Surrogate endpoints for overall survival in randomized clinical trials testing immune checkpoint inhibitors: a systematic review and meta-analysis.

Introduction: There is debate on which are the best surrogate endpoint and metric to capture treatment effect on overall survival (OS) in RCTs testing immune-checkpoint inhibitors (ICIs). Methods: We systematically searched for RCTs testing ICIs in patients with advanced solid tumors. Inclusion criteria were: RCTs i) assessing PD-(L)1 and CTLA-4 inhibitors either as monotherapy or in combination with another ICI, and/or targeted therapy, and/or chemotherapy, in patients with advanced solid tumors; ii) randomizing at least 100 patients. We performed a meta-analysis of RCTs to compare the surrogacy value of PFS and modified-PFS (mPFS) for OS in RCTs testing ICIs, when the treatment effect is measured by the hazard ratio (HR) for OS, and by the HR and the ratio of restricted mean survival time (rRMST) for PFS and mPFS. Results: 61 RCTs (67 treatment comparisons and 36,034 patients) were included in the analysis. In comparisons testing ICI plus chemotherapy, HRPFS and HRmPFS both had a strong surrogacy value (R2 = 0.74 and R2 = 0.81, respectively). In comparisons testing ICI as monotherapy, HRPFS was the best surrogate, although having a moderate correlation (R2 = 0.58). In comparisons testing ICI plus other treatment(s), the associations were very weak for all the surrogate endpoints and treatment effect measures, with R2 ranging from 0.01 to 0.22. Conclusion: In RCTs testing ICIs, the value of potential surrogates for HROS was strongly affected by the type of treatment(s) tested. The evidence available supports HRPFS as the best surrogate, and disproves the use of alternative endpoints, such as the mPFS, or treatment effect measures, such as the RMST.

"Heterogeneity of treatment effect on patients' long-term outcome according to pathological response type in neoadjuvant RCTs for breast cancer."

INTRODUCTION: To provide evidence explaining the poor association between pCR and patients' long-term outcome at trial-level in neoadjuvant RCTs for breast cancer (BC), we performed a systematic-review and meta-analysis of all RCTs testing neoadjuvant treatments for early-BC and reporting the hazard ratio of DFS (HRDFS) for the intervention versus control arm stratified by pathological response type (i.e., pCR yes versus no). METHODS: The objective was to explore differences of treatment effects on DFS across patients with and without pCR. We calculated the pooled HRDFS in the two strata of pathological response (i.e., pCR yes versus no) using a random-effects model, and assessed the difference between these two estimates using an interaction test. RESULTS: Ten RCTs and 8496 patients were included in the analysis. Patients obtaining pCR in the intervention-arm had a higher, although not statistically significant, risk of DFS-event as compared with patients obtaining pCR in the control-arm: the pooled HRDFS for the experimental versus control arm was 1.23 (95%CI, 0.91-1.65). On the opposite, the risk of DFS-event was higher for control as compared with the intervention-arm in the stratum of patients without pCR: the pooled HRDFS was 0.86 (95%CI, 0.78-0.95). Treatment effect on DFS was significantly different according to pathological response type (interaction test p: 0.014). CONCLUSION: We reported new evidence that contributes to explaining the poor surrogacy value of pCR at trial-level in neoadjuvant RCTs for early-BC.

Fine-Tuning Adjuvant Endocrine Therapy for Early-Stage Breast Cancer: An Expert Consensus on Open Issues for Future Research.

After decades of research, improving the efficacy of adjuvant endocrine therapy (ET) for early-stage breast cancer becomes increasingly difficult. Beyond technological breakthroughs and the availability of new classes of drugs, further improvement of adjuvant ET will require applying a rigorous research approach in poorly investigated areas. We critically discuss some key principles that should inform future research to improve ET efficacy, including identifying specific subgroups of patients who can benefit from escalating or de-escalating approaches, optimizing available and new treatment strategies for different clinical contexts, and dissecting the direct and indirect biological effects of therapeutic interventions. Four main issues regarding adjuvant ET were identified as relevant areas, where a better application of such principles can provide positive results in the near future: (i) tailoring the optimal duration of adjuvant ET, (ii) optimizing ovarian function suppression for premenopausal women, (iii) dissecting the biological effects of estrogen receptor manipulation, and (iv) refining the selection of patients to candidate for treatments escalation.

