[Bispecific antibodies targeting CD3 in oncology and hematology]

A novel immune-related gene signature for diagnosis and potential immunotherapy of microsatellite stable endometrial carcinoma

An immune-related gene signature (IRGS) was established to better understand the molecular and immunologic characteristics of microsatellite instable (MSI) and microsatellite stable (MSS) endometrial carcinoma (EC), and provide potential immunotherapy directions for MSS patients. Top 20 immune-related hub genes were screened by weight gene coexpression network analysis (WGCNA), and an IRGS was further established through Cox regression analysis. The molecular and immune characteristics were clarified in IRGS high and low risk groups. Expression and MS status validation of the IRGS were conducted through quantitative real-time Polymerase Chain Reaction (rt-qPCR) and immunohistochemistry (IHC) analysis. The IRGS includes 2 oncogenes (AGTR1 and HTR3C) and 2 tumor suppressor genes (CD3E and SERPIND1). Patients in IRGS high-risk group were more with MSS status, higher tumor grade, later FIGO stage, serous histology and elder ages compared with IRGS low-risk group (P < 0.05). Besides, patients in MSS group were more FIGO stages II-IV (42.7% vs. 26%), serous histology (35.7% vs. 5.3%) and with higher IRGS risk score (1.51 ± 3.11 vs. 1.02 ± 0.67) (P < 0.05) than patients in MSI group. Furthermore, patients in IRGS high-risk group had higher tumor purity, more Macrophages M1 and Macrophages M2 infiltrating, higher proportion of Macrophages M2 and Dendritic cells activated, lower proportion of T cells regulatory (Tregs), lower tumor mutation burden (TMB). Correspondingly, subjects in IRGS low-risk group had higher immunphenoscores than IRGS high-risk group. The relative mRNA level of AGTR1 and HTR3C were gradually increase, while CD3E and SERPIND1 were reversed in rt-qPCR. Through IHC experiments, AGTR1(69.2% vs 30%, P = 0.074) and HTR3C (76.9% vs 30%, P = 0.024) had higher positive staining rates in ECs than non-ECs. While SERPIND1 (84.6% vs 20%, P = 0.003) and CD3E (61.5% vs 40%, P = 0.000) had higher positive staining rates in non-ECs. IRGS is a potential diagnostic and prognostic biomarker for EC. IRGS low risk group might benefit from immune checkpoint inhibitors, while IRGS high risk group deserve other potential immunotherapy.

[Antibody drug conjugates (ADC) and bispecific antibodies in oncology - report of the 2022 Saint Louis day]

Antibody Drug Conjugates (ADC) and bispecific antibodies are booming and were the subject of the scientific event proposed by the French Society of Oncological Pharmacy, October 13, 2022. An ADC is composed of the antibody targeting a receptor expressed on the tumor cell, the spacer making it possible to attach the cytotoxic to the antibody and to control its distribution in the body, and the cytotoxic. Therapeutic antibodies, monoclonal and conjugated, have particular pharmacokinetics. Unlike monoclonal antibodies for which the standard dose is most often fixed, this is expressed in mg/m2 (or mg/kg) and capped at 2m2 (or 100kg) for conjugates. The linked cytotoxics are powerful cytotoxics: mitotic spindle poisons (emtansine, monomethyl auristatin E or vedotin), topoisomerase I inhibitors (deruxtecan, SN 38) or antibiotics (ozogamicin). In senology, trastuzumab deruxtecan (anti-HER2) and sacituzumab govitecan (anti-Trop 2) are now modifying treatment standards for patients with metastatic breast cancer, respectively HER2 3X or HER2 low and triple negative. In metastatic bladder cancer, enfortumab vedotin (anti-nectin 4) is positioned as the 2nd line of treatment. Bispecific antibodies, on the other hand, are able to target two epitopes, an antigen specific to a tumor cell and one to an immune cell, allowing a bridge between the killer immune cells and the tumor cells. For lymphoma proliferation, many bispecific antibodies are in development. The most advanced are glofitamab, epcoritamab and mosunetuzumab, which target the CD20 of B lymphocytes and the CD3 of T lymphocytes. Bispecific antibodies are also emerging in the treatment of myeloma with teclistamab and elranatamab (anti-CD3 and anti-BCMA) or talquetamab (anti-GPRC5D and anti-CD3). Conjugated antibodies, and more recently bispecific antibodies, are potential game changers in cancer treatment and researchs are needed to improve their efficacy and safety.