Combination therapy of tyrosine kinase inhibitor and activin type 2 receptor antagonist for treating pulmonary arterial hypertension (PAH)

Abstract

Disclosed herein are kits and methods for treating pulmonary arterial hypertension (PAH), comprising administering to a subject in need thereof a therapeutically effective amount of a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof, and a therapeutically effective amount of a dimeric fusion protein comprising the extracellular domain of activin receptor type 2A (ACTR IIA) or activin receptor type 2B (ACTR IIB) and the Fc domain of human immunoglobulin G1 (IgG1). In some embodiments, the tyrosine kinase inhibitor is seraltinib or a pharmaceutically acceptable salt thereof, and the fusion protein is sotatercept.

Description

[Technical Field]

[0001] The present invention relates to tyrosine kinase inhibitors and dimeric fusion proteins, and their combinations in the treatment of disease. [Background technology]

[0002] Pulmonary hypertension (PH) is a chronic disease affecting the small arteries of the lungs, associated with significant morbidity and mortality. The World Health Organization classifies PH based on the underlying associated disease: Pulmonary arterial hypertension (PAH), Pulmonary hypertension due to left heart disease, pulmonary hypertension due to lung disease and / or hypoxia, Chronic thromboembolic pulmonary hypertension (CTEPH), or It classifies pulmonary hypertension into five groups with other multifactorial mechanisms.

[0003] Pulmonary arterial hypertension (PAH) is a progressive disorder characterized by pulmonary vascular remodeling, resulting in elevated pulmonary arterial pressure and progressive right ventricular dysfunction. The pathology of this disease involves unregulated angiogenesis and plexiform lesions of abnormal neointimal cell proliferation, which obstruct blood flow through pulmonary arterioles. PAH can be associated with several etiologies, including familial and predisposing genetic abnormalities, such as gene mutations in bone morphogenetic receptor type 2 (BMPR2), endoglin, activin-like receptor kinase 1 (ALK1), mother's against decapodactylic acid 9 (SMAD9), and related pathways; autoimmune disorders (e.g., systemic sclerosis and scleroderma); congenital heart disease; liver disease with portal hypertension; and HIV infection.

[0004] Treatment of PAH was recently reviewed ("Pulmonary arterial hypertension: Tailoring treatment to risk in the current era," Gaine and McLaughlin, European Respiratory Review, 2017, 26, 170095). For most patients, combination therapy is the standard of care. This includes dual combination therapy with agents targeting the endothelin and nitric oxide pathways (e.g., a combination of an endothelin receptor antagonist (ERA) and a phosphodiesterase-5 (PDE-5) inhibitor). Triple combination therapy with agents targeting the endothelin, nitric oxide, and prostacyclin (PGI2) pathways has also been used.

[0005] Despite these advances, PAH remains an ultimately fatal disease, and efforts to slow disease progression are essential. While current treatments are effective in slowing disease progression, the 5-year survival rate is only 60%. Therefore, treatments for this disease are critical and urgently needed. Summary of the Invention

[0006] Provided herein is a method for treating a disease, particularly pulmonary arterial hypertension (PAH), comprising administering to a subject in need thereof: a therapeutically effective amount of a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof; a therapeutically effective amount of a dimeric fusion protein, the extracellular domain of activin type 2A receptor (ACTR IIA) or activin type 2B receptor (ACTR IIB), and and a dimeric fusion protein comprising the Fc domain of human immunoglobulin G1 (IgG1).

[0007] In some embodiments, the tyrosine kinase inhibitor is a PDGF receptor inhibitor, a CSF1R receptor inhibitor, a c-KIT kinase inhibitor, or a combination thereof. In some embodiments, the tyrosine kinase inhibitor is seraltinib or a pharmaceutically acceptable salt thereof.

[0008] In some embodiments, the dimeric fusion protein comprises the extracellular domain of an activin type 2A receptor. In other embodiments, the dimeric fusion protein comprises the extracellular domain of an activin type 2B receptor. In yet other embodiments, the dimeric fusion protein is sotatercept.

[0009] In another embodiment, a method for treating pulmonary arterial hypertension (PAH) comprises administering to a subject in need thereof a therapeutically effective amount of seraltinib or a pharmaceutically acceptable salt thereof, and a therapeutically effective amount of sotatercept. [Brief explanation of the drawings]

[0010] [Figure 1A]We show that inhaled seraltinib plus injected sotatercept demonstrates greater than additive efficacy in the SuHx model of PAH. PAH was induced in animals by administering a single injection of SU5416 (20 mg / kg) on day 0, followed by exposing the animals to hypoxia (10% oxygen) for 21 days. SuHx rats were divided into four groups and treated with: i) control: seraltinib vehicle inhalation + sotatercept vehicle injection (gray bars); ii) seraltinib 15 mg / kg twice daily by inhalation + sotatercept vehicle subcutaneous injection twice weekly (horizontal bars); iii) sotatercept 5 mg / kg twice weekly by subcutaneous injection + seraltinib vehicle by inhalation twice daily (vertical bars); or iv) seraltinib 15 mg / kg twice daily by inhalation + sotatercept 5 mg / kg subcutaneous injection twice weekly (white bars). Animals under normoxic conditions served as healthy controls. Figure A shows bar graphs showing individual normalized data points for right ventricular systolic pressure (RVSP). [Figure 1B] We show that inhaled seraltinib plus injected sotatercept demonstrates greater than additive efficacy in the SuHx model of PAH. PAH was induced in animals by administering a single injection of SU5416 (20 mg / kg) on day 0, followed by exposing the animals to hypoxia (10% oxygen) for 21 days. SuHx rats were divided into four groups and treated with: i) control: seraltinib vehicle inhalation + sotatercept vehicle injection (gray bars); ii) seraltinib 15 mg / kg twice daily by inhalation + sotatercept vehicle subcutaneous injection twice weekly (horizontal bars); iii) sotatercept 5 mg / kg twice weekly by subcutaneous injection + seraltinib vehicle by inhalation twice daily (vertical bars); or iv) seraltinib 15 mg / kg twice daily by inhalation + sotatercept 5 mg / kg subcutaneous injection twice weekly (white bars). Animals under normoxic conditions served as healthy controls. Panel B shows bar graphs showing individual normalized data points for mean pulmonary artery pressure (mPAP). [Figure 1C]We show that inhaled seraltinib plus injected sotatercept demonstrates greater than additive efficacy in the SuHx model of PAH. PAH was induced in animals by administering a single injection of SU5416 (20 mg / kg) on day 0, followed by exposing the animals to hypoxia (10% oxygen) for 21 days. SuHx rats were divided into four groups and treated with: i) control: seraltinib vehicle inhalation + sotatercept vehicle injection (gray bars); ii) seraltinib 15 mg / kg twice daily by inhalation + sotatercept vehicle subcutaneous injection twice weekly (horizontal bars); iii) sotatercept 5 mg / kg twice weekly by subcutaneous injection + seraltinib vehicle by inhalation twice daily (vertical bars); or iv) seraltinib 15 mg / kg twice daily by inhalation + sotatercept 5 mg / kg subcutaneous injection twice weekly (white bars). Animals under normoxic conditions served as healthy controls. Figure C shows bar graphs showing individual normalized data points for right ventricular hypertrophy measured by Fulton's index. [Figure 1D] We show that inhaled seraltinib plus injected sotatercept demonstrates greater than additive efficacy in the SuHx model of PAH. PAH was induced in animals by administering a single injection of SU5416 (20 mg / kg) on day 0, followed by exposing the animals to hypoxia (10% oxygen) for 21 days. SuHx rats were divided into four groups and treated with: i) control: seraltinib vehicle inhalation + sotatercept vehicle injection (gray bars); ii) seraltinib 15 mg / kg twice daily by inhalation + sotatercept vehicle subcutaneous injection twice weekly (horizontal bars); iii) sotatercept 5 mg / kg subcutaneous injection twice weekly + seraltinib vehicle by inhalation twice daily (vertical bars); or iv) seraltinib 15 mg / kg twice daily by inhalation + sotatercept 5 mg / kg subcutaneous injection twice weekly (white bars). Animals under normoxic conditions served as healthy controls. Figure D shows bar graphs showing individual normalized data points for the PVR index. [Figure 2] Representative images of lung histological changes stained with hematoxylin and eosin are shown. DETAILED DESCRIPTION OF THE INVENTION

[0011] As noted above, provided herein are methods for treating pulmonary arterial hypertension (PAH), comprising administering to a subject in need thereof: a therapeutically effective amount of a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof; a therapeutically effective amount of a dimeric fusion protein, the extracellular domain of activin type 2A receptor (ACTR IIA) or activin type 2B receptor (ACTR IIB), and and a dimeric fusion protein comprising the Fc domain of human immunoglobulin G1 (IgG1).

