Dostarlimab: A promising new PD-1 inhibitor for cancer immunotherapy

OBJECTIVE

Dostarlimab, a humanized monoclonal PD-1 blocking antibody, is being tested as a cancer therapy in this review. Specifically, it addresses mismatch repair failure in endometrial cancer and locally progressed rectal cancer patients.

DATA SOURCES

A thorough database search found Dostarlimab clinical trials and studies. Published publications and ongoing clinical trials on Dostarlimab's efficacy as a single therapy and in conjunction with other medicines across cancer types were searched.

DATA SUMMARY

The review recommends Dostarlimab for endometrial cancer mismatch repair failure, as supported by GARNET studies. The analysis also highlights locally advanced rectal cancer findings. In the evolving area of cancer therapy, immune checkpoint inhibitors including pembrolizumab, avelumab, atezolizumab, nivolumab, and durvalumab were discussed.

CONCLUSIONS

Locally advanced rectal cancer patients responded 100% to Dostarlimab. Many clinical trials, including ROSCAN, AMBER, IOLite, CITRINO, JASPER, OPAL, PRIME, PERLA, and others, are investigating Dostarlimab in combination treatment. This research sheds light on Dostarlimab's current and future possibilities, in improving cancer immunotherapy understanding.

Bibliometric analysis of research trends on the combination of immune checkpoint inhibitors and PARP inhibitors in solid tumors

Introduction

Immune checkpoint inhibitors (ICIs) has made significant achievements in the therapeutics of various tumor types, and recently growing evidence from preclinical studies and clinical trials has indicated that poly-ADP-ribose polymerase inhibitors (PARPi) are exhibiting encouraging synergism with ICIs. The aim of our current study is to explore the development pattern of literature related to the combined therapy of ICIs and PARPi in solid tumors from a bibliometric perspective.

Methods

Publications concerning the combination of ICIs and PARPi in solid tumors during 2008-2022 were extracted from the WOSCC database. VOSviewer and R-bibliometrix were applied to conduct bibliometrics.

Results

In total, 1113 articles were finally included. The USA was the most dominant country, and University of Texas MD Anderson Cancer Center was the most fruitful institute. Andreas Schneeweiss ranked first concerning the amount of publications in this research domain, and Timothy Yap had the most citations on this theme. The analysis of keyword co-occurrence indicated that research frontiers were shifted from the biological mechanisms of cell death to the combined strategy of ICIs and PARPi in clinical trials.

Conclusions

Our study comprehensively examined the publications on the combination of ICIs and PARPi in solid tumors from a bibliometric perspective. The research on this topic is in its rapid growth stage, and the USA is possessing an absolutely leading position in this field by its scientific accumulations and productivity. Moreover, the research frontiers have shifted from the mechanisms of ICIs and PARPi to their combined treatment in clinical application. In summary, our results demonstrated a comprehensive overview of the knowledge atlas and a valuable reference for the future investigations in this field.

The potential of PARP inhibitors in targeted cancer therapy and immunotherapy

DNA damage response (DDR) deficiencies result in genome instability, which is one of the hallmarks of cancer. Poly (ADP-ribose) polymerase (PARP) enzymes take part in various DDR pathways, determining cell fate in the wake of DNA damage. PARPs are readily druggable and PARP inhibitors (PARPi) against the main DDR-associated PARPs, PARP1 and PARP2, are currently approved for the treatment of a range of tumor types. Inhibition of efficient PARP1/2-dependent DDR is fatal for tumor cells with homologous recombination deficiencies (HRD), especially defects in breast cancer type 1 susceptibility protein 1 or 2 (BRCA1/2)-dependent pathway, while allowing healthy cells to survive. Moreover, PARPi indirectly influence the tumor microenvironment by increasing genomic instability, immune pathway activation and PD-L1 expression on cancer cells. For this reason, PARPi might enhance sensitivity to immune checkpoint inhibitors (ICIs), such as anti-PD-(L)1 or anti-CTLA4, providing a rationale for PARPi-ICI combination therapies. In this review, we discuss the complex background of the different roles of PARP1/2 in the cell and summarize the basics of how PARPi work from bench to bedside. Furthermore, we detail the early data of ongoing clinical trials indicating the synergistic effect of PARPi and ICIs. We also introduce the diagnostic tools for therapy development and discuss the future perspectives and limitations of this approach.

