Abstract
Rifampicin, Hyperforin, and Ursodeoxycholic Acid for Genetic Diseases
International Patent Application WO/2021/001518, PXR Ligands for the Prevention or Treatment of Metabolic Disorders (Inventors: Wagner M, Panzitt K; applicant: Medizinische Universität Graz, Graz, Austria; published: January 7, 2021).
In α1 antitrypsin deficiency, a metabolic disorder caused by mutations in the SERPINA1 gene, mutant α1 antitrypsin polymerizes within hepatocytes, precluding it from being secreted into the bloodstream from where it should reach the lungs to protect alveolar tissue from proteolytic damage, primarily from lung neutrophil elastase. Instead, the mutant protein forms aggregates in hepatocytes that can ultimately cause liver cirrhosis. 1 To an extent, this is analogous to lysosomal storage diseases, where accumulation of substrates occurs within lysosomes. 2 The inventors' discovery that the pregnane X receptor (Pxr, a promiscuous and xenosensing nuclear transcription factor 3 ) can stimulate autophagy both directly and via the transcription factor EB (TFEB), 4 thereby enhancing the elimination of intracellular aggregates, provides a potential treatment avenue for both types of genetic diseases. It also makes known Pxr activators such as the antibiotic rifampicin, the antidepressant phytochemical hyperforin, and the prototypical cholelithiasis drug ursodeoxycholic acid candidates for treating disorders such as α1 antitrypsin deficiency and lysosomal acid lipase deficiency. Reanalysis of a published Pxr ChIP-Seq dataset 5 showed a robust Pxr binding site in the first intron of TFEB, which the inventors could recapitulate by Pxr ChIP polymerase chain reaction in human liver. In livers of rifampicin-treated patients, LC3-II (a microtubule-associated protein that serves as a readout marker for autophagy) was significantly increased, as was the transcription of several autophagy-related genes. Both rifampicin and hyperforin robustly reduced pathological α1 antitrypsin aggregates in HeLa cells.
A Broad Spectrum of Repurposing Candidates for Prion Diseases
International Patent Application WO/2021/005189, Novel Pfar-Inhibiting Compounds (Inventors: Simonelig M, Bihel F, Voisset C, Trollet C; applicants: Université de Bretagne Occidentale [UBO], Brest, France; Centre Nationale de la Recherche Scientifique [CNRS], Paris, France; Institut National de la Santé et de la Recherche Médicale [INSERM], Paris, France; Université de Montpellier, Montpellier, France; Université de Strasbourg, Strasbourg, France; Centre Hospitalier Régional et Universitaire de Brest, Brest, France; Sorbonne Université, Paris, France; Etablissement Français du Sang, Saint Denis, France; Association Institut de Myologie, Paris, France; Association Française contre les Myopathies, Paris, France; published: January 14, 2021).
Ribosomes do not only translate RNA, but they also modulate the folding of the resulting protein by acting as chaperones. This is the ribosomal RNA-dependent protein folding activity of the ribosome (PFAR), which has been suggested as a drug target for prion diseases because it stabilizes the pathogenic folding of the nascent prion proteins. 6,7 Several candidate drugs have already emerged, including the old antihypertensive guanabenz, 8 the TLR7 agonist imiquimod 9 which is widely used as a topical treatment for precancerous skin conditions, and others. The inventors opted for the SOSA approach (Selective Optimization of Side Activities) to screen drugs already in use or in clinical trials to determine whether they are likely to have additional pharmacological targets. This was followed by testing the hits for activity against the ovine prion PrPSc protein in culture and by a PFAR interference assay published earlier. 10 Thus they expanded their earlier work not only to many other known compounds, ebastine, azelastine, and duloxetine (the preferred ones), but also to atomoxetine, benzydamine, biperidone, chloropyramine, citalopram, dicyclomine, nefopam, orphenadrine, prenylamine, triflupromazine, and zimelidine. The document also identified preferred drug combinations for the treatment of prion diseases: ebastine with flunarizine, azelastine, or loperamide; azelastine with flunarizine or loperamide; and flunarizine and loperamide. Most were active at concentrations in the 0.75–3.5 μM range for each component. For the peer review companion article, see Bamia et al. 11
Azasetron Protects the Inner Ear Beyond its Hair Cells
International Patent Application WO/2021/014014, Treatment and/or Prevention of Lesions in the Central Auditory Nervous System (Inventors: Dyhrfjeld-Johnsen J; applicant: Sensorion SA, Montpellier, France; published: January 28, 2021).
