Seliciclib (roscovitine or CYC202) is an experimental

drug A drug is any chemical substance other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Consumption of drugs can be via insufflation (medicine), inhalation, drug i ...

candidate in the family of pharmacological

cyclin-dependent kinase Cyclin-dependent kinases (CDKs) are a predominant group of serine/threonine protein kinases involved in the regulation of the cell cycle and its progression, ensuring the integrity and functionality of cellular machinery. These regulatory enzym ...

(CDK) inhibitors that preferentially inhibit multiple enzyme targets including

CDK2 Cyclin-dependent kinase 2, also known as cell division protein kinase 2, or Cdk2, is an enzyme that in humans is encoded by the ''CDK2'' gene. The protein encoded by this gene is a member of the cyclin-dependent kinase family of serine/threonine ...

, CDK7 and

CDK9 Cyclin-dependent kinase 9 or CDK9 is a cyclin-dependent kinase associated with P-TEFb. Function The protein encoded by this gene is a member of the cyclin-dependent kinase (CDK) family. CDK family members are highly similar to the gene produ ...

, which alter the growth phase or state within the

cell cycle The cell cycle, or cell-division cycle, is the sequential series of events that take place in a cell (biology), cell that causes it to divide into two daughter cells. These events include the growth of the cell, duplication of its DNA (DNA re ...

of treated cells. Seliciclib is being developed by Cyclacel. This is a phase II, dose ranging, multicenter, randomized, double-blind, placebo-controlled study. The aim of this study is to assess the safety of increasing doses of roscovitine administered orally for 4 cycles of 4 consecutive days (treatment "on") separated by a 3 days treatment free period (treatment "off") in adult CF subjects with Cystic Fibrosis carrying 2 Cystic Fibrosis causing mutations with at least one F508del-CFTR mutation and chronically infected with Pseudomonas aeruginosa. This study involved 36 Cystic Fibrosis patients: 24 treated and 12 controls. Seliciclib is being researched for the treatment of

non-small cell lung cancer Non-small-cell lung cancer (NSCLC), or non-small-cell lung carcinoma, is any type of epithelial lung cancer other than small-cell lung cancer (SCLC). NSCLC accounts for about 85% of all lung cancers. As a class, NSCLCs are relatively insensitiv ...

(NSCLC),

Cushing's disease Cushing's disease is one cause of Cushing's syndrome characterised by increased secretion of adrenocorticotropic hormone (ACTH) from the anterior pituitary (secondary hypercortisolism). This is most often as a result of a pituitary adenoma (spec ...

leukemia Leukemia ( also spelled leukaemia; pronounced ) is a group of blood cancers that usually begin in the bone marrow and produce high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or '' ...

HIV infection The human immunodeficiency virus (HIV) is a retrovirus that attacks the immune system. Without treatment, it can lead to a spectrum of conditions including acquired immunodeficiency syndrome (AIDS). It is a preventable disease. It can ...

Parkinson's disease Parkinson's disease (PD), or simply Parkinson's, is a neurodegenerative disease primarily of the central nervous system, affecting both motor system, motor and non-motor systems. Symptoms typically develop gradually and non-motor issues become ...

herpes simplex Herpes simplex, often known simply as herpes, is a viral disease, viral infection caused by the herpes simplex virus. Herpes infections are categorized by the area of the body that is infected. The two major types of herpes are Cold sore, ora ...

infection,

cystic fibrosis Cystic fibrosis (CF) is a genetic disorder inherited in an autosomal recessive manner that impairs the normal clearance of Sputum, mucus from the lungs, which facilitates the colonization and infection of the lungs by bacteria, notably ''Staphy ...

,3-byrazines derivatives as submicromolar affinity activators of wild type, G551D, and F508del cystic fibrosis transmembrane conductance regulator chloride channels.J Pharmacol Exp Ther. 2006 Oct;319(1):349-59.Noel S, Faveau C, Norez C, Rogier C, Mettey Y, Becq F."> and the mechanisms of chronic

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

disorders. Seliciclib is a 2,6,9-substituted

purine Purine is a heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted puri ...

analog. Its structure in complex with CDK2 was determined in 1996. Seliciclib inhibits CDK2/E, CDK2/A, CDK7 and CDK9.

