Major adverse cardiac events and cardiovascular toxicity with PARP inhibitors-based therapy for solid tumors: a systematic review and safety meta-analysis

BACKGROUND

Poly(ADP-ribose) polymerase (PARP) inhibitors (PARPi) provided significant antitumor activity in various tumors, mainly carrying deleterious mutations of BRCA1/BRCA2 genes. Only few data are available regarding the cardiac and vascular safety profile of this drug class. We carried out a meta-analysis for assessing the incidence and relative risk (RR) of major adverse cardiovascular events (MACEs), hypertension, and thromboembolic events in patients with solid tumors treated with PARPi-based therapy.

METHODS

Prospective studies were identified by searching the Medline/PubMed, Cochrane Library, and ASCO Meeting abstracts. Data extraction was conducted according to the Preferred Reporting Items for Systematic review and Meta-Analyses (PRISMA) statement. Combined odds ratios (ORs), RRs, and 95% confidence intervals (CIs) were calculated using fixed- or random-effects methods, depending on studies heterogeneity. RevMan software for meta-analysis (v.5.2.3) was used to carry out statistical analyses.

RESULTS

Thirty-two studies were selected for the final analysis. The incidence of PARPi-related MACEs of any and high grade was 5.0% and 0.9%, respectively, compared with 3.6% and 0.9% in the control arms, corresponding to a significant increased risk of MACEs of any grade (Peto OR 1.62; P = 0.0009) but not of high grade (P = 0.49). The incidence of hypertension of any grade and high grade was 17.5% and 6.0% with PARPi, respectively, compared with 12.6% and 4.4% in the controls. Treatment with PARPi significantly increased the risk of hypertension of any grade (random-effects, RR = 1.53; P = 0.03) but not of high grade (random-effects, RR = 1.47; P = 0.09) compared with controls. Finally, PARPi-based therapies significantly increased the risk of thromboembolic events of any grade (Peto OR = 1.49, P = 0.004) and not of high grade (Peto OR = 1.31; P = 0.13) compared with controls.

CONCLUSIONS

PARPi-based therapy is associated with a significantly increased risk of MACEs, hypertension, and thromboembolic events of any grade compared with controls. The lack of a significant increased risk of high-grade events together with the absolute low incidence of these adverse events led not to consider routine cardiovascular monitoring as recommended in asymptomatic patients.

First-line avelumab for patients with PD-L1-positive metastatic or locally advanced urothelial cancer who are unfit for cisplatin

BACKGROUND

Cisplatin-based chemotherapy is the most recommended treatment for metastatic urothelial cancer (mUC). However, about 50% of patients are considered to be cisplatin ineligible. Anti-PD1/PD-L1 therapies have, nevertheless, increased the options available to clinicians and are especially valuable for treating these patients. This study therefore tested the activity and safety of avelumab as first-line therapy for mUC.

PATIENTS AND METHODS

Patients with mUC who were ineligible for cisplatin-based chemotherapy were screened centrally for PD-L1 expression and only those with a tumour proportion score (TPS) ≥5% were enrolled in the trial. The primary endpoint was 1-year overall survival (OS), and the secondary endpoints were median OS, median PFS, the ORR, the duration of the response, safety, and tolerability. All the survival rates were estimated with the Kaplan-Meier product-limit methodology and compared across groups using the log-rank test.

RESULTS

198 patients were screened, with 71 (35.9%) whose PD-L1 expression was ≥5% enrolled in the study. The median age was 75 years, bladder cancer was the primary tumour in 73.2% of cases, and 25.3% had liver metastases. The main reasons for the cisplatin ineligibility were a low rate of creatinine clearance (< 60 ml/min), present in 70.4% of patients, and an ECOG performance status of 2, which affected 31%. The median OS was 10.0 months (95% CI, 5.5-14.5) and 43% of patients were alive at one year. A complete response was achieved in 8.5% of cases and 15.5% had a partial response. Adverse any-grade and high-grade events occurred in 49.3% and 8.5% of patients, respectively. A grade 3 infusion reaction was the only high-grade treatment-related adverse event. No treatment-related deaths were reported.

CONCLUSIONS

This ARIES trial confirmed the activity and safety of avelumab for treating mUC, adding a new therapy option to the armamentarium of checkpoint inhibitors already approved for platinum-ineligible, locally advanced/mUC.