[0012] definition Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods and materials are described below. For purposes of the present invention, the following terms are defined below.

[0013] The articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

[0014] As used herein, the term "about" refers to an amount, level, value, dimension, size, or quantity that varies by as much as 30%, 25%, 20%, 15%, 10%, or 5% from a reference amount, level, value, dimension, size, or amount.

[0015] Throughout this specification, unless the context requires otherwise, "comprise", "comprises", and "comprising" will be understood to refer to the inclusion of a stated step or element or group of steps or elements, but not to the exclusion of any other step or element or group of steps or elements.

[0016] As used herein, a "subject" is a mammal, a bird, an aquatic animal (e.g., a fish), or a reptile. In some embodiments, the subject is a human or a laboratory animal such as a mouse, rat, or rabbit; a companion animal such as a dog or cat; a working animal such as a horse or donkey; livestock such as a cow, ox, pig, sheep, goat, deer, llama, or alpaca; or a captive wild animal such as one found in a zoo or wildlife park, including lions, leopards, cheetahs, elephants, zebras, antelopes, giraffes, koalas, kangaroos, and reptiles such as crocodiles, lizards, and snakes; a bird, particularly a captive bird such as a budgerigar or canary, a cockatiel, a parakeet, a macaw, or a parrot; or a fish, particularly a captive fish such as a tropical fish (e.g., zebrafish, guppies, Siamese fighting fish, clownfish, cardinal tetras), a dolphin, or a whale. In certain embodiments, the subject is a human.

[0017] The subject treated according to the methods described herein may be a subject diagnosed with pulmonary hypertension, particularly pulmonary arterial hypertension. Diagnosis may be performed by any method or technique known in the art. Those skilled in the art will understand that a subject treated according to the present disclosure may have undergone standard testing or may have been identified as at risk due to the presence of one or more risk factors associated with the disease or condition, without testing. It is further understood that a subject treated according to the present disclosure may have undergone prior standard treatment, including monotherapy, dual therapy, triple therapy, or quadruple therapy. In certain embodiments, the subject diagnosed with pulmonary hypertension, particularly pulmonary arterial hypertension, is a human.

[0018] As used herein, the term "effective amount" or "therapeutically effective amount" refers to an amount of a tyrosine kinase inhibitor and a dimeric fusion protein sufficient to achieve a desired effect in a subject treated with the agents. Ideally, an effective amount is an amount sufficient to inhibit or treat a disease without causing substantial toxicity in the subject. The effective amount required of a tyrosine kinase inhibitor alone or in combination with a therapy other than the dimeric fusion protein may differ from the effective amount required of a tyrosine kinase inhibitor in combination with the dimeric fusion protein. Similarly, the effective amount required of a dimeric fusion protein alone or in combination with a therapy other than the tyrosine kinase inhibitor may differ from the effective amount required of a dimeric fusion protein in combination with a tyrosine kinase inhibitor. The effective amount depends on the subject being treated, the severity of the disease, whether the subject has previously been treated for the disease, and the mode of drug administration. Those skilled in the art will understand how to determine an effective amount of the disclosed therapies sufficient to achieve a desired effect in a subject.

[0019] As used herein, the term "in combination with" refers to the administration of the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof and the dimeric fusion protein in a single composition or separately, simultaneously or sequentially. The tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof and the dimeric fusion protein may be administered at different times and with different frequencies, but in combination, they exert their biological effects at the same or overlapping times.

[0020] As used herein, "seraltinib" refers to N-{3-[(1S-1-{[6-(3,4-dimethoxyphenyl)pyrazin-2-yl]amino}ethyl]phenyl}-5-methylpyridine-3-carboxamide, also known as GB002 or PK10571, shown below.

[0021] [ka]

[0022] Seraltinib is a highly potent and selective inhibitor of PDGFRα and PDGFRβ, CSF1R, and c-KIT. Amorphous forms of seraltinib are described in U.S. Patent Nos. 9,815,815 and 10,231,966. Formulations containing seraltinib are described in U.S. Patent No. 9,925,184 and U.S. Patent Application Publication No. 2021 / 0038510. Combinations containing seraltinib are described in U.S. Patent Nos. 10,231,966 and 11,364,238.

[0023] Inhaled seraltinib was an effective treatment for severe PAH in two animal models, with improved cardiopulmonary hemodynamics, reduced NT-proBNP, reversed remodeling of pulmonary vascular lesions, and improved inflammatory biomarkers. Seraltinib demonstrated greater efficacy compared with imatinib in preclinical studies (see "Inhaled Seralutinib Exhibits Potent Efficacy in Models of Pulmonary Arterial Hypertension," Galkin et al., European Respiratory Journal, 2022). A phase 2, randomized, double-blind, placebo-controlled trial evaluating the efficacy and safety of inhaled seraltinib in subjects with WHO Group 1 pulmonary hypertension is ongoing.

[0024] As used herein, "sotatercept" refers to a soluble fusion protein composed of the extracellular domain of activin receptor type IIA (ActR IIA) linked to the Fc portion of human IgG1, which has osteogenic activity. Sotatercept captures multiple members of the TGF-β superfamily, including activins and growth differentiation factors. Mutations in bone morphogenetic protein receptor type 2 (BMPR2), a member of the transforming growth factor β (TGF-β) superfamily, are a major factor underlying hereditary PAH. BMPR2 is important in maintaining endothelial integrity in pulmonary arteries. Mutations that reduce signaling in the BMPR-II pathway promote endothelial dysfunction, increased cell proliferation, and pulmonary vascular remodeling. Sotatercept restores the balance between the growth-promoting activin growth differentiation factor pathway and the growth-inhibitory BMP pathway.

[0025] Therapeutic treatment with a rodent analog of sotatercept (RAP-011) reverses vascular remodeling in rats with PAH. In a phase 2 clinical trial, beneficial effects of sotatercept were reported in PAH patients treated with standard of care therapy. In 2019, the U.S. Food and Drug Administration (FDA) designated sotatercept an orphan drug for the treatment of pulmonary arterial hypertension (PAH). In 2020, sotatercept received breakthrough therapy designation from the FDA and was granted fast track designation by the European Medicines Agency (EMA) for the same indication.

[0026] How to Treat PAH In one embodiment, a method of treating pulmonary arterial hypertension (PAH) is provided, comprising administering to a subject in need thereof: a therapeutically effective amount of a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof; a therapeutically effective amount of a dimeric fusion protein, the extracellular domain of activin type 2A receptor (ACTR IIA) or activin type 2B receptor (ACTR IIB), and and a dimeric fusion protein comprising the Fc domain of human immunoglobulin G1 (IgG1).

[0027] Receptor tyrosine kinases (RTKs) or tyrosine kinase receptors (TKRs) are polypeptides that regulate cell renewal, remodeling, development, and differentiation. They are high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Mutations in receptor tyrosine kinases result in the activation of a series of signaling cascades, which in turn result in protein expression. Receptor tyrosine kinases are part of a larger family of protein tyrosine kinases, including receptor tyrosine kinase proteins that contain transmembrane domains and non-receptor tyrosine kinases that lack transmembrane domains. Approximately 20 different RTK classes have been identified, including the EGF (or ErbB), insulin, PDGF, VEGF, FGF, CCK, NGF, HGF, Eph, AXL, TIE, RYK, DDR, RET, ROS, LTK, ROR, and MuSK receptor families.

[0028] Platelet-derived growth factor receptor (PDGF-R) is a tyrosine kinase receptor for members of the platelet-derived growth factor (PDGF) family. PDGF subunits-A and -B are key regulators of cell proliferation, differentiation, growth, and development. PDGF-R exists in two forms, alpha and beta, encoded by different genes. Platelet-derived growth factor receptor (PDGFR) is associated with lung disease, tissue fibrosis, and solid tumors.

