Novel dual acting 5’-C-ethyl-tetrazolyl-N6-substituted adenosine derivatives: synthesis and biological evaluation

Adenosine receptors (ARs) are members of the G protein-coupled receptors superfamily (GPCRs). They can be subdivided into four subtypes A1, A2A, A2B and A3. Over the past two decades, many synthetic ligands have been developed that selectively bind to a determined receptor subtype along with different functional profiles: partial or full agonists and antagonists. Potent and selective ligands of a certain AR subtype are in advanced clinical trials. Recent findings indicated that some compounds might act through two different subtypes of a receptor family, with both pathways leading to beneficial effects. A dual A2B and A3 AR antagonist was developed by Novartis as an antiasthmatic agent, while GlaxoSmithKline has investigated a dual A2A agonist and A3 antagonist as anti-inflammatory agent. Dual A2A agonists and A3 antagonists that might be advantageous for asthma or other inflammatory diseases, have been also reported [1]. Our recent work discovered the first dual acting A1AR agonists and A3AR antagonists [2] potentially useful in the treatment of some pathological conditions such as glaucoma and epilepsy. We found that the combination of 5’- C-ethyl-tetrazolyl moiety with the appropriate N6-substitution in adenosine derivatives improved affinity for both A1 and A3AR. A methyl- group at the N6 position of the 5′-C-2- ethyl-2H-tetrazolyl-adenosine derivatives was beneficial for high binding affinity at the A3, whereas a cyclopentyl-, endo-(±)-norbornyl- or 2-fluoro-4-chlorobenzyl-group conferred subnanomolar affinity for A1. Unexpectedly, the 5′-C-2-ethyl-2H-tetrazolyl-adenosine and the corresponding 2-chloro-adenosine showed high affinities for A1 and A3 and also for A2A, resulting in potent but non selective ligands. In order to better explore the influence of N6- substitution on AR affinity and selectivity of this class of AR ligands, novel 5’-C-2-ethyl- tetrazolyl-N6-substituted adenosine derivatives were synthesized and assayed at all human adenosine receptor subtypes. The results of these studies will be discussed. [1] Hou X, Majik MS, Kim K, Pyee Y, Lee Y, Alexander V, Chung H-J et al. J. Med. Chem. 2012, 55, 342. [2] Petrelli R, Lavecchia A, Luongo L, Maione S, Klotz KN, Cappellacci L et al J. Med. Chem. 2015, 58, 2560. This work was supported by the Italian MIUR fund (PRIN2009, prot. no. 200928EEX4_004 to P.R.)

Design, Synthesis, and Anticancer Activity of Novel Pyridyl and Aryl Hydrazones

Cancer is continuing to be a major health issue and despite the recent improvements in the chemotherapeutic management of some type of cancers, the therapeutic effectiveness toward the majority of solid tumors is relatively low. Half of all cancer patients fail to respond to chemotherapy and ultimately die for the disease progression. Recently, combination chemotherapy has improved dramatically the clinical outcomes of cancer patients. Even so, current treatments often do not completely release patients of their cancers and cancer cells can become resistant to various anticancer agents. Thus, the continued commitment to the arduous task of discovering new antineoplastic therapeutic agents remains critically important. The pronounced antineoplastic efficacy of hydrazones has been widely attributed to their inhibition of the mammalian enzyme Ribonucleotide Reductase (RNR), a key enzyme in DNA synthesis and cell growth control [1]. The enzyme is composed of a complex of two subunits, named R1 and R2. The R1 subunit contains the active site, while the R2 subunit contains a diferric-tyrosyl radical cofactor. Potent inhibitors interfering with the R2 subunit include the R-(N)-heterocyclic carboxaldehyde thiosemicarbazones (TSCs, such as Triapine) and the 2-acylpyridine-R-(N)-hetarylhydrazones. Currently, Triapine is in phase II clinical trial for cancer treatment, even though causes neutropenia, hypoxia and methaemoglobinemia. Following these observations, a range of chelators have been developed with improved iron chelation efficacy, lipophilicity and anti-cancer activity. Among these ligands are those of the hydrazone and thiosemicarbazone classes that demonstrate better efficacy than Triapine (e.g. Desforrioxamine, DFO or 2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone, Dp44mT). From SAR studies of these compounds, it has been deducted that an N*-N*-S* or N*-N*-N* structural motif is essential for RNR inhibition [2]. As a logical continuation, we have synthesized a series of pyridyl and aryl hydrazones as potential RNR inhibitors. In addition, compounds containing a carbon-nitrogen C=N double bond (e.g. hydrazones, acyl hydrazones) present the very attractive feature of being double dynamic entities capable of undergoing both configurational and constitutional changes, as well as metal-ion coordination. The configuration of these compounds has been assigned according to the literature and was established to be E by means of 2D-1H-NMR spectroscopy. The antiproliferative activity of the novel pyridyl and aryl hydazones against a panel of human tumor cell lines will be presented. 1. Aye, Y.; Li, M.; Long, M.J.; Weiss, R.S. Ribonucleotide reductase and cancer: biological mechanisms and targeted therapies. Oncogene, 2014, 6, 155-163. 2. Shao J, Liu X, Zhu L, Yen Y Targeting ribonucleotide reductase for cancer therapy. Expert Opin Ther Targets. 2013, 12, 1423-1437

Small-scale manufacturing of neoantigen-encoding messenger RNA for early-phase clinical trials

Messenger RNA (mRNA) has become a promising tool in therapeutic cancer vaccine strategies. Owing to its flexible design and rapid production, mRNA is an attractive antigen delivery format for cancer vaccines targeting mutated peptides expressed in a tumor-the so-called neoantigens. These neoantigens are rarely shared between patients, and inclusion of these antigens in a vaccine requires the production of individual batches of patient-tailored mRNA. The authors have developed MIDRIXNEO, a personalized mRNA-loaded dendritic cell vaccine targeting tumor neoantigens, which is currently being evaluated in a phase 1 clinical study in lung cancer patients. To facilitate this study, the authors set up a Good Manufacturing Practice (GMP)-compliant production process for the manufacture of small batches of personalized neoantigenencoding mRNA. In this article, the authors describe the complete mRNA production process and the extensive quality assessment to which the mRNA is subjected. Validation runs have shown that the process delivers mRNA of reproducible, high quality. This process is now successfully applied for the production of neoantigen-encoding mRNA for the clinical evaluation of MIDRIXNEO. To the authors' knowledge, this is the first time that a GMP-based production process of patient-tailored neoantigen mRNA has been described. (c) 2021 International Society for Cell & Gene Therapy. Published by Elsevier Inc. This is an open access articl

Neoantigen-targeted dendritic cell vaccination in lung cancer patients induces long-lived T cells exhibiting the full differentiation spectrum

Non-small cell lung cancer (NSCLC) is known for high relapse rates despite resection in early stages. Here, we present the results of a phase I clinical trial in which a dendritic cell (DC) vaccine targeting patient-individual neoantigens is evaluated in patients with resected NSCLC. Vaccine manufacturing is feasible in six of 10 enrolled patients. Toxicity is limited to grade 1–2 adverse events. Systemic T cell responses are observed in five out of six vaccinated patients, with T cell responses remaining detectable up to 19 months post vaccination. Single-cell analysis indicates that the responsive T cell population is polyclonal and exhibits the near-entire spectrum of T cell differentiation states, including a naive-like state, but excluding exhausted cell states. Three of six vaccinated patients experience disease recurrence during the follow-up period of 2 years. Collectively, these data support the feasibility, safety, and immunogenicity of this treatment in resected NSCLC