Abstract
Cefazolin for Autoimmune Diseases and Leukemia
Cefazolin is a first-generation cephalosporin with broad-spectrum antibiotic action that, due to its long time of generic availability, is sold under a multitude of trade names. It must have come as a real surprise when the researchers, who were screening the ZINC small molecule database for compounds that could be docked into the interleukin-15 receptor in silico, identified cefazolin as the best hit—also for the interleukin-2 receptor that shares two subunits with the IL-15 receptor. The results were verified in vitro: at 20 μM–1 mM, cefazolin significantly reduced IL-15 or IL-2-induced proliferation and TNF-α synthesis in peripheral blood mononuclear cells. A strong inhibitory effect of cefazolin on IL-17 synthesis was observed in cells stimulated with IL-2.—IL-15 is quite at the top of the proinflammatory cascade, and it is considered a crucial cytokine in the etiology of rheumatoid arthritis 1 and psoriasis; IL-2 promotes the differentiation of T-cell precursors into effector and memory T cells, which are central in cellular immune reactions; the IL-2 receptor-α is associated with rheumatoid arthritis. 2 There is a reasonable rationale to claim cefazolin for rheumatoid arthritis, psoriasis, inflammatory bowel disease, sarcoidosis, T-cell leukemias, and transplant rejection, as the inventors have done.
Cefazolin PubChem CID: 33255
Metformin for Benign Thyroid Disease
Metformin, the oldest small-molecule drug for the treatment of diabetes, might very well take off on a second career path in oncology. Korean researchers have recently reported that it also decreases gene expression and osteoclastogenic activity in the mouse model of collagen-induced arthritis, indicating immunomodulatory actions through the inhibition of Th17 cell differentiation and the upregulation of regulatory T-cell differentiation, along with the suppression of osteoclast differentiation. 3,4 This patent application takes this further by claiming metformin for thyroid autoimmune diseases, especially thyroid-associated ophthalmopathy, by way of significantly inhibiting hyaluronan production and adipocyte differentiation.—Note that adenosine monophosphate-activated protein kinase (AMPK), a central target for the modulation of insulin sensitivity (as exploited by metformin in its original therapeutic indication) and also for the feedback of thyroid hormones on appetite and energy expenditure, provides a link between thyroid disease and diabetes mellitus. 5 Also, metformin prevents uveitis in a rat model, 6 and diabetes patients on metformin have a reduced thyroid cancer risk. 7 —WO/2015/076430 from the same group of inventors makes broader claims for autoimmune diseases, inflammatory diseases, and transplant rejection.
Metformin PubChem CID: 4091
A Discontinued Antithrombotic for Mucopolysaccharidoses
Odiparcil (SB-424323), a beta-d-thioxyloside analog, is an orally active antithrombotic with an uncommon mechanism: it is a substrate for galactosyl transferase 1, which initiates the synthesis of endogenous chondroitin sulfate-related glycosaminoglycans (GAGs) that activate inhibition of thrombin by heparin cofactor II. 8 GlaxoSmithKline discontinued its development in 2007. Inventiva has now found that odiparcil, by increasing the synthesis of total GAG at the extracellular level, contributes to decrease in the intracellular charge of GAGs by acting as a decoy, making N-acetylgalactosamine-4-sulfatase more efficient. This enzyme, also known as arylsulfatase B or chondroitinsulfatase, is deficient in mucopolysaccharidosis type VI (Maroteaux-Lamy disease), which suggests a new therapeutic indication for odiparcil. Provided data show an increase in the synthesis of total GAG (in human fibroblasts), in the concentration of extracellular chondroitin GAG (in bovine aortic endothelial cells) and in total and chondroitin-type extracellular plasma GAG (in New Zealand rabbits dosed at 400 mg/kg).—Most likely this is the mucopolysaccharidosis candidate, which the applicant presents on its website under research code IVA336, stating that it “has demonstrated good tolerability, safety and efficacy in phase I and phase II studies, in ∼600 healthy volunteers and ∼1,200 patients.” If successfully developed, odipacril tablets might become a competitor for BioMarin Pharmaceutical's Naglazyme (galsulfase), the approved weekly infusion treatment for MPS VI and one of the world's most expensive drugs. Sanfilippo syndrome (MPS-III) and Sly syndrome (MPS-VII) are other mucopolysaccharidoses that might respond to odipacril.