[0029] In one embodiment, the tyrosine kinase inhibitor in the method of treating PAH is a PDGF receptor inhibitor or a pharmaceutically acceptable salt thereof, a CSF1R receptor inhibitor or a pharmaceutically acceptable salt thereof, a c-KIT kinase inhibitor or a pharmaceutically acceptable salt thereof, or a combination thereof. In some embodiments, the tyrosine kinase inhibitor is acalabrutinib or a pharmaceutically acceptable salt thereof, afatinib or a pharmaceutically acceptable salt thereof, alectinib or a pharmaceutically acceptable salt thereof, avapritinib or a pharmaceutically acceptable salt thereof, axitinib (Inlyta®) or a pharmaceutically acceptable salt thereof, baricitinib or a pharmaceutically acceptable salt thereof, binimetinib or a pharmaceutically acceptable salt thereof, bosutinib (Bosuri®) or a pharmaceutically acceptable salt thereof. (registered trademark) or a pharmaceutically acceptable salt thereof, brigutinib or a pharmaceutically acceptable salt thereof, cabozantinib or a pharmaceutically acceptable salt thereof, capmatinib or a pharmaceutically acceptable salt thereof, ceritinib or a pharmaceutically acceptable salt thereof, cobimetinib or a pharmaceutically acceptable salt thereof, crizotinib or a pharmaceutically acceptable salt thereof, dacomitinib or a pharmaceutically acceptable salt thereof, entrectinib or a pharmaceutically acceptable salt thereof, rudafitinib or a pharmaceutically acceptable salt thereof, erlotinib (Tarceva (registered trademark)) or a pharmaceutically acceptable salt thereof, fedratinib or a pharmaceutically acceptable salt thereof, fostamatinib or a pharmaceutically acceptable salt thereof, gefitinib or a pharmaceutically acceptable salt thereof, gilteritinib or a pharmaceutically acceptable salt thereof, ibrutinib or a pharmaceutically acceptable salt thereof, imatinib (Gleevec (registered trademark)) or a pharmaceutically acceptable salt thereof, lapatinib or a pharmaceutically acceptable salt thereof, larotrectinib or a pharmaceutically acceptable salt thereof, lenvatinib or a pharmaceutically acceptable salt thereof, lorlatinib or a pharmaceutically acceptable salt thereof, midostaurin or a pharmaceutically acceptable salt thereof, neratinib (Tasigna®) or a pharmaceutically acceptable salt thereof, osimertinib or a pharmaceutically acceptable salt thereof, pazopanib (Votrient®) or a pharmaceutically acceptable salt thereof,pemigatinib or a pharmaceutically acceptable salt thereof, pexidartinib or a pharmaceutically acceptable salt thereof, ponatinib or a pharmaceutically acceptable salt thereof, regorafenib or a pharmaceutically acceptable salt thereof, ripretinib or a pharmaceutically acceptable salt thereof, ruxolitinib or a pharmaceutically acceptable salt thereof, selpercatinib or a pharmaceutically acceptable salt thereof, selumetinib or a pharmaceutically acceptable salt thereof, seraltinib or a pharmaceutically acceptable salt thereof, sorafenib or a pharmaceutically acceptable salt thereof, sunitinib (Sutent®) or a pharmaceutically acceptable salt thereof, tofacitinib or a pharmaceutically acceptable salt thereof, trametinib or a pharmaceutically acceptable salt thereof, tucatinib or a pharmaceutically acceptable salt thereof, upadacitinib or a pharmaceutically acceptable salt thereof, vandetanib or a pharmaceutically acceptable salt thereof, zanubrutinib or a pharmaceutically acceptable salt thereof, or a combination thereof.

[0030] In some embodiments, the tyrosine kinase inhibitor is seraltinib or a pharmaceutically acceptable salt thereof. In some embodiments, the tyrosine kinase inhibitor is seraltinib. In some embodiments, the tyrosine kinase inhibitor is a pharmaceutically acceptable salt of seraltinib.

[0031] In some embodiments, the dimeric fusion protein comprises the extracellular domain of an activin type 2A receptor. In other embodiments, the dimeric fusion protein comprises the extracellular domain of an activin type 2B receptor. In other embodiments, the dimeric fusion protein is sotatercept.

[0032] Further described herein are methods for treating pulmonary arterial hypertension (PAH), comprising administering to a subject in need thereof: a therapeutically effective amount of seraltinib or a pharmaceutically acceptable salt thereof, and The method comprises administering a therapeutically effective amount of sotatercept.

[0033] The combination therapy described herein is intended to encompass administration of the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof and the dimeric fusion protein as a standalone dual combination therapy, as well as administration in further combination with other biologically active ingredients and non-drug therapies (e.g., holistic therapies). When the combination therapy further includes a non-drug therapy, the non-drug therapy may be administered at any suitable time, so long as a beneficial effect from the synergistic action of the combination of the therapeutic agent and the non-drug therapy is achieved. For example, in appropriate cases, a beneficial effect is achieved even when the non-drug therapy is temporarily removed from the administration of the therapeutic agent, perhaps for several days or even weeks.

[0034] In some embodiments, the subject is receiving stable basal therapy for pulmonary arterial hypertension. In some embodiments, the stable basal therapy is monotherapy, dual therapy, or triple therapy. In other embodiments, the stable basal therapy is monotherapy. In other embodiments, the stable basal therapy is dual therapy. In other embodiments, the stable basal therapy is triple therapy. In some embodiments, the stable basal therapy comprises an endothelin receptor antagonist, a phosphodiesterase-5 (PDE-5) inhibitor, a prostacyclin analog, a prostacyclin receptor agonist, a soluble guanylate cyclase stimulator, or a combination thereof. In some embodiments, the stable basal therapy comprises an endothelin receptor antagonist. In some embodiments, the stable basal therapy comprises a phosphodiesterase-5 (PDE-5) inhibitor. In some embodiments, the stable basal therapy comprises a prostacyclin analog. In some embodiments, the stable basal therapy comprises a soluble guanylate cyclase stimulator. In some embodiments, the stable basal therapy comprises a combination of at least two therapies selected from an endothelin receptor antagonist, a phosphodiesterase-5 (PDE-5) inhibitor, a prostacyclin analog, and a prostacyclin receptor agonist.

[0035] In some embodiments, the method further comprises administering to the subject an endothelin receptor antagonist, a phosphodiesterase type 5 (PDE-5) inhibitor, a prostacyclin analog, a prostacyclin receptor agonist, a soluble guanylate cyclase stimulator, or a combination thereof.

[0036] In some embodiments, the method further includes administering to the subject a therapeutically effective amount of an endothelin receptor agonist, hi some embodiments, the endothelin receptor agonist is ambrisentan (Letairis®), macitentan (Opsumit®), or bosentan.

[0037] In some embodiments, the method further includes administering to the subject a therapeutically effective amount of a phosphodiesterase type 5 (PDE-5) inhibitor, hi some embodiments, the phosphodiesterase type 5 (PDE-5) inhibitor is sildenafil, tadalafil, vardenafil, avanafil, or udenafil.

[0038] In some embodiments, the method further comprises administering to the subject a prostacyclin analog, hi some embodiments, the prostacyclin receptor analog is epoprostenol, treprostinil, iloprost, or beraprost.

[0039] In some embodiments, the method further comprises administering to the subject a prostacyclin receptor agonist, hi some embodiments, the prostacyclin receptor agonist is selexipag or ralinepag.

[0040] In some embodiments, the method further comprises administering to the subject a soluble guanylate cyclase stimulator, hi some embodiments, the soluble guanylate cyclase stimulator is riociguat or veruiciguat.

[0041] In some embodiments, the method further comprises administering to the subject tadalafil, selexipag, ralinepag, or a combination thereof. In other embodiments, the method further comprises administering to the subject tadalafil, selexipag, or a combination thereof.