Clinical trials and lab tests

Cancer treatment

Seliciclib has been found to produce

apoptosis Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemistry, Biochemical events lead to characteristic cell changes (Morphology (biol ...

in treated cancerous cells of non-small cell lung cancer (NSCLC) and other cancers. Seliciclib has previously undergone Phase IIa clinical trials, in 240 NSCLC patients as a combined dose with existing first- and second-line treatments. In the current ''APPRAISE'' trial, the research drug is undergoing Phase IIb clinical trial as a monotherapy for NSCLC in third-line patients. The

side-effects In medicine, a side effect is an effect of the use of a medicinal drug or other treatment, usually adverse but sometimes beneficial, that is unintended. Herbal and traditional medicines also have side effects. A drug or procedure usually used ...

reported in Phase I trials of seliciclib for NSCLC were "

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

, vomiting, transient elevations in serum creatinine and liver function parameters and transient

hypokalemia Hypokalemia is a low level of potassium (K+) in the blood serum. Mild low potassium does not typically cause symptoms. Symptoms may include feeling tired, leg cramps, weakness, and constipation. Low potassium also increases the risk of an a ...

Immunological disorders

Seliciclib is also in clinical trials for

B-cell B cells, also known as B lymphocytes, are a type of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or inserted into the plasm ...

lymphomas, including

multiple myeloma Multiple myeloma (MM), also known as plasma cell myeloma and simply myeloma, is a cancer of plasma cells, a type of white blood cell that normally produces antibody, antibodies. Often, no symptoms are noticed initially. As it progresses, bone ...

. Seliciclib has been shown to inhibit

RNA polymerase II RNA polymerase II (RNAP II and Pol II) is a Protein complex, multiprotein complex that Transcription (biology), transcribes DNA into precursors of messenger RNA (mRNA) and most small nuclear RNA (snRNA) and microRNA. It is one of the three RNA pol ...

-dependent transcription and down-regulation of the protein MCL1. Seliciclib has been shown ''in vitro'' to induce

in neutrophil granulocytes. If this mechanism turns out to be safe, reliable and efficient ''in vivo'', the drug could improve treatment of chronic inflammation diseases such as

and

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

. These are usually treated with

glucocorticoid Glucocorticoids (or, less commonly, glucocorticosteroids) are a class of corticosteroids, which are a class of steroid hormones. Glucocorticoids are corticosteroids that bind to the glucocorticoid receptor that is present in almost every vertebra ...

s which often have serious side effects

Neurological therapies

In the nervous system, seliciclib has been shown to suppress

microglia Microglia are a type of glia, glial cell located throughout the brain and spinal cord of the central nervous system (CNS). Microglia account for about around 5–10% of cells found within the brain. As the resident macrophage cells, they act as t ...

l activation and to provide some

neuroprotection Neuroprotection refers to the relative preservation of neuronal structure and/or function. In the case of an ongoing insult (a neurodegenerative insult) the relative preservation of neuronal integrity implies a reduction in the rate of neuronal l ...

in animal models of cerebral ischemia. Furthermore, it increases antitumor activity of temozolomide in treatment of

glioblastoma multiforme Glioblastoma, previously known as glioblastoma multiforme (GBM), is the most aggressive and most common type of cancer that originates in the brain, and has a very poor prognosis for survival. Initial signs and symptoms of glioblastoma are nons ...

and is considered as a possible therapeutic option for glioma.

Antiviral effect

Seliciclib is also a possible antiviral agent. It causes the death of cells infected with HIV and preventing the replication of

virus.

Ovum production

Seliciclib has been shown to cause parthenogenetic egg activation. However it does create abnormal second polar bodies and therefore possible aneuploid zygotes. Egg activation usually involves calcium oscillations however this does not happen with seliciclib. Seciclib causes egg activation by inhibiting protein kinases which results in the inactivation of the maturation promoting factor (MPF).

Renal hypertrophy

Seliciclib reduces renal hypertrophy by 45% after 5/6 nephrectomy.

Side effects

Causes severe side effects that can not be tolerated on daily bases. Side effects include hypokalemia and elevation of liver enzymes. Due to these side effects Seliciclib has not been approved by the USFDA.

References

{{Intracellular chemotherapeutic agents Primary alcohols Purines Protein kinase inhibitors Experimental drugs Isopropyl compounds