The appearance of modulators immune synapse in clinical practice has become a revolution in metastatic skin melanoma treatment. However, blockade PD-1 allows to achieve objective response in only 30–40 % of patients. Recently, many mechanisms of primary resistance of melanoma to immunotherapy studied, they related both to the characteristics of the tumor and the tumor microenvironment. The response to anti-PD-1 therapy usually is durable, but acquired resistance emerges in 25 % of patients, who had an objective response to this treatment. This review will describe the main mechanisms of resistance to anti-PD-1 therapy in metastatic skin melanoma and possible ways of their overcoming.

Introduction. PARP inhibitors demonstrated high efficacy in BRCA1/2-associated Her2-negative metastatic breast cancer (BC). They were included in the current standard chemotherapy regimen and recognized as a priority option for the treatment of such tumours following the results of clinical studies.Aim. Review the experience with talazoparib (Talzenna) in the real-world clinical practice of 6 medical centers in Russia.Materials and methods. The review included data from 29 patients with HER2-negative metastatic breast cancer associated with a gBRCA mutation, who have been receiving talazoparib therapy in 6 medical centers of Russia since April 2021. Talazoparib was given at the standard dose 1 mg once daily, the dose was reduced, if any adverse event developed.Results. The median age of the patients was 50 years. 23 patients had a BRCA1 mutation, 5 patients had a BRCA2 mutation and one of the patients had a PALB2 mutation. Prior to starting talazoparib therapy, patients had received up to 9 lines of therapy for metastatic disease, the median was 1 line. The median follow-up period at that time was only 4.6 months. The median recurrence-free survival (RFS) was not reached. Progression was observed in 10 patients with a treatment period of 1 to 7.5 months, 19 patients continued to receive PARP inhibitor therapy without signs of disease progression, with a treatment period of 2 to 18 months. The objective response rate (ORR) was 57.2%, the clinical efficacy was confirmed in 85.7% of cases. The subgroup analysis showed that the lowest efficacy of therapy was reported in the group of patients, who had received prior therapy with platinum-based drugs, the median progression-free time (mPFT) was 4.5 months. (95% CI: 1.79-9.2). While for patients who had not received the prior platinum drug regimens, the median was not reached. Haematologic toxicities were common adverse events (AEs) for the talazoparib therapy, which were reported in 34.5% of cases. Transfusions of blood components were required in 3 patients, one of them required them repeatedly. All dose modifications were due to hematological toxicities. 7 patients (24.1%) required a dose reduction and 3 patients (10.3%) - repeated dose reduction.Conclusions. Testing for BRCA1/2 mutations in Her2-negative mBC should be a mandatory diagnostic procedure. Talazoparib therapy is an effective and safe treatment option for patients with gBRCAmut HER2-mBC.

Tumor-infiltrating lymphocytes (TILs) play a key role in the formation of anti-tumor immunity and, as studies have shown, can be one of the markers of treatment effectiveness and cancer prognosis. The aim was to study the subpopulation composition of the lymphoid infiltrate in early luminal breast cancer in patients receiving neoadjuvant chemotherapy (NACT) and its effect on achieving a pathological complete response (pCR). Materials and methods. We included 24 patients who received anthracycline-taxane-contain-ing preoperative chemotherapy. The subpopulation composition of TIL was assessed in core-biopsy samples before starting NACT in all patients; after treatment, the assessment was made on postoperative material. The analysis was carried out by flow cytometry. Clinical and immunological assessment was carried out for the following seven subpopulations of lymphocytes: CD3+, CD3+CD4+, CD3+CD8+, CD4+CD127+CD25+, CD3 CD19+ CD3CD16+CD56+, CD3+CD16+CD56+. Results. The incidence pCR was 16.7 %. It was revealed that the initial level before treatment of CD3+, CD3+CD4+, CD3+CD8+, CD4+C-D127+CD25+, CD3-CD19+, CD3 CD16+CD56+, CD3+CD16+CD56+ lymphocytes did not differ depending on the stage of the disease (II or III), tumor subtype (luminal A/B) and Ki-67 level (up to 20, 20-39, 40 and more). No correlations were found between Ki-67 and TIL content. When conducting regression analysis, it was revealed that only the level of CD3+, CD3+CD8+ and CD19+ was a significant factor in achieving a pCR (p = 0.005). When an empirical subgroup was identified, which was characterized by a high content (above or equal to the median) of CD3+, CD3+CD8+ and low (below the median) CD19+ (four observations), the frequency of pCR reached 75 %. Conclusion. Thus, the initial level of T-lymphocytes (CD3+, CD3+CD8+) and B-lymphocytes (CD19+) in the tumor, regardless of the stage of the disease, tumor subtype, ki-67 index, was a predictor of high sensitivity to neoadjuvant chemotherapy of luminal breast cancer and was associated with higher frequency of pCR.