[0042] In some embodiments of the methods of treating PAH, the PAH is mild or moderate PAH. In some embodiments, the PAH is mild PAH. In some embodiments, the PAH is moderate PAH. In some embodiments, the method reduces the risk of morbidity and mortality from PAH. In some embodiments, the method reduces the risk of morbidity from PAH. In some embodiments, the method reduces the risk of mortality from PAH. In some embodiments, the method reduces the risk of morbidity, mortality, or both from PAH.

[0043] In some embodiments of the present invention, the tyrosine kinase inhibitor is administered by inhalation. In some embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered by inhalation. In some embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered by inhalation using a dry powder inhaler. In some embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered once daily or twice daily. In some embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered once. In some embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered twice daily. In some embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered three times daily.

[0044] In some embodiments, the dimeric fusion protein is administered by injection. In some embodiments, sotatercept is administered by injection. In some embodiments, sotatercept is administered by subcutaneous injection. In some embodiments, sotatercept is administered once a week, once every two weeks, once every three weeks, or once a month. In other embodiments, sotatercept is administered once a week. In some embodiments, sotatercept is administered once every two weeks. In some embodiments, sotatercept is administered every three weeks. In some embodiments, sotatercept is administered once a month.

[0045] Dosage regimen The therapeutic agents described herein can be administered before, during, or after the onset or diagnosis of a disease, and the timing of administering the agent may vary. For example, the agent can be used as a prophylactic and administered to a subject with a predisposition to a particular disease to reduce the likelihood of the disease occurring. The agent can be administered to a subject during the onset of symptoms or as soon as possible after the onset. Initial administration can be via any practical route. The therapeutic agent can be administered as soon as practicable after the onset of a disease or symptom is detected or suspected, for the period necessary to treat the disease. The length of treatment can vary for each subject.

[0046] In some embodiments, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered to a subject in need thereof separately from the dimeric fusion protein.

[0047] In some embodiments, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered by inhalation. In some embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered by inhalation.

[0048] In some embodiments, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered once daily or twice daily. In some embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered once daily. In other embodiments, seraltinib or a pharmaceutically acceptable salt thereof is administered twice daily.

[0049] In some embodiments, the dimeric fusion protein is administered by injection. In some embodiments, the dimeric fusion protein is administered by subcutaneous injection. In some embodiments, sotatercept is administered by injection. In some embodiments, sotatercept is administered by subcutaneous injection.

[0050] In some embodiments, the dimeric fusion protein is administered twice a week, once a week, once every two weeks, once every three weeks, or once a month. In some embodiments, sotatercept is administered twice a week, once a week, once every two weeks, once every three weeks, or once a month. In some embodiments, sotatercept is administered twice a week. In other embodiments, sotatercept is administered once a week. In other embodiments, sotatercept is administered once every two weeks. In other embodiments, sotatercept is administered once every three weeks. In other embodiments, sotatercept is administered once a month.

[0051] In some embodiments, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered at least once prior to, simultaneously with, or sequentially with the dimeric fusion protein, hi certain embodiments, multiple doses of the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof are administered beginning before or with administration of the dimeric fusion protein and then over a period of time that continues after administration of the dimeric fusion protein.

[0052] In some embodiments, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered periodically, two or more times, before, simultaneously with, and after administration of the dimeric fusion protein. In some embodiments, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered before administration of the dimeric fusion protein. In other embodiments, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered simultaneously with or consecutively to administration of the dimeric fusion protein, with at least one administration following administration of the dimeric fusion protein. The tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof may be administered one week to one day before administration of the dimeric fusion protein, particularly one to three days before administration of the dimeric fusion protein. The tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof may be administered simultaneously with or consecutively to administration of the dimeric fusion protein, either immediately before or immediately after administration of the dimeric fusion protein. The tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof may also be administered one or more times per month following administration of the dimeric fusion protein, for example, once a week, once every five days, once every four days, once every three days, once every two days, once a day, or twice a day, particularly once or twice a day. Subsequent administrations of the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof may be continued such that the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered 1 to 10 times after administration of the dimeric fusion protein, particularly 1 to 70, 1 to 60, 1 to 50, 1 to 40, 1 to 30, 1 to 20, 1 to 10, 1 to 8, 1 to 6, 1 to 4, or 1 to 2 times.

[0053] The dimeric fusion protein is administered in an effective amount. "Effective amount" refers to the amount necessary to at least partially achieve the desired therapeutic response. The amount will vary depending on the health and physical condition of the individual being treated, the pulmonary hypertension classification of the individual being treated, the formulation of the composition, the severity of the pulmonary hypertension, an evaluation of the medical situation, and other relevant factors. It is expected that this amount will fall within a relatively broad range. An effective amount may be, for example, within the range of about 0.1 ng / kg body weight to 1 g / kg body weight per dose. The dosage is preferably in the range of 1 μg to 0.5 g / kg body weight per dose, for example, 0.1 mg to 100 mg / kg body weight per dose, 1 mg to 25 mg / kg body weight per dose, or 5 mg / kg body weight per dose. In some embodiments, when the dimeric fusion protein dosage is administered by subcutaneous injection, the dosage ranges from 0.1 mg to 25 mg / kg body weight, e.g., 1 mg to 10 mg / kg body weight, e.g., 1 mg / kg body weight, 2 mg / kg body weight, 3 mg / kg body weight, 4 mg / kg body weight, or 5 mg / kg body weight. The dosing regimen can be adjusted to provide the optimal therapeutic response. For example, in some embodiments, when the dimeric fusion protein is administered by subcutaneous injection, the dimeric fusion protein is administered once a month and the course of treatment is observed. In other embodiments, the dimeric fusion protein is administered once every three weeks and the course of treatment is observed. In other embodiments, the dimeric fusion protein is administered once every two weeks and the course of treatment is observed. In other embodiments, the dimeric fusion protein is administered once a week and the course of treatment is observed. In other embodiments, the dimeric fusion protein is administered twice a week and the course of treatment is observed.

[0054] The tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof may also be administered in an effective amount. The amount of the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof that is deemed effective will depend on the health and physical condition of the individual being treated, the pulmonary hypertension classification of the individual being treated, the formulation of the composition, the severity of the pulmonary hypertension, an evaluation of the medical situation, and other relevant factors. It is expected that the amount of the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof will fall within a fairly broad range. An effective amount may range from about 0.1 ng / kg to about 500 mg / kg body weight per dose. The dosage is preferably in the range of 100 μg to 100 mg / kg body weight per dose, 1 mg to 50 mg / kg body weight per dose, 1 mg to 20 mg / kg body weight per dose, or 5 mg to 15 mg / kg body weight per dose. In some embodiments, when the dosage of the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered by inhalation, the dosage is in the range of 1 mg to 100 mg / kg body weight, e.g., 5 mg to 25 mg / kg body weight, e.g., 5 mg / kg body weight, 10 mg / kg body weight, 15 mg / kg body weight, 20 mg / kg body weight, or 25 mg / kg body weight. The dosing regimen can be adjusted to provide the optimal therapeutic response. For example, in some embodiments, when the administration of the tyrosine kinase inhibitor, a pharmaceutically acceptable salt thereof, is by inhalation, the pharmaceutically acceptable salt of the tyrosine kinase inhibitor is administered twice daily and a course of treatment is observed. In other embodiments, the pharmaceutically acceptable salt of the tyrosine kinase inhibitor is administered once daily and a course of treatment is observed. In other embodiments, the pharmaceutically acceptable salt of the tyrosine kinase inhibitor is administered once every two days and a course of treatment is observed. In another embodiment, the pharmaceutically acceptable salt of the tyrosine kinase inhibitor is administered once every three days and the course of treatment is observed. In another embodiment, the pharmaceutically acceptable salt of the tyrosine kinase inhibitor is administered once every five days and the course of treatment is observed. In another embodiment, the pharmaceutically acceptable salt of the tyrosine kinase inhibitor is administered once every six days and the course of treatment is observed. In another embodiment, the pharmaceutically acceptable salt of the tyrosine kinase inhibitor is administered once a week and the course of treatment is observed.

[0055] kit The tyrosine kinase inhibitor or pharmaceutically acceptable salt thereof and the dimeric fusion protein compositions may be formulated separately and sold together in a kit or package. In one embodiment, each kit may contain one or more doses of each compound useful for treating or preventing PAH. In another embodiment, each kit may contain one or more containers. In a further embodiment, each container of the kit may contain one or more doses of one or more compounds useful for treating or preventing PAH. In one embodiment, each container of the kit contains one or more doses of different compounds useful for treating or preventing PAH.

