Checkpoint inhibitors have been implicated in the treatment of several cancers due to their ability to exploit the immune system\'s regulatory pathways. This article serves to emphasize the importance of these immunotherapeutic agents and provide further insight into their mechanisms, efficacies, and safety profiles. The main agents in question include programmed cell death protein 1 (PD-1) and programmed death ligand 1 (PD-L1). Several literature sources were found to assess the use of these inhibitors in cancers involving the lung, breast, and skin. Several peer-reviewed systematic reviews and the outcomes of clinical trials are combined within this article to support the use and further investigation of these agents in treating neoplasms. Further research into these forms of therapy underscores the revolutionary advancement of oncological interventions, which is important given the rising incidence of neoplasms within populations.

The PD-1/PD-L1 pathway plays a significant role in inhibiting, escaping from immune response, and promoting self-tolerance of the tumour. Dostarlimab is a selective humanized monoclonal antibody designed to target PD-1 and block its activity with PD-L1, which further prevents the escape of tumour cells from immune surveillance. It got accelerated approval from the FDA for treating adults with mismatch repair deficient, recurrent, or advanced endometrial cancer, and studies confirmed its beneficial effects. A recently published clinical trial reported 100 % remission of advanced rectal cancer without significant side effects in the participants. This clinical trial is still going on and enrolling patients with different types of cancer, including ovarian cancer, melanoma, head and neck cancer, and breast cancer therapy. The clinical trial result gave hope and proof to the medical fraternity and patients for better treatment. The focus of this review is to summarise pre-clinical and clinical studies of Dostarlimab.

BACKGROUND: Whether PD-L1 testing is needed to identify patients receiving PD-1/PD-L1 inhibitors is an area of debate.
METHODS: PubMed and Embase were searched for phase III randomized clinical trials. We assessed the heterogeneity of overall survival (OS) between patients with high and low PD-L1 expression using an interaction test.
RESULTS: Seventy studies representing 44791 patients were included. Both the CPS and TPS can predict better survival from anti-PD-1/PD-L1 therapy in patients with high PD-L1 expression. However, only CPS 1 has the ability to select patients who are unlikely to respond to anti-PD-1/PD-L1 therapy, while an OS advantage can be obtained from PD-1/PD-L1 inhibitors both in patients with high and low PD-L1 expression defined by CPS 5, CPS 10 and TPS.
CONCLUSIONS: CPS 1 is recommended to select patients with the likelihood of benefiting from PD-1/PD-L1 inhibitors while excluding patients who may not respond.

This meta-analysis aims to evaluate the efficacy and safety of neoadjuvant PD-1 inhibitors or PD-L1 inhibitors [PD-(L)1 inhibitors] for muscle-invasive bladder carcinoma (MIBC).
Four databases (Medline, Embase, Web of Science, and 21 CENTRAL) were searched for articles studying neoadjuvant PD-(L)1 inhibitors for MIBC. The search time period was from the establishment of each database to 21 July 2023. Meta-analyses of pCR, pPR, Grade≥ 3 irAEs rate, RFS, and OS were performed.
In total, 22 studies were included for meta-analysis. The overall pooled pCR of neoadjuvant PD-(L)1 inhibitors was 0.36 (95%CI=0.30-0.42, p=0.00). In subgroup meta-analysis, the pooled PCR of PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.27 (95%CI=0.19-0.35, p=0.1), 0.41 (95%CI=0.21-0.62, p=0.01), 0.43 (95%CI=0.35-0.50, p=0.06), respectively. The overall pooled pPR of neoadjuvant PD-(L)1 inhibitors was 0.53 (95%CI=0.46-0.60, p=0.00). In subgroup meta-analysis, the pooled pPR of PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.36 (95%CI=0.22-0.51, p=0.01), 0.51 (95%CI=0.39-0.62, p=0.43), and 0.61 (95%CI=0.53-0.69, p=0.01), respectively. Kaplan-Meier curves for OS and RFS were reconstructed, but there was no significant difference among three groups in terms of OS or RFS. The pooled result of Grade≥ 3 irAEs rate for neoadjuvant PD-(L)1 inhibitors was 0.15 (95%CI=0.09-0.22, p=0.00%). In subgroup analysis, the pooled result of Grade≥ 3 irAEs rate for PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI, and PD-(L)1 inhibitors plus chemotherapy was 0.07 (95%CI=0.04-0.11, p=0.84), 0.31 (95%CI=0.16-0.47, p=0.06), and 0.17 (95%CI=0.06-0.31, I2 = 71.27%, p=0.01), respectively.
Neoadjuvant PD-(L)1 inhibitors were feasible and safe for muscle invasive bladder cancer. Compared with PD-(L)1 inhibitors alone, PD-(L)1 inhibitors plus other ICI and PD-(L)1 inhibitors plus chemotherapy were associated with higher pCR and pPR, but higher Grade≥3 irAEs. Kaplan-Meier curves for OS and RFS indicated that neoadjuvant PD-(L)1 inhibitors had an acceptable long-term prognostic, but it was not possible to discern statistical differences between the three neoadjuvant subgroups.
https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023452437, identifier PROSPERO (CRD42023452437).