Odiparcil PubChem CID: 216385
Silmasertib for Conditions Involving Misdirected Splicing
Silmitasertib (CX-4945) is a well-characterized inhibitor of casein kinase 2 (Ck2) with which the Korean company, Senhwa Biosciences is conducting a Phase I/II clinical trial (NCT02128282) in patients with cholangiocarcinoma. The inventors report that silmitasertib also inhibits Cdc2-like kinases (in particular, Clk2) with low-nanomolar IC50 values, better than that of TG-003, the strongest inhibitor reported to date. Cdc2-like kinases play a critical role in regulating pre-RNA splicing and post-transcriptional gene expression. In particular, Clk inhibitors suppress phosphorylation of serine-arginine signaling kinases, components of the splicing machinery that are crucial for exon selection. 9 TG-003 has been reported to modulate alternative splicing, 10 and at first look this would seem to suggest only yet another angle of attack against cancer. 11 However, a number of other diseases caused by misdirected alternative splicing have been reported, such as in neurodegenerative tauopathies. 12 Also, because Clk2 suppresses fatty acid oxidation and ketone body production during diet-induced obesity, inhibition of hepatic Clk2 might offer new perspectives for the treatment of fatty liver disease. 13 —For the peer review companion article see Kim et al. 14
Silmitasertib PubChem CID: 24748573
Granulocyte Colony Stimulating Factor for a Pregnancy Complication
This is one of the relatively rare examples where a recombinant biotechnology product is claimed as a repurposing candidate. Granulocyte colony stimulating factor (G-CSF; filgrastim, nartograstim, lenograstim, or their biosimilars), administered in daily doses from 50 μg upward, is claimed for chronic or recurrent inflammation of the chorionic villi for which no clear cause (such as an infection) can be identified. This villitis of unknown etiology (VUE) is believed to be a frequent cause of pregnancy complications, from fetal growth restriction and preterm birth to habitual miscarriages. 15 In VUE, maternal and fetal T lymphocytes and placental macrophages (Höfbauer cells) interact, indicating a breakdown of feto-maternal tolerance. 16 The rationale of using G-CSF in VUE is that healthy, nonpregnant women treated with G-CSF show reduced levels of circulating CXCR3-expressing Th1 cells (which is the finding at the core of the invention), indicating that VUE patients (who typically have elevated levels of this chemokine) might reduce their response to CXCL9, CXCL10, and CXCL11, leading to a reduction in the typical cytotoxic activation pattern seen in VUE. 17
Human Endogenous Retrovirus K Links Yellow Fever and Breast Cancer
While repurposing of therapeutic proteins is rare, it is almost unheard of for vaccines. The missing link between immunogenic antigen preparations of yellow fever virus (a mosquito-borne flavirus) and breast cancer is supposed to be the human endogenous retrovirus K (HERV-K) family. Whether the presence of HERV-K mRNAs, proteins, and even virions in cancer tissues is an epiphenomenon, or has an etiological role, remains a hotly debated topic. 18 A supposed protective effect of the most widely used yellow fever vaccine (Stamaril®, Sanofi Pasteur MSD; based on the live attenuated strain 17D) against melanoma, suspected because of sequence homology of some of its antigenic determinants with HERV-K-MEL (a viral subtype found in most melanomas) has not been confirmed in a case–control epidemiological study of over 7,000 U.S. military personnel. 19 The inventors have latched onto a recent article reporting that the HERV-K envelope protein is expressed in 65% of breast tumor cells; that a monoclonal antibody directed against this protein inhibits the growth of breast cancer cells in vitro; and that it reduces the growth of human breast cancer xenotransplants in mice. 20 They conducted a retrospective registry-based study in a cohort of 12,804 Stamaril-vaccinated women from the Italian Veneto region and evaluated the time-effect relation. In the subgroup of 3,141 women who were 40–54 years old (but not in other age classes), the risk of breast cancer was reduced by two thirds if vaccination was 2–6 years past; the protective effect vanished after 8–10 years. While such a U-shaped curve is typical for vaccine effects, the narrow age limitation does not support immune cross-reaction or antigenic mimicry as the mechanism. —For the peer review companion article see Cegolon et al. 21