[0056] In one embodiment, there is provided a kit useful for treating or preventing pulmonary arterial hypertension (PAH), comprising: a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof; A dimeric fusion protein comprising: the extracellular domain of activin type 2A receptor (ACTR IIA) or activin type 2B receptor (ACTR IIB), and A kit is provided that includes one or more containers containing a dimeric fusion protein comprising the Fc domain of human immunoglobulin G1 (IgG1).

[0057] In one embodiment, at least one container of the kit contains a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof. In a preferred embodiment, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is seraltinib or a pharmaceutically acceptable salt thereof. In another embodiment, at least one container of the kit contains a dimeric fusion protein. In a preferred embodiment, the dimeric fusion protein is sotatercept. In one embodiment, the kit contains at least one container containing seraltinib or a pharmaceutically acceptable salt thereof and at least one separate container containing sotatercept.

[0058] In one embodiment, a kit comprising: one or more doses of a therapeutically effective amount of a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof; a therapeutically effective amount of a dimeric fusion protein, the extracellular domain of activin type 2A receptor (ACTR IIA) or activin type 2B receptor (ACTR IIB), and and one or more doses of a dimeric fusion protein comprising the Fc domain of human immunoglobulin G1 (IgG1).

[0059] In some embodiments, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is formulated for administration by inhalation. In one embodiment, the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is formulated as a dry powder for administration by inhalation using a dry powder inhaler. In some embodiments, the kit comprises one or more doses of the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof and a dry powder inhaler.

[0060] In some embodiments, the dimeric fusion protein is formulated for subcutaneous injection in the form of a single bolus dose or multiple doses. For example, the kit may include the dimeric fusion protein in a pre-filled syringe, either as a liquid in a vial ready for incorporation into a syringe, or as a solid ready for dissolution prior to incorporation into a syringe. The liquid or solid formulation may be a single-dose formulation or a multi-dose formulation. In other embodiments, the kit may include multiple doses of the dimeric fusion protein, each separately formulated in a pre-filled syringe, either as a liquid in a vial ready for incorporation into a syringe, or as a solid ready for dissolution and incorporation into a syringe.

[0061] The kit may further include one or more of the various pharmaceutical kit components, such as, for example, a container with one or more pharmaceutically acceptable carriers. The kit may further include an insert or label containing instructions for use of each formulation. The insert or label may further include, as appropriate, instructions for preparing each dosage form, including the amounts of the components to be administered and / or guidelines for mixing the components, how to administer each dose, and / or when to administer each dose. [Example]

[0062] The following examples are provided for illustrative purposes only and are not intended to limit the scope of the claims provided herein. While preferred embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the invention. It is understood that various alternatives to the embodiments of the invention described herein may be used in practicing the invention. The following claims define the scope of the invention, and it is intended to cover thereby methods and structures within the scope of these claims and their equivalents.

[0063] Example 1: PAH Rat Model SuHx-mediated (SU5416 + hypoxia) pulmonary hypertension was induced in male Sprague-Dawley rats (see "Inhibition of the VEGF receptor 2 combined with chronic hypoxia causes cell death-dependent pulmonary endothelial cell proliferation and severe pulmonary hypertension," Taraseviciene-Stewart et al., FASEB J, 2001, 15, 427-438 and "TORREY, a Phase 2 study to evaluate the efficacy and safety of inhaled seralutinib for the treatment of pulmonary arterial hypertension," Frantz RP, et al., Pulmonary Circulation 2021;11(4), 1-7). Semaxanib (SU5416) was administered as a single subcutaneous injection (20 mg / kg) to rats weighing 200–250 g. Rats were housed in 10% oxygen for 3 weeks, followed by re-exposure to normoxia during a 4-week treatment period.

[0064] Rats were divided into five treatment groups, as summarized in Table 1 .

[0065] [Table 1]

[0066] Rats were treated as described above for 4 weeks, starting on day 22 after disease induction. After 4 weeks of treatment, the following parameters were assessed: right ventricular systolic pressure (RVSP), Fulton's index (ratio of right ventricle to left ventricle and septum mass), and mean pulmonary arterial pressure (mPAP).

[0067] For each of the measured parameters (RVSP, Fulton index, and mPAP), the combination of seraltinib plus sotatercept (Group 5) resulted in a significant reduction compared to the control (Group 2, inhaled seraltinib vehicle plus sotatercept vehicle, subcutaneous injection), seraltinib treatment alone (Group 3), and sotatercept treatment alone (Group 4).

[0068] In each case, the observed effects were synergistic for the combination, rather than additive for either drug alone. Furthermore, three of seven animals from the seraltinib + sotatercept combination treatment group (Group 5) exhibited RVSP levels that were reduced to the same level as healthy animals (Group 1). More specific details regarding this study are provided below.

[0069] Induction of PAH Animals from groups 2-5 received a single subcutaneous injection of SU5416 (20 mg / kg) on day 0 and were exposed to hypoxia (10% O2) for 21 days, followed by normoxia for 4 weeks. Animals in group 1 (healthy group) were caged and exposed to ambient oxygen concentrations (normoxia) for 49 days. Food and water were provided ad libitum. Animals were randomized between treatment groups on day 21 based on body weight and transthoracic echocardiography results.

[0070] Treatment with test substances Treatment with inhaled seraltinib or vehicle RAP-011 or mIgG2A was as described in Table 2.

[0071] [Table 2] SER = seraltinib, SOR = sotatercept (RAP-011, administered as the rat analogue of sotatercept) Inh = administered by inhalation, SC = administered as a subcutaneous injection

[0072] Briefly, treatment with aerosolized seraltinib or vehicle was administered BID over 45 minutes for 4 weeks, starting on day 22 (as outlined in Table 1), at an estimated dose of up to 15 mg / kg / dose using a Vilnius aerosol generator connected to an inhalation tower. Powder concentrations were continuously monitored by a handheld aerosol monitor. Aerodynamic particle size distribution measurements were performed using a Mercer-type cascade impactor. RAP-011 or mIgG was administered twice weekly by SC injection at a dose of 5 mg / kg for 4 weeks, as described in Table 2, starting on day 22.

[0073] Hemodynamics, RV hypertrophy and echocardiographic measurements Echocardiographic monitoring of disease progression was performed for all groups on day 21 (pretreatment) and on the day of surgery (day 49). Echocardiographic results from day 21 were used to randomize animals to ensure that only animals with sufficiently severe disease were selected and that there was similar disease stage across all groups.

[0074] On day 49, after 4 weeks of treatment, the end-of-study procedure was performed. Mean pulmonary artery pressure (mPAP) and right ventricular systolic pressure (RVSP) were measured via an intraventricular fluid-filled catheter manufactured by AD instruments. Mean pulmonary artery pressure values were calculated using the formula mPAP = diastolic pressure + (systolic pressure - diastolic pressure) / 3. Pulmonary vascular resistance index (PVRI) was calculated using the following formula: PVRI = mPAP / CI. where mPAP is mean pulmonary artery pressure (mmHg) and CI (cardiac index) is the cardiac index defined as cardiac output (ml / min) normalized to 100 g body weight. As part of the Fulton index, the heart was dissected to separate the right ventricle from the left ventricle along with the septum, which were then weighed separately (Fulton index = right ventricle weight / ventricular septum weight + left ventricle weight).

[0075] Effect of test substance (recovery rate) The effect of the test substance was calculated using the following formula: ((vehicle group value - test substance group value) / (vehicle group value - normoxic group value))

[0076] statistical analysis Data are presented as medians with interquartile ranges. One-way ANOVA followed by Fisher's LSD test was performed for all experimental conditions in GraphPad Prism 10.0, comparing treatment groups with either healthy animals (normoxic control) or diseased animals (SuHx + placebo and mIgG2A). Differences were * p<0.05, ** p<0.01, *** p<0.001, **** p<0.0001 was considered significant.

