCD-263 and Opdivo® as Monotherapy in Subjects With Advanced Melanoma of the Skin

Inclusion Criteria:

1. Age ≥18 years at the time of signing the informed consent form;
2. Body weight 60 to 90 kg.
3. Histologically confirmed melanoma with the following prognostic characteristics:

• LDH <ULN of local laboratory (enrollment of subjects with LDH <2x ULN of locallaboratory is allowed until the number of subjects with LDH >ULN is 30% of thetotal population of randomized subjects. The Sponsor will inform when enrollmentof subjects is limited by LDH level <ULN of the local laboratory).
• Absence, according to the Investigator, of clinically significant symptomsassociated with the tumor.
• Absence, according to the Investigator, of rapidly progressing metastaticmelanoma.

4. Newly diagnosed advanced unresectable (stage III) or metastatic disease (stage IV), orprogressive disease during / relapsing after radical treatment.

Exclusion Criteria:

1. Indications for radical treatment (surgery, radiation therapy).
2. Uveal or mucosal melanoma.
3. Previous systemic anticancer therapy for advanced unresectable or metastatic skinmelanoma (a history of neoadjuvant or adjuvant therapy is allowed, provided that thetherapy was completed at least 12 weeks before randomization).
4. Active CNS metastases and/or carcinomatous meningitis.
5. Previous invasive cancer, excluding diseases treated with potentially curative therapywith no evidence of recurrence for 2 years from the start of this therapy (subjectswith radically resected basal cell carcinoma of the skin, superficial bladder cancer,squamous cell carcinoma of the skin, cervical carcinoma in situ of the uterus andother carcinomas in situ may be included).
6. Subjects with severe concomitant disorders, life-threatening acute complications ofthe primary disease (including massive pleural, pericardial, or peritoneal effusionsrequiring intervention, pulmonary lymphangitis, bleeding or organ perforation) at thetime of signing the informed consent and during the screening period.
7. Concomitant diseases and/or conditions that significantly increase the risk of adverseevents (AEs) during the study.