gdc-0973 and Colonic-Neoplasms

Cardiovascular adverse events (CVAEs) associated with BRAF inhibitors alone versus combination BRAF/MEK inhibitors are not fully understood.. This study included all adult patients who received BRAF inhibitors (vemurafenib, dabrafenib, encorafenib) or combinations BRAF/MEK inhibitors (vemurafenib/cobimetinib; dabrafenib/trametinib; encorafenib/binimetinib). We utilized the cross-sectional FDA's Adverse Events Reporting System (FAERS) and longitudinal Truven Health Analytics/IBM MarketScan database from 2011 to 2018. Various CVAEs, including arterial hypertension, heart failure (HF), and venous thromboembolism (VTE), were studied using adjusted regression techniques.. In FAERS, 7752 AEs were reported (40% BRAF and 60% BRAF/MEK). Median age was 60 (IQR 49-69) years with 45% females and 97% with melanoma. Among these, 567 (7.4%) were cardiovascular adverse events (mortality rate 19%). Compared with monotherapy, combination therapy was associated with increased risk for HF (reporting odds ratio [ROR] = 1.62 (CI = 1.14-2.30); p = 0.007), arterial hypertension (ROR = 1.75 (CI = 1.12-2.89); p = 0.02) and VTE (ROR = 1.80 (CI = 1.12-2.89); p = 0.02). Marketscan had 657 patients with median age of 53 years (IQR 46-60), 39.3% female, and 88.7% with melanoma. There were 26.2% CVAEs (CI: 14.8%-36%) within 6 months of medication start in those receiving combination therapy versus 16.7% CVAEs (CI: 13.1%-20.2%) among those receiving monotherapy. Combination therapy was associated with CVAEs compared to monotherapy (adjusted HR: 1.56 (CI: 1.01-2.42); p = 0.045).. In two independent real-world cohorts, combination BRAF/MEK inhibitors were associated with increased CVAEs compared to monotherapy, especially HF, and hypertension.

Topics: Adult; Aged; Aged, 80 and over; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Azetidines; Benzimidazoles; Carbamates; Carcinoma, Non-Small-Cell Lung; Cardiotoxicity; Cardiovascular Diseases; Colonic Neoplasms; Cross-Sectional Studies; Female; Heart Failure; Humans; Hypertension; Imidazoles; Lung Neoplasms; Male; Melanoma; Middle Aged; Mitogen-Activated Protein Kinase Kinases; Oximes; Piperidines; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Pyridones; Pyrimidinones; Registries; Regression Analysis; Skin Neoplasms; Sulfonamides; Vemurafenib; Venous Thromboembolism; Young Adult

Mitogen-activated protein kinase (MAPK) kinase (MEK) is an integral component of the RAS pathway and a therapeutic target in RAS-driven cancers. Although tumor responses to MEK inhibition are rarely durable, MEK inhibitors have shown substantial activity and durable tumor regressions when combined with systemic immunotherapies in preclinical models of RAS-driven tumors. MEK inhibitors have been shown to potentiate anti-tumor T cell immunity, but little is known about the effects of MEK inhibition on other immune subsets, including B cells. We show here that treatment with a MEK inhibitor reduces B regulatory cells (Bregs) in vitro, and reduces the number of Bregs in tumor draining lymph nodes in a colorectal cancer model in vivo. MEK inhibition does not impede anti-tumor humoral immunity, and B cells contribute meaningfully to anti-tumor immunity in the context of MEK inhibitor therapy. Treatment with a MEK inhibitor is associated with improved T cell infiltration and an enhanced response to anti-PD1 immunotherapy. Together these data indicate that MEK inhibition may reduce Bregs while sparing anti-tumor B cell function, resulting in enhanced anti-tumor immunity.