Immune-checkpoint inhibitors in anal squamous cell carcinoma: a systematic review and meta-analysis.

INTRODUCTION: Squamous cell carcinoma of the anus (SCCA) is a rare tumor. While most patients with locally advanced disease are cured with chemo-radiotherapy, about a quarter eventually experience metastatic recurrence. Standard treatment for advanced disease is chemotherapy, but recently evidence on the activity of immunotherapy has been reported. We performed a systematic review and meta-analysis of prospective trials testing immune-checkpoint inhibitors (ICIs) in patients with SCCA. OBJECTIVE: We aimed to evaluate the overall response rate (ORR) and the disease control rate (DCR) of ICIs in patients with advanced SCCA. METHODS: We systematically searched PubMed, Embase, and Scopus, through December 31, 2022, for prospective trials assessing ICIs in patients with advanced SCCA. The primary and secondary endpoints were respectively ORR and DCR. RESULTS: Six prospective trials were included in the analysis, one of which was randomized. Overall, seven treatment arms and 347 patients have been analyzed. Five treatment arms tested ICIs as monotherapy and two arms examined ICIs in combination with cetuximab and bevacizumab, respectively. The pooled ORR was 13% (95%CI, 10%-17%), with a DCR of 57% (95%CI, 40%-74%). Results did not change in a sensitivity analysis, which excluded the two treatment arms testing the combination of ICIs with other drugs. CONCLUSIONS: The efficacy of ICIs in SCCAs is low. Combination strategies with targeted drugs or chemotherapy might represent a better therapeutic strategy for these patients. Further studies are awaited to identify resistance mechanisms to ICIs and optimize their efficacy.

Improved outcomes in women with BRAF-mutant melanoma treated with BRAF/MEK-targeted therapy across randomized clinical trials. A systematic review and meta-analysis.

Available evidence suggests that in patients with advanced BRAF V600-mutant melanoma treated with the combination of BRAF and MEK inhibitors, gender could be associated with survival outcome. We performed a systematic review and meta-analysis of all randomized clinical trials (RCTs) testing the combination of BRAF and MEK inhibitors, to assess the interaction between treatment effect and patients' gender. We searched PubMed, MEDLINE, Embase, and Scopus, for phase II and III RCTs up to January 30, 2022. We included all RCTs that enrolled patients with BRAF V600-mutant advanced cutaneous melanoma and assessed combinations of BRAF and MEK inhibitors versus BRAF inhibitor monotherapy. Our aim was to assess differences if any in treatment efficacy between men and women, measured in terms of the differences in progression-free survival (PFS) and overall survival (OS) log-hazard ratios (log-HRs). We calculated the pooled PFS- and OS-HRs with 95% confidence intervals (CIs) in men and women using a random-effects model and assessed the heterogeneity between the estimates using an interaction test. Five RCTs that enrolled a total of 2,113 patients were included in the analysis. In women, the combination of BRAF and MEK inhibitors halved the risk of progression or death as compared with BRAF inhibitor monotherapy with a pooled PFS-HR of 0.50 (95%CI 0.41-0.61). In men, the benefit obtained with BRAF and MEK inhibitors was smaller with a pooled PFS-HR of 0.63 (95%CI 0.54-0.74), P-heterogeneity = .05. A similar trend was observed for OS where the pooled OS-HR was 0.62 (95%CI 0.48-0.80) in women and only 0.78, (95%CI 0.67-0.92) in men, P-heterogeneity = 0.11. These results support meaningful gender-based heterogeneity of response to combination of BRAF and MEK inhibitors targeted therapy in patients with advanced BRAF-mutant melanoma, that should be considered in future research to improve treatment effectiveness.

Exon-18-EGFR Mutated Transformed Small-Cell Lung Cancer: A Case Report and Literature Review.

