Mulpleo: Uses, Dosage & Side Effects

What Is Mulpleo and What Is It Used For?

Mulpleo contains the active substance lusutrombopag, a small-molecule, non-peptide thrombopoietin (TPO) receptor agonist. TPO is the primary endogenous growth factor responsible for regulating platelet production in the body. By mimicking the action of TPO at its receptor on megakaryocyte progenitor cells in the bone marrow, lusutrombopag stimulates these cells to proliferate and mature into platelet-producing megakaryocytes, ultimately leading to an increase in circulating platelet counts.

Thrombocytopenia, defined as a platelet count below 150 × 10⁹/L, is extremely common in patients with chronic liver disease (CLD), occurring in up to 76% of patients with cirrhosis. The causes of thrombocytopenia in CLD are multifactorial: reduced production of TPO by the diseased liver, splenic sequestration of platelets due to portal hypertension and splenomegaly, bone marrow suppression from alcohol or hepatitis viruses, and increased platelet destruction through immune-mediated mechanisms and disseminated intravascular coagulation. These patients frequently require invasive diagnostic or therapeutic procedures such as liver biopsies, paracentesis, dental extractions, catheter placements, and various surgical interventions. A low platelet count increases the risk of clinically significant bleeding during and after these procedures.

Historically, the standard approach to managing preprocedural thrombocytopenia in CLD patients has been platelet transfusion. However, platelet transfusions carry several inherent risks and limitations. These include transfusion reactions (febrile, allergic, and rarely anaphylactic), alloimmunization (development of antibodies against donor platelet antigens that can make future transfusions less effective), transfusion-related acute lung injury (TRALI), bacterial contamination (platelets are stored at room temperature, increasing bacterial growth risk), and potential transmission of bloodborne pathogens. Furthermore, platelet transfusions provide only a transient increase in platelet count, typically lasting only 3 to 5 days, require intravenous administration in a clinical setting, and may not always be available in a timely manner.

Lusutrombopag addresses these limitations by stimulating the patient's own bone marrow to produce platelets endogenously. Unlike recombinant TPO proteins, which bind to the extracellular domain of the TPO receptor and can induce neutralizing antibodies, lusutrombopag binds to the transmembrane domain of the human TPO receptor (also known as c-Mpl or the myeloproliferative leukemia protein receptor). This unique binding site means that lusutrombopag does not compete with endogenous TPO for receptor binding, and both molecules can activate the receptor simultaneously, producing an additive effect on platelet production. Once bound to the transmembrane domain, lusutrombopag activates the intracellular signaling cascades downstream of the TPO receptor, including the JAK2/STAT5, MAPK (mitogen-activated protein kinase), and PI3K/AKT pathways. These signaling pathways drive the proliferation and differentiation of megakaryocyte progenitor cells, the maturation of megakaryocytes, and ultimately the release of platelets into the bloodstream.

The efficacy of Mulpleo was established in two pivotal phase III clinical trials:

• L-PLUS 1 (Japan): This randomized, double-blind, placebo-controlled trial enrolled 97 patients with chronic liver disease and thrombocytopenia (platelet count <50 × 10⁹/L) who were scheduled to undergo an invasive procedure. Patients received lusutrombopag 3 mg or placebo once daily for 7 days. The primary endpoint was the proportion of patients who did not require a platelet transfusion before the procedure. In the lusutrombopag group, 79.2% of patients did not need a transfusion, compared to 12.5% in the placebo group (p<0.0001). The mean platelet count increase was approximately 32.0 × 10⁹/L in the treatment group.
• L-PLUS 2 (Global): This multinational, randomized, double-blind, placebo-controlled trial enrolled 215 patients across North America, Europe, and the Asia-Pacific region. Patients with CLD and a platelet count <50 × 10⁹/L who were scheduled for an invasive procedure received lusutrombopag 3 mg or placebo once daily for 7 days. The primary endpoint was the proportion of patients who did not require a platelet transfusion and did not experience rescue therapy for bleeding from randomization through 7 days following the invasive procedure. In the lusutrombopag group, 64.8% of patients met this endpoint, compared to 29.0% in the placebo group (p<0.0001).

Across both trials, the onset of platelet count increase was observed approximately 5 to 8 days after the first dose, with peak platelet counts typically reached 10 to 14 days after the start of treatment (approximately 5 to 8 days after the last dose). This predictable time course allows clinicians to plan the timing of invasive procedures to coincide with the peak platelet response. The platelet count generally returns to baseline levels within 28 days of the last dose, reflecting the natural lifespan of the newly produced platelets.

Mulpleo was first approved in Japan in September 2015 by the Pharmaceuticals and Medical Devices Agency (PMDA), followed by FDA approval in the United States in July 2018 and EMA authorization in the European Union in February 2019. It is marketed by Shionogi and is available in multiple countries worldwide.

What Should You Know Before Taking Mulpleo?

