Nivolumab in pretreated pleural mesothelioma: Results from an observational real-world study of patients treated within the AIFA 5% Fund

BACKGROUND

Pleural mesothelioma is a rare cancer with a dismal prognosis and few therapeutic options, especially in the pretreated setting. Immunotherapy with checkpoint inhibitors as single agents yielded interesting results in refractory pleural mesothelioma, achieving a response rate between 10-20%, median progression-free survival of 2-5 months and median overall survival of 7-13 months.

PATIENTS AND METHODS

A retrospective, multi-institutional study of pleural mesothelioma patients treated with nivolumab in second and further line was performed. The endpoints of the study are response rate, disease control rate, progression free survival and overall survival.

RESULTS

Sixty-five patients with pleural mesothelioma treated with nivolumab in second and further line were enrolled at seven Italian institutions. The response rate was 8%, disease control rate was 37%, median progression free survival was 5.7 months (95% CI: 2.9-9.0) and median overall survival was 11.1 (95% CI 6.2-19.9) months. A higher neutrophils and neutrophils to lymphocytes ratio at baseline were associated with worse prognosis.

CONCLUSION

Nivolumab as a single agent is fairly active in a cohort of unselected pretreated pleural mesothelioma patients. Further investigations on clinical and translational factors are needed to define which patient might benefit most from nivolumab treatment in pleural mesothelioma.

Neoadjuvant Systemic Therapy in Early Breast Cancer: Results of a Prospective Observational Multicenter BRIDE Study

To evaluate the rate of early breast cancer (EBC) patients treated with neoadjuvant systemic therapy (NAT) in Italy, criteria of patient selection and types of therapies delivered, an analysis of 1276 patients with stage I-II-III was conducted out of 1633 patients enrolled in the multicenter prospective observational BRIDE study. A total of 177 patients (13.9%) were treated with NAT and 1099 (85.9%) with surgery; in multivariate analysis, menopausal status, cT, cN, grade, HER2-positive and Triple negative (TN) subgroups were significantly associated with the decision to administer NAT. The type of NAT delivered was influenced by EBC subtype. NAT was administered to 53.2% of HER2+/HR-negative, 27.9% of HER2+/HR+, 7.1% of HER2-negative/HR+ and 30.3% of TN EBC patients. The pCR rates were similar to the ones reported in the literature: 74.2% in HER2+/HR-negative, 52.3% in HER2+/HR+, 17.2% in HER2-negative/HR+ and 37.9% in TN. In clinical practice, patient and tumor characteristics influenced oncologists in the decision to administer NAT in EBC and in the choice of the type of systemic therapy, according to ESMO and AIOM Guidelines. Currently, it is recommended always to evaluate the use of NAT in EBC, mainly in HER2+ and TN patients, considering that pCR is associated with significantly better survival of the patient and that effective therapies are now available for residual disease.

Tumor treating fields affect mesothelioma cell proliferation by exerting histotype-dependent cell cycle checkpoint activations and transcriptional modulations

Although clinical antitumor activity of Tumor Treating Fields (TTFields) has been reported in malignant pleural mesothelioma (MPM) patients, the mechanisms behind the different selectivity displayed by the various MPM histotypes to this physical therapy has not been elucidated yet. Taking advantage of the development of well characterized human MPM cell lines derived from pleural effusion and/or lavages of patients' thoracic cavity, we investigated the biological effects of TTFields against these cells, representative of epithelioid, biphasic, and sarcomatoid histotypes. Growth inhibition and cell cycle perturbations caused by TTFields were investigated side by side with RNA-Seq analyses at different exposure times to identify pathways involved in cell response to treatment. We observed significant differences of response to TTFields among the cell lines. Cell cycle analysis revealed that the most sensitive cells (epithelioid CD473) were blocked in G₂M phase followed by formation of polyploid cells. The least sensitive cells (sarcomatoid CD60) were only slightly affected by TTFields with a general delay in all cell cycle phases. Apoptosis was present in all samples, but while epithelioid cell death was already observed during the first 24 h of treatment, sarcomatoid cells needed longer times before they engaged apoptotic pathways. RNA-Seq experiments demonstrated that TTFields induced a transcriptional response already detectable at early time points (8 h). The number of differentially expressed genes was higher in CD473 than in CD60 cells, involving several pathways, such as those pertinent to cell cycle checkpoints, DNA repair, and histone modifications. Our data provide further support to the notion that the antitumor effects of TTFields are not simply related to a non-specific reaction to a physical stimulus, but are dependent on the biological background of the cells and the particular sensitivity to TTFields observed in epithelioid MPM cells is associated with a higher transcriptional activity than that observed in sarcomatoid models.

