ORY-2001: Dual effect for neurodegenerative diseases
ORY-2001 is a first-in-class, selective dual inhibitor of LSD1/MAOB. The first clinical data from Phase I with healthy volunteers were reported in March 2017. Oryzon has developed a broad R&D programme for this asset and is targeting a range of neurological disorders. AD and MS are the leading indications with two Phase IIa trials underway, while a new basket trial is planned to commence in H218, which will explore ORY-2001 use in a variety of neurological indications where aggression is a hallmark.
Rationale for bi-specific effect in neurological disorders
Historically, the recognition of the role of epigenetics and its importance was first described in oncology and then extended to neurodevelopment and neurodegenerative diseases.2 The potential use of LSD1 inhibitors is not limited to oncological diseases and Oryzon’s decision to choose oncology and neurodegeneration as primary areas of interest is supported by a significant amount of preclinical work.3 ORY-2001 is a unique dual inhibitor and its mode of action is possible due to the structural similarity of MAOB and LSD1.
Monoamine oxidases (MAO) are a very well-researched family of enzymes that are targets for already marketed drugs, such as first-generation antidepressants, and has two forms, A and B. Non-specific monoamine oxidase inhibitors were the first type of antidepressants developed but, due to the inhibition of MAOA, suffered from numerous side effects associated with its more widespread presence. A new generation of selective MAOB inhibitors (eg selegiline) was developed, which cause fewer side effects and are used in early-stage Parkinson’s disease. Due to an abundance of data about the effects of MAOB inhibition and its relatively good safety profile, we believe the downside of potential ‘negative’ interactions between inhibition of LSD1 and MAOB is significantly reduced, while there is potential upside from synergistic effects. This idea is also supported by Oryzon’s preclinical studies.
Two Phase IIa trials in AD and MS ongoing
Two Phase IIa trials with ORY-2001, a dual LSD1/MAOB inhibitor for CNS indications, are underway. A randomised, double-blind, placebo-controlled, 36-week Phase II SATEEN study (n=24) will evaluate ORY-2001 in patients with relapsing-remitting MS and secondary progressive MS. A second randomised, double-blind, placebo-controlled, 24-week Phase IIa ETHERAL trial (n=90) with ORY-2001 in mild-to-moderate AD started enrolling patients in June 2018. The data readouts from both studies are planned around mid-2019 and represent the main catalysts in the near term.
Oryzon has identified different biomarkers that could be used to monitor the response to treatment with ORY-2001. At this stage, the most promising is S100A9, which is a pro-inflammatory protein typically upregulated in the context of inflammation-related neurodegenerative diseases, such as in patients with AD, postoperative cognitive dysfunction and traumatic brain injury. Therefore, the observed downregulation of the S100A9 protein by ORY-2001 is particularly interesting. While the work is still early stage, a progression biomarker may eventually prove invaluable in the context of a late-stage clinical trial designed to prove the disease-modifying effect of a drug. This is because it may be difficult to clearly differentiate between symptomatic and disease-modifying effects just with clinical endpoints (eg cognition, function).4 The key to convincing regulators of disease-modifying effects (which have never happened in the case of AD) may be the link between the slowdown in the progression of symptoms and a significant effect on validated biomarkers.
Basket trial – novel concept in psychotherapeutics R&D
Most recent update from Oryzon on its R&D plans includes a newly designed concept to conduct a so-called basket trial with ORY-2001 in a variety of neuropsychiatric conditions. This concept is similar to drug development strategy in oncology. For example, vemurafenib is an inhibitor of mutated BRAFV600E kinase. Vemurafenib received FDA approval for the treatment of late-stage melanoma with BRAFV600E in August 2011. During the development, vemurafenib was explored in a variety of tumours with BRAFV600E before the specific melanoma indication was determined for late-stage trials. Trials in subsequent indications followed and clinicaltrials.gov lists around 70 active trials with this drug in a variety of combinations.
Oryzon believes it can employ a similar strategy to develop ORY-2001 for neuropsychiatric disorders due to observed holistic effects on aggression and behaviour in preclinical models with LSD1/MAOB inhibition (described below). Aggression is one of the more widespread alterations in patients with neurodegenerative and developmental disorders, as a well as social withdrawal and depression. To establish a more specific psychiatric setting where ORY-2001 could be used, Oryzon plans to initiate a Phase IIa trial (CTA filed with a Spanish agency) and enrol at least six patients per each indication: Alzheimer’s dementia, dementia with Lewy bodies, attention deficit hyperactivity disorder, autism spectrum disorder and borderline personality disorder. The open-label treatment with ORY-2001 will last for eight weeks with the last patient out expected in Q418/Q119. The main goal is the assessment of reduction in aggression.
