Tyk2 JH2 (IC50 = 0.2 nM); JAK1 JH2 (IC50 = 1 nM)

Small molecule JAK inhibitors have emerged as a major therapeutic advancement in treating autoimmune diseases. The discovery of isoform selective JAK inhibitors that traditionally target the catalytically active site of this kinase family has been a formidable challenge. Our strategy to achieve high selectivity for TYK2 relies on targeting the TYK2 pseudokinase (JH2) domain. Herein we report the late stage optimization efforts including a structure-guided design and water displacement strategy that led to the discovery of BMS-986165 (11) as a high affinity JH2 ligand and potent allosteric inhibitor of TYK2. In addition to unprecedented JAK isoform and kinome selectivity, 11 shows excellent pharmacokinetic properties with minimal profiling liabilities and is efficacious in several murine models of autoimmune disease. On the basis of these findings, 11 appears differentiated from all other reported JAK inhibitors and has been advanced as the first pseudokinase-directed therapeutic in clinical development as an oral treatment for autoimmune diseases [1].
Drug compounds have included stable heavy isotopes of carbon, hydrogen, and other elements, mostly as quantitative tracers while the drugs were being developed. Because deuteration may have an effect on a drug's pharmacokinetics and metabolic properties, it is a cause for concern [1]. Potential benefits of compounds with deuteration: Longer half-life in living things. Deuterated compounds might be able to increase the compound's pharmacokinetic properties, or in vivo half-life. This can facilitate administration and enhance the compound's safety, effectiveness, and tolerance. Boost oral bioavailability, second. Greater amounts of the unmetabolized medicine are able to reach their target of action because deuterated substances lessen the amount of undesired metabolism (first-pass metabolism) in the liver and intestinal wall. Better tolerance and activity at low doses are determined by high bioavailability. (3) Enhance the properties of metabolism. Deuterated substances can enhance medication metabolism and lessen the production of hazardous or reactive metabolites. (4) Enhance the security of medications. Deuterated chemicals are harmless and can lessen or eliminate the undesirable side effects of medicinal substances. (5) Preserve the treatment outcome. According to earlier research, deuterated molecules should maintain biological potency and selectivity comparable to hydrogen analogs.

Lupus-like disease is strongly inhibited in NZB/W mice treated with Tyk2-IN-4. Tyk2-IN-4 is safe and overall well-tolerated. There are no serious adverse events and the frequency of non-serious adverse events are similar in the active (75%) and placebo (76%) groups. After oral administration, Tyk2-IN-4 is rapidly absorbed and exhibits an apparent elimination half-life of 8-15 hours[1].

Small molecule JAK inhibitors have emerged as a major therapeutic advancement in treating autoimmune diseases. The discovery of isoform selective JAK inhibitors that traditionally target the catalytically active site of this kinase family has been a formidable challenge. Our strategy to achieve high selectivity for TYK2 relies on targeting the TYK2 pseudokinase (JH2) domain. Herein we report the late stage optimization efforts including a structure-guided design and water displacement strategy that led to the discovery of BMS-986165 (11) as a high affinity JH2 ligand and potent allosteric inhibitor of TYK2 [1].

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All biochemical potencies and selectivities were determined using homogeneous time-resolved fluorescence (HTRF) assays where compounds were shown to compete with a fluorescent probe for binding to human recombinant JAK1, JAK2, JAK3, and TYK2 JH1 domain proteins in addition to TYK2 and JAK1 JH2 protein domains. Dose–response curves were generated to determine the concentration required for inhibiting 50% of the HTRF signal (IC50) as derived by nonlinear regression analysis. Cellular potencies and selectivities were determined using stably integrated STAT-dependent luciferase reporter assays in T-cells using IFNα-stimulation for measuring TYK2/JAK1 dependent signaling and IL-23 stimulation for measuring TYK2/JAK1 dependent signaling. JAK2 dependent signaling was measured in TF-1 cells using GM-CSF stimulation. Dose–response curves were generated to determine the concentration required to inhibit 50% of cellular response (IC50) as derived by nonlinear regression analysis. Potencies and selectivities for JAK-dependent signaling were also measured in human and mouse whole blood using specific cytokine stimulations and measuring the phosphorylation of specific STAT proteins by cellular staining and flow cytometry. Experimental details for all assays have been previously reported. All compounds active in biological assays were electronically filtered for structural attributes common to pan assay interference compounds (PAINS) and were found to be negative [1].

Cellular potencies and selectivities were determined using stably integrated STAT-dependent luciferase reporter assays in T-cells using IFNα-stimulation for measuring TYK2/JAK1 dependent signaling and IL-23 stimulation for measuring TYK2/JAK1 dependent signaling. JAK2 dependent signaling was measured in TF-1 cells using GM-CSF stimulation. Dose–response curves were generated to determine the concentration required to inhibit 50% of cellular response (IC50) as derived by nonlinear regression analysis. Potencies and selectivities for JAK-dependent signaling were also measured in human and mouse whole blood using specific cytokine stimulations and measuring the phosphorylation of specific STAT proteins by cellular staining and flow cytometry. Experimental details for all assays have been previously reported. All compounds active in biological assays were electronically filtered for structural attributes common to pan assay interference compounds (PAINS) and were found to be negative[1].