Combination therapy for pancreatic cancer: anti-PD-(L)1-based strategy

Mortality associated with pancreatic cancer is among the highest of all malignancies, with a 5-year overall survival of 5-10%. Immunotherapy, represented by the blocking antibodies against programmed cell death protein 1 or its ligand 1 (anti-PD-(L)1), has achieved remarkable success in a number of malignancies. However, due to the immune-suppressive tumor microenvironment, the therapeutic efficacy of anti-PD-(L)1 in pancreatic cancer is far from expectation. To address such a fundamental issue, chemotherapy, radiotherapy, targeted therapy and even immunotherapy itself, have individually been attempted to combine with anti-PD-(L)1 in preclinical and clinical investigation. This review, with a particular focus on pancreatic cancer therapy, collects current anti-PD-(L)1-based combination strategy, highlights potential adverse effects of accumulative combination, and further points out future direction in optimization of combination, including targeting post-translational modification of PD-(L)1 and improving precision of treatment.

From Bench to Bedside: How the Tumor Microenvironment Is Impacting the Future of Immunotherapy for Renal Cell Carcinoma

Immunotherapy has revolutionized the treatment landscape for many cancer types. The treatment for renal cell carcinoma (RCC) has especially evolved in recent years, from cytokine-based immunotherapies to immune checkpoint inhibitors. Although clinical benefit from immunotherapy is limited to a subset of patients, many combination-based approaches have led to improved outcomes. The success of such approaches is a direct result of the tumor immunology knowledge accrued regarding the RCC microenvironment, which, while highly immunogenic, demonstrates many unique characteristics. Ongoing translational work has elucidated some of the mechanisms of response, as well as primary and secondary resistance, to immunotherapy. Here, we provide a comprehensive review of the RCC immunophenotype with a specific focus on how preclinical and clinical data are shaping the future of immunotherapy.

Dostarlimab: First Approval

Dostarlimab (Jemperli™; GlaxoSmithKline) is a humanized monoclonal antibody programmed death-1 (PD-1) receptor antagonist being developed for the treatment of various cancers. Based on preliminary results from the GARNET trial dostarlimab has recently been approved in the EU and USA for the treatment of adult patients with mismatch repair deficient recurrent or advanced endometrial cancer. This article summarizes the milestones in the development of dostarlimab leading to these first approvals.

Dostarlimab in the treatment of recurrent or primary advanced endometrial cancer

Immune checkpoint inhibitors have demonstrated significant clinical activity across various tumor subtypes; however, their utility in gynecologic malignancies has thus far proven modest. Since the identification of a molecular subclassification system for endometrial cancer (EC), research in immune checkpoint inhibitor therapies has been focusing on certain subgroups predictive for response, particularly microsatellite instability hypermutated/DNA mismatch repair-deficient subtype. Dostarlimab, a PD-1 inhibitor, has demonstrated preliminary evidence of clinical activity and acceptable safety profile in patients with across recurrent EC, particularly microsatellite instability-hypermutated/DNA mismatch repair-deficient EC. This review outlines existing data for the efficacy and safety of dostarlimab in recurrent or advanced-stage EC.

Therapeutic Potential of Combining PARP Inhibitor and Immunotherapy in Solid Tumors

Immunotherapy has revolutionized the treatment of both hematological malignancies and solid tumors. The use of immunotherapy has improved outcome for patients with cancer across multiple tumor types, including lung, melanoma, ovarian, genitourinary, and more recently breast cancer with durable responses seen even in patients with widespread metastatic disease. Despite the promising results, immunotherapy still helps only a subset of patients due to overall low response rates. Moreover, the response to immunotherapy is highly cancer specific and results have not been as promising in cancers that are considered less immunogenic. The strategies to improve immunotherapy responses have focused on biomarker selection, like PD-L1 status, and usage of combinatorial agents, such as chemotherapy, targeted therapy, and radiotherapy. Of particular interest, DNA-damaging agents have the potential to enhance the response to immunotherapy by promoting neoantigen release, increasing tumor mutational burden, and enhancing PD-L1 expression. Poly-ADP-ribose polymerase (PARP) inhibitors are one such class of drugs that has shown synergy with immunotherapy in preclinical and early clinical studies. PARP-based therapies work through the inhibition of single-strand DNA repair leading to DNA damage, increased tumor mutational burden, making the tumor a more attractive target for immunotherapy. Of the solid tumors reviewed, breast, ovarian, and prostate cancers have demonstrated efficacy in the combination of PARP inhibition and immunotherapy, predominately in BRCA-mutated tumors. However, initial investigations into wildtype BRCA and gastrointestinal tumors have shown moderate overall response or disease control rates, dependent on the tumor type. In contrast, although a number of clinical trials underway, there is a paucity of published results for the use of the combination in lung or urothelial cancers. Overall this article focuses on the promise of combinatorial PARP inhibition and immunotherapy to improve patient outcomes in solid tumors, summarizing both early results and looking toward ongoing trials.