gdc-0973 and Colorectal-Neoplasms

Microsatellite-stable metastatic colorectal cancer is typically unresponsive to immunotherapy. This phase 3 study was designed to assess atezolizumab plus cobimetinib in metastatic colorectal cancer. Here, we report the comparison of atezolizumab plus cobimetinib or atezolizumab monotherapy versus regorafenib in the third-line setting.. IMblaze 370 is a multicentre, open-label, phase 3, randomised, controlled trial, done at 73 academic medical centres and community oncology practices in 11 countries. Patients aged at least 18 years with unresectable locally advanced or metastatic colorectal cancer, baseline Eastern Cooperative Oncology Group performance status of 0-1, and disease progression on or intolerance to at least two previous systemic chemotherapy regimens were enrolled. We used permuted-block randomisation (block size four) to assign patients (2:1:1) via an interactive voice and web response system to atezolizumab (840 mg intravenously every 2 weeks) plus cobimetinib (60 mg orally once daily for days 1-21 of a 28-day cycle), atezolizumab monotherapy (1200 mg intravenously every 3 weeks), or regorafenib (160 mg orally once daily for days 1-21 of a 28-day cycle). Stratification factors were extended RAS status (wild-type vs mutant) and time since diagnosis of first metastasis (<18 months vs ≥18 months). Recruitment of patients with high microsatellite instability was capped at 5%. The primary endpoint was overall survival in the intention-to-treat population. Safety was assessed in the population of patients who received at least one dose of their assigned treatment. IMblaze370 is ongoing and is registered with ClinicalTrials.gov, number NCT02788279.. Between July 27, 2016, and Jan 19, 2017, 363 patients were enrolled (183 patients in the atezolizumab plus cobimetinib group, 90 in the atezolizumab group, and 90 in the regorafenib group). At data cutoff (March 9, 2018), median follow-up was 7·3 months (IQR 3·7-13·6). Median overall survival was 8·87 months (95% CI 7·00-10·61) with atezolizumab plus cobimetinib, 7·10 months (6·05-10·05) with atezolizumab, and 8·51 months (6·41-10·71) with regorafenib; the hazard ratio was 1·00 (95% CI 0·73-1·38; p=0·99) for the combination versus regorafenib and 1·19 (0·83-1·71; p=0·34) for atezolizumab versus regorafenib. Grade 3-4 adverse events were reported in 109 (61%) of 179 patients in the atezolizumab plus cobimetinib group, 28 (31%) of 90 in the atezolizumab group, and 46 (58%) of 80 in the regorafenib group. The most common all-cause grade 3-4 adverse events in the combination group were diarrhoea (20 [11%] of 179), anaemia (ten [6%]), increased blood creatine phosphokinase (12 [7%]), and fatigue (eight [4%]). Serious adverse events were reported in 71 (40%) of 179 patients in the combination group, 15 (17%) of 90 in the atezolizumab group, and 18 (23%) of 80 in the regorafenib group. Two treatment-related deaths occurred in the combination group (sepsis) and one in the regorafenib group (intestinal perforation).. IMblaze370 did not meet its primary endpoint of improved overall survival with atezolizumab plus cobimetinib or atezolizumab versus regorafenib. The safety of atezolizumab plus cobimetinib was consistent with those of the individual drugs. These results underscore the challenge of expanding the benefit of immunotherapy to patients whose tumours have lower baseline levels of immune inflammation, such as those with microsatellite-stable metastatic colorectal cancer.. F Hoffmann-La Roche Ltd/Genentech Inc.

Topics: Aged; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Azetidines; Colorectal Neoplasms; Female; Follow-Up Studies; Humans; Liver Neoplasms; Male; Middle Aged; Phenylurea Compounds; Piperidines; Prognosis; Pyridines; Salvage Therapy; Survival Rate

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

Topics: Antibodies, Monoclonal, Humanized; Azetidines; B7-H1 Antigen; Colorectal Neoplasms; Humans; Phenylurea Compounds; Piperidines; Pyridines

