KD: 7.9 nM (factor B)[2] IC50: 10 nM (factor B)[2]

In 50% of human serum, iptacopan (LNP023) efficiently prevents the formation of membrane attack complexes (MAC) caused by the alternative complement pathway (AP) (IC50 value: 130 nM) [2]. Among 41 human proteases, iptacopan (LNP023) has IC50 values >30 μM, demonstrating excellent selectivity over other proteases, including AP protein factor D (>100 μM) [3].

In an experimental model of rat membranous nephropathy, diptacopan (LNP023; 20-180 mg/kg; oral) is effective at both preventive and therapeutic doses and prevents arthritis induced by KRN (150 μL) in mice [2]. ?LNP023 shows a moderate half-life (T1/2; Wistar Han rat 3.4 hours, beagle 5.5 hours) and Cmax (Wistar Han rat 5.5 hours) 410 nM, Beagle 2200 nM) after oral administration (dog 10 mg/kg, rat 30 mg/kg) [3]. ?Iptacopan is caused by large distribution volume (2.3 and 0.6 L/kg) and high plasma clearance (8 and 2 mL/min/kg, respectively) following intravenous administration (1.0 mg/kg in dogs and 0.1 mg/kg in rats) [3].

In Vitro Inhibition Assays [2].
  Compounds were tested for FB inhibition either by using CVF:Bb as stable surrogate of the C3 convertase and purified endogenous C3 as substrate or by using a competition binding assay with FB and a Cy5-labeled small-molecule inhibitor as probe. AP inhibition was measured in 50% human serum or 50% human whole blood by following zymosan A-induced MAC formation. Serum or whole blood was preincubated with compound for 30 min before transfer to zymosan A-coated plates. MAC formation was detected with an anti-C9 neoepitope antibody by ELISA. AP complement deposition in mouse serum was measured in an analogous way except that C3b deposition was detected instead of MAC formation. Further details on protein purification and all in vitro assays are given in SI Appendix.

Animal/Disease Models: C57BL/6 mice with KRN-induced arthritis [2]
Doses: 20, 60 and 180 mg/kg: po (oral gavage); twice (two times) daily (bid) for 14 days
Experimental Results: Blocks KRN-induced arthritis arthritis.

Absorption, Distribution and Excretion
Following oral administration, iptacopan reached peak plasma concentrations approximately 2 hours post-dose. At the recommended dosing regimen of 200 mg twice daily, a steady state is achieved in approximately 5 days with minor accumulation (1.4-fold). Based on a food-effect study in healthy volunteers, a high-fat meal did not affect the exposure of iptacopan to a clinically meaningful degree.
In a human study, following a single 100 mg oral dose of [¹⁴C]-iptacopan, the mean total excretion of radioactivity (iptacopan and metabolites) was 71.5% in the feces and 24.8% in the urine, for a total mean excretion of >96% of the dose. Specifically, 17.9% of the dose was excreted as parent iptacopan in the urine, and 16.8% of the dose was excreted as parent iptacopan in feces.
After administration of iptacopan 200 mg twice daily, the apparent volume of distribution at steady state was approximately 288 L.
The clearance of iptacopan at steady state is 7.96 L/h after administration of 200 mg twice daily.

---

Metabolism / Metabolites
Metabolism is a predominant elimination pathway for iptacopan with approximately 50% of the dose attributed to oxidative pathways. Metabolism of iptacopan includes N-dealkylation, O-deethylation, oxidation, and dehydrogenation, mostly driven by CYP2C8 (98%) with a small contribution from CYP2D6 (2%). Iptacopan undergoes Phase 2 metabolism through glucuronidation by UGT1A1, UGT1A3, and UGT1A8. In plasma, iptacopan was the major component, accounting for 83% of the drug-related species. Two acyl glucuronides were the only metabolites detected in plasma and were minor, accounting for 8% and 5% of the drug-related species. Iptacopan metabolites are not pharmacologically active.

---

Biological Half-Life
The half-life (t_1/2) of iptacopan at steady state is approximately 25 hours after administration of 200 mg twice daily.

Protein Binding
Iptacopan showed concentration-dependent plasma protein binding due to binding to the target Factor B in the systemic circulation. Iptacopan was 75% to 93% protein-bound in vitro at the relevant clinical plasma concentrations.

[1]. Expanding Complement Therapeutics for the Treatment of Paroxysmal Nocturnal Hemoglobinuria. Semin Hematol. 2018 Jul;55(3):167-175.

[2]. Small-molecule Factor B Inhibitor for the Treatment of Complement-Mediated Diseases. Proc Natl Acad Sci U S A. 2019 Apr 16;116(16):7926-7931.

[3]. Discovery of 4-((2 S,4 S)-4-Ethoxy-1-((5-methoxy-7-methyl-1 H-indol-4-yl)methyl)piperidin-2-yl)benzoic Acid (LNP023), a Factor B Inhibitor Specifically Designed To Be Applicable to Treating a Diverse Array of Complement Mediated Diseases. J Med Chem. 2020 Jun 11;63(11):5697-5722.

