Efficacy and Safety of the Valemetostat in Patients With Selected Solid Tumors.

Rational, objective and design: Some cancer-protecting genes are inactivated when the EZH2 enzyme is too active or the SWI/SNF complex is less active. The EZH1/2 enzymes and the SWI/SNFs complex play opposing roles in gene expression: we hypothesize that valemetostat, an inhibitor of the EZH1/2 enzymes, will stop/slow down the growth of cancer cells by reactivating these genes. Numerous clinical trials are currently underway worldwide to optimize the development of valemetostat tosylate and potentially offer a new targeted therapeutic option for patients suffering from various cancer pathologies. The aim of this research is to evaluate the efficacy of valemetostat on solid tumors, which have an alteration in certain genes: SMARC (B1/A4/A2/C1/C2), ARID (1A/1B), PBRM1, BAP1 and other SWI/SNF sub-units. The research will be conducted in two phases: 1) Pre-selection of patients with the desired alterations. 2) Treatment with valemetostat, 200mg/day, for a maximum of 2 years, with examinations every 28 days. This is a multicenter, international, phase II open-label, multicenter modular study exploring the efficacy and safety of valemetostat. Module 1 will be the SWI/SNF basket monotherapy study describe below. Such design will allow the study to evolve considering signals for further monotherapy and/or combination modules. The Primary endpoint of the study is Overall Response Rate at 24 weeks, defined as the proportion of patients with a confirmed best overall response. Trial population: Adult patients with histologically/cytologically confirmed progressive metastatic or recurrent solid tumor, who have selected chromatin remodeling deficiency in at least one of the following genes: SMARCB1, SMARCA4, SMARCA2, SMARCC1, SMARCC2, ARID1A, ARID1B, PBRM1, BAP1and other SWI/SNF sub-units; or molecularly (Wildtype) and phenotypically-selected Clear cell endometrial or ovarian carcinoma cancers. Patients must be using an effective method of contraception and have signed the consent form. They must not participate in another clinical study with an investigational product during the last 3 weeks, during the study treatment and not have a contraindication to the study treatment (…) Intervention: After confirmation by IHC of the loss of expression in tumors cells of SMARCB1, SMARCA4, SMARCA2, SMARCC1, SMARCC2, ARID1A, ARID1B, PBRM1, BAP1and other SWI/SNF sub-units and validation of inclusion/exclusion criteria patients will included in different cohorts (refer to investigation scheme). All patients will receive Valemetostat (200 mg per day), divided into 28-day periods called treatment cycles, for a maximum of two years. The main interventions scheduled are blood samples (to evaluate biological parameters and for translational research), electrocardiogram, echocardiography and CTscan. For patients who have consented, sequential biopsies will be performed as follow: at baseline, on treatment and at progression. Ethical consideration: This research will make it possible to collectively evaluate the interest of EZH1/2 inhibitor in solids tumors with SWI/SNF defect. Individually, by participating in this research, patients could benefit from these treatments based on cell-based results and in the treatment of relapsed/refractory peripheral T-cell lymphomas, with an improvement in symptoms and quality of life. As with any research, the investigational drug and other procedures that take place may involve risks, some of which are already known and others not yet described. The main risks (described in the consent form) are side effects of the valemetostat. If they agree, patients will also be monitored more closely with their safety assessed through patient-reported outcomes (PRO), the evaluation of their experience through qualitative interviews \& assessment of quality of care and the evaluation of their biometric physiological via a wearable device.