Angela Buonadonna

Background: Substantial inter-individual variability in imatinib systemic exposure may influence both efficacy and toxicity. Based on recommendations of the International Association for Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT), the IRCCS-CRO of Aviano started in 2018 offering physicians the opportunity to monitor plasma concentrations of imatinib and its active metabolite, norimatinib, as part of a diagnostic service for patients with Gastrointestinal Stromal Tumor (GIST). This study aims to evaluate the potential clinical utility of imatinib Therapeutic Drug Monitoring (TDM) in predicting response and toxicity in a real-world cohort of 63 patients with GIST. Methods: Imatinib and its active metabolite norimatinib trough concentrations (C_min) were quantified using a validated LC–MS/MS method. Associations between drug exposure and clinical–demographic characteristics, treatment-related toxicity, and progression-free survival (PFS) were evaluated. Results: A total of 437 plasma samples from 63 patients were collected. Marked inter- and intra-patient variability in imatinib exposure was observed (43% and 31% respectively); 67% of patients receiving 400 mg/day had a C_min below the recommended target concentration (1100 ng/mL). Female sex was significantly associated with higher imatinib exposure (median C_min 1114 vs. 786 ng/mL in males; p = 0.0018). Combined age–sex analysis showed a significant difference between women and men < 60 years (1041 vs. 668 ng/mL; p = 0.0068, Bonferroni-adjusted). A strong exposure–toxicity relationship emerged, with higher imatinib levels in samples collected at toxicity occurrence vs. the others (1728 vs. 927 ng/mL; p < 0.0001), without a direct association between sex and toxicity. No significant association between C_min and PFS was observed; however, disease progression was more frequent in patients with C_min < 500 ng/mL and absent in those with C_min >1500 ng/mL (60% vs. 0%, respectively). Conclusions: TDM was found to be a potentially useful tool for predicting clinically relevant toxicity and outcome. Sex and age significantly influence exposure, supporting tailored dosing strategies.

The immunohistochemical assessment of mismatch repair (MMR) proteins represents a pivotal screening tool for identifying Lynch syndrome (LS)-related cancers, as the loss of their expression often indicates MMR dysfunction associated with genetic or epigenetic alterations. Frequently, LS-related colorectal cancers present germline pathogenic variants in the MLH1 or MSH2 genes, which result in the simultaneous immunohistochemical loss of MLH1 and PMS2 or MSH2 and MSH6 proteins expression, respectively. Less commonly observed is the single involvement of the MSH6 or PMS2 proteins expression, indicative of the presence of germline pathogenic variants in the corresponding genes. Extremely rarely reported are the null immunohistochemistry phenotypes represented by the complete loss of expression of all MMR proteins. The molecular mechanisms contributing to the raising of this latter uncommon immunohistochemical phenotype are derived from the combination of pathogenic germline variants in MMR genes with the somatic hypermethylation of the MLH1 gene promoter. This study focuses on elucidating the molecular cascade leading to the development of the null immunohistochemical phenotype, providing valuable insights into understanding the sequential molecular events driving the LS-associated tumorigenesis, which may have pivotal implications in the clinical management of patients with LS-related cancers.

Doxorubicin is a widely used anticancer agent as a first-line treatment for various tumor types, including sarcomas. Its use is hampered by adverse events, among which is the risk of dose dependence. The potential cardiotoxicity, which increases with higher doses, poses a significant challenge to its safe and effective application. To try to overcome these undesired effects, encapsulation of doxorubicin in liposomes has been proposed. Caelyx and Myocet are different formulations of pegylated (PLD) and non-pegylated liposomal doxorubicin (NPLD), respectively. Both PLD and NPLD have shown similar activity compared with free drugs but with reduced cardiotoxicity. While the hand–foot syndrome exhibits a high occurrence among patients treated with PLD, its frequency is notably reduced in those receiving NPLD. In this prospective, multicenter, one-stage, single-arm phase II trial, we assessed the combination of NPLD and ifosfamide as first-line treatment for advanced/metastatic soft tissue sarcoma (STS). Patients received six cycles of NPLD (50 mg/m²) on day 1 along with ifosfamide (3000 mg/m² on days 1, 2, and 3 with equidose MESNA) administered every 3 weeks. The overall response rate, yielding 40% (95% CI: 0.29–0.51), resulted in statistical significance; the disease control rate stood at 81% (95% CI: 0.73—0.90), while only 16% (95% CI: 0.08–0.24) of patients experienced a progressive disease. These findings indicate that the combination of NPLD and ifosfamide yields a statistically significant response rate in advanced/metastatic STS with limited toxicity.