[0077] data Figures 1A-1D show that inhaled seraltinib plus injected sotatercept resulted in greater than additive efficacy in this PAH model. Referring to Figure 1, the data presents the changes in RVSP, mPAP, RV hypertrophy (Fulton's index), and PVR index for each treatment group (i.e., Figures 1A, 1B, 1C, and 1D, respectively). The presented data were calculated by normalizing the median values for each treatment to vehicle and normal controls. Parameter value = (value - normal value) / (vehicle value - normal value), n = 5-7 per group. As shown by Figure 1, the seraltinib plus sotatercept treatment group demonstrated more than additive benefits in four of the parameters tested (RVSP, mPAP, Fulton's index, and PVR index).

[0078] Figure 2 shows representative images of pulmonary vessels from each treatment group. Vehicle-control animals with significantly elevated mPAP and RVSP also had obstructed pulmonary vessels, accompanied by neointimal proliferation and plexiform lesions, whereas the pulmonary vessels in healthy animals were not obstructed. The seraltinib monotherapy group, sotatercept monotherapy group, and seraltinib + sotatercept combination therapy groups showed improved hemodynamic parameters, with unobstructed pulmonary vessels similar to those in the healthy group.

[0079] result The Sugen-hypoxia rat model is a widely used and recognized model of severe PAH. Sugen 5416 (SU5416) is known to induce pulmonary endothelial cell apoptosis, and when used at a single working dose of 20 mg / kg and combined with a 3-week hypoxic (10% O2) course, as in this study, it results in severe PAH. Endothelial cell apoptosis under hypoxic conditions induces endothelial cell proliferation in precapillary arterioles and leads to the selection of an apoptosis-resistant subset of endothelial cells. This occurs in addition to vascular smooth muscle cell remodeling and contraction, promoting the development of PAH (Taraseviciene-Stewart, L., 2020). This obstruction of pulmonary arterioles results in reduced blood flow, significantly increasing pulmonary arterial pressure (PAP), right ventricular systolic pressure, and right ventricular hypertrophy.

[0080] In this study, vehicle-control animals receiving SuHx with inhaled seraltinib vehicle and sotatercept control IgG2A for 4 weeks developed severe PAH by day 49. Vehicle-control (placebo inhaled + IgG2A) animals had statistically significantly elevated RVSP (57.3 mmHg, IQR 65.7-55.7 mmHg) and mPAP (38.1 mmHg, IQR 43.3-34.2 mmHg) compared with normoxic controls (RVSP 23.8 mmHg, IQR 26.95-22.4 mmHg and mPAP 18.2 mmHg, IQR 18.7-17.2 mmHg, p<0.0001). Similarly, vehicle control animals also had significantly greater RV hypertrophy as measured using the Fulton index (0.62, IQR 0.66-0.56) compared to healthy controls (0.26, IQR 0.26-0.24, p<0.0001).

[0081] The data presented were calculated by normalizing each data point to the vehicle (considered as 1 and the normal control as 0). Animals treated with seraltinib monotherapy had a 13, 23, 9, and 26% reduction in RVSP, mPAP, Fulton's index (RV hypertrophy measure), and PVR index, respectively, and sotatercept monotherapy animals had a 31, 28, 15, and 25% reduction. Meanwhile, the seraltinib + sotatercept combination treatment group had a 77% reduction in RVSP, a 78% reduction in mPAP, a 55% reduction in Fulton's index, and a 73% reduction in PVR index. Seraltinib + sotatercept combination therapy demonstrated significant reductions in RVSP, mPAP, Fulton index, and PVR index compared with seraltinib monotherapy (p<0.001 for RVSP and mPAP, and p<0.01 for Fulton index and PVR index), and significant reductions in RVSP, mPAP, and Fulton index compared with sotatercept monotherapy (p<0.05 for RVSP, mPAP, and Fulton index).

[0082] The various embodiments described above can be combined to provide further embodiments. All U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications, and non-patent publications mentioned herein and / or listed in the Application Data Sheets are incorporated herein by reference in their entirety. Aspects of the embodiments can be modified, if necessary, to provide further embodiments using concepts from the various patents, specifications, and publications.

[0083] These and other changes can be made to the embodiments in light of the above Detailed Description. In general, the terms used in the following claims should not be construed to limit the claims to the specific embodiments disclosed in the specification and claims, but rather to include all possible embodiments and the full scope of equivalents to which such claims are entitled. Accordingly, the claims are not limited by the disclosure herein.

[0084] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 396,899, filed August 10, 2022, which is incorporated herein by reference in its entirety.

Claims

1. 1. A method of treating pulmonary arterial hypertension (PAH), comprising administering to a subject in need thereof: a therapeutically effective amount of a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof; a therapeutically effective amount of a dimeric fusion protein, the extracellular domain of activin type 2A receptor (ACTR IIA) or activin type 2B receptor (ACTR IIB), and A method for treating pulmonary arterial hypertension (PAH), comprising administering a dimeric fusion protein comprising the Fc domain of human immunoglobulin G1 (IgG1).

2. 2. The method of claim 1, wherein the tyrosine kinase inhibitor is a PDGF receptor inhibitor or a pharmaceutically acceptable salt thereof, a CSF1R receptor inhibitor or a pharmaceutically acceptable salt thereof, a c-KIT kinase inhibitor or a pharmaceutically acceptable salt thereof, or a combination thereof.

3. The tyrosine kinase inhibitor is selected from the group consisting of acalabrutinib or a pharmaceutically acceptable salt thereof, afatinib or a pharmaceutically acceptable salt thereof, alectinib or a pharmaceutically acceptable salt thereof, avapritinib or a pharmaceutically acceptable salt thereof, axitinib (Inlyta (registered trademark)) or a pharmaceutically acceptable salt thereof, baricitinib or a pharmaceutically acceptable salt thereof, binimetinib or a pharmaceutically acceptable salt thereof, bosutinib (Bosulif (registered trademark)) or a pharmaceutically acceptable salt thereof, brigutinib or a pharmaceutically acceptable salt thereof or a pharmaceutically acceptable salt thereof, cabozantinib or a pharmaceutically acceptable salt thereof, capmatinib or a pharmaceutically acceptable salt thereof, ceritinib or a pharmaceutically acceptable salt thereof, cobimetinib or a pharmaceutically acceptable salt thereof, crizotinib or a pharmaceutically acceptable salt thereof, dacomitinib or a pharmaceutically acceptable salt thereof, entrectinib or a pharmaceutically acceptable salt thereof, erdafitinib or a pharmaceutically acceptable salt thereof, erlotinib (Tarceva®) or a pharmaceutically acceptable salt thereof, fedratinib or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable salt thereof, fostamatinib or a pharmaceutically acceptable salt thereof, gefitinib or a pharmaceutically acceptable salt thereof, gilteritinib or a pharmaceutically acceptable salt thereof, ibrutinib or a pharmaceutically acceptable salt thereof, imatinib (Gleevec (registered trademark)) or a pharmaceutically acceptable salt thereof, lapatinib or a pharmaceutically acceptable salt thereof, larotrectinib or a pharmaceutically acceptable salt thereof, lenvatinib or a pharmaceutically acceptable salt thereof, lorlatinib or a pharmaceutically acceptable salt thereof, midostaurin or a pharmaceutically acceptable salt thereof pharmaceutically acceptable salts thereof, neratinib (Tasigna®) or a pharmaceutically acceptable salt thereof, osimertinib or a pharmaceutically acceptable salt thereof, pazopanib (Votrient®) or a pharmaceutically acceptable salt thereof, pemigatinib or a pharmaceutically acceptable salt thereof, pexidartinib or a pharmaceutically acceptable salt thereof, ponatinib or a pharmaceutically acceptable salt thereof, regorafenib or a pharmaceutically acceptable salt thereof, ripretinib or a pharmaceutically acceptable salt thereof, ruxolitinib or a pharmaceutically acceptable salt thereof,The method of claim 1 or 2, wherein the agent is selpercatinib or a pharmaceutically acceptable salt thereof, selumetinib or a pharmaceutically acceptable salt thereof, seraltinib or a pharmaceutically acceptable salt thereof, sorafenib or a pharmaceutically acceptable salt thereof, sunitinib (Sutent®) or a pharmaceutically acceptable salt thereof, tofacitinib or a pharmaceutically acceptable salt thereof, trametinib or a pharmaceutically acceptable salt thereof, tucatinib or a pharmaceutically acceptable salt thereof, upadacitinib or a pharmaceutically acceptable salt thereof, vandetanib or a pharmaceutically acceptable salt thereof, zanubrutinib or a pharmaceutically acceptable salt thereof, or a combination thereof.