The vestibular system expresses 5-HT3 receptors 12 that are coupled to the calcineurin pathway; this makes antagonists potential treatments for inner ear disorders. 13,14 Sensorion, a company specializing in the treatment of inner ear diseases, is developing the R-isomer of the 5-HT3 receptor antagonist antiemetic, azasetron for sudden sensorineural hearing loss under research code SENS-401; the Phase II/III AUDIBLE-S trial (NCT03603314) has been underway since March 2021. The company's WO/2017/178645 already covered the isomer's use in ear disorders, following-up from the more general WO/2016/184900, which claims the use of the “setron” class of compounds for this purpose, on the basis of their calcineurin inhibitor activity (an effect first described for tropisetron 13 ). The present document closes a remaining gap by providing experimental data showing that (R)-azasetron besylate also reduces deeper neuronal damage in the ventral cochlear nucleus after acoustic trauma. Oral administration of 26.4 mg/kg to NMRI mice 0–72 h after their exposure to various levels and frequency spectra of damaging noise (in ketamine anesthesia) did not significantly affect the threshold shift of the auditory brainstem response, but protected against the loss of outer hair cells in the cochlea at growing distances from the apex, and also protected neurons in the inferior colliculus, independent of the time of administration. For the peer review companion article using a rat model and showing the dose-response relationship, see Petremann et al. 15
Disulfiram: an Antidepressant, Anxiolytic, and Nootropic Beyond Alcohol Withdrawal
International Patent Application WO/2021/015300, Agent for Treating, Preventing, or Improving Psychiatric and Nervous System Disorders or Symptoms (Inventors: Saitoh A, Terashima Y, Matsushima K, Sano Y; applicant: Tokyo University of Science Foundation, Tokyo, Japan; published: January 28, 2021).
Disulfiram, the classic aversive drug in alcohol withdrawal therapy, inhibits acetaldehyde dehydrogenase, thereby causing extreme hangover from the alcohol catabolism product, acetaldehyde. It also is among the drugs with the most repurposing claims: numerous other pharmacological activities have been described, such as inhibition of ATPases, blockade of angiogenesis, and proapoptotic effects in cancer, 15 and most recently, even protection against obesity and metabolic syndrome. 16 Many of these activities of disulfiram can be traced to its copper-binding activity, 17 which makes it a potent autophagy inducer. In neuropsychiatry, alteration of amyloid precursor protein cleavage 18,19 could give it potential in Alzheimer's disease. However, the peer review literature seems to contain very few reports suggesting antidepressant and anxiolytic activity of disulfiram and its active metabolite, diethyldithiocarbamate, outside of the alcohol withdrawal context. 20 In the mouse elevated cross-maze paradigm, anxiolytic efficacy of these compounds and their prodrugs (20–80 mg/kg i.p.) was comparable to that of diazepam; ICR mice showed reduced hyperactivity and less stress reaction in social interaction. With disulfiram (200 mg/day) given in food to cognitively unimpaired animals, there was a positive effect in the novel object recognition paradigm, and after 4 weeks, of disulfiram exposure performance in the Morris water maze was also improved. These doses are very high, and disulfiram has considerable toxicity; however, it might be useful as an adjunct drug at lower doses.
A Dangerous Clozapine Side Effect of Potential use to Treat Autoimmune Diseases
International Patent Application WO/2021/019249, Clozapine for Use in Treating Pathogenic Immunoglobulin Driven B Cell Disease (Inventors: Jolles S, Ashrafian H, Mchale D; applicant: Zarodex Therapeutics Ltd., London, United Kingdom; published: February 4, 2021).
Clozapine, the first atypical antipsychotic to reach the market, is also the most effective one. However, it is only a second-line drug, to be used in treatment-resistant schizophrenia because of its significant side effects, which include agranulocytosis, for which blood testing is mandatory. Testing for antibody deficiency is not part of current clozapine monitoring protocols, although recent studies have shown that such an association exists 21 and that clozapine induces a B cell signature resembling common variable immunodeficiency. 22 The inventors have now shown that clozapine significantly and preferentially reduces levels of class-switched memory B cells (i.e., mature B cells that have replaced their primary encoded membrane receptor, IgM by IgG, IgA, or IgE in response to repeated antigen recognition) and plasmablasts (short-lived rapidly cycling antibody-secreting B cells at a later stage of maturity). Both are significant producers of pathogenic autoantibodies as seen in multiple sclerosis, Type 1 diabetes, myasthenia gravis, scleroderma, pemphigus, and other autoimmune diseases that show incomplete response to anti-CD20 antibodies such as rituximab. Among many other immunological assays, an established in vitro platform, which uses a CD40L/IL-2/1L-21-based stimulus to drive B cell activation and differentiation in a three-step process to generate plasmablasts and functional polyclonal mature plasma cells, 23 was used to evaluate the impact of clozapine, its major metabolite norclozapine, and a comparator antipsychotic (haloperidol) on the generation and differentiation and viability of human plasma cells. None of the drugs was directly toxic to differentiating B cells. In mice, clozapine (10 or 25 mg/kg) reduced both primary (IgM-dominated and early IgG response) and secondary humoral responses to immunization with keyhole limpet hemocyanin (a T cell-dependent antigen), a process which involves antigen processing and presentation, priming and interaction between T and B cells, B cell activation, antibody generation by B cells, and cytokine-dependent class-switch recombination.