Small-cell lung cancer (SCLC) transformation from EGFR mutant adenocarcinoma is a rare entity that is considered to be a new phenotype of SCLC. While transformation from adenocarcinoma (ADC) with EGFR exon 19 deletions and exon 21 L858R point mutations has been described, to our knowledge, no cases of transformation to SCLC from exon-18-mutated ADC have been reported. We reported a clinical case of a patient with exon-18-EGFR-transformed SCLC, and we performed a systematic review of the literature.

Tailoring the optimal duration of the extended adjuvant endocrine therapy in patients with early-stage breast cancer. A systematic review and meta-analysis of randomized clinical trials.

BACKGROUND: Controversy exists regarding the optimal duration of the extended adjuvant endocrine treatment (ET) in patients with early-stage breast-cancer (eBC). We performed a systematic review and trial-level meta-analysis of all randomized clinical trials (RCTs) comparing a "limited-extended" adjuvant ET (defined as more than 5 but less than 7.5 years of treatment overall) versus a "full-extended" adjuvant ET (defined as more than 7.5 years of treatment overall) in eBC. METHODS: To be eligible, RCTs had to i) compare a "limited-extended" adjuvant ET versus a "full-extended" adjuvant ET in patients with eBC; and ii) report disease-free survival (DFS) hazard ratio (HR) according to the disease nodal-status [i.e., nodal-negative (N-ve) versus nodal-positive (N + ve)]. The primary endpoint was to assess the difference in efficacy of full-versus limited-extended ET, measured in terms of the difference in DFS log-HR, according to the disease nodal-status. Secondary endpoint was the difference in efficacy of full-versus limited-extended ET according to tumor size (i.e., pT1 vs pT2/3/4), histological grade (i.e., G1/G2 vs G3), patients' age (i.e., ≤60 vs > 60 years) and previous type of ET (i.e., aromatase inhibitors vs tamoxifen vs switch strategy). RESULTS: Three phase III RCTs fulfilled the inclusion criteria. A total of 6689 patients were included in the analysis, of which 3506 (53%) had N + ve disease. The full-extended ET provided no DFS-benefit as compared with the limited-extended ET in patients with N-ve disease (pooled DFS-HR = 1.04, 95%CI: 0.89 to 1.22; I2 = 18%). Conversely, in patients with N + ve disease the full-extended ET significantly improved DFS, with a pooled DFS-HR of 0.85 (95%CI: 0.74 to 0.97; I2 = 0%). There was a significant interaction between the disease nodal-status and the efficacy of the full-versus limited-extended ET (p-heterogeneity = 0.048). The full-extended ET provided no significant DFS-benefit as compared with the limited-extended ET in all the other subgroups analyzed. CONCLUSIONS: Patients with eBC and N + ve disease can obtain a significant DFS-benefit from the full-extended as compared with the limited-extended adjuvant ET.

Orthorexia nervosa and type 1 diabetes: results of a cross-sectional study.

AIM: Orthorexia nervosa (ON) is a condition characterized by an excessive importance attributed to the intake of healthy foods. This study was aimed at investigating the prevalence of ON in subjects with type 1 diabetes (T1D) compared to control subjects. METHODS: Patient with T1D using either flash glucose monitoring or continuous glucose monitoring were enrolled. For the selection of control group, each patient was asked to indicate one non-diabetic subject of their same sex and approximate age among colleagues at work and school. Patients and controls completed the following questionnaires: ORTO-15, Dusseldorf Orthorexie Scale (DOS), Eating Disorder Examination Questionnaire (EDE-Q) and Brief Symptom Inventory (BSI). The principal outcome was the prevalence of ON among T1D and control subjects. RESULTS: We enrolled 44 patients with T1D aged 39.7 ± 15.7 years, with BMI 24.3 ± 4.3 kg/m2, and mean HbA1c 53.5 [49-57] mmol/mol. Control subjects were similar to T1D with respect to sex, age and BMI. Thirty-two [72%] and 29 [65%] subjects among patients and controls, respectively, had ORTO15 < 40 (between-group p = 0.48). Two (4.5%) and zero subjects among patients and controls, respectively, had DOS ≥ 30 (p = 0.29). Median scores of DOS, but not of ORTO-15, were significantly higher in patients than in controls. None of the metabolic variables showed a correlation with psychometric tests in T1D. CONCLUSION: Although the prevalence of ON was not significantly higher in T1D than in controls, patients with T1D showed higher scores of some, but not all, tests assessing orthorexia, without any significant correlation with metabolic parameters.