4. The method according to any one of claims 1 to 3, wherein the tyrosine kinase inhibitor is seraltinib or a pharmaceutically acceptable salt thereof.

5. The method of any one of claims 1 to 4, wherein the dimeric fusion protein comprises the extracellular domain of the activin type 2A receptor.

6. The method of any one of claims 1 to 5, wherein the dimeric fusion protein comprises the extracellular domain of activin 2A Fc-type receptor.

7. The method of any one of claims 1 to 4, wherein the dimeric fusion protein comprises the extracellular domain of the activin type 2B receptor.

8. The method of any one of claims 1 to 6, wherein the dimeric fusion protein is sotatercept.

9. The method of any one of claims 1 to 6 and 8, wherein the tyrosine kinase inhibitor is seraltinib or a pharmaceutically acceptable salt thereof, and the dimeric fusion protein is sotatercept.

10. The method of any one of claims 1 to 9, wherein the subject is receiving stable baseline therapy for pulmonary arterial hypertension.

11. 11. The method of claim 10, wherein the stable background therapy is monotherapy, dual therapy, triple therapy, or quadruple therapy.

12. 12. The method of claim 10 or 11, wherein the stable basal therapy comprises an endothelin receptor antagonist, a phosphodiesterase-5 (PDE-5) inhibitor, a prostacyclin analog, a prostacyclin receptor agonist, a soluble guanylate cyclase stimulator, or a combination thereof.

13. 13. The method of any one of claims 1 to 12, further comprising administering to the subject an endothelin receptor antagonist, a phosphodiesterase type 5 (PDE-5) inhibitor, a prostacyclin analog, a prostacyclin receptor agonist, a soluble guanylate cyclase stimulator, or a combination thereof.

14. The method of any one of claims 1 to 13, further comprising administering a therapeutically effective amount of an endothelin receptor agonist.

15. 15. The method of claim 14, wherein the endothelin receptor agonist is ambrisentan (Letairis®), macitentan (Opsumit®), or bosentan.

16. 16. The method of any one of claims 1 to 15, further comprising administering a therapeutically effective amount of a phosphodiesterase type 5 (PDE-5) inhibitor.

17. 17. The method of claim 16, wherein the phosphodiesterase type 5 (PDE-5) inhibitor is sildenafil, tadalafil, vardenafil, avanafil, or udenafil.

18. The method of any one of claims 1 to 17, further comprising administering to the subject a prostacyclin analogue.

19. 19. The method of claim 18, wherein the prostacyclin receptor analog is epoprostenol, treprostinil, iloprost, or beraprost.

20. 20. The method of any one of claims 1 to 19, further comprising administering to the subject a prostacyclin receptor agonist.

21. 21. The method of claim 20, wherein the prostacyclin receptor agonist is selexipag or larinepag.

22. 22. The method of any one of claims 1 to 21, further comprising administering to the subject a soluble guanylate cyclase stimulator.

23. 23. The method of claim 22, wherein the soluble guanylate cyclase stimulator is riociguat or veruiciguat.

24. 24. The method of any one of claims 1 to 23, further comprising administering to the subject tadalafil, selexipag, or a combination thereof.

25. 25. The method of any one of claims 1-24, further comprising administering to the subject tadalafil, selexipag, ralinepag, or a combination thereof.

26. The method according to any one of claims 1 to 25, wherein the PAH is mild or moderate PAH.

27. 27. The method of any one of claims 1 to 26, wherein the PAH is a moderate PAH.

28. 28. The method of any one of claims 1 to 27, wherein the method reduces the risk of morbidity, mortality, or both from PAH.

29. 29. The method of any one of claims 1 to 28, wherein the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is administered by inhalation.

30. 30. The method of any one of claims 1 to 29, wherein seraltinib or a pharmaceutically acceptable salt thereof is administered by inhalation.

31. 31. The method of any one of claims 1 to 30, wherein seraltinib or a pharmaceutically acceptable salt thereof is administered once daily or twice daily.

32. The method of any one of claims 1 to 31, wherein the dimeric fusion protein is administered by injection.

33. The method of any one of claims 1 to 28, wherein sotatercept is administered by injection.

34. 34. The method of any one of claims 1 to 33, wherein sotatercept is administered by subcutaneous injection.

35. 35. The method of any one of claims 1 to 34, wherein sotatercept is administered once a week, once every two weeks, once every three weeks, or once a month.

36. 36. The method of any one of claims 1 to 35, wherein said therapeutically effective amount of said tyrosine kinase inhibitor, or a pharmaceutically acceptable salt thereof, is administered prior to, concurrently with, and / or after said administration of said therapeutically effective amount of said dimeric fusion protein.

37. 37. The method of claim 36, wherein said therapeutically effective amount of said tyrosine kinase inhibitor, or a pharmaceutically acceptable salt thereof, is administered prior to said administration of said therapeutically effective amount of said dimeric fusion protein.

38. 37. The method of claim 36, wherein said therapeutically effective amount of said tyrosine kinase inhibitor, or a pharmaceutically acceptable salt thereof, is administered simultaneously with said administration of said therapeutically effective amount of said dimeric fusion protein.

39. 37. The method of claim 36, wherein said therapeutically effective amount of said tyrosine kinase inhibitor, or a pharmaceutically acceptable salt thereof, is administered after said administration of said therapeutically effective amount of a dimeric fusion protein.

40. 1. A method of treating pulmonary arterial hypertension (PAH), comprising administering to a subject in need thereof: a therapeutically effective amount of seraltinib or a pharmaceutically acceptable salt thereof, and A method for treating pulmonary arterial hypertension (PAH), comprising administering a therapeutically effective amount of sotatercept.

41. A kit comprising: one or more doses of a therapeutically effective amount of a tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof; a therapeutically effective amount of a dimeric fusion protein, the extracellular domain of activin type 2A receptor (ACTR IIA) or activin type 2B receptor (ACTR IIB), and and one or more doses of a dimeric fusion protein comprising the Fc domain of human immunoglobulin G1 (IgG1).

42. The kit according to claim 41, wherein the tyrosine kinase inhibitor or a pharmaceutically acceptable salt thereof is a PDGF receptor inhibitor or a pharmaceutically acceptable salt thereof, a CSF1R receptor inhibitor or a pharmaceutically acceptable salt thereof, a c-KIT kinase inhibitor or a pharmaceutically acceptable salt thereof, or a combination thereof.