Aggression is a widespread issue in various psychiatric conditions especially where dementia is involved or neurodevelopment is impaired. Therefore, we find such basket trial strategy is the fastest route to establish more precise indications or settings. Given the novelty of the trial design, the small sample sizes and lack of visibility of a more concrete regulatory pathway that could lead to the market, we do not make any change to our OUR-2001 valuation approach. But if this study delivers efficacy signals sufficient to progress to more advanced trials, we will revisit this direction, which would be clearly a step beyond currently targeted AD and MS.
ORY-2001’s first clinical data
The results of the Phase I trial with ORY-2001 in healthy volunteers were the first in-human data. The study was double-blind with a single ascending dose (SAD; subjects receive single doses from the dose range selected for the study) and multiple ascending dose (MAD; subjects receive repeated, increasing doses) and included more than 100 healthy volunteers. A dose range of 0.2-4.0mg was explored. The main safety and PK/PD findings were:
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Overall, ORY-2001 was well tolerated; among the complaints, headache episodes were the most common, but moderate in nature.
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Of special interest to us was ORY-2001’s haematological safety, as haematopoiesis (blood production) is a known target of LSD1 inhibition. Orally administered ORY-2001 was well tolerated and did not provoke significant clinical or laboratory changes or adverse events in the MAD up to 2.5mg. Single and multiple ascending doses were haematologically safe. Originally the 2.5mg dose was the highest in the MAD range, but Oryzon added a 4mg dose to obtain robust safety data. It therefore appears the therapeutic window is more than sufficient for further investigation. Sub-1.2mg doses are used in the Phase IIa trials now.
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The PK profile was beneficial with a relatively long half-life after rapid oral absorption and proportional dose-response relationship. ORY-2001 efficiently crossed the blood-brain barrier and the half-life of 22 hours could allow a once-daily dosing regimen, which is especially useful for patients with neurodegenerative conditions. In PD tests, dose-dependent target engagement (the percentage of LSD1 bound to ORY-2001) in selected cells (peripheral blood mononuclear cells) was observed (Exhibit 3).
Exhibit 3: Selected PK/PD data from ORY-2001’s Phase I trial
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Highlights of preclinical data in AD
AD was the first indication for which Oryzon published ORY-2001’s preclinical data. Oryzon tested the drug in 10 different oral treatment studies with more than 340 SAMP8 mice, a non-transgenic model for accelerated ageing and AD. The effect on cognition was examined with an established test, the novel object recognition task (NORT), which uses a calculated discrimination index. Key findings include:
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After two and four months of chronic oral treatment, ORY-2001 provided a dose-dependent and protective effect on the memory of SAMP8 mice compared to age-matched SAMR1 mice.
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LSD1 inhibition alone was able to produce a significant effect, but was less pronounced (Exhibit 4A). It appears that memory protection is driven by LSD1 inhibition, but the combination with MAOB inhibition (ie a dual compound, ORY-2001) has a synergistic effect.
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Meta-analysis conducted on this model demonstrates a potentially disease-modifying effect. Using NORT test scores as above, the cognitive decline in animals treated with ORY-2001 was compared to untreated SAMP8 mice and control SAMR1 mice. At five months of age, when treatment with ORY-2001 started, the animals already had a cognitive impairment, but ORY-2001 restored the function to similar levels to those observed in age-matched SAMR1 mice.
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Oryzon’s crossover experiment with SAMP8 mice further supports disease-modifying effects. The mice were treated starting at the sixth or seventh month after the after the neurological symptoms started to show. The treatment with ORY-2001 or sham was assigned in the pattern showed in Exhibit 4B. ORY-2001 restored memory function after the deficit had developed (1+1 group), the delayed start group (0+1) also experienced the full benefit, whereas the early start (1+0) group showed significant benefit, which also persisted one month after the treatment interruption.
Exhibit 4: Chronic treatment with ORY-2001 protects memory and restores the cognitive function of SAMP8 mice compared to control SAMR1 mice
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Source: Oryzon. Note: mpk = milligrams/kilo; SAMR1 mice – control.
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ORY-2001’s holistic effects may improve behavioural alterations
Oryzon’s more recent preclinical data with ORY-2001 suggested that in addition to rescuing memory impairment, the drug could help to treat the behavioural alterations seen in patients with neurodegenerative diseases. The new data were first presented at the Society for Neuroscience 47th annual meeting, Washington DC, on 11-15 November 2017.
The SAMP8 mice were treated with a range of clinically feasible doses of ORY-2001 or a vehicle. SAMR1 mice were treated with a vehicle only and acted as a normal control. The new data demonstrate ORY-2001’s effects on behavioural alterations after six weeks of treatment using a so-called resident intruder (RI) test, which is an established test for aggression and evaluates the response of the test mouse to a new animal introduced to its environment. Gene expression analysis was then carried out on the mice’s prefrontal cortices. The main findings were:
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ORY-2001-treated SAMP8 mice showed reduced aggression in the RI test measured by number of attacks and number of clinch attacks compared with SAMP8 control mice, to a similar level to the SAMR1 control mice (Exhibit 5).