IL-23-Induced Acanthosis in Mice
Acanthosis was induced in 6–8-week-old C57BL/6 female mice (19–20 g average weight, Jackson Laboratories) by intradermal injection of dual chain, recombinant human IL-23 into the right ear. IL-23 injections were administered every other day from day 0 through day 9 of the study. Treatment groups consisted of eight mice per group. Compound 11 at 7.5, 15, and 30 mg/kg BID in vehicle (EtOH:TPGS:PEG300, 5:5:90) and vehicle alone dosed BID by oral gavage, with the first dose given the evening before the first IL-23 injection. An anti-IL-23 adnectin (3 mg/kg) and PBS control were administered subcutaneously approximately 1 h prior to the first IL-23 injection and then twice a week thereafter. Ear thickness was measured using a Mitutoyo (no. 2412F) dial caliper and calculated as the percent change in thickness from the baseline measurement taken on day 0 before initial IL-23 injections for each animal. At the end of the study, IL-23-injected ears as well as naïve control ears were collected from four animals per group for histological examination and gene expression analyses. Terminal blood samples collected via the retro-orbital sinus were used for PK determinations. Statistical analyses were performed using Student’s t tests or ANOVA with Dunnett’s post test. At the end of the study, ears were removed and fixed in 10% neutral-buffered formalin for 24–48 h. The fixed ears were then cut longitudinally, and two pieces were parallel embedded to make the paraffin blocks. The paraffin blocks were then sectioned and placed on microscope slides for H&E staining for histological evaluation. Severity of ear inflammation was scored using an objective scoring system based on the following parameters: extent of the lesion, severity of hyperkeratosis, number and size of pustules, height of epidermal hyperplasia (acanthosis, measured in interfollicular epidermis), and the amount of inflammatory infiltrate in the dermis and soft tissue. The latter two parameters, acanthosis and inflammatory infiltrate, were scored independently on a scale from 0 to 4: 0, none; 1, minimal; 2, mild; 3, moderate; 4, marked. The histological changes were blindly evaluated by a pathologist. Statistical analyses was performed using one-way ANOVA with Dunnett’s test for comparison of each treatment versus the vehicle control.

Absorption, Distribution and Excretion
Following oral administration, deucravacitinib plasma Cmax and AUC increased proportionally over a dose range from 3 mg to 36 mg (0.5 to 6 times the approved recommended dosage) in healthy subjects. The steady state Cmax and AUC24 of deucravacitinib following administration of 6 mg once daily were 45 ng/mL and 473 ng x hr/mL, respectively. The steady state Cmax and AUC24 of the active deucravacitinib metabolite, BMT-153261, following administration of 6 mg once daily were 5 ng/mL and 95 ng x hr/mL, respectively. The absolute oral bioavailability of deucravacitinib was 99% and the median Tmax ranged from two to three hours. A high-fat, high-calorie meal decreased Cmax and AUC of deucravacitinib by 24% and 11%, respectively, and prolonged Tmax by one hour; however, this has clinically significant effects on drug absorption and exposure.
After a single dose of radiolabeled deucravacitinib, approximately 13% and 26% of the dose was recovered as unchanged in urine and feces, respectively. Approximately 6% and 12% of the dose was detected as BMT-153261 in urine and feces, respectively.
The volume of distribution of deucravacitinib at steady state is 140 L.
The renal clearance of deucravacitinib ranged from 27 to 54 mL/minute.

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Metabolism / Metabolites
Deucravacitinib undergoes N-demethylation mediated by cytochrome P-450 (CYP) 1A2 to form major metabolite BMT-153261, which has a comparable pharmacological activity to the parent drug. However, the circulating exposure of BMT-153261 accounts for approximately 20% of the systemic exposure of the total drug-related components. Deucravacitinib is also metabolized by CYP2B6, CYP2D6, carboxylesterase (CES) 2, and uridine glucuronyl transferase (UGT) 1A9.

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Biological Half-Life
The terminal half-life of deucravacitinib was 10 hours.