A Preservative and Antidandruff Agent for Small Cell Lung Cancer?
International Patent Application WO/2021/023290, Application of Zinc Pyrithione in Treatment of Lung Cancer (Inventors: Chen Y, Wang G, Hong J, Wu Q, Chen R, Huang P, et al.; applicant: Xiamen University, Xiamen, China; published: February 11, 2021).
Zinc pyrithione, an antimicrobial agent modeled after aspergillic acid, has two major uses: as a preservative in paints and clothes and in dermatology—mainly for dandruff and seborrheic dermatitis. It upregulates heat shock response genes in human skin and induces DNA damage 24 and acts as a ionophore for zinc, a necessary trace element associated with several cancers, 25 but its pharmacology is complex and not understood to the last detail. 26 Hep2 cervical tumor cells were the first to be reported as being sensitive to zinc pyrithione, 27 followed by prostate cancer cell lines (which differ dramatically from normal cells in their zinc handling ability); zinc pyrithione kills them through Erk- and PKC-dependent necrosis, as opposed to apoptosis induced by zinc chelators. 28 In contrast, the work disclosed by the inventors suggests that killing of various lung carcinoma cell lines (A549 adenocarcinoma, H661 large cell cancer, and—most notably—H1417 small cell carcinoma) rather proceeds through apoptosis, at concentrations of 10 μM or less. Migration of A549 cells is significantly inhibited at 2.5 μM. After intraperitoneal injection of 10 mg/kg, A549 proliferation in SCID mice was significantly inhibited. The extremely low solubility of zinc pyrithione might be an advantage for depot injections.
Cholinesterase Inhibitors for Impaired Stereopsis: A Case of on-Target Repurposing
International Patent Application WO/2021/026653, Cholinergic Potentiation of Binocular Vision (Inventors: Hess RF, Sheynin J, Vaucher E; applicant: The Royal Institution for the Advancement of Learning/McGill University, Montréal, Canada; Université de Montréal, Montréal, Canada; published: February 18, 2021).
To produce a 3D representation of the visual field, the visual cortex must integrate the separate signals from the two eyes that arrive from the fourth thalamorecipient. This requires a delicate balance between the gain of thalamocortical synapses and inhibition of intracortical interactions. This crucial function, in which acetylcholine is centrally involved, 29 is impaired in amblyopia or diplopia, other oculomotor imbalances, and in certain conditions, occurring after eye or brain surgery: once the development of the visual system is complete, structural and functional brakes such as dampening of acetylcholine receptor signaling and formation of perineuronal nets limit the synaptic remodeling that would be required for a spontaneous correction. 30 The inventors investigated the effect of donepezil on binocular rivalry 31 dynamics: participants with normal binocular function viewed left-tilted and right-tilted gratings presented individually to the two eyes and two replay runs where computer-generated videos of simulated binocular rivalry were presented identically to both eyes. Participants indicated via key-press whether they were seeing left or right eye's image, a piecemeal mixture of the two images, or a superimposed mixture of the two images. The cholinesterase inhibitor, administered in a single 5 mg dose (the daily dose used to improve cognition in Alzheimer's disease), improved binocular vision and/or binocular stability (e.g., reducing or eliminating intermittent diplopia) in the subjects. This could be an interesting option to aid visual recovery after strabismus surgery. For the peer review companion article, see Sheynin et al. 32
An old Antihelminthic Takes Muscle Wasting at the Root
International Patent Application WO/2021/030978, Use of Niclosamide Ethanolamine Salt in Preparation of Drugs for Treating Chemotherapy-Related Muscle Injury (Inventors: Shao M, Sun H, Zhan H, Han P, Yu X, Weng W; applicant: Shenzen Traditional Chinese Medicine Hospital, Shenzen, China; published: February 25, 2021).