Mutations in the Ras/Raf/MEK/ERK pathway are detected in 50% of colorectal cancer cases and play a crucial role in cancer development and progression. Cobimetinib is a MEK inhibitor approved for the treatment of advanced melanoma and inhibits the cell viability of other types of cancer cells.. HCT116 colorectal cancer cells were treated with cobimetinib, and MTT assay, colony formation assay, and flow cytometry were used to evaluate cell viability, cell cycle, and apoptosis, respectively. The expression of genes associated with the cell cycle and apoptosis were evaluated by quantitative real-time PCR and western blotting. To explore use of cobimetinib in colorectal cancer treatment and further understand its mechanisms, RNA-seq technology was used to identify differentially expressed genes (DEGs) between cobimetinib-treated and untreated HCT116 cells. Furthermore, we compared these DEGs with Gene Expression Omnibus data from colorectal cancer tissues and normal colonic epithelial tissues.. We found that cobimetinib not only inhibited cell proliferation but also induced G1 phase arrest and apoptosis in HCT116 colorectal cancer cells, suggesting that cobimetinib may useful in colorectal cancer therapy. After cobimetinib treatment, 3,495 DEGs were obtained, including 2,089 upregulated genes and 1,406 downregulated genes, and most of these DEGs were enriched in the cell cycle, DNA replication, and DNA damage repair pathways. Our results revealed that some genes with high expression in colorectal cancer tissues were downregulated by cobimetinib in HCT116 cells, including CCND1, E2F1, CDC25C, CCNE2, MYC, and PCNA. These genes have vital roles in DNA replication and the cell cycle. Furthermore, genes with low expression in colorectal cancer tissues were upregulated by cobimetinib, including PRKCA, PI3K, RTK, and PKC. Based on our results, the PKC and PI3K pathways were activated after cobimetinib treatment, and inhibition of these two pathways can increase the cytotoxicity of cobimetinib in HCT116 cells. Notably, cobimetinib appeared to enhance the efficacy of 5-fluorouracil (5-FU) by decreasing TYMS expression, high expression of which is responsible for 5-FU resistance in colorectal cancer.. Our results suggest the potential use of cobimetinib in colorectal cancer therapy.

Topics: Apoptosis; Azetidines; Cell Line, Tumor; Colorectal Neoplasms; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Down-Regulation; Drug Resistance, Neoplasm; Fluorouracil; G1 Phase Cell Cycle Checkpoints; HCT116 Cells; Humans; MAP Kinase Kinase Kinases; Phosphatidylinositol 3-Kinases; Piperidines; Protein Kinase Inhibitors; Thymidylate Synthase; Tumor Suppressor Protein p53; Up-Regulation

[3,4-Difluoro-2-(2-fluoro-4-iodo-phenylamino)-phenyl]-((S)-3-hydroxy-3-piperidin-2-yl-azetidin-1-yl)-methanone (GDC-0973) is a potent and highly selective inhibitor of mitogen-activated protein kinase(MAPK)/extracellular signal-regulated kinase (ERK) 1/2 (MEK1/2), a MAPK kinase that activates ERK1/2. The objectives of these studies were to characterize the disposition of GDC-0973 in preclinical species and to determine the relationship of GDC-0973 plasma concentrations to efficacy in Colo205 mouse xenograft models. The clearance (CL) of GDC-0973 was moderate in mouse (33.5 ml · min(-1) · kg(-1)), rat (37.9 ± 7.2 ml · min(-1) · kg(-1)), and monkey (29.6 ± 8.5 ml · min(-1) · kg(-1)). CL in dog was low (5.5 ± 0.3 ml · min(-1) · kg(-1)). The volume of distribution across species was large, 6-fold to 15-fold body water; half-lives ranged from 4 to 13 h. Protein binding in mouse, rat, dog, monkey, and human was high, with percentage unbound, 1 to 6%. GDC-0973-related radioactivity was rapidly and extensively distributed to tissues; however, low concentrations were observed in the brain. In rats and dogs, [(14)C]GDC-0973 was well absorbed (fraction absorbed, 70-80%). The majority of [(14)C]GDC-0973-related radioactivity was recovered in the bile of rat (74-81%) and dog (65%). The CL and volume of distribution of GDC-0973 in human, predicted by allometry, was 2.9 ml · min(-1) · kg(-1) and 9.9 l/kg, respectively. The predicted half-life was 39 h. To characterize the relationship between plasma concentration of GDC-0973 and tumor growth inhibition, pharmacokinetic-pharmacodynamic modeling was applied using an indirect response model. The KC(50) value for tumor growth inhibition in Colo205 xenografts was estimated to be 0.389 μM, and the predicted clinical efficacious dose was ∼10 mg. Taken together, these data are useful in assessing the disposition of GDC-0973, and where available, comparisons with human data were made.

Topics: Administration, Oral; Animals; Antineoplastic Agents; Autoradiography; Azetidines; Bile; Brain; Cell Line, Tumor; Cell Membrane; Cell Membrane Permeability; Colorectal Neoplasms; Dogs; Dose-Response Relationship, Drug; Female; Humans; Injections, Intravenous; Macaca fascicularis; Male; Mice; Mice, Nude; Microsomes, Liver; Models, Biological; Piperidines; Predictive Value of Tests; Prospective Studies; Protein Kinase Inhibitors; Rats; Rats, Long-Evans; Rats, Sprague-Dawley; Retrospective Studies; Species Specificity; Tissue Distribution; Xenograft Model Antitumor Assays