High-dose continuous-infusion ifosfamide in advanced thymic epithelial Tumors: A TYME network study.

BACKGROUND: We reported the efficacy and safety results of high-dose, continuous-infusion Ifosfamide,in patients with advanced thymoma (TM) and thymic carcinoma (TC). METHODS: This was a multicentric, prospective study in patients with advanced TM or TC, who had progressed after at least one line of platinum-based chemotherapy. Previous treatment with an anti-angiogenesis or anti-PD(L)1 was allowed. Patients received Ifosfamide (1 g/m2/day) and sodium-2-mercaptoethanesulfonate (1 g/m2/day), as continuous infusion, via a portable pumps for 14 consecutive days. Treatment was administered every 4 weeks until progression or unacceptable toxicity, up to a maximum of 6 cycles. The primary endpoint was the overall response rate (ORR) assessed by RECIST1.1. Secondary endpoints included disease control rate (DCR), Progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Eighteen patients were enrolled from October 2020 to January 2022. Twelve patients had a TC, 5 a TM and 1 a mixed TM/TC. Sixty-one percent of patients (11/18) had stage IVB disease according to Masaoka-Koga, and 39% (7/18) had an ECOG-PS 2. The median number of previous lines of therapy was 2 (range:1-5), and 72% (13/18) and 61% (11/18) of patients were pretreated with an anti-angiogenesis drug and an anti-PD(L)1 drug respectively. The ORR and the disease control rate (DCR) were 28 % (95 %CI: 10 %-53 %) and 67 % (95 %CI: 41 %-86 %), respectively. The median follow-up for PFS was 17.3 months (95 %CI: 4.3-NA), and median PFS was 5.4 months (95 %CI: 2.9-6.4). The median duration of response and SD was respectively 19.6 months (95 %CI: 3.5-NA) and 6.0 months (95 % CI: 3.8-6.4). In patients with TC, the ORR and DCR were 15 % (95 % CI: 2 %-45 %) and 54 % (95 % CI: 25 %-81 %), respectively. In the subgroup of 5 patients with TM, 2 PR and 3 SD were observed. Most patients had only mild (grade 1-2) AEs, the most common being nausea and vomiting (39%; 7/18) and transaminases elevation (33%; 6/18). Twenty-two percent of patients (4/18) experienced an AEs of grade 3 and required ifosfamide dose reduction. No patients had severe AEs. CONCLUSION: High-dose continuous-infusion Ifosfamide can be considered as a valuable treatment option in patients with advanced thymic epithelial tumors.

Genetic Alterations of Melanoma Brain Metastases: A Systematic Review and Meta-Analysis.

BACKGROUND: Data on molecular alterations harbored by melanoma brain metastases (MBMs) are limited, and this has hampered the development of more effective therapeutic strategies. We conducted a systematic review and meta-analysis of all the studies reporting DNA sequencing data of MBMs, in order to identify recurrently mutated genes and molecular pathways significantly enriched for genetic alterations. METHODS: We searched PubMed, Embase and Scopus for articles published from the inception of each database to June 30, 2021. We included in the analysis all the studies that reported individual patient data on DNA sequencing of MBMs, assessing single nucleotide variants (SNVs) and/or gene copy number variations (CNVs) in at least five tumor samples. Meta-analysis was performed for genes evaluated for SNVs and/or CNVs in at least two studies. Pooled proportions of samples with SNVs and/or CNVs was calculated by applying random-effect models based on the DerSimonian-Laird method. Gene-set enrichment analysis (GSEA) was performed to identify molecular pathways significantly enriched for mutated genes. RESULTS: Ten studies fulfilled the inclusion criteria and were included in the analysis, for a total of 531 samples of MBMs evaluated. Twenty-seven genes were found recurrently mutated with a meta-analytic rate of SNVs higher than 5%. GSEA conducted on the list of these 27 recurrently mutated genes revealed vascular endothelial growth factor-activated receptor activity and transmembrane receptor protein tyrosine kinase activity to be among the top 10 gene ontology (GO) molecular functions significantly enriched for mutated genes, while regulation of apoptosis and cell proliferation were among the top 10 significantly enriched GO biological processes. Notably, a high meta-analytic rate of SNVs was found in several actionable cancer-associated genes, such as all the vascular endothelial growth factor (VEGF) receptor isoforms (i.e., Flt1 and Flt2 genes, for both SNV rate: 0.22, 95% CI 0.04-0.49; KDR gene, SNV rate: 0.1, 95% CI 0.05-0.16). Finally, two tumor suppressor genes were characterized by a high meta-analytic rate of CNVs: CDKN2A/B (CNV rate: 0.59, 95% CI 0.23-0.90) and PTEN (CNV rate: 0.31, 95% CI 0.02-0.95). CONCLUSION: MBMs harbored actionable molecular alterations that could be exploited as therapeutic targets to improve the poor prognosis of patients.

