bmn-673 and Endometrial-Neoplasms

New molecular therapeutic approaches have emerged in recent years for advanced gynaecological cancers, including targeted therapies such as poly-ADP-ribose polymerase inhibitors (PARPi). These have demonstrated efficacy in high-grade serous ovarian cancers in patients carrying a mutation in the BRCA gene, which predisposes them to breast and ovarian cancers. Clinical and pre-clinical data suggest that the activity of PARPi inhibitors may not be limited to BRCA mutated tumours and may involve the homologous recombination pathway. These data raise the question of the potential efficacy of PARPi in advanced endometrial and cervical cancers where treatment options are currently limited. At present, there are few data available on the activity of PARPi in endometrial and cervical cancers, but some results seem promising. In this review, we present a synthesis of the available studies concerning PARPi in endometrial and cervical cancer.

Topics: Antineoplastic Agents; Cell Line, Tumor; Cisplatin; Clinical Trials as Topic; DNA Damage; DNA Repair-Deficiency Disorders; Endometrial Neoplasms; Female; Humans; Indazoles; Indoles; Ovarian Neoplasms; Papillomavirus Infections; Phthalazines; Piperazines; Piperidines; Poly(ADP-ribose) Polymerase Inhibitors; Uterine Cervical Neoplasms

Although the activity of pembrolizumab and lenvatinib (the only US Food and Drug Administration-approved immunotherapy for mismatch repair proficient endometrial cancer [MMRP EC]) is compelling, there are no biomarkers of response and most patients do not tolerate, do not respond to, or develop resistance to this regimen, highlighting the need for additional, potentially biomarker-driven therapeutic approaches for patients with recurrent MMRP EC.. To assess the potential positive outcomes and safety of the combination of the polyadenosine diphosphate-ribose polymerase inhibitor talazoparib and the programmed cell death ligand 1 (PD-L1) inhibitor avelumab in recurrent MMRP EC.. This investigator-initiated, open-label, single-arm, 2-stage, phase 2 study nonrandomized controlled trial patients at 4 institutions in the US. Key eligibility criteria included measurable disease, unlimited prior therapies, and all endometrial cancer histologies.. Talazoparib, 1 mg, orally, daily, and avelumab, 10 mg/kg, intravenously, every 2 weeks, were administered until disease progression or unacceptable toxic effects.. Statistical considerations were developed for 2 coprimary objectives of objective response rate and rate of progression-free survival at 6 months, with a 2-stage design that allowed for early discontinuation for futility. Prespecified exploratory objectives included the association of immunogenomic features (determined by targeted-panel next-generation sequencing and immunohistochemistry) with activity.. Thirty-five female patients (mean [SD] age, 67.9 [8.41] years) received protocol therapy; 9 (25.7%) derived clinical benefit after meeting at least 1 of the 2 coprimary end points. Four patients (11.4%) exhibited confirmed objective response rates (4 partial responses), and 8 (22.9%) survived progression free at 6 months. The most common grade 3 and 4 treatment-related toxic effects were anemia (16 [46%]), thrombocytopenia (10 [29%]), and neutropenia (4 [11%]); no patient discontinued receipt of therapy because of toxic effects. Tumors with homologous recombination repair alterations were associated with clinical benefit from treatment with avelumab and talazoparib. Tumor mutational burden, tumor-infiltrating lymphocytes, and PD-L1 status were not associated with clinical benefit.. The results of this nonrandomized controlled trial suggest that treatment with avelumab and talazoparib demonstrated a favorable toxic effect profile and met the predetermined criteria to be considered worthy of further evaluation in MMRP EC. Immunogenomic profiling provided insights that may inform ongoing and future studies of polyadenosine diphosphate-ribose polymerase and PD-L1 inhibitor combinations in endometrial cancer.. ClinicalTrials.gov Identifier: NCT02912572.

Topics: Aged; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; B7-H1 Antigen; Diphosphates; DNA Mismatch Repair; Endometrial Neoplasms; Female; Humans; Immune Checkpoint Inhibitors; Ligands; Neoplasm Recurrence, Local; Phthalazines; Ribose

Phosphatase and Tensin homolog (PTEN) is a tumor suppressor gene. Loss of its function is the most frequent genetic alteration in endometrioid endometrial cancers (70-80%) and high grade tumors (90%). We assessed the sensitivity of endometrial cancer cell lines to PARP inhibitors (olaparib and BMN-673) and a PI3K inhibitor (BKM-120), alone or in combination, in the context of their PTEN mutation status. We also highlighted a direct pathway linking PTEN to DNA repair.. Using endometrial cancer cellular models with known PTEN status, we evaluated their homologous recombination (HR) functionality by RAD51 foci formation assay. The 50% Inhibitory concentration (IC50) of PI3K and PARP inhibitors in these cells was assessed, and western blotting was performed to determine the expression of proteins involved in the PI3K/mTOR pathway. Moreover, we explored the interaction between RAD51 and PI3K/mTOR by immunofluorescence. Next, the combination effect of PI3K and PARP inhibitors on cell proliferation was evaluated by a clonogenic assay.. Cells with mutated PTEN showed over-activation of the PI3K/mTOR pathway. These cells were more sensitive to PARP inhibition compared to PTEN wild-type cells. In addition, PI3K inhibitor treatment reduced RAD51 foci formation in PTEN mutated cells, and sensitized these cells to PARP inhibitor.. Targeting both PARP and PI3K might lead to improved personalized therapeutic approaches in endometrial cancer patients with PTEN mutations. Understanding the complex interaction of PTEN mutations with DNA repair in endometrial cancer will help to better select patients that are likely to respond to some of the new and costly targeted therapies.

Topics: Antineoplastic Combined Chemotherapy Protocols; Cell Line, Tumor; Cell Proliferation; DNA Repair; Drug Resistance, Neoplasm; Endometrial Neoplasms; Female; Gene Expression Regulation, Neoplastic; Humans; Mutation; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Phthalazines; Piperazines; Poly(ADP-ribose) Polymerase Inhibitors; PTEN Phosphohydrolase; Rad51 Recombinase; Signal Transduction; TOR Serine-Threonine Kinases