Phase III study to compare bevacizumab or cetuximab plus FOLFIRI in patients with advanced colorectal cancer RAS/BRAF wild type (wt) on tumor tissue and RAS mutated (mut) in liquid biopsy: LIBImAb Study

TPS3636

Background: KRAS, NRAS, and BRAF mutations are well-established negative predictive biomarkers of response to anti-EGFR monoclonal antibodies (MoAbs) in metastatic colorectal cancer (mCRC) patients (pts). In clinical practice, RAS/BRAF wild-type (wt) patients receive first-line therapy regimens containing anti-EGFR agents. However, tumor heterogeneity might drive primary and acquired resistance to anti-EGFR MoAbs. In fact, circulating tumor DNA (ctDNA) testing reveals RAS/BRAF mutations in approximately 10% of pts who resulted in wt at tumor tissue. In addition, 30% to 50% RAS wt pts develop, during the treatment with anti-EGFR MoAbs, RAS mut can be detected in the ctDNA several weeks before clinical progression. As today, it is not known whether revealing RAS mut in liquid biopsy (LB) earlier than the appearance of a clinical/radiological disease progression, could impact pts’ outcomes. Similarly, there are no data suggesting the best therapeutic approach in patients with RAS/BRAF wt tissue and mutated ctDNA. Methods: This is a phase III, randomized, open-label, comparative, multicenter study to assess the superiority of Bevacizumab (BEV) compared to Cetuximab (CET) plus FOLFIRI in treatment naïve mCRC RAS/BRAF wt on tumor tissue (TT) and mutated in plasma samples. RAS/BRAF wt pts on TT will undergo the first LB, and RAS mut pts will be randomized 1:1 to receive FOLFIRI/CET (control arm) or FOLFIRI/BEV (experimental arm). Instead, RAS wt pts at first LB will be treated with FOLFIRI/CET up to 8 cycles. Pts who have not progressed after 8 cycles of treatment will undergo a second LB. If RAS mut was detected, pts will be randomized 1:1 to continue FOLFIRI/CET or switch to FOLFIRI/BEV. If not, pts will continue FOLFIRI/CET outside the clinical trial. Pts will be treated until disease progression, unacceptable toxicity, or withdrawal of consent. Among 26 pts screened at the first LB, actually 1 KRAS mut and 1 BRAF mut pts were detected. The primary endpoint is the PFS Plasma samples will be analyzed for KRAS, NRAS, and BRAF mutations by Idylla ctKRAS and Idylla ctNRAS-BRAF-EGFGR. All samples will be also analyzed by NGS, in order to better evaluate the correlation of tumor heterogeneity with pts’ outcomes. Clinical trial information: EudraCT Number: 2020-005078-82, NCT04776655.

Epithelioid Pleural Mesothelioma Is Characterized by Tertiary Lymphoid Structures in Long Survivors: Results from the MATCH Study

Pleural mesothelioma (PM) is an aggressive tumor with few therapeutic options. Although patients with epithelioid PM (ePM) survive longer than non-epithelioid PM (non-ePM), heterogeneity of tumor response in ePM is observed. The role of the tumor immune microenvironment (TIME) in the development and progression of PM is currently considered a promising biomarker. A few studies have used high-throughput technologies correlated with TIME evaluation and morphologic and clinical data. This study aimed to identify different morphological, immunohistochemical, and transcriptional profiles that could potentially predict the outcome. A retrospective multicenter cohort of 129 chemonaive PM patients was recruited. Tissue slides were reviewed by dedicated pathologists for histotype classification and immunophenotype of tumor-infiltrating lymphocytes (TILs) and lymphoid aggregates or tertiary lymphoid structures (TLS). ePM (n = 99) survivors were further classified into long (>36 months) or short (<12 months) survivors. RNAseq was performed on a subset of 69 samples. Distinct transcriptional profiling in long and short ePM survivors was found. An inflammatory background with a higher number of B lymphocytes and a prevalence of TLS formations were detected in long compared to short ePM survivors. These results suggest that B cell infiltration could be important in modulating disease aggressiveness, opening a pathway for novel immunotherapeutic approaches.

Antiepileptic treatment and survival in newly diagnosed glioblastoma patients: Retrospective multicentre study in 285 Italian patients

Glioblastoma multiforme (GBM) has a dismal prognosis even with the best available treatment. Different studies have suggested a possible impact of antiepileptic drugs (AED) on survival in patients with GBM. A recent pooled analysis of prospective clinical trials in newly diagnosed GBM found no significant survival benefit in GBM patients treated with AED. We performed a retrospective study on adult patients with GBM in order to evaluate the impact of AED therapy on overall survival (OS), after adjusting for known prognostic factor (age, extent of surgery, Karnofsky performance status, radiochemotherapy). A total of 285 patients were analyzed. Of them 144 received a non-enzyme-inducing (NEIAED) and 95 an enzyme-inducing AED (EIAED). At univariate analysis the OS of patients receiving AED was not significantly different from that of patients not receiving an AED (HR 0.98, 95%CI 0.69-1.4, p = 0.925), moreover OS was not significantly different between patients receiving EIAED or NEIAED. At multivariate analysis a trend to more prolonged survival (HR 0.8, 95% CI 0.59-1.08, p = 0.15) was detected in patients treated with NEIAED. The question whether treatment with AED may increase OS in GBM patients remains unanswered and randomized extremely large controlled clinical trial would be necessary to elucidate the possible impact of AED on prognosis. In the meantime the use of AED in GBM patients, based on the presumed potential antitumour activity, is not recommended.