Niclosamide, an antihelminthic that has been used to treat tapeworm infections for over half a century, might be the agent with the most published and patented repurposing applications—enough to warrant dedicated reviews. 33,34 Suggested utility spans the space from cancer to obesity and diabetes to viral infections. The present inventors have added yet another possibility, but unfortunately the document does not inform about the mouse model that was used to test the effect of 2 g/kg niclosamide ethoamolamine salt on chemotherapy-related muscle injury in Balb/c mice for 2 weeks. Body weight, gripping force, and histopathology all show muscle deterioration being either prevented or reversed. The p38 MAPK expression level was almost identical in treated and untreated muscle-degraded animals and in the healthy and untreated control group, but phosphorylated (i.e., activated) MAPK and also the FoxO3 levels were highest in the untreated model animals; niclosamide tended to normalize this. FoxO3, which is activated by p38 MAPK, controls the two major systems of protein breakdown in skeletal muscle, the ubiquitin-proteasomal and autophagic/lysosomal pathways, independently. 35,36 Blockade of the Erk/MAPK pathway by niclosamide has been suggested earlier, in the context of dendritic cell modulation. 37
Second Generation Antihistamines for Melanoma: But only two of them
International Patent Application WO/2021/040600, Desloratadine and/or Loratadine for Treatment and/or Prophylactic Treatment of Melanoma (Inventors: Olsson H; applicant: Hakmed AB, Lund, Sweden; published: March 4, 2021).
Cancer developing against the background of chronic inflammation is such a common event that it seems curious that modern antihistamines acting at the histamine H1 receptor have not been systematically studied in relationship to cancer therapy or prevention despite being ubiquitous, affordable, and safe. The immunomodulatory potential of the H2 receptor blocker, cimetidine, has been extensively reported during the past 30 years, 38 especially in the context of oncology. 39 In a nation-wide register-based study of all 35,905 Swedish individuals newly diagnosed with melanoma between 2005 and 2014, the inventors analyzed the effects of the 6 major H1-antihistamines on melanoma-specific and overall mortality: loratadine and its active metabolite desloratadine (a separate drug), cetirizine, clemastine, ebastine, and fexofenadine. Both peri- and postdiagnostic antihistamine use was analyzed using Cox regression models, as well as different subgroups of patients with regard to age, gender, and tumor status. Surprisingly, only desloratadine and loratadine showed strong and robust effects on survival, which suggests that the mechanism of action is only partially H1 receptor dependent. The melanoma-specific mortality for desloratadine users was 0.93 (0.87–1.00), p = 0.0496 when looking at defined daily doses, similar for both genders. When adjusted for Breslow thickness (i.e., tumor invasion depth), p-values were 0.012 for loratadine and 0.019 for desloratadine. Both drugs also significantly reduced the risk of a new primary melanoma when used for more than 3 years after the first diagnosis (HR 0.88, p < 0.05). For the much broader companion peer review article (which also analyzed other cancers, finding loratadine and desloratadine efficacy only in those associated with immune checkpoint inhibition), see Fritz et al. 40
Reverse Transcriptase Inhibitors for Sterile Inflammatory Diseases
International Patent Application WO/2021/041317, Ddx17 and Nlrc4 Targeting for Inflammatory Diseases (Inventors: Ambati J, Wang SB, Ambati K; applicant: University of Virginia Patent Foundation, Charlottesville, USA; published: March 4, 2021).
Short interspersed nuclear elements (SINEs) are noncoding and nonautonomous retrotransposons that comprise at least 10% of mammalian genomes. They are transcribed by RNA polymerase III and can be retrotranscribed and inserted back into the genome with the help of other autonomous retroelements. 41 The Nlrc4 inflammasome has been implicated in multiple diseases such as multiple sclerosis, 42 ischemic stroke, 43 and many other conditions characterized by a sterile inflammatory response, but the mode of its activation in these settings was unclear. The inventors show that SINEs can cause activation of Nlrc4 in the absence of bacterial infection. SINE RNAs are recognized by Ddx17, a multifunctional DEAD box helicase, 44 which can activate Nlrc4 separately from the flagellin-recognizing apoptosis inhibitor protein, Naip. Immunofluorescence studies show increased Nlrc4 and apoptosis speck-like protein complexes in SINE RNA-treated mouse bone marrow-derived macrophages. This Ddx7-mediated noncanonical activation, and also the canonical flagellin-induced activation, of the Nlrc4 inflammasome can be blocked by nucleoside reverse transcriptase inhibitors (NRTIs) used to treat HIV infection, as is demonstrated for stavudine and lamivudine. Currently, multiple Nlrp3 inflammasome inhibitors are available, but none that inhibits Nlrc4, which makes the marketed reverse transcriptase inhibitors repurposing candidates for a different range of sterile inflammatory diseases, such as age-related macular degeneration. These agents bind directly to the Nlrp3/Nlrc4 complex to inhibit its activation. See closely related research from the inventors and others showing that the adjusted risk of incident diabetes is 33% lower in patients with NRTI exposure, traceable to a similar SINE-related mechanism acting at the Nlrp3 inflammasome. 45
A Local Treatment of Severe Vascular Malformations with Temsirolimus
International Patent Application WO/2021/050743, Compositions and Methods for Treating Slow-Flow Vascular Malformations (Inventors: Nassiri N, Patel P; applicant: Yale University, New Haven, USA; published: March 18, 2021).
