Is P2Y12 inhibitor therapy associated with an increased risk of cancer?

Antiplatelet therapy is a mainstay of cardiovascular therapy and is well established in clinical routine. Recently, the potential risk of solid cancers with P2Y12 inhibitor therapy has been an issue of growing interest. The alleged association primarily originated from the findings of an US Food and Drug Administration (FDA) review of the randomized controlled TRITON-TIMI 38 trial and the following results of the DAPT trial. The higher risk of cancer was predominately observed with the newer, more potent P2Y12 inhibitors and in the setting of prolonged dual antiplatelet therapy (DAPT). Current European Society of Cardiology (ESC) Guidelines suggest consideration of prolonged DAPT beyond the recommended duration of 6 months in stable coronary artery disease and 12 months in acute coronary syndrome if ischaemic risk prevails over the risk of bleeding. Several trials, studies and meta-analyses have addressed the potential interplay of cancer and P2Y12 inhibition since then. The effect of P2Y12 inhibition on cancer has been investigated extensively in basic research as well. In this review, we summarize current available evidence of cancer risk with P2Y12 inhibitor therapy and discuss the resulting clinical implications.

Platelets in cancer. From basic research to therapeutic implications

Platelets are well-known for their major role in primary hemostasis and thrombosis. Cancer patients frequently manifest thrombotic events and present abnormalities in blood coagulation which appear to be linked to altered platelet function and turnover. Moreover, numerous studies indicate an intimate cross-talk between platelets and tumor growth, angiogenesis and metastatic dissemination. Finally, several experimental data and clinical trials suggest possible benefits of anti-platelet drugs on some cancers. Here, we will review the current state of basic biological research regarding the role of platelets in cancer progression. We also critically review the possible clinical applicability of some anti-platelet therapies to limit tumor growth and prevent metastatic dissemination.

Carcinogenicity risk assessment supports the chronic safety of dapagliflozin, an inhibitor of sodium-glucose co-transporter 2, in the treatment of type 2 diabetes mellitus

INTRODUCTION

Dapagliflozin is a selective inhibitor of the sodium-glucose co-transporter 2 (SGLT2) that increases urinary glucose excretion to reduce hyperglycemia in the treatment of type 2 diabetes mellitus. A robust carcinogenicity risk assessment was undertaken to assess the chronic safety of dapagliflozin and SGLT2 inhibition.

METHODS

Genotoxicity potential of dapagliflozin and its metabolites was assessed in silico, in vitro, and in vivo. Dapagliflozin was administered daily by oral gavage to mice, rats, and dogs to evaluate carcinogenicity risks, including the potential for tumor promotion. SGLT2(-/-) mice were observed to evaluate the effects of chronic glucosuria. The effects of dapagliflozin and increased glucose levels on a panel of human bladder transitional cell carcinoma (TCC) cell lines were also evaluated in vitro and in an in vivo xenograft model.

RESULTS

Dapagliflozin and its metabolites were not genotoxic. In CD-1 mice and Sprague-Dawley rats treated for up to 2 years at ≥100× human clinical exposures, dapagliflozin showed no differences versus controls for tumor incidence, time to onset for background tumors, or urinary bladder proliferative/preneoplastic lesions. No tumors or preneoplastic lesions were observed in dogs over 1 year at >3,000× the clinical exposure of dapagliflozin or in SGLT2(-/-) mice observed over 15 months. Transcription profiling in Zucker diabetic fatty rats showed that 5-week dapagliflozin treatment did not induce tumor promoter-associated or cell proliferation genes. Increasing concentrations of glucose, dapagliflozin, or its primary metabolite, dapagliflozin 3-O-glucuronide, did not affect in vitro TCC proliferation rates and dapagliflozin did not enhance tumor growth in nude mice heterotopically implanted with human bladder TCC cell lines.

CONCLUSION

A multitude of assessments of tumorigenicity risk consistently showed no effects, suggesting that selective SGLT2 inhibition and, specifically, dapagliflozin are predicted to not be associated with increased cancer risk.

Nonclinical Assessment of Tumor Growth Enhancement Potential by B2A-Coated Ceramic Granules Used in Arthodesis

B2A is a synthetic peptide that augments osteodifferentiation and improves bony fusion when delivered on ceramic granules during arthrodesis surgery. Nonclinical safety assessments, including genotoxicity, supported the use of B2A-coated granules as a combination medical device in pilot clinical studies. As a prelude to pivotal clinical studies, an assessment of the possibility that B2A-coated granules (and B2A) could enhance tumor growth was undertaken. B2A-coated granules demonstrated no evidence of genotoxicity. Cell culture studies with human tumor cell lines demonstrated that neither exposure of cells to B2A or B2A-coated granules increased cell proliferation or invasive capability relative to controls. In vivo, surgically implanted B2A-coated granules did not increase tumor growth (4 human tumor cell lines) or metastasis (1 cell line) relative to vehicle controls in immune-compromised rodents. Thus, traditional genotoxicity, as well as specially designed tumor growth enhancement studies, indicates that the possibility of tumor enhancement appears unlikely.