Metastatic soft-tissue sarcomas (mSTS) encompass a highly heterogeneous group of rare tumours characterized by different clinical behaviours and outcomes. Currently, prognostic factors for mSTS are very limited, posing significant challenges in predicting patient survival. Within a cohort of 39 mSTS patients undergoing trabectedin treatment, it was remarkable to find one patient who underwent 73 cycles of trabectedin achieving an unforeseen clinical outcome. To identify contributing factors to her exceptional long-term survival, we have explored circulation metabolomics and biohumoral biomarkers to uncover a potential distinct host biochemical phenotype. The long-term survival patient compared with the other mSTS patients exhibited a distinctive metabolic profile characterized by remarkably higher levels of ursodeoxycholic acid (UDCA) derivatives and vitamin D and lower levels of lithocholic acid (LCA) derivatives, as well as reduced levels of inflammatory C-Reactive Protein 4 (C-RP4) biomarker. Despite its exploratory nature, this study reveals a potential association between specific bile acid metabolic profiles and mSTS patients’ prognosis. Enhanced clinical understanding of the interplay between bile acid metabolism and disease progression could pave the way for new targeted therapeutic interventions which may improve the overall survival of mSTS patients.

Background: Chronic oral anticancer therapies, are increasingly prescribed and present new challenges including the enhanced risk of overlooked drug-drug interactions (DDIs). Lengthy treatments and patients’ management by different professionals can lead to serious prescribing errors that therapeutic drug monitoring (TDM) can help identifying thus allowing a more effective and safer treatment of patients with polypharmacy. Objectives: This report aims to exemplify how an intensified pharmacological approach could help in the clinical monitoring of patients on chronic treatments. Methods: A patient with gastrointestinal stromal tumor was referred to our clinical pharmacology service due to tumor progression while on imatinib therapy. The investigation was based on TDM, pharmacogenetics, DDI evaluation and Circulating tumor DNA (ctDNA) analysis. The patient underwent repeated blood samplings to measure imatinib and norimatinib plasma concentrations through a validated LC-MS/MS method. Polymorphisms affecting genes involved in imatinib metabolism and transport were investigated using SNPline PCR Genotyping System. Drug-drug interactions were evaluated though Lexicomp. ctDNA analysis was performed on MiSeq platform. Results: TDM analysis revealed that the patient was underexposed to imatinib (C_min = 406 ng/mL; target C_min = 1100 ng/mL). Subsequent DDI analysis highlighted a dangerous interaction with carbamazepine, via CYP3A4 and P-gp strong induction, omitted at the time of imatinib treatment start. No relevant pharmacogenetic variants were identified and appropriate compliance to treatment was ascertained. ctDNA monitoring was performed to assess potential tumor-related resistance to imatinib. Carbamazepine was cautiously switched to a non-interacting antiepileptic drug, restoting IMA plasma concentration (i.e. C_min = 4298 ng/mL). The progression of the disease, which in turn led to the patient’s death, was also witnessed by an increasing fraction of ctDNA in plasma. Conclusion: The active pharmacological monitoring allowed the identification of a dangerous previously over-looked DDI leading to IMA under-exposure. The switch to a different antiepileptic treatment, reversed the effect of DDI, restoring therapeutic IMA plasmatic concentrations. Graphical

Adequate imatinib plasma levels are necessary to guarantee an efficacious and safe treatment in gastrointestinal stromal tumor (GIST) and chronic myeloid leukemia (CML) patients. Imatinib is a substrate of the drug transporters ATP-binding cassette subfamily B member 1 (ABCB1) and ATP-binding cassette subfamily G member 2 (ABCG2) that can affect its plasma concentration. In the present study, the association between three genetic polymorphisms in ABCB1 (rs1045642, rs2032582, rs1128503) and one in ABCG2 (rs2231142) and the imatinib plasma trough concentration (C_trough) was investigated in 33 GIST patients enrolled in a prospective clinical trial. The results of the study were meta-analyzed with those of other seven studies (including a total of 649 patients) selected from the literature through a systematic review process. The ABCG2 c.421C>A genotype demonstrated, in our cohort of patients, a borderline association with imatinib plasma trough levels that became significant in the meta-analysis. Specifically, homozygous carriers of the ABCG2 c.421 A allele showed higher imatinib plasma C_trough with respect to the CC/CA carriers (C_trough, 1463.2 ng/mL AA, vs. 1196.6 ng/mL CC + AC, p = 0.04) in 293 patients eligible for the evaluation of this polymorphism in the meta-analysis. The results remained significant under the additive model. No significant association could be described between ABCB1 polymorphisms and imatinib C_trough, neither in our cohort nor in the meta-analysis. In conclusion, our results and the available literature studies sustain an association between ABCG2 c.421C>A and imatinib plasma C_trough in GIST and CML patients.

