Introduction: A high proportion of metastatic melanoma patients do not respond to immune checkpoint inhibitors (ICI), and until now, no validated biomarkers for response and survival have been known. Methods: We performed a retrospective analysis of outcomes in patients with metastatic melanoma treated with first-line ICI at the Institute of Oncology Ljubljana from January 2018 to December 2020. The immune-related adverse events (irAEs) and serum immune-inflammation parameters (neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (LR), systemic immune-inflammation index (SII) and pan-immune-inflammation value (PIV)) were analyzed as potential biomarkers for response and survival. Survival rates were calculated using the Kaplan–Meier method and then compared with the log-rank test. Multivariate regression Cox analysis was used to determine independent prognostic factors for progression-free survival (PFS) and overall survival (OS). Results: Median follow-up was 22.5 months. The estimated median progression-free survival (PFS) was 15 months (95% CI 3.3–26.2). The two-year survival rate (OS) was 66.6%. Among 129 treated patients, 24 (18.6%) achieved complete response, 28 (21.7%) achieved partial response, 26 (20.2%) had stable disease and 51 (39.5%) patients experienced a progressive disease. There was a higher response rate in patients with irAEs (p < 0.001) and high NLR before the second cycle of ICI (p = 0.052). Independent prognostic factors for PFS were irAE (HR 0.41 (95% CI 0.23–0.71)), SII before the first cycle of ICI (HR 1.94 (95% CI 1.09–3.45)) and PLR before the second cycle of ICI (HR 1.71 (95% CI 1.03–2.83)). The only independent prognostic factor for OS was SII before the first cycle of ICI (HR 2.60 (95% CI 0.91–7.50)). Conclusions: Patients with high pre-treatment levels of SII had a higher risk of progression and death; however, patients with irAEs in the high-SII group might respond well to ICI. Patients who develop irAEs and have high NLRs before the second ICI application have higher rates of CR and PR, which implicates their use as early biomarkers for responsiveness to ICI.

Upon first exposure to cetuximab, hypersensitivity reactions can occur. We aimed to assess the utility of the basophil activation test (BAT) to alpha-gal and cetuximab for predicting severe reactions. We prospectively recruited 38 patients and evaluated sIgE to alpha-gal in all patients before the first application of cetuximab. In all alpha-gal-sensitized patients, we evaluated skin tests to meat extracts, gelatine, and cetuximab and performed BAT with alpha-gal and cetuximab. In 24% (9/38) of patients, sIgE to alpha-gal was >0.10 kUA/L, and 8/9 reacted to the cetuximab. Basophil activation tests with alpha-gal were positive in all sensitized patients and were higher in those with severe reactions (18.3% in grade 4 [n = 4] vs. 1.8% in grade 2 [n = 3] or no reaction [n = 1] at 3.3 ng/mL of alpha-gal; p = 0.03). All patients with severe grade 4 reactions had a positive CD63 BAT response to cetuximab compared to patients with moderate or no reaction, who all had negative BAT (57.7% vs. 0.9% at 500 µg/mL, 63.2% vs. 4.1% at 100 µg/mL, 58.2% vs. 2.7% at 10 µg/mL, and 32.1% vs. 3.3% at 1 µg/mL of cetuximab, respectively; p ≤ 0.001). In summary, before initiating cetuximab treatment, sIgE to alpha-gal should be assessed in all patients. To predict the severity of the reaction and to assess the risk of cetuximab-induced anaphylaxis, we should perform BATs with alpha-gal or more discriminative BATs with cetuximab.

Background: Vismodegib is a first-in-class inhibitor of the hedgehog pathway for treatment of locally advanced basal cell carcinoma (laBCC) and metastatic BCC. Objectives: The purpose of this study is to report outcomes of patients with laBCC, with basal cell carcinoma nevus syndrome (Gorlin Goltz syndrome [G-G Syn]) treated with vismodegib in routine clinical practice in Slovenia in 8.3-year period. Methods: In this retrospective cohort study, we analyzed baseline characteristics, outcomes, and treatment-related adverse events from locally advanced BCC. The patients were divided into two cohorts: 39 laBCC or multiple BCC patients and 7 patients with G-G Syn who were treated with vismodegib from November 2012 till January 2021. Results: During 100-month period, 46 patients were diagnosed with laBCC (26), multiple BCC (13), and G-G Syn (7), all inappropriate for surgery or radiotherapy. Baseline characteristics: median age was 72.8 years in laBCC + multiple BCC cohort and 47.4 years in G-G Syn cohort. The objective response rate was 80% in laBCC + multiple BCC and 86% in G-G Syn cohort. Disease control rate (DCR) was 95% in laBCC + multiple BCC and 100% in G-G Syn cohort. Median duration of treatment was 9.9 months (range: 1.5–43.1) in laBCC and multiple BCC cohort and 19.5 months (range: 3.6–94.1) in G-G Syn cohort. Majority of treatment-emergent adverse events (TEAEs) in laBCC or multiple BCC cohort were grade 1 or 2 (96%), only 4% of AEs were grade 3. Majority of TEAEs in G-G Syn cohort were also grade 1 or 2 (87%), 13% of AEs were grade 3. No grade 4 or 5 vismodegib-related AEs were reported. Conclusion: Vismodegib has shown meaningful efficacy with DCR from 95% to 100% in patients with laBCC, multiple BCC, and G-G Syn in Slovenia. TEAEs were successfully alleviated with multidisciplinary approach and early supportive care.