Hepatotoxicity
In the preregistration clinical trials of deucravacitinib that included data on 1519 subjects, only 1.8% of patients had serum ALT or AST elevations above 5 times ULN, none of which were considered likely due to drug induced liver injury, with myositis accounting for many of the elevations, and underlying alcoholic or nonalcoholic fatty liver disease accounting for a few. Elevations of ALT levels above 3 times the ULN arose in 1.1% to 1.3% of recipients of deucravacitinib in a 24 week trial compared to 1.2% of placebo recipients. While there were no instances of reactivation of hepatitis B in patients receiving deucravacitinib, patients with preexisting HBsAg in serum were excluded from enrollment and most treatment courses were limited in duration. Since its approval and more widespread clinical use, there have been no further reports of clinically apparent liver injury attributed to deucravacitinib, but it has been available for a limited time only.
Likelihood score: E (suspected but unproven cause of clinically apparent liver injury including reactivation of hepatitis B).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
No information is available on the use of deucravacitinib during breastfeeding. Because it is more than 80% bound to plasma proteins, the amount in milk is likely to be low. However, it is well absorbed orally. If deucravacitinib is required by the mother of an older infant, it is not a reason to discontinue breastfeeding, but until more data become available, an alternate drug may be preferred, especially while nursing a newborn or preterm infant.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.
◈ What is deucravacitinib?
Deucravacitinib is a medication that has been approved for the treatment of moderate-to-severe plaque psoriasis. MotherToBaby has a fact sheet on psoriasis & psoriatic arthritis at: https://mothertobaby.org/fact-sheets/psoriasis-and-pregnancy/. A brand name for deucravacitinib is SOTYKTU™.Sometimes when people find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take this medication. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy.
◈ I take deucravacitinib. Can it make it harder for me to get pregnant?
Studies have not been done to see if deucravacitinib can make it harder to get pregnant.
◈ Does taking deucravacitinib increase the chance of miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. Studies have not been done to see if deucravacitinib increases the chance for miscarriage.
◈ Does taking deucravacitinib increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Human pregnancy studies have not been with deucravacitinib. Experimental animal studies reported by the manufacturer did not find an increased chance of birth defects.
◈ Does taking deucravacitinib in pregnancy increase the chance of other pregnancy related problems?
Studies have not been done to see if deucravacitinib increases the chance for pregnancy-related problems such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth).
◈ Does taking deucravacitinib in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if deucravacitinib can cause behavior or learning issues for the child.
◈ Breastfeeding while taking deucravacitinib:
Deucravacitinib has not been studied for use while breastfeeding. Be sure to talk to your healthcare provider about all of your breastfeeding questions.
◈ If a male takes deucravacitinib, could it affect fertility (ability to get partner pregnant) or increase the chance of birth defects in a partner’s pregnancy?
Studies have not been done to see if deucravacitinib could affect male fertility or increase the chance of birth defects in a partner’s pregnancy. In general, exposures that fathers or sperm donors have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.

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Protein Binding
Protein binding of deucravacitinib was 82 to 90% and the blood-to-plasma concentration ratio was 1.26.

[1]. Highly Selective Inhibition of Tyrosine Kinase 2 (TYK2) for the Treatment of Autoimmune Diseases: Discovery of the Allosteric Inhibitor BMS-986165. J Med Chem. 2019 Jul 18.

[2]. SAT0226 A first-in-human, study of BMS-986165, a selective, potent, allosteric small molecule inhibitor of tyrosine kinase 2. Annals of the Rheumatic Diseases 2017;76:859.

Pharmacodynamics
Deucravacitinib is a tyrosine kinase 2 (TYK2) inhibitor that works to suppress the immune signaling pathways in inflammatory disorders, such as plaque psoriasis. In clinical studies comprising patients with psoriasis, deucravacitinib reduced psoriasis-associated gene expression in psoriatic skin in a dose dependent manner, including reductions in IL-23-pathway and type I IFN pathway regulated genes. Following 16 weeks of once-daily treatment, deucravacitinib reduced inflammatory markers such as IL-17A, IL-19 and beta-defensin by 47 to 50%, 72%, and 81 to 84%, respectively. Deucravacitinib does not affect with JAK2-dependent hematopoietic functions.

C20H22N8O3

425.4590

425.2

C, 56.46; H, 5.92; N, 26.34; O, 11.28

1609392-27-9

1609392-28-0 (HCl);1609392-27-9;

134821691

Off-white to light yellow solid

1.2

3

8

7

31

648

0

[2H]C([2H])([2H])NC(=O)C1=NN=C(C=C1NC2=CC=CC(=C2OC)C3=NN(C=N3)C)NC(=O)C4CC4

BZZKEPGENYLQSC-FIBGUPNXSA-N

InChI=1S/C20H22N8O3/c1-21-20(30)16-14(9-15(25-26-16)24-19(29)11-7-8-11)23-13-6-4-5-12(17(13)31-3)18-22-10-28(2)27-18/h4-6,9-11H,7-8H2,1-3H3,(H,21,30)(H2,23,24,25,29)/i1D3

6-(cyclopropanecarboxamido)-4-((2-methoxy-3-(1-methyl-1H-1,2,4-triazol-3-yl)phenyl)amino)-N-(methyl-d3)pyridazine-3-carboxamide

BMS 986165; Deucravacitinib; BMS-986165; Sotyktu; Tyk2-IN-4; Sotyktu; BMS986165; N0A21N6RAU; Deucravacitinib [USAN]; BMS986165

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~33.33 mg/mL (~78.34 mM)

Solubility in Formulation 1: 3.83 mg/mL (9.00 mM) in 5% DMSO + 40% PEG300 + 5% Tween80 + 50% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (5.88 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (5.88 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 10 mg/mL (23.50 mM) in 50% PEG300 + 50% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)