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ORY-2001 normalised pathological gene expression changes observed in SAMP8 mice (resembling those in AD) compared with SAMR1 mice, measured by a genome-wide microarray-based survey.
Exhibit 5: RI test showing reduced attacks and clinch attacks by ORY-2001-treated mice
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Source: Oryzon Genomics poster presentation
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The RI test was also conducted in the rat isolation model with ORY-2001. Rats are very social rodents and do not tolerate isolation. Rat isolation therefore was used as a model for social avoidance seen in AD patients. Rats were divided into control arm (three to four animals per cage) or isolated (one animal per cage). Isolated animals were treated with vehicle or ORY-2001 for five weeks; control animals were given vehicle. After that all animals were tested in the RI test. The findings were:
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No aggressive behaviour was observed in the rats in either group, confirming the social nature of the animals.
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Social avoidance measured by time without social interaction and number of evitations was significantly increased in isolated rats treated with vehicle, indicating the socially detrimental effect of the isolation. However, the treatment with ORY-2001 significantly improved both parameters.
Exhibit 6: RI test demonstrates ORY-2001’s efficacy in rat isolation model
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Source: Oryzon Genomics poster presentation
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These results suggest that ORY-2001 could have an effect on both cognitive decline and behavioural alterations in AD patients. Specific treatments for behavioural alterations such as aggression and social isolation are lacking and so tackling these could help to make ORY-2001 more competitive in the market. A large proportion of AD patients (20-50%) exhibit clinically significant aggression. Currently this is managed by non-pharmacological as well as pharmacological means. There is no FDA approved specific medication for the treatment of aggression in AD or other neuropsychiatric disorders. Memantine is the only drug approved for AD that has also been shown to reduce agitation and aggression, whereas other drugs used are more general antipsychotics, antidepressants or anxiolytic drugs and often have unfavourable safety profiles.
Preclinical proof-of-concept of ORY-2001 in multiple sclerosis
MS emerged as a second potential indication after AD for ORY-2001 following publication of preclinical data from specific inflammation models by Oryzon at multiple conferences over the last two years. ORY-2001 has been tested in preclinical proof-of-concept trials using the experimental autoimmune encephalomyelitis (EAE) mice model, a widely used proxy for MS. One of the EAE studies included three controlled arms: EAE mice treated with ORY-2001 (dual LSD1/MAOB inhibitor), ORY-LSD1 (proprietary selective LSD1 inhibitor) or rasagiline (a widely used, selective MAOB inhibitor).
During these studies mice were injected with a specific peptide, which triggered an autoimmune reaction and the production of antibodies against the myelin sheet protecting the motor neurons. A gradual demyelination (destruction of the neurons’ protective sheet) leads to the development of different degrees of paralysis, mimicking the natural course of MS. Key findings include:
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Treatment with ORY-2001 effectively reduced the severity of the disease (Exhibit 7A) and cumulative disease index (Exhibit 7B). Dual inhibition of LSD1/MAOB with ORY-2001 was more effective than standalone inhibition of LSD1 with ORY-LSD1 or MAOB with rasagiline. ORY-2001 has also been shown to reduce the EAE clinical score at lower doses (0.5 and 0.05mg/kg).
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The histopathological analysis two weeks after the first symptoms showed absent or substantially lower number of demyelination plaques in the lumbar and cervical regions of ORY-2001-treated animals (Exhibit 7D).
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Treatment with ORY-2001 and ORY-LSD1 resulted in a significant increase in the number of immune cells retained in the spleen and lymph nodes of treated animals, suggesting a reduced egress of lymphocytes from immune tissues (egress is usually associated with an inflammatory response) (Exhibit 7C).
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Treatment with ORY-2001 also caused a reduction of various pro-inflammatory cytokines such as IL-6 and IL-1beta and chemokines such as IP-10 and MCP-1, which are involved in inflammation leading to the destruction of motor neurons in MS (Exhibit 7E).
Cumulatively, these findings indicate that ORY-2001 shows an ability to counteract a number of pathophysiological processes associated with MS and that the dual inhibition of LSD1-MAOB (ORY-2001’s mechanism of action) appears to be more efficacious in this context than LSD1 inhibition alone.
Oryzon has also presented a head-to-head comparison of ORY-2001 in MS against fingolimod (Gilenya, Novartis; $3.2bn in 2017) in the EAE mouse model. The data showed that ORY-2001 performed as well as or better than fingolimod in reducing immune cell infiltration of CNS tissues, providing neuroprotection and thereby reducing demyelination (detailed analysis in our 14 December 2017 report).
Exhibit 7: Effects of the treatment with ORY-2001, ORY-LSD1 and rasagiline in EAE mice model
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Source: T. Maes et al. Note: Cumulative disease index = the sum of clinical scores reached for each animal every day until day 51 post-immunisation. Clinical score reflects the extent of the paralysis – 0 = no signs; 5.0 = hind and foreleg paralysis.
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