Lycera (United States)

Abstract The retinoic acid-related orphan receptor γt (RORγt) is a nuclear receptor transcription factor that acts as an immune cell master control switch driving the generation and function of Th17 (helper) and Tc17 (cytotoxic) T cells. Preclinical data show that synthetic RORγ agonists modulate immune cell gene expression to both increase immune activity and decrease immunosuppressive mechanisms in the tumor microenvironment. Because RORγ agonists impact multiple antitumor mechanisms, these compounds have the potential to combine with other agents to enhance tumor immunity. In addition to preclinical data supporting a biologic rationale, bioinformatic and machine learning approaches based on the RORγ pathway were undertaken to prioritize possible clinical combinations. This work highlighted other immuno-oncology agents as well as targeted therapies and more conventional treatments. Preclinical, syngeneic mouse cancer models were used to test some of the hypotheses. Based on the finding that RORγ agonists decrease PD-1 expression and that anti-CTLA4 induces ICOS, which stabilizes RORγ expression, anti-PD1 or anti-CTLA4 agents were combined with the RORγ agonist LYC-54143 in 12 syngeneic murine models. Compared with individual agents, combination treatments elicited superior tumor growth inhibition in 6 of the models (Table). RORγ agonist treatment was also able to augment antitumor activity of doxorubicin. In preclinical and phase 1 clinical testing, the first-in-class, investigational oral small-molecule RORγ agonist LYC-55716 has demonstrated a favorable safety profile supporting combination with other immuno-oncology agents. Ongoing clinical trials include a phase 2a trial of LYC-55716 in patients with select solid tumors (NCT02929862) and a phase 1b trial of LYC-55716 combined with pembrolizumab in patients with non-small cell lung cancer. Percentage of tumor growth inhibition induced in syngeneic murine models of cancer.Murine modelAnti-PD1 aloneAnti-CTLA4 aloneRORγ agonist aloneRORγ agonist + anti-PD1RORγ agonist + anti-CTLA4H22 (Liver)30-50%>50%*10-30%>50%*>50%*Pan02 (Pancreas)<10%10-30%<10%10-30%*10-30%*CT26 (Colon)10-30%<10%<10%<10%30-50%B16F10 (Melanoma)10-30%10%10-30%10-30%30-50%A230 (Lymphoma)<10%<10%10-30%30-50%10%Renca (Renal)<10%10-30%30-50%*30-50%*30-50%*P<.05 vs vehicle. Citation Format: Xiao Hu, Xikui Liu, Hongxiu Li, Garry Weems, Elizabeth Zawidzka, Yilin Gao, H. Jeffrey Wilkins, Laura Carter. LYC-55716, a first-in-class RORγ agonist: Rationale and preclinical data to support clinical combinations with established immunotherapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5566.

This chapter discusses the pharmacology, discovery program, preclinical and clinical profiles, early process and commercial process developments of palbociclib. The importance of CDKs in regulating cell proliferation led many researchers to seek small-molecule inhibitors of cyclin-dependent kinases (CDKs) for use in cancer therapy. Palbociclib was the first highly selective CDK4/6 inhibitor described, and has received approvals for breast cancer treatment. The early discovery chemistry work to explore the structure-activity relationship (SAR) of pyridopyrimidinone CDK inhibitors built on the TK inhibitor literature and initially focused on two positions, the C2 aniline and the N-8 alkyl group. The routes for early synthesis processes for palbociclib include reversal in the order of the SNAr reaction and the Heck reaction, synthesis of aminopyridine 22 and chloropyrimidine 21, and hydrolysis and deprotection processes.

Abstract Adoptive cell transfer (ACT) therapy using tumor infiltrating lymphocytes (TILs) or T cells modified to express chimeric antigen receptors is a promising anti-cancer approach. Evidence suggests that Th17 or Tc17 cells display superior anti-tumor activity over unpolarized T cells commonly used in ACT clinical trials. As an approach to improve the potency and persistence of ACT, synthetic RORɣ agonists were designed to bolster the generation of type 17 cells. In vitro stimulation in the presence of RORɣ agonists modulates expression of costimulatory and coinhibitory molecules and increases IL-17A, IL-22 and GM-CSF production while maintaining IFNɣ production. Additional investigation revealed that treating tumor-specific Th0, Th17, Tc0 or Tc17 T cells with a RORɣt agonist in vitro significantly enhanced their ability to regress large and established EG.7 lymphoma and B16F10 melanoma tumors in vivo. Animals receiving RORɣ agonist-treated T cells had increased frequency of transferred cells, elevated IL-17A levels and decreased PD-1 expression in tumors and spleen compared to control animals. Previous studies have also shown that systemic delivery of an RORɣ agonist can also enhance anti-tumor immune response in syngeneic pre-clinical tumor models. By enhancing cytokine/chemokine production, promoting survival as well as decreasing PD-1 expression, RORɣ agonist molecules provide an effective means to enhance the potency of adoptively transferred T cell products.

Retinoic acid receptor-related orphan receptor γ (RORγt) controls the differentiation of naive CD4(+) T cells into the TH17 lineage, which are critical cells in the pathogenesis of autoimmune diseases. Here we report that during TH17 differentiation, cholesterol biosynthesis and uptake programs are induced, whereas their metabolism and efflux programs are suppressed. These changes result in the accumulation of the cholesterol precursor, desmosterol, which functions as a potent endogenous RORγ agonist. Generation of cholesterol precursors is essential for TH17 differentiation as blocking cholesterol synthesis with chemical inhibitors at steps before the formation of active precursors reduces differentiation. Upon activation, metabolic changes also lead to production of specific sterol-sulfate conjugates that favor activation of RORγ over the TH17-inhibiting sterol receptor LXR. Thus, TH17 differentiation is orchestrated by coordinated sterol synthesis, mobilization and metabolism to selectively activate RORγ.

To better define the activity of soluble CXCL16 in the recruitment of polymorphonuclear neutrophils (PMNs) in vivo, utilizing a novel animal model of gout involving engraftment of SCID mice with normal human synovial tissue (ST) injected intragraft with gouty human synovial fluid (SF). For in vitro studies, a modified Boyden chemotaxis system was used to identify CXCL16 as an active recruitment factor for PMNs in gouty SF. Migration of PMNs could be reduced by neutralization of CXCL16 activity in gouty SF. For in vivo analyses, fluorescent dye-tagged PMNs were injected intravenously into SCID mice while, simultaneously, diluted gouty SF containing CXCL16, or depleted of CXCL16 by antibody blocking, was administered intragraft. In addition, the receptor for CXCL16, CXCR6, was inhibited by incubating PMNs with a neutralizing anti-CXCR6 antibody prior to injection into the mouse chimeras. Recruitment of PMNs to the gouty SF-injected normal human ST was then examined in this SCID mouse chimera system. CXCL16 concentrations were highly elevated in gouty SF, and PMNs were observed to migrate in response to CXCL16 in vitro. Normal human ST-SCID mouse chimeras injected intragraft with gouty SF that had been depleted of CXCL16 during PMN transfer showed a significant reduction of 50% in PMN recruitment to engrafted tissue as compared with that after administration of sham-depleted gouty SF. Similar findings were achieved when PMNs were incubated with a neutralizing anti-CXCR6 antibody before injection into chimeras. Overall, the results of this study outline the effectiveness of the human-SCID mouse chimera system as a viable animal model of gout, serving to identify the primary function of CXCL16 as a significant mediator of in vivo recruitment of PMNs to gouty SF.