Topics: Animals; Azetidines; B-Lymphocytes, Regulatory; Cell Line, Tumor; Colonic Neoplasms; Colorectal Neoplasms; Extracellular Signal-Regulated MAP Kinases; Genes, ras; Humans; Immunotherapy; Male; Mice; Mice, Inbred BALB C; Mitogen-Activated Protein Kinase Kinases; Piperidines; Protein Kinase Inhibitors; Proto-Oncogene Proteins B-raf; Xenograft Model Antitumor Assays

Targeted inhibition of mitogen-activated protein kinase (MAPK) kinase (MEK) can induce regression of tumors bearing activating mutations in the Ras pathway but rarely leads to tumor eradication. Although combining MEK inhibition with T-cell-directed immunotherapy might lead to more durable efficacy, T cell responses are themselves at least partially dependent on MEK activity. We show here that MEK inhibition did profoundly block naive CD8(+) T cell priming in tumor-bearing mice, but actually increased the number of effector-phenotype antigen-specific CD8(+) T cells within the tumor. MEK inhibition protected tumor-infiltrating CD8(+) T cells from death driven by chronic TCR stimulation while sparing cytotoxic activity. Combining MEK inhibition with anti-programmed death-ligand 1 (PD-L1) resulted in synergistic and durable tumor regression even where either agent alone was only modestly effective. Thus, despite the central importance of the MAP kinase pathway in some aspects of T cell function, MEK-targeted agents can be compatible with T-cell-dependent immunotherapy.

Topics: Animals; Antibodies, Monoclonal; Apoptosis; Azetidines; B7-H1 Antigen; Carcinoma; CD8-Positive T-Lymphocytes; Cell Cycle Checkpoints; Cell Line, Tumor; Colonic Neoplasms; Drug Synergism; Drug Therapy; Drug Therapy, Combination; Extracellular Signal-Regulated MAP Kinases; Humans; Immunotherapy; Lymphocyte Activation; Mice; Mice, Inbred BALB C; Molecular Targeted Therapy; Neoplasm Transplantation; Piperidines

The overactivation of signaling pathways, such as the PI3K and MAPK, which are crucial to cell growth and survival, is a common feature in many cancer types. Though a number of advances have been made in the development of molecular agents targeting these pathways, their application as monotherapies has not significantly improved clinical outcome. A novel liposomal preparation was developed, co-loaded with NCL-240, a small-molecule inhibitor of the PI3K/mTOR pathway, along with cobimetinib, a MEK/ERK pathway inhibitor. This combination drug-loaded nanocarrier, (N+C)-LP, was able to significantly enhance the cytotoxicity of these drugs against colon carcinoma cells in vitro demonstrating a clear synergistic effect (combination index of 0.79). The (N+C)-LP was also able to induce cell cycle arrest of the cells, specifically in the G1 phase thereby preventing their progression to the S-phase, typical of the action of MEK inhibitors. Analyzing the apoptotic events, it was found that this effect on cell cycle regulation is followed by the induction of apoptosis. The quantified distribution of apoptotic events showed that the (N+C)-LP induced apoptosis significantly by over 3-4 fold (P<0.001) compared to other treatment groups. The co-loaded liposomal preparation was also targeted to the transferrin receptor of cancer cells by modifying the surface of the liposome with transferrin. FACS analysis showed that transferrin-mediated targeting enhanced the association of liposomes to HCT 116 cells by almost 5-fold. This could potentially allow for cancer cell-specific effects in vivo thereby minimizing any non-specific interactions of the liposomes with non-cancerous cells. Taken together, this study clearly shows that the combined inhibition of the PI3K and MEK pathways correlates with a significant anti-proliferative effect, due to cell-cycle regulation leading to the induction of apoptosis.

Topics: Apoptosis; Azetidines; Chlorophenols; Colonic Neoplasms; HCT116 Cells; Humans; Liposomes; Mitogen-Activated Protein Kinase Kinases; Phosphoinositide-3 Kinase Inhibitors; Piperidines; Polyethylene Glycols; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Triazoles