Under-representation of women in Randomized Clinical Trials testing anticancer immunotherapy may undermine female patients care. A call to action.

Immunotherapy with immune-checkpoint inhibitors (ICIs) has revolutionized the landscape of cancer treatment, dramatically improving the prognosis of patients with several solid tumors. Sex and gender are variables that affect immune responses to both foreign and self-antigens and growing preclinical and clinical evidence show that they also affect efficacy and tolerability of anticancer immunotherapy in patients with several advanced solid tumors. Despite such strong biological rationale and available evidence highlighting the need to take into account sex-based differences in the context of both research and clinical practice for anticancer immunotherapy, we described here an impressive under-representation of women enrolled in randomized clinical trials (RCTs) testing such drugs over the last 10 years. We critically discuss limitations the under-representation of women has on the generalization of results of RCTs to female patients, as well as the importance in the future of ensuring increased enrollment of women in trials, including sex as stratifying factor in trials design, and guaranteeing sex-specific analysis of efficacy and safety results, in order to avoid less than optimal treatment of women with cancer.

Surrogacy of Pathologic Complete Response in Trials of Neoadjuvant Therapy for Early Breast Cancer: Critical Analysis of Strengths, Weaknesses, and Misinterpretations.

Importance: The pathologic complete response (pCR) is supported by regulatory agencies as a surrogate end point for long-term patients' clinical outcomes in the accelerated approval process of new drugs tested in neoadjuvant randomized clinical trials (RCTs) for early breast cancer (BC). However, a meaningful association between pCR and patients' survival has been proven only at the patient level (ie, significantly better survival of patients who achieved pCR compared with those who did not), but not at trial level (ie, poor association between degree of improvement in pCR rate and survival reported across trials). Observations: We critically discuss the potential reasons of such discrepancy between pCR surrogacy value at the patient and trial level, as well as the relevant implications for both clinical research and drug regulatory policy. We also describe alternative surrogate end points, including combined end points that jointly analyzed pathological response and event-free survival data, or the assessment of circulating tumor DNA (ctDNA). Such proposed surrogate end points could overcome limits of pCR and provide a reasonable trade-off between the 2 conflicting needs to have access to effective therapies rapidly, and to reliably assess patients' clinical benefit. Conclusions and Relevance: Using surrogate end points to grant drug approvals is justified only when they can provide accurate prediction of a drug's effect on the long-term patient outcomes. Evidence currently available does not support pCR used alone as a reliable surrogate end point in regulatory neoadjuvant RCTs for BC. The surrogacy value at trial level of potentially more robust surrogate end points needs to be urgently tested.

Avelumab plus axitinib in unresectable or metastatic type B3 thymomas and thymic carcinomas (CAVEATT): a single-arm, multicentre, phase 2 trial.