Montelukast for Mild Cognitive Impairment Caused By Mold Exposure
Based on case studies, this application claims oral sustained release presentations of the antiasthmatic leukotriene D4 receptor blocker, montelukast (Merck & Co.'s Singulair®; generically available since 2012) for psychiatric disorders such as mild cognitive impairment with or without depressive symptoms. This would seem somewhat paradoxical (because montelukast has been suspected to cause nightmares, behavioral disturbances, and even suicidality, 22,23 although no connection was ever firmly established) if the claims were not limited to a very specific cause of the ailments—exposure to allergens from Stachybotrys ssp. and other molds that grow on damp building materials. Actual fungal airway infections and spore-induced allergic asthma not considered, this ties into the controversial “sick building syndrome,” a spectrum condition that continues to be broadly discussed but has largely failed verification in scientific studies. However, improvement by montelukast (used together with the cyclooxygenase-2 inhibitor rofecoxib) has been reported in a rat model of cognitive dysfunction induced by NMDA receptor blockade; 24 this might provide a clue how blockade of the lipoxygenase pathway could be beneficial in subclinical neuroinflammation with mild neuropsychiatric manifestations. —Zafirlukast-based drugs such as Accolate® and Vanticon® are also claimed. In all cases, the doses are similar to those used in asthma or allergic rhinitis.
Montelukast PubChem CID: 5281040
Zafirlukast PubChem CID: 5717
A Malaria Drug for Osteoporosis
Artemisinin is one of the classical antimalarial drugs (its discovery was honored with the 2015 Nobel prize for medicine and physiology), and it is no stranger to repurposing attempts. Besides having been shown to be broadly useful in schistosomiasis (a helminth infection), 25 artemisinin (and the closely related dihydroartemisinin and artesunate) might be useful in multidrug-resistant herpes simplex virus infection; 26 the agents have anticancer activity; 27,28 and they might even be analgesic 29 —to name only a few observations. Potential utility in osteoporosis, attributed to promotion of differentiation of bone marrow cells as is claimed here, is something entirely new again. The inventors provide no data concerning the mechanistic background for their observations in C57BL/6 murine primary cell cultures; but with the plurality of interferences in kinase signaling pathways that have been documented for this class of sesquiterpene lactones, an effect on osteoporosis seems conceivable.
Artemisinin PubChem CID: 68827
Apremilast Prevents Cytokine Storms in Viral Infections
In this application Celgene claims two selective phosphodiesterase-4 (PDE-4) inhibitors, of which “Compound B” can be identified as apremilast (Celgene's Otezla®, recently approved for plaque psoriasis and psoriatric arthrithis), for use in influenza, Argentine hemorrhagic fever, Lassa fever, and other viral infections that cause a cytokine storm. Apremilast has a strong effect on innate immunity; 30 at least in rhinovirus infection, PDE-4 inhibitors are anti-inflammatory during Toll-like receptor activation by modulating the induction of these chemotactic cytokines; 31 and roflumilast (Takeda's Daxas®/Daliresp®, another oral PDE-4 inhibitor which is approved for COPD) inhibits cytokine release in human lung parenchyma. 32 This makes the conceptual jump not huge for those who follow the PDE inhibitor field closely. However, all these articles were published very recently, and therefore they do not conflict with the application's priority date of November 6, 2013. For the immunological side effects that can make the claimed viral diseases so deadly, especially in young people with strongly reactive immune systems, there is no mention of PDE-4 inhibitors even in the newest peer review literature.