Background: Emerging data suggest that gender-related immune system composition affects both immune response and efficacy of immunotherapy in cancer patients (pts). This study aimed to investigate the sex-related prognostic role of MLR in metastatic colorectal cancer (mCRC) pts. Methods: We analyzed a retrospective consecutive cohort of 490 mCRC patients treated from 2009 to 2018 at the Oncology Departments of Aviano and Pordenone (training set) and Udine (validation set), Italy. The prognostic impact of MLR on overall survival (OS) was evaluated with uni- and multivariable Cox regression models. The best cut-off value to predict survival was defined through ROC analyses. Results: Overall, we identified 288 males (59%) and 202 females (41%); 161 patients (33%) had a right-sided, 202 (42%) a left-sided primary, and 122 (25%) a rectal tumor. Interestingly, gender was associated with MLR (p = 0.004) and sidedness (p = 0.006). The obtained cut-off value for MLR in females and males was 0.27 and 0.49, respectively. According to univariate analysis of the training set, MLR (HR 9.07, p ≤ 0.001), MLR > 0.27 in females (HR 1.95, p = 0.003), and MLR > 0.49 in males (HR 2.65, p = 0.010) were associated with poorer OS, which was also confirmed in the validation set. In multivariate analysis, MLR > 0.27 in females (HR 2.77, p = 0.002), MLR > 0.49 in males (HR 5.39, p ≤ 0.001), BRAF mutation (HR 3.38, p ≤ 0.001), and peritoneal metastases (HR 2.50, p = 0.003) were still independently associated with worse OS. Conclusions: Males and females have a different immune response. Our study showed that high MLR, both in males and females, is an unfavorable Independent prognostic factor. Further prospective studies are needed to confirm these data.

Microenvironmental factors such as non-classical human leukocyte antigen-G (HLA-G) have been associated with cancer invasiveness and metastatic progression. HLA-G expression has been associated with specific single-nucleotide polymorphisms (SNP) in HLA-G 3′untranslated region (UTR) in several diseases. The primary aim was to investigate the predictive role of HLA-G polymorphisms on treatment efficacy in metastatic colorectal cancer (mCRC) patients homogeneously treated with first-line FOLFIRI (irinotecan, 5-fluorouracil, and leucovorin) and their association with soluble HLA-G (sHLA-G) plasma concentration. HLA-G 3′UTR was sequenced in 248 patients. A set of eight polymorphisms and related haplotypes were analyzed for their association with best tumor response, overall survival (OS), and progression-free survival (PFS). sHLA-G was measured by immunoassay in 35 available plasma samples and correlated with HLA-G 3′UTR polymorphisms/haplotypes. Our results showed that carriers of rs371194629 (+2960)-Ins allele were at risk for lack of complete response (hazard ratio (HR):0.29, p_BH = 0.0336), while carriers of rs1710 (+3010)-G allele (rs1063320 (+3142)-C allele in linkage-disequilibrium), and rs9380142 (+3187)-G allele had a higher chance of complete response according to additive models (HR:4.58, p_BH = 0.0245; HR:3.18, p_BH = 0.0336, respectively). The combination of rs371194629-Del, rs1710-G, and rs9380142-G alleles forms the UTR1 haplotype. Patients who were carriers of UTR1/UTR-1 diplotype had a greater chance of complete response to therapy (HR:10.59, p_BH = 0.0294). The same three beneficial alleles showed a trend toward higher pre-treatment sHLA-G plasma levels, supporting a functional role for polymorphisms in protein secretion. In conclusion, genetic variants of HLA-G are associated with treatment efficacy in mCRC patients treated with first-line FOLFIRI. This finding shed light on the combined effect of this immune system factor and chemotherapy in cancer patients.

The epidermal growth factor receptor inhibitor (EGFRIs) treatments are commonly associated with the development of adverse skin effects. This study aims to investigate the lipid composition change in sebum during cetuximab-based treatment in an attempt to identify specific metabolic signatures useful in predicting the occurrence of severe skin toxicity. Sebum from 30 metastatic colorectal cancer (mCRC) patients was collected at three time points during the targeted therapy by the application of Sebutape^® on the forehead, and the major lipid classes were analyzed and quantified by ¹H-NMR. Univariate analysis was performed to reveal significant alterations among patients in sebum production as well as lipid composition and over the course of cetuximab therapy. A transient but significant decrease in sebum production associated with a reduction in the relative content of triglycerides (TG) and squalene (SQ) was found to be induced by cetuximab administration. The reduction of these two lipid classes was also found to be associated with the severity of skin rash experienced by patients. The results of this study indicate that cetuximab-based treatment can reduce sebum gland activity, leading to an overall decrease in sebum production and the induction of specific modifications to its composition. The extent of the loss of skin barrier function may be important for determining the severity of skin toxicity development.