BACKGROUND: Patients with advanced type B3 thymoma and thymic carcinoma resistant to chemotherapy have few treatment options. We report the efficacy and safety results of the combination of the anti-PD-L1 inhibitor avelumab with the anti-angiogenesis drug axitinib in patients with advanced type B3 thymoma and thymic carcinoma. METHODS: CAVEATT was a single-arm, multicentre, phase 2 trial, conducted in two Italian centres (the European Instituteof Oncology and the Humanitas Institute, Milan) in patients with histologically confirmed type B3 thymoma or thymic carcinoma, with advanced stage of disease who had progressed after at least one line of platinum-based chemotherapy. Previous treatment with an anti-angiogenesis drug was allowed but not with immune checkpoint inhibitors. Other inclusion criteria were age 18 years or older, an Eastern Cooperative Oncology Group performance status of 0-2, progressive disease, and presence of measurable disease according to Response Evaluation Criteria In Solid Tumours (RECIST) version 1.1. Patients received avelumab 10 mg/kg intravenously every 2 weeks and axitinib 5 mg orally twice daily until disease progression or unacceptable toxicity. The primary endpoint was the centrally assessed overall response rate according to RECIST version 1.1. Patients who received at least one cycle of treatment and had at least one CT scan after treatment start at scheduled time point by protocol were judged assessable for response and were included in efficacy and safety analyses. This study is registered with EUDRACT, 2017-004048-38; enrolment is completed and follow-up is ongoing. FINDINGS: Between April 22, 2019, and June 30, 2021, 32 patients were enrolled. 27 patients had a thymic carcinoma, three a type B3 thymoma, and two a mixed type B3 thymoma and thymic carcinoma. 29 (91%) of 32 patients had stage IVB disease and 13 (41%) of 32 had been pretreated with an anti-angiogenesis drug. 11 of 32 patients had an overall response; thus the overall response rate was 34% (90% CI 21-50); no patients had a complete response, 11 (34%) had a partial response, 18 (56%) had stable disease, and in two patients (6%) progressive disease was the best response. The most common grade 3 or 4 adverse event was hypertension (grade 3 in six [19%] of 32 patients). Four (12%) of 32 patients developed serious adverse events that were new-onset immune-related adverse events, including one grade 3 interstitial pneumonitis, one grade 4 polymyositis, and two grade 3 polymyositis. There were no treatment-related deaths. INTERPRETATION: Avelumab combined with axitinib has promising anti-tumour activity and acceptable toxicity in patients with advanced type B3 thymoma and thymic carcinoma progressing after chemotherapy, and could emerge as a new standard treatment option in this setting. FUNDING: Pfizer.

Association of Anticancer Immune Checkpoint Inhibitors With Patient-Reported Outcomes Assessed in Randomized Clinical Trials: A Systematic Review and Meta-analysis.

Importance: The association of immune checkpoint inhibitors (ICIs) with patient quality of life has been poorly explored. Objective: To evaluate patient-reported outcomes (PROs) assessed in randomized clinical trials (RCTs) of immunotherapy-based treatments. Data Sources: This systematic review and random-effects meta-analysis used RCTs identified in PubMed, MEDLINE, Embase, and Scopus from database inception to June 1, 2021. Study Selection: A total of 2259 RCTs were identified that assessed ICIs as monotherapy or in combination with chemotherapy or combined with another ICI and/or targeted therapy vs control groups not containing immunotherapy in patients with advanced solid tumors. Studies were reviewed independently by 2 authors. Data Extraction and Synthesis: This meta-analysis followed the PRISMA guidelines and recommendations of the Setting International Standards in Analyzing Patient-Reported Outcomes and Quality of Life Endpoints Data Consortium. Main Outcomes and Measures: The coprimary aims of the meta-analysis were (1) pooled differences between treatment groups in the mean change of PRO score from baseline to 12 and 24 weeks of follow-up and (2) pooled differences between treatment groups in the time to deterioration of PRO score. For each end point, RCTs have been analyzed according to the type of treatment administered in the experimental group: ICIs given as monotherapy, ICIs combined with chemotherapy, or ICIs in association with another ICI and/or with targeted therapies. Results: Of the 2259 identified RCTs, 34 (18 709 patients) met the selection criteria and were analyzed. In the group of 19 RCTs testing ICIs as monotherapy, the pooled between-groups difference of mean change from baseline to 12 weeks of follow-up was 4.6 (95% CI, 2.8-6.4), and the mean change from baseline to 24 weeks of follow-up was 6.1 (95% CI, 4.2-8.1), significantly favoring ICIs. The pooled difference was 1.4 (95% CI, -0.4 to 3.2) at week 12 and 2.5 (95% CI, -0.8 to 5.9) at week 24 in the group of 8 RCTs testing ICIs combined with chemotherapy and 2.1 (95% CI, -0.8 to 5.0) at week 12 and 2.1 (95% CI, -0.4 to 4.5) at week 24 in the group of 8 RCTs testing other ICI-containing combinations. The time to deterioration was significantly longer in the immunotherapy-containing groups compared with control groups in all 3 groups of RCTs evaluated (hazard ratios of 0.80 [95% CI, 0.70-0.91] for ICIs as monotherapy, 0.89 [95% CI, 0.78-1.00] for ICIs plus chemotherapy, and 0.78 [95% CI, 0.63-0.96] for other ICI-containing combinations). Conclusions and Relevance: Immune checkpoint inhibitors as monotherapy appear to have a favorable association with patient-reported quality of life and can be combined with other classes of anticancer drugs without worsening this quality of life.