43. The tyrosine kinase inhibitor is selected from the group consisting of acalabrutinib or a pharmaceutically acceptable salt thereof, afatinib or a pharmaceutically acceptable salt thereof, alectinib or a pharmaceutically acceptable salt thereof, avapritinib or a pharmaceutically acceptable salt thereof, axitinib (Inlyta (registered trademark)) or a pharmaceutically acceptable salt thereof, baricitinib or a pharmaceutically acceptable salt thereof, binimetinib or a pharmaceutically acceptable salt thereof, bosutinib (Bosulif (registered trademark)) or a pharmaceutically acceptable salt thereof, brigutinib or a pharmaceutically acceptable salt thereof or a pharmaceutically acceptable salt thereof, cabozantinib or a pharmaceutically acceptable salt thereof, capmatinib or a pharmaceutically acceptable salt thereof, ceritinib or a pharmaceutically acceptable salt thereof, cobimetinib or a pharmaceutically acceptable salt thereof, crizotinib or a pharmaceutically acceptable salt thereof, dacomitinib or a pharmaceutically acceptable salt thereof, entrectinib or a pharmaceutically acceptable salt thereof, erdafitinib or a pharmaceutically acceptable salt thereof, erlotinib (Tarceva®) or a pharmaceutically acceptable salt thereof, fedratinib or a pharmaceutically acceptable salt thereof and a pharmaceutically acceptable salt thereof, fostamatinib or a pharmaceutically acceptable salt thereof, gefitinib or a pharmaceutically acceptable salt thereof, gilteritinib or a pharmaceutically acceptable salt thereof, ibrutinib or a pharmaceutically acceptable salt thereof, imatinib (Gleevec (registered trademark)) or a pharmaceutically acceptable salt thereof, lapatinib or a pharmaceutically acceptable salt thereof, larotrectinib or a pharmaceutically acceptable salt thereof, lenvatinib or a pharmaceutically acceptable salt thereof, lorlatinib or a pharmaceutically acceptable salt thereof, midostaurin or a pharmaceutically acceptable salt thereof pharmaceutically acceptable salts thereof, neratinib (Tasigna®) or a pharmaceutically acceptable salt thereof, osimertinib or a pharmaceutically acceptable salt thereof, pazopanib (Votrient®) or a pharmaceutically acceptable salt thereof, pemigatinib or a pharmaceutically acceptable salt thereof, pexidartinib or a pharmaceutically acceptable salt thereof, ponatinib or a pharmaceutically acceptable salt thereof, regorafenib or a pharmaceutically acceptable salt thereof, ripretinib or a pharmaceutically acceptable salt thereof, ruxolitinib or a pharmaceutically acceptable salt thereof,43. The kit of claim 41 or 42, wherein the active ingredient is selpercatinib or a pharmaceutically acceptable salt thereof, selumetinib or a pharmaceutically acceptable salt thereof, seraltinib or a pharmaceutically acceptable salt thereof, sorafenib or a pharmaceutically acceptable salt thereof, sunitinib (Sutent®) or a pharmaceutically acceptable salt thereof, tofacitinib or a pharmaceutically acceptable salt thereof, trametinib or a pharmaceutically acceptable salt thereof, tucatinib or a pharmaceutically acceptable salt thereof, upadacitinib or a pharmaceutically acceptable salt thereof, vandetanib or a pharmaceutically acceptable salt thereof, zanubrutinib or a pharmaceutically acceptable salt thereof, or a combination thereof.

44. The kit according to any one of claims 41 to 43, wherein the tyrosine kinase inhibitor is seraltinib, or a pharmaceutically acceptable salt thereof.

45. The kit of any one of claims 41 to 44, wherein the dimeric fusion protein comprises the extracellular domain of the activin type 2A receptor.

46. The kit according to any one of claims 41 to 45, wherein the dimeric fusion protein comprises the extracellular domain of activin 2A Fc-type receptor.

47. The kit of any one of claims 41 to 44, wherein the dimeric fusion protein comprises the extracellular domain of the activin type 2B receptor.

48. The kit of any one of claims 41 to 46, wherein the dimeric fusion protein is sotatercept.

49. The kit of any one of claims 41 to 46 and 48, wherein the tyrosine kinase inhibitor is seraltinib or a pharmaceutically acceptable salt thereof, and the dimeric fusion protein is sotatercept.

50. 50. The kit of any one of claims 41-49, further comprising one or more doses of a therapeutically effective amount of an endothelin receptor antagonist, a phosphodiesterase-5 (PDE-5) inhibitor, a prostacyclin analog, a prostacyclin receptor agonist, a soluble guanylate cyclase stimulator, or a combination thereof.

51. 51. The kit of any one of claims 41 to 50, further comprising one or more doses of a therapeutically effective amount of an endothelin receptor agonist.

52. 52. The kit of claim 51, wherein the endothelin receptor agonist is ambrisentan (Letairis®), macitentan (Opsumit®), or bosentan.

53. 53. The kit of any one of claims 41 to 52, further comprising one or more doses of a therapeutically effective amount of a phosphodiesterase type 5 (PDE-5) inhibitor.

54. 54. The kit of claim 53, wherein the phosphodiesterase type 5 (PDE-5) inhibitor is sildenafil, tadalafil, vardenafil, avanafil, or udenafil.

55. 55. The kit of any one of claims 41 to 54, further comprising one or more doses of a therapeutically effective amount of a prostacyclin analogue.

56. 56. The kit of claim 55, wherein the prostacyclin receptor analog is epoprostenol, treprostinil, iloprost, or beraprost.

57. 57. The kit of any one of claims 41 to 56, further comprising one or more doses of a therapeutically effective amount of a prostacyclin receptor agonist.

58. 58. The kit of claim 57, wherein the prostacyclin receptor agonist is selexipag or larinepag.

59. 59. The kit of any one of claims 41 to 58, further comprising one or more doses of a therapeutically effective amount of a soluble guanylate cyclase stimulator.

60. 60. The kit of claim 59, wherein the soluble guanylate cyclase stimulator is riociguat or veruiciguat.

61. 61. The kit of any one of claims 41-60, further comprising one or more doses of a therapeutically effective amount of tadalafil, selexipag, ralinepag, or a combination thereof.

62. 62. The kit of any one of claims 41-61, wherein the one or more doses of a therapeutically effective amount of the tyrosine kinase inhibitor are formulated for administration by inhalation.

63. 63. The kit of any one of claims 41 to 62, wherein the one or more doses of a therapeutically effective amount of seraltinib or a pharmaceutically acceptable salt thereof are formulated for administration by inhalation.

64. 64. The kit of any one of claims 41 to 63, wherein the one or more doses of a therapeutically effective amount of seraltinib or a pharmaceutically acceptable salt thereof are formulated as a dry powder for administration by inhalation using a dry powder inhaler.

65. 65. The kit of any one of claims 41 to 64, further comprising a dry powder inhaler.

66. 66. The kit of any one of claims 41 to 65, wherein said one or more doses of a therapeutically effective amount of said dimeric fusion protein are formulated for administration by injection.

67. 67. The kit of any one of claims 41 to 66, wherein the one or more doses of therapeutically effective amount of sotatercept are formulated for administration by injection.

68. 68. The kit of any one of claims 41 to 67, wherein the one or more doses of a therapeutically effective amount of sotatercept are formulated for administration by subcutaneous injection.

69. 69. The kit of any one of claims 41 to 68, wherein the one or more doses of a therapeutically effective amount of sotatercept are formulated for subcutaneous injection in the form of a single bolus or multiple doses.

70. 70. The kit of any one of claims 41 to 69, wherein the one or more doses of a therapeutically effective amount of sotatercept are formulated for subcutaneous injection in one or more pre-filled syringes.

71. 70. The kit of any one of claims 41 to 69, wherein the one or more doses of a therapeutically effective amount of sotatercept are formulated for subcutaneous injection as a liquid in a vial ready for incorporation into a syringe.

72. 72. The kit of claim 71, wherein the liquid in the vial is a single-dose formulation of a therapeutically effective amount of sotatercept.

73. 72. The kit of claim 71, wherein the liquid in the vial is a multi-dose formulation of a therapeutically effective amount of sotatercept.

74. 70. The kit of any one of claims 41 to 69, wherein the one or more doses of a therapeutically effective amount of sotatercept are formulated for subcutaneous injection as a solid ready to dissolve prior to incorporation into a syringe.

75. 75. The kit of claim 74, wherein the solid ready to dissolve prior to incorporation into a syringe is a single-dose formulation of a therapeutically effective amount of sotatercept.

76. 75. The kit of claim 74, wherein the solid ready to dissolve prior to incorporation into a syringe is a multi-dose formulation of a therapeutically effective amount of sotatercept.

77. 77. The kit of any one of claims 41 to 76, comprising one or more containers.

78. 78. The kit of any one of claims 41 to 77, comprising at least one container comprising seraltinib or a pharmaceutically acceptable salt thereof.

79. 78. The kit of any one of claims 41 to 77, comprising at least one container containing soteracept.

80. 80. The kit of any one of claims 41 to 79, comprising at least one container containing soteracept and at least one other container containing soteracept.

81. 81. The kit of any one of claims 41 to 80, further comprising an insert or label containing instructions for use.

82. 82. The kit of claim 81, wherein the instructions-containing insert or label includes instructions on how to prepare each dosage form.

83. 82. The kit of claim 81, wherein the insert or label containing instructions for use includes instructions on the amounts of components to be administered, guidelines for mixing the components, how to administer each dosage form, or when to administer each dosage form.

84. A kit comprising: one or more doses of a therapeutically effective amount of seraltinib or a pharmaceutically acceptable salt thereof, and A kit comprising one or more doses of a therapeutically effective amount of sotatercept.

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