Background: Immunotherapy has been successful in treating advanced melanoma, but a large proportion of patients do not respond to the treatment with immune checkpoint inhibitors (ICIs). Preclinical and small cohort studies suggest gastrointestinal microbiome composition and exosomal mRNA expression of PD-L1 and IFNγ from the primary tumor, stool and body fluids as potential biomarkers for response. Methods: Patients treated with immune checkpoint inhibitors as a first line treatment for metastatic melanoma are recruted to this prospective study. Stool samples are submitted before the start of treatment, at the 12th (+/−2) week and 28th (+/−2) week, and at the occurrence of event (suspected disease progression/hyperprogression, immune-related adverse event (irAE), deterioration). Peripheral venous blood samples are taken additionally at the same time points for cytologic and molecular tests. Histological material from the tumor tissue is obtained before the start of immunotherapy treatment. Primary objectives are to determine whether the human gastrointestinal microbiome (bacterial and viral) and the exosomal mRNA expression of PD-L1 and IFNγ and its dynamics predicts the response to treatment with PD-1 and CTLA-4 inhibitors and its association with the occurrence of irAE. The response is evaluated radiologically with imaging methods in accordance with the irRECIST criteria. Conclusions: This is the first study to combine and investigate multiple potential predictive and prognostic biomarkers and their dynamics in first line ICI in metastatic melanoma patients.

Background. The aim of the study was to estimate the direct medical costs of metastatic colorectal cancer (mCRC) treated at the Institute of Oncology Ljubljana and to question the healthcare payment system in Slovenia. Methods. Using an internal patient database, the costs of mCRC patients were estimated in 2009 by examining (1) mCRC direct medical related costs, and (2) the cost difference between payment received by Slovenian health insurance and actual mCRC costs. Costs were analysed in the treatment phase of the disease by assessing the direct medical costs of hospital treatment with systemic therapy together with hospital treatment of side effects, without assessing radiotherapy or surgical treatment. Follow-up costs, indirect medical costs, and nonmedical costs were not included. Results. A total of 209 mCRC patients met all eligibility criteria. The direct medical costs of mCRC hospitalization with systemic therapy in Slovenia for 2009 were estimated as the cost of medications (cost of systemic therapy + cost of drugs for premedication) + labor cost (the cost of carrying out systemic treatment) + cost of lab tests + cost of imaging tests + KRAS testing cost + cost of hospital treatment due to side effects of mCRC treatment, and amounted to €3,914,697. The difference between the cost paid by health insurance and actual costs, estimated as direct medical costs of hospitalization of mCRC patients treated with systemic therapy at the Institute of Oncology Ljubljana in 2009, was €1,900,757.80. Conclusions. The costs paid to the Institute of Oncology Ljubljana by health insurance for treating mCRC with systemic therapy do not match the actual cost of treatment. In fact, the difference between the payment and the actual cost estimated as direct medical costs of hospitalization of mCRC patients treated with systemic therapy at the Institute of Oncology Ljubljana in 2009 was €1,900,757.80. The model Australian Refined Diagnosis Related Groups (AR-DRG) for cost assessment in oncology being currently used is probably one of the reasons for the discrepancy between pay-outs and actual costs. We propose new method for more precise cost assessment in oncology.

Immune checkpoint inhibitors have revolutionized the treatment of patients with unresectable metastatic malignant melanoma. In addition to systemic side effects, several usually mild ocular adverse effects have been reported. We report a case of rarely reported vision-threatening bilateral panuveitis with serous retinal detachment, thickened choroid, and chorioretinal folds associated with dabrafenib and trametinib targeted therapy for B-Raf proto-oncogene serine/threonine kinase (BRAF) mutant metastatic cutaneous melanoma. A 59-year-old female patient with metastatic melanoma treated with dabrafenib and trametinib presented with blurry vision and central scotoma lasting for 3 d in both eyes. Clinical examination and multimodal imaging revealed inflammatory cells in the anterior chamber, mild vitritis, bullous multiple serous retinal detachments, and chorioretinal folds in both eyes. Treatment with dabrafenib and trametinib was suspended, and the patient was treated with topical and intravenous corticosteroids followed by oral corticosteroid treatment with a tapering schedule. One and a half months after the disease onset, ocular morphological and functional improvement was noted. Due to the metastatic melanoma dissemination, BRAF/mitogen-activated protein kinase inhibitors were reintroduced and some mild ocular adverse effects reappeared, which later subsided after receiving oral corticosteroids. Patients on combination therapy with dabrafenib and trametinib may rarely develop severe bilateral panuveitis with a good prognosis. Further studies have to establish potential usefulness of ophthalmological examination for asymptomatic patients. Furthermore, appropriate guidelines for managing panuveitis associated with dabrafenib and trametinib should be established.