Investigational drugs for the treatment of thymic cancer: a focus on phase 1 and 2 clinical trials.

INTRODUCTION: Thymic epithelial tumors (TETs) are rare tumors of thymic epithelial cells. Treatment options for advanced disease patients who failed standard platinum-based chemotherapy are limited. AREAS COVERED: Phase I and II trials published in the last five years testing new systemic treatments for advanced TET patients are discussed, as well as ongoing trials. A PubMed database literature review was conducted for articles published between January 2016 and December 2021, and ongoing clinical trials were retrieved from ClinicalTrials.gov database. EXPERT OPINION: The most promising classes of new drugs in TET patients are angiogenesis inhibitors and immune checkpoint antibodies (ICIs). Sunitinib and Lenvatinib showed response rates of 26% and 38%, respectively, and ICIs showed durable responses in 20-25% in thymic carcinoma (TCs). Both approaches are mainly active in TCs, therefore new treatment options for thymomas are an unmet medical need.Two major new therapeutic strategies are ICI combinations with other drugs and drugs that target pathways that are dysregulated in TETs.Future challenges include the development of preclinical models to help identify novel targets and test new treatment strategies, and randomized clinical trials to provide reliable evidence based on survival endpoints.

Differential activity of avapritinib in patients with metastases from mucosal melanoma and thymic carcinoma harbouring KIT exon 17 mutations: Initial experience from a Compassionate Use Program in Italy.

INTRODUCTION: Proto-oncogene KIT is the gene encoding the receptor tyrosine kinase protein KIT. Activating mutations are found in 2.9% of neoplasms, with the highest prevalence in gastrointestinal stromal tumour. Exon 17 mutations typically alter the kinase activation loop and are relatively rare, representing 11.7% of all activating KIT mutations. Recently, KIT exon 17 mutants turned out to be a potential molecular target for the type 1 kinase inhibitor avapritinib (BLU-285). OBJECTIVE: In this framework, we aimed at investigating the potential activity of avapritinib in mucosal melanoma and thymic carcinoma, two disease histologies with dismal prognosis, currently lacking evidence-based second line treatment options and in which KIT exon 17 activating mutations could represent a relevant therapeutic target. RESULTS: In this series, we report the only four cases of patients affected by exon 17 mutant mucosal melanoma and thymic carcinoma that have been treated in Italy with avapritinib within a Compassionate Use Program. Two patients harboured mucosal melanoma and the other two were diagnosed with thymic carcinoma. We describe a differential activity of avapritinib (3/4 patients responded, 1/4 did not respond), along with possible hypotheses to justify such differences and potential implications for precision oncology. CONCLUSIONS: Taken together, the inactivity of imatinib on KIT exon 17 mutations, the general low clinical efficacy of immunotherapy, as well as the consequent formal lack of standard available and active second line systemic treatments in both mucosal melanoma and thymic carcinoma, support the implementation of avapritinib in the therapeutic armamentarium, even though further prospective evidence is warranted.