Complete response to immune checkpoint inhibitors-based therapy in advanced renal cell carcinoma patients. A meta-analysis of randomized clinical trials

BACKGROUND

A major breakthrough with immunotherapy is its potential to achieve complete responses (CR) in a subset of advanced renal cell carcinoma (RCC) patients. We aim at evaluating the incidence and relative risk (RR) of CR in RCC patients treated with immune checkpoint inhibitors (ICIs).

MATERIALS AND METHODS

Searching the MEDLINE/PubMed, Cochrane Library and ASCO Meeting abstracts prospective studies were identified. The proportion of patients with CR events and the derived 95% confidence intervals (CIs) were calculated for each study. Combined relative risks (RRs) and 95% CIs were calculated using fixed- or random-effects methods. The analysis was performed in the intention to treat population, in the PD-L1 expressing (≥1%) RCC tumors and in patients treated with the combination of ICIs and anti-VEGFR tyrosine kinase inhibitors.

RESULTS

Six articles were considered for final analysis (total of 4.531 patients). The incidence of CR was 6.2% with ICIs and 2.6% with SOC. Treatment with ICIs significantly increased the risk of achieving CR compared to SOC (RR = 2.40; P = 0.001). This data was confirmed for patients treated with the combination of ICIs plus anti-VEGFR tyrosine kinase inhibitors (RR = 2.50; P = 0.002). In PD-L1 positive tumors, the incidence of CR was 10.0% with ICIs and 4.0% in the SOC arm (RR = 2.49; P < 0.0001).

CONCLUSIONS

ICIs provide higher rates of CR compared to SOC, even higher in patients with PD-L1 positive tumors.

New toxicity profile for novel immunotherapy agents: focus on immune-checkpoint inhibitors

INTRODUCTION

Tumor development results from a cancer-induced immunosuppression (immune-editing). Immunotherapy has revolutionized the treatment paradigm for many malignancies, putting clinicians before novel toxicities, of immune-mediated etiology (immune-related adverse events).

AREAS COVERED

Immune-mediated toxicity depends on both innate and adaptive immunity mechanisms. Healthy tissue damage depends on an aspecific T-cell hyperactivation response causing cross-reaction with normal tissues, which leads to an overproduction of CD4 T-helper cell cytokines and an abnormal migration of cytolytic CD8 T-cells. By stimulating a diffuse T-cell repertoire expansion, immune-checkpoint inhibitors counteract tumor growth but reduce the self-tolerance, damaging healthy organs. In this review, we summarize the toxicity profile of the novel immune-checkpoint inhibitors and their clinical implications, we are convinced that a deep understanding and a prompt resolution of the paradigmatic toxicities of these drugs will result in clinical benefits to patients and an enhanced antitumor effect.

EXPERT OPINION

A focus on immunotoxicity is important in the education of clinicians and will improve patient safety. There is a willingness to tailor specific immune-therapies to each cancer patient, and to stimulate researchers through understanding of the physiopathogenesis, using the hypothesis that immune-mediated toxicities can be used as predictors of response or a prognostic sign of survival, thereby guiding therapeutic decisions.

PD-1 blockade therapy in renal cell carcinoma: current studies and future promises

RCC is considered an immunogenic tumor with a prominent dysfunctional immune cell infiltrate, unable to control tumor growth. Evasion of immune surveillance, a process defined immune-editing, leads to malignant progression. The striking improvement of knowledge in immunology has led to the identification of immune checkpoints (such as CTLA-4 and PD-1), whose blockage enhances the antitumor immunity. The interaction between PD-1, an inducible inhibitory receptor expressed on lymphocytes and DCs, and PD-L1 ligand, expressed by tumor cells, results in a down-regulation of the T-cell response. Therefore, the PD-1/PD-L1 axis inhibition by targeted-antibodies, increasing the T-cell proliferation and cytotoxicity, represents a promising mechanism to stimulate the anti-tumor activity of the immune system, improving the outcomes of cancer patients. Several PD-1 and PD-L1 inhibitors have been evaluated in different tumor types, showing promising results. The interesting correlation between lymphocytes PD-1 expression and RCC advanced stage, grade and prognosis, as well as the selective PD-L1 expression by RCC tumor cells and its potential association with worse clinical outcomes, have led to the development of new anti PD-1/PD-L1 agents, alone or in combination with anti-angiogenic drugs or other immunotherapeutic approaches, for the treatment of RCC. In this review we discuss the role of PD-1/PD-L1 in RCC, focusing on the biological rationale, current clinical studies and promising therapeutic perspectives to target the PD-1 pathway.