The level of tumor mutation burden (TMB) is a predictive factor of immune checkpoints that determines the potential effectiveness of immune checkpoint inhibitors and indications for their prescription regardless of the type of tumor in adults and children. However, the prevalence of tumors with high TMB in the pediatric population has not been well studied. Objective of the research: to assess the detection frequency of high TMB (>10 mutations per megabase) in pediatric hepatocellular carcinoma (HCC). Materials and methods of research: Next Generation Sequencing, Ion AmpliSeq™ Comprehensive Cancer Panel (409 genes) of tumor DNA samples from 4 children with HCC was performed. The calculation of the mutational load was carried out according to the work of Z.R. Chalmers et al. Results: out of 4 analyzed samples, TMB levels have lower cut-off value than needed for the immunity checkpoint inhibitors for 2 patients to administer: 5,9 mut/MB (primary tumor), 9,2 mut/MB (metastasis), while in 2 other patients the TMB has level above the threshold – 10,9 mut/MB (primary tumor) and 48,5 mut/MB (relapse metastasis), respectively. Conclusion: this paper presents the initial experience of estimation of the TMB level in children with HCC. In our case series report, the level allowing the prescription of immunotherapy (>10 mut/MB) was observed in 2 patients. Further research on a larger cohort of patients is useful to assess the role of mutational burden in disease prediction and effectiveness of immunotherapy.

Background. Combination of gemcitabine, metronomic capecitabine and mitotane (GemCap + m) is the most studied regimen in second and subsequent lines of therapy for advanced adrenocortical cancer (ACC). Previously published studies do not give a definitive answer to the question- what plays a key role in realizing the response to treatment: chemotherapy or mitotane in therapeutic concentration.Aim. Evaluation the efficacy and safety of GemCap + m combination with the standard dosing regimen of capecitabine in patients with metastatic ACC.Materials and methods. This retrospective single-center clinical study included patients over 18 years of age with histologically confirmed ACC with disease progression after completion of platinum-containing therapy. They received chemotherapy regimen gemcitabine 800 mg/m2 for days 1, 8 and capecitabine 1000 mg/m2 orally 2 times at days 1–14 of the 21-day cycle with mitotane. we evaluated objective response, stabilization of disease, 6-months disease control rate and median progression-free and overall survival. Radiological assessment according to RECIST 1.1 criteria was carried out every 6–8 weeks of treatment.Results. The study included 25 patients. mitotane concentration above 14 ng/mL was achieved in 22 (88 %) patients, of which 21 (84 %) reached therapeutic concentration in previous treatment lines. 80 % of patients received treatment as 2nd line, 20 % as 3rd and subsequent lines. The objective responses and disease stabilization was observed in 1 (4 %) and 11 (44 %) of patients, respectively. Disease control for at least 6 months rate was 24 %. median progression-free and overall survival were 3.2 months and 12.17 months, respectively. Toxicity grade 3–4 was observed in 28 % of patients. gemcitabine dose reductions due to thrombocytopenia grade 1–2 were required in 2 cases (8 %), no capecitabine reductions were necessary.Conclusion. This study demonstrates the effectiveness of a new dose regimen of chemotherapy GemCap + m in the second and subsequent lines of therapy for metastatic ACC. The progression of the disease against the background of previous lines of therapy at a therapeutic concentration of mitotane in the majority of patients indicates the effectiveness of the chemotherapeutic component of gemCap in a cohort of patients resistant to platinum and mitotane.