Apremilast PubChem CID: 11561674
Various Drugs and Drug Candidates to Prevent Malaria Transmission
One postulate for the development of new antimalarial drugs is the necessity to switch the target from the asexual parasites that cause malaria symptoms (but not transmission) to gametocytocidal drugs. At present the only such drug serving both purposes is primaquine, which is not widely used. The same holds for methylene blue. 33 The inventors screened several libraries for gametocidal effects against Plasmodium falciparum 3D7 gametocytes: a collection of 4,265 compounds that included 49% drugs approved for human or veterinary use by the U.S. Food and Drug Administration, 23% approved in Canada, Europe, or Japan, and the remaining 28% either in clinical trials or research tool compounds; the Malaria Box (400 drugs or tool compounds with confirmed activities on blood-stage P. falciparum); and the MIPE library, an internal collection of 550 kinase inhibitors in various stages of drug development. Twenty-seven compounds with previously unknown gametocytocidal activity (IC50 < 1 μM) were identified. Among these, 21 had more than 10-fold selectivity against gametocytes over the mammalian cell line HepG2. NSC 174938 (a tyrosyl-DNA phosphodiesterase inhibitor), Torin 2 (mTORC1 inhibitor), luminespib (hsp90 inhibitor)—all originally investigated as anticancer candidates, and the antiprotozoal ionophores, maduramicin, and narasin were the most potent compounds (IC50 values, 3–50 nM). Interestingly, several of these compounds exhibited similar or more favorable activities against the asexual drug-resistant strains HB3 or Dd2 compared with the drug sensitive 3D7 strain. DARTS (drug affinity responsive target stability) assays were conducted, and effects on parasitemia, gametocytemia, and exflagellation were examined in a mouse model of malaria. Claims are made to a series of tricyclic compounds that are mostly (phenyl)-l-(3-(trifluoromethyl)phenyl)benzo[h][l,6]naphthyridin-2(lH)-ones. Some of this work might be described in a recently published article. 34
NSC174938 PubChem CID: 3003870
Torin 2 PubChem CID: 51358113
NVP-AUY922 PubChem CID: 10096043
Maduramicin PubChem CID: 6917874
Narasin PubChem CID: 65452
XPO1 Inhibitor Drug Candidates for Anemia in β-Thalassemia
Despite extensive knowledge of the molecular defects causing β-thalassemia major, less is known about the mechanisms that are responsible for the ineffective erythropoiesis that leads to profound anemia. The inventors have clarified the role of the chaperone protein hsp70 in erythroblasts: in the nucleus, it binds to the erythrocyte maturation protein GATA-1, preventing its cleavage and proteolytic degradation by caspase-3, and ensuring erythrocyte maturation. A secondary function of hsp70 is to bind to a cytoplasmic globin and ensuring that tetrameric (α/β)2 hemoglobin properly folds. In β- thalassemia erythroblasts, hsp70 is monopolized by the excess of free alpha chains that accumulate in the cytoplasm, causing insufficient amounts of hsp70 to be available for binding and protecting GATA-1 in the nucleus. 35 Because nuclear export of hsp70 relies on the major nuclear export receptor, exportin 1 (XPO1, also chromosome region maintenance 1, CRM1) the inventors claim XPO1 inhibitors—a new and narrow class of compounds under development for malignancies 36 —for the treatment of anemia in β- thalassemia. Compound I-3 of this patent application is Karyopharm Therapeutics' selinexor (KPT-330); 37,38 compound I-4 is verdinexor (KPT-335). Compounds with similar activity, disclosed in Karyopharm's WO/2011/109799, WO/2012/099807, WO/2013/020024, and WO/2013/019548 (including KPT-251), are also considered to be within the scope of the invention. Karyopharm's Phase II study, Selinexor in Older Patients With Relapsed AML (SOPRA) is currently recruiting patients; the closely related verdinexor has completed a Phase I clinical trial, and is intended for development as an influenza replication inhibitor 39 and for canine lymphomas.