The immune checkpoint inhibitor (ICI), anti-programmed cell death receptor-1 (PD-1) antibody, has gained widespread approval for treating various malignancies. Among the immune-related adverse reactions (irAEs) during ICI treatment, the lichenoid reaction is noteworthy. Sintilimab, a new PD-1 inhibitor, has secured approval in China for treating refractory non-Hodgkin\'s lymphoma, and phase I/II clinical trials for other solid tumors are ongoing both domestically and abroad. This paper presents a case of a mucocutaneous lichenoid reaction associated with sintilimab therapy, its diagnosis, and management. Our study, using multiplex immunofluorescence staining, reveals localized infiltration of CD4+ and CD8+ T lymphocytes in the subepithelial lamina propria region with upregulated PD-1 expression, implying an association between PD-1 expression upregulation and lichenoid reactions provoked by PD-1 monoclonal antibody. We provide a summary of clinical characteristics and treatment guidelines for lichenoid reactions induced by ICIs from previous reports, highlighting the success of a combined therapeutic regimen of oral antihistamines and topical corticosteroids in controlling symptoms without interrupting ICI treatment.

Immunotherapy with PD-1 blockade has achieved a great success in colorectal cancers (CRCs) with high microsatellite instability (MSI-H) and deficient mismatch repair (dMMR), and has become the first-line therapy in metastatic setting. Studies of neoadjuvant immunotherapy also report exciting results, showing high rates of clinical complete response (cCR) and pathological complete response. The high efficacy and long duration of response of immunotherapy has prompt attempts to adopt watch-and-wait strategy for patients achieving cCR following the treatment. Thankfully, the watch-and-wait approach has been proposed for nearly 20 years for patients undergoing chemoradiotherapy and has gained ground among patients as well as clinicians. In this narrative review, we combed through the available information on immunotherapy for CRC and on the watch-and-wait strategy in chemoradiotherapy, and looked forward to a future where neoadjuvant immunotherapy as a curative therapy would play a big part in the treatment of MSI-H/dMMR CRC.

Intrahepatic cholangiocarcinoma (ICC) is a highly aggressive malignancy rising from the biliary tree with poor prognosis. We report the feasibility and efficacy of transarterial chemoembolization (TACE) combined with PD-1 inhibitor and apatinib for the treatment of a patient with unresectable ICC. A 70-year-old female presented with intermittent right upper abdominal distension, abdominal pain, and vomiting after eating for more than one month. Enhanced computed tomography (CT) and magnetic resonance imaging (MRI) scan revealed multiple intrahepatic lesions, retroperitoneal lymph node, and left lung metastasis. Based on the patient\'s medical history and pathology, the diagnosis was confirmed as locally advanced unresectable ICC. Multimodal therapy was applied to the ICC. The therapy comprised TACE every three months, and a combination regimen of the PD-1 inhibitor camrelizumab and the antiangiogenic agent apatinib. The patient underwent microwave ablation for a lesion on the left lung that had not responded to systemic therapies. Enhanced CT scan after every 2-3 months was performed. After several sessions, the primary lesion reduced dramatically in size. At 20 months from diagnosis, the patient was alive, in good condition, and stable. The patient experienced no critical complications and toxicity associated with the administered therapies. This case suggests that treatment with TACE combined with systemic therapy of camrelizumab combined with apatinib may be a safe and effective treatment option for patients with inoperable ICC.

Monoclonal antibodies directed against immune checkpoint proteins have been widely used to treat various cancers and have resulted in favorable clinical outcomes. Despite these beneficial properties, immune checkpoint inhibitors (ICIs) can induce side effects called immune-related adverse events, including sarcoidosis-like reactions (SLR) across multiple organs. Here, we report a case of renal SLR after ICI treatment, and we review the related literature. A 66-year-old Korean patient with non-small cell lung cancer was referred to the nephrology clinic for renal failure after the 14th pembrolizumab treatment dose. A renal biopsy revealed multiple epithelioid cell granulomas, with several lymphoid aggregates in the renal interstitium and a moderate degree of inflammatory cell infiltration in the tubulointerstitium. A moderate dose of steroid therapy was initiated, and the serum creatinine level partially recovered after four weeks of treatment. Judicious monitoring of renal SLR is, therefore, required during ICI therapy, and a timely diagnosis by renal biopsy and appropriate treatment are important.