Complex congenital venous and lymphatic vessel malformations associated with minimal flow can be far more serious than simple varicose veins; they can become limb-threatening risk factors that require surgery. Milder forms are often treated with direct chemical embolization but often remain refractory, requiring multiple sessions. In some rare genetic disorders (Klippel-Trénaunay, CLOVES, and Proteus syndromes) low-flow vascular malformations are part of the clinically defining hallmarks. Understanding of the mechanisms that are involved centers on mosaic mutations of genes in the mechanistic (or mammalian) target of rapamycin (mTOR) signalling pathway. 46 A recent clinical study with oral sirolimus (rapamycin; the prototypical mTOR inhibitor used to prevent organ transplant rejection and restenosis in vascular stents) was positive, but had used a pharmacokinetic-guided b.i.d. dosing schedule with frequent blood monitoring to maintain a target serum concentration of 10–15 ng/mL. 47 Instead, the present document claims direct intralesional delivery of the active prodrug, temsirolimus (approved for renal cell carcinoma, as once-weekly infusions) at 1 mg/mL under ultrasound, fluoroscopic, or radiographic guidance. Two case studies are presented. Also claimed are most other rapalogs and dactolisib, a dual PI3K/mTOR inhibitor from Novartis originally developed for cancer, and now in Phase II/III programs for respiratory infections.
Navitoclax and Ganciclovir Make Mouse Spinal Cords Heal Better
International Patent Application WO/2021/052962, Treatment of spinal cord injury (Inventors: Saúde MLT, Carvalho D, Jacinto AAC, Martins IVA; applicant: Instituto de Medicina Molecular João Lobo Antunes, Lisboa, Portugal; published: March 25, 2021).
While lower vertebrates can functionally recover from a spinal cord injury, neuronal reconnection in mammals is inhibited by the formation of glial scars consisting of astrocytes that develop from neural stem cells and form a physical barrier at the injury site. 48 This seems to be a specific effect of the mammalian spinal cord microenvironment: when allowed to differentiate in vitro, these stem cells can generate, inter alia, neurons 49 in the same way as in zebrafish, which develop no glial scars. The inventors saw a similarity with dermal wound healing, where a transient burst of fibroblasts with a senescence-associated secretory phenotype occurs, which have to be cleared by macrophages. The wound will not close, and instead form excessive scar tissue, if the formation of these senescent cells or their removal is impeded. They reasoned that removing the senescent cells at the spinal cord injury site with senolytics should improve reconnection of axons across this site. Navitoclax, 50 a specific inhibitor of antiapoptotic proteins Bcl-2 and Bcl-xL created by Abbott Laboratories and now in Phase III for myelofibrosis, is known to selectively and efficiently kill senescent cells in mice. 51 It was orally administered to adult 10-week-old C57BL/6 female mice for 10 days starting 5 days after a moderately severe (75 kDynes) T9 spinal cord contusion injury. Locomotor behavior in the open field (as captured by the Basso Mouse Locomotor Scale) and in the horizontal ladder test paradigms improved significantly during the treatment period and extended for up to two more weeks after navitoclax administration had ceased. By day 30 postinjury, all navitoclax-treated mice achieved frequent plantar stepping with 93% of mice displaying parallel placement of both hindpaws at initial contact and 40% also at lift off; 33% exhibited consistent plantar stepping and mild trunk stability. Although overall performance on the ladder at the end of treatment was not statistically different between vehicle and navitoclax, animals treated with the senolytic made significantly less stepping mistakes, and displayed significantly more positive stepping events at 30 and 60 days postinjury. Navitoclax also delayed the nocifensive reaction to cold (but not to heat) at 30 days postinjury. Comparable results were seen with ganciclovir, which in senescent cells is converted into a toxic DNA chain terminator by thymidine kinase, causing their selective death by apoptosis. In contrast to navitoclax, which has to be administered as long as the injury remains open, ganciclovir has no such restrictions because it crosses the blood–brain barrier.