VV-GMCSF-Lact(Oncostar)

Purpose of the study is to evaluate the safety, tolerability and pharmacokinetic parameters of the drug based on double recombinant vaccinia virus VV-GMCSF-Lact, in patients with recurrent/refractory metastatic breast cancer in successive cohorts with dose escalation with single and multiple administration.
The study provides: determination of the maximum tolerated dose of the drug and the frequency, nature, intensity and duration of adverse events connected with the use of the study drug in escalating doses; detection of dose-limiting toxicity, its severity, duration and reversibility; determination of the profile of virus pharmacokinetics and antivirus antibodies; assessment of the objective response to the treatment.
Stage 1,: The virus drug is administered intratumorally once according to a "3+3" design in the dosage from 1*107 PFU to 10*107 PFU. The frequency of dose-limiting toxicity (DLT) will be evaluated (non-hematological toxicity III degree and above; development of febrile neutropenia and body temperature > 38.3°C more than two days after drug administration; thrombocytopenia III degree and above and/or hemorrhagic complications; repeated increase in ALT and/or AST activity is more than 4 times higher than the normal upper limit).
Escalation to the next level occurs if there is no DLT in the entire cohort under study. The study stops if the incidence of DLT in a cohort of 3 patients is 2 or 3. The maximum tolerated dose (MTD) will be considered the studied dose that is lower than the dose which DLT was determined. Stage 1 assumes randomization of no more than 36 patients.
Stage 2, multiple administration: According to Stage 1 the study will move to the second stage if there will be possibility to study at least one dosage regimen based on the previously studied dose. At Stage 2 two doses in ascending order below the MTD and MTD are planned to be used. Escalation to the next level occurs if no DLT is observed during dosing of the first three patients. If DLT develops and drug administration is discontinued, the patient is not excluded from the study, her drug administration visits are skipped, and she goes through all follow-up visits. The drug will be administered intratumorally 1 time per week for 4 weeks in 3 dosages: MTD and 2 lower dosages. Each cohort will include up to 6 patients in a "3+3" design. It is expected to include up to 24 patients, taking into account the possible inclusion of patients to replace those who left.