BACKGROUND: Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death, worldwide. The predominant causative factor for HCC is hepatitis B virus (HBV) infection. We conducted a meta-analysis to estimate the efficacy and safety of PD-1/PD-L1 inhibitors combined with anti-angiogenic therapy for the first-line treatment of the unresectable HCC and to evaluate the benefits of different geographic regions and etiology stratifications.
METHODS: Randomized clinical trials published up to 12th November 2022 were searched by online databases. Moreover, effects of hazard ratio (HR) for overall survival (OS) and progression-free survival (PFS) were extracted from included studies. Pooled odds ratio (OR) and 95% CI for objective response rate (ORR), disease control rate (DCR), and treatment-related adverse events (TRAEs) were calculated.
RESULTS: A total of 3057 patients from five phase III randomized clinical trials were collected and reviewed for this meta-analysis. The pooled HR of OS (HR = 0.71; 95% CI: 0.60-0.85) and PFS (HR = 0.64; 95% CI: 0.53-0.77) demonstrated significantly better benefit in PD-1/PD-L1 inhibitors combination group than targeted monotherapy to treat unresectable HCC. In addition, combination therapy showed better ORR and DCR, with ORs of 3.29 (95% CI: 1.92-5.62) and 1.88 (95% CI: 1.35-2.61), respectively. The subgroup analysis indicated that PD-1/PD-L1 inhibitors combination therapy was significantly superior to anti-angiogenic monotherapy for HBV-related HCC in terms of OS (HR = 0.64; 95% CI: 0.55-0.74) and PFS (HR = 0.53; 95% CI:0.47-0.59), while there was no significant difference in patients with HCV (OS, HR = 0.81, p = 0.1) or non-viral (OS, HR = 0.91, p = 0.37; PFS, HR = 0.77, p = 0.05).
CONCLUSIONS: Meta-analysis revealed for the first-time that PD-1/PD-L1 inhibitors combination therapy for unresectable HCC was associated with better clinical outcomes than anti-angiogenic monotherapy, especially for HBV infection and Asian population.

In recent years, a number of clinical trials have shown that programmed death 1 (PD-1) inhibitors offer significant survival benefits in patients with esophageal squamous cell carcinoma (ESCC). We conducted a meta-analysis to explore the antitumour efficacy of PD-1 inhibitor-based therapy in specific subgroups of patient with advanced ESCC.
We searched for eligible studies from the PubMed, Embase, Web of Science, Cochrane Library databases and conference abstracts. The indicators related to survival outcomes were extracted. The pooled hazard ratios (HRs) for overall survival (OS), progression-free survival (PFS) and duration of response (DOR) and the pooled odds ratio (OR) for objective response rate (ORR) were calculated to evaluate the efficacy of PD-1 inhibitor-based therapy in ESCC. Data regarding treatment lines, treatment regimens, programmed death ligand 1 (PD-L1) status, baseline demographic and disease characteristics were extracted. Subgroup analyses were conducted in specific populations of ESCC patients. The Cochrane risk of bias tool and sensitivity analysis were used to assess the quality of the meta-analysis.
Eleven phase 3 randomized controlled trials (RCTs) involving 6267 patients with ESCC were included in this meta-analysis. Compared with standard chemotherapy, PD-1 inhibitor-based therapy provided benefits in terms of OS, PFS, ORR, and DOR in all populations, the first-line treatment group, the second-line treatment group, the immunotherapy group, and the immunochemotherapy group. Although a limited PFS benefit was observed in second-line treatments and immunotherapy alone, PD-1 inhibitor-based therapy still reduced the risk of disease progression or death. Patients with high PD-L1 expression had a better OS benefit than those with low PD-L1 expression. The HR for OS favoured PD-1 inhibitor-based therapy over standard chemotherapy for all prespecified clinical subgroups.
Compared with standard chemotherapy, PD-1 inhibitor-based therapy exhibited clinically meaningful benefits in patients with ESCC. Survival benefits were better in patients with high PD-L1 expression than in those with low PD-L1 expression, suggesting that the PD-L1 expression level can be used as a predictor of survival benefit from PD-1 inhibitor therapy. PD-1 inhibitor-based therapy provided a consistent benefit in reducing the risk of death according to prespecified subgroup analyses of clinical characteristics.