Iptacopan is a member of the class of indoles that is 1H-indole substituted by [(2S,4S)-2-(4-carboxyphenyl)-4-ethoxypiperidin-1-yl]methyl, methoxy, and methyl groups at positions 4, 5, and 6, respectively. It is a potent inhibitor of complement factor B (IC50 = 10nM) with potential immunomodulatory activity. It has a role as a complement factor B inhibitor and an immunomodulator. It is a member of benzoic acids, a member of piperidines, an ether, a member of indoles, a diether, a monocarboxylic acid and a tertiary amino compound. It is a conjugate base of an iptacopan(1+).
Iptacopan is a small-molecule factor B inhibitor previously investigated as a potential treatment for the rare blood disease paroxysmal nocturnal hemoglobinuria (PNH) by inhibiting the complement factor B. Factor B is a positive regulator of the alternative complement pathway, where it activates C3 convertase and subsequently C5 convertase. This is of particular importance to PNH, where one of the disease hallmarks is the mutation of the PIGA gene. Due to this mutation, all progeny erythrocytes will lack the glycosyl phosphatidylinositol–anchored proteins that normally anchor 2 membrane proteins, CD55 and CD59, that protect blood cells against the alternative complement pathway. Additionally, iptacopan has the benefit of targeting factor B, which only affect the alternative complement pathway, leaving the classic and lectin pathway untouched for the body to still mount adequate immune responses against pathogens. On December 6th, 2023, Iptacopan under the brand name Fabhalta was approved by the FDA for the treatment of adults with PNH. This approval was based on favorable results obtained from the phase III APPL-PNH and APPOINT-PNH studies, where 82.3% and 77.5% of patients experienced a sustained hemoglobin improvement without transfusions respectively.
Iptacopan is an orally available, small-molecule inhibitor of complement factor B (FB) with potential immunomodulatory activity. Upon administration, iptacopan binds to FB and prevents the formation of the alternative pathway (AP) C3-convertase (C3bBb). This limits the cleavage of C3 to the active fragment C3b and may prevent C3b-mediated extravascular hemolysis in certain complement-driven disorders such as paroxysmal nocturnal hemoglobinuria (PNH).

---

Drug Indication
Iptacopan is indicated for the treatment of adults with paroxysmal nocturnal hemoglobinuria.
Treatment of paroxysmal nocturnal haemoglobinuria

---

Mechanism of Action
Iptacopan binds to Factor B of the alternative complement pathway and regulates the cleavage of C3, the generation of downstream effectors, and the amplification of the terminal pathway. In paroxysmal nocturnal hemoglobinuria, intravascular hemolysis (IVH) is mediated by the downstream membrane attack complex (MAC), while extravascular hemolysis (EVH) is facilitated by C3b opsonization. Iptacopan acts proximally in the alternative pathway of the complement cascade to control both C3b-mediated EVH and terminal complement-mediated IVH.

---

Pharmacodynamics
Inhibition of the alternative complement pathway biomarkers, in vitro alternative pathway assay, and plasma Bb (fragment Bb of Factor B), started approximately 2 hours after a single iptacopan dose in healthy volunteers. In paroxysmal nocturnal hemoglobinuria (PNH) patients receiving concomitant anti-C5 treatment and iptacopan 200 mg twice daily, the in vitro alternative pathway assay and plasma Bb decreased from baseline by 54.1% and 56.1%, respectively, on the first observation on Day 8. In treatment-naive PNH patients, these same biomarkers decreased from baseline by 78.4% and 58.9%, respectively, on the first observation after 4 weeks of treatment with iptacopan 200 mg twice daily. In PNH patients on concomitant anti-C5 treatment and FABHALTA 200 mg twice daily, the mean PNH red blood cell (RBC) clone size was 54.8% at baseline and increased to 89.2% after 13 weeks; the proportion of PNH Type II + III RBCs with C3 deposition was 12.4% at baseline and decreased to 0.2% after 13 weeks. In treatment-naive PNH patients, the mean PNH RBC clone size was 49.1% at baseline and increased to 91.1% after 12 weeks; there were negligible PNH Type II + III RBCs with C3 deposition in this population due to the predominance of IVH. Iptacopan reduces serum LDH levels. In PNH patients previously treated with eculizumab, all patients treated with FABHALTA 200 mg twice daily achieved a reduction of LDH levels to < 1.5 times the upper limit of normal (ULN) at 13 weeks. In treatment-naive PNH patients, iptacopan 200 mg twice daily reduced LDH by > 60% compared to baseline after 12 weeks and maintained the effect through the end of the study at 2 years. In a QTc clinical study in healthy volunteers, single supra-therapeutic iptacopan doses up to 1,200 mg (which provided greater than 4-fold peak concentration of the MRHD) showed no effect on cardiac repolarization or QT interval.

C25H30N2O4

422.516706943512

422.22

C, 71.07; H, 7.16; N, 6.63; O, 15.15

1644670-37-0

Iptacopan hydrochloride;1646321-63-2

90467622

Off-white to gray solid powder

1.8

2

5

7

31

594

2

CCO[C@H]1CCN([C@@H](C1)C2=CC=C(C=C2)C(=O)O)CC3=C(C=C(C4=C3C=CN4)C)OC

RENRQMCACQEWFC-UGKGYDQZSA-N

InChI=1S/C25H30N2O4/c1-4-31-19-10-12-27(22(14-19)17-5-7-18(8-6-17)25(28)29)15-21-20-9-11-26-24(20)16(2)13-23(21)30-3/h5-9,11,13,19,22,26H,4,10,12,14-15H2,1-3H3,(H,28,29)/t19-,22-/m0/s1

4-((2S,4S)-4-ethoxy-1-((5-methoxy-7-methyl-1H-indol-4-yl)methyl)piperidin-2-yl)benzoic acid

LNP023 Iptacopan LNP-023 LNP 023; Fabhalta

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 : ~50 mg/mL (~118.34 mM)

Solubility in Formulation 1: ≥ 5 mg/mL (11.83 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 50.0 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.

---

Solubility in Formulation 2: ≥ 5 mg/mL (11.83 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 50.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

---

View More

Solubility in Formulation 3: ≥ 5 mg/mL (11.83 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 50.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

---

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