Selinexor PubChem CID: 71481097
Verdinexor PubChem CID: 71492799
New Mechanism for Chlorhexidine and Pyrvinium Suggests Antimetastasis Potential
Synaptojanin-2 is a 5′-phosphatidylinositol lipid phosphatase that can initiate cell migration. In this patent application and its peer review companion article 40 the inventors have shown that it is not only involved in the formation of cellular lamellipodia and invadopodia, promoting lung metastasis of breast tumor xenografts in mice, but also in the endocytic recycling of the epidermal growth factor receptor. Almost as a side note in the wake of this identification of a new and potentially druggable target to interfere with cancer metastasis, it is reported that screening of the compound libraries identified two well-known drugs as synaptojanin inhibitors: the antibacterial bisbiguanide, clorhexidine; and the antihelminthic, pyrvinium. With an IC50 of 10 μM in an assay for specific phosphatase activity, chlorhexidine (which has recently been reported as a potential inhibitor of wild-type Abl1 kinase, and was suggested as a repurposing candidate for chronic myeloic leukemia 41 ) is among the less active synaptojanin-2 inhibitors reported here. With an IC50 of 1.25 μM pyrvinium pamoate is almost one order of magnitude better, but in contrast to all other compounds that are listed here it is even more active against synaptojanin-1. (This is interesting in itself: considering the role of synaptojanin-1 in synaptic vesicle recycling and receptor trafficking in neurons, which could mean that pyrvinium has repurposing potential for Alzheimer's disease and Down syndrome. 42 ) The antitumor activity of pyrvinium has been known since at least 2004 but was originally attributed to its inhibition of Akt phosphorylation. 43 The newest reports have shown that its activity in chronic myeloic leukemia does not depend on inhibition of the Wnt/β-catenin signaling pathway. 44
Chlorhexidine PubChem CID: 9552079
Pyrvinium pamoate PubChem CID: 54680693
Looming Diuretics for Down Syndrome
Using the classical Ts65Dn mouse model of Down syndrome, the inventors have obtained experimental evidence linking excessive neuronal chloride import mediated by the Na-K-Cl co-transporter (NKCC) to the Alzheimer-like cognitive defects that characterize this trisomy. The elevated intracellular chloride levels facilitate neuronal depolarization, and these can lead to paradoxical excitatory actions of γ-aminobutyric acid when it binds to its GABA-A receptor (which is also a chloride channel). This serves to maintain a degree of random glutamatergic overactivity that will perturb behaviorally relevant excitatory signals. The loop diurectic, bumetanide restored long-term potentiation and hyperpolarizing GABA actions in hippocampal slices of the mutant mice, reduced elevated glutamatergic activity, and rescued impaired animal performance in novel object recognition, memory formation, and behavior after 1–4 weeks of treatment. It is only logical that other loop diurectics such as furosemide, torasemide, and azosemide, but also thiazide-like diuretics (which compete with chloride at an electroneutral Na/Cl co-transporter in nephrons) are also claimed.—The implications of this discovery could be broader because NKCC-driven neuronal overstimulation is also seen in epilepsy, spinal cord lesions, and traumatic brain injuries. —For the peer review companion article see Deidda et al. 45 Note that inverse GABA-A receptor agonists (which reduce inhibitory GABAergic transmission), also rescue learning and memory deficits in Ts65Dn mice. 46
Bumetanide PubChem CID: 2471
Furosemide PubChem CID: 3440
Torasemide PubChem CID: 41781
Azosemide PubChem CID: 2273
Hydrochlorothiazide PubChem CID: 3639
A Migraine Medication for Rosacea
Rosacea is a common dermatological condition, and although its root causes continue to be incompletely understood its manifestations involve neurogenic inflammation and neurovascular dysregulation in the facial skin. Environmental and psychological factors are also obvious. This pattern of pathology is not too dissimilar from what is seen in migraine, the primary difference being that intracranial vessels are affected. An epidemiological correlation between the two conditions has first been reported 40 years ago. 47 In retrospect, the inventor's conclusion to investigate triptans for utility as topical agents for rosacea appears obvious; but there is no immediate indication in the peer review or patent literature suggesting that such studies have been reported. Naratriptan (Abbott's Amerge® and generics) was the only triptan that satisfied the criteria for topical use: good dermal penetration to the subcutaneous vessels expressing 5-HT1B and 1D receptors, and a broad systemic safety window. Myography results obtained with fresh subcutaneous human veins are presented.—A large retrospective case–control study has recently confirmed a slightly increased risk for older female (but not male) migraineurs to develop rosacea, with such elevated risk also seen in elderly women who used triptans for the symptoms of their migraine. 48 But obviously, the subdermal triptan concentrations that are achieved by systemic triptan doses used for migraine are almost negligable compared to those that can be achieved by a topical formulation. Only a randomized, double-blind multi-week study in patients with vascular rosacea (as outlined in the application, although the planned number of 25 subjects seems low) can clarify whether the inventor's conclusion holds.This is one of a larger series of Galderma patent applications claiming various topical therapies for all four types of rosacea.
Naratriptan PubChem CID: 4440