Contraindications

The primary contraindication to Mulpleo use is known hypersensitivity (allergy) to lusutrombopag or to any of the excipients in the formulation. The excipients include D-mannitol, microcrystalline cellulose, magnesium oxide, sodium lauryl sulfate, hydroxypropylcellulose, carmellose calcium, and magnesium stearate. The film coating contains hypromellose, titanium dioxide (E171), red iron oxide (E172), yellow iron oxide (E172), and macrogol 8000. If you have known allergies to any of these components, inform your healthcare provider before starting treatment.

Mulpleo is specifically indicated for use in patients with chronic liver disease and severe thrombocytopenia who are scheduled for an invasive procedure. It is not intended for use as a general treatment for thrombocytopenia in other clinical settings, such as immune thrombocytopenia (ITP), myelodysplastic syndromes, or chemotherapy-induced thrombocytopenia. Using Mulpleo outside of its approved indication has not been studied and may not be appropriate.

Warnings and Precautions

Before starting Mulpleo, discuss the following with your healthcare provider:

• Portal vein thrombosis: Portal vein thrombosis (PVT) is a known complication in patients with chronic liver disease and has been reported in patients treated with TPO receptor agonists in this population. In the L-PLUS 2 trial, portal vein thrombosis was reported in 1.4% of lusutrombopag-treated patients. Risk factors for PVT include advanced cirrhosis, reduced portal vein flow velocity, previous history of PVT, and the presence of hepatocellular carcinoma. Your doctor should assess your individual thromboembolic risk before prescribing Mulpleo and monitor you during and after treatment.
• Excessive platelet elevation: In some patients, lusutrombopag may increase platelet counts above the normal range. Excessively high platelet counts can increase the risk of thrombotic complications. Regular platelet count monitoring is recommended during and after the treatment course. If platelet counts rise above 200 × 10⁹/L, your doctor should evaluate the need for intervention and consider the timing of any planned procedures.
• Hepatic impairment: Mulpleo is specifically designed for patients with hepatic impairment (liver disease). However, the degree of liver impairment may affect the drug's metabolism and the overall benefit-risk balance. The pivotal trials enrolled patients with Child-Pugh Class A and B cirrhosis. Data in patients with Child-Pugh Class C (severe decompensated) cirrhosis are limited, and Mulpleo should be used with caution in this population under close medical supervision.
• Coagulation abnormalities: Patients with chronic liver disease often have complex coagulation abnormalities that go beyond simple thrombocytopenia. While Mulpleo increases platelet counts, it does not address other coagulation factor deficiencies or fibrinolytic imbalances that may contribute to bleeding risk. Your doctor will assess your overall coagulation status as part of preprocedural planning.

Pregnancy and Breastfeeding

There are no adequate and well-controlled studies of lusutrombopag use in pregnant women. Animal reproductive studies have demonstrated adverse effects on embryo-fetal development. In rat studies, lusutrombopag was associated with decreased fetal body weight and skeletal variations at doses that were approximately 4 times the human clinical exposure based on AUC. In rabbit studies, post-implantation loss and skeletal anomalies were observed at supratherapeutic doses. Based on these findings, Mulpleo should not be used during pregnancy unless the potential benefit to the mother clearly outweighs the potential risk to the fetus. Women of childbearing potential should use effective contraception during treatment with Mulpleo.

It is not known whether lusutrombopag or its metabolites are excreted in human breast milk. In animal studies, lusutrombopag was detected in the milk of lactating rats. A risk to the breastfed infant cannot be excluded. The decision to discontinue breastfeeding or to discontinue Mulpleo treatment should be made in consultation with your healthcare provider, taking into account the benefit of breastfeeding for the child and the benefit of treatment for the mother.

Children and Adolescents

The safety and efficacy of Mulpleo have not been established in patients under 18 years of age. No data are available in the pediatric population. Mulpleo is not recommended for use in children and adolescents.

Driving and Operating Machinery

Mulpleo has no or negligible influence on the ability to drive and use machines. Based on its pharmacological profile and the adverse reactions observed in clinical trials, lusutrombopag is not expected to impair cognitive function, coordination, or reaction time. However, patients should be aware that their underlying chronic liver disease may itself affect their ability to drive or operate machinery.

How Does Mulpleo Interact with Other Drugs?

Lusutrombopag undergoes metabolism primarily through two main pathways: omega-oxidation catalyzed by cytochrome P450 4A11 (CYP4A11) and glucuronidation by uridine diphosphate-glucuronosyltransferases UGT1A1 and UGT1A3. In addition, lusutrombopag is a substrate of the efflux transporters P-glycoprotein (P-gp, also known as MDR1 or ABCB1) and breast cancer resistance protein (BCRP, also known as ABCG2). These metabolic and transport pathways are relevant for understanding potential drug interactions.

In clinical pharmacology studies and population pharmacokinetic analyses, no clinically significant drug-drug interactions have been identified. This is partly because lusutrombopag is used for only a short duration (7 days), which limits the window for clinically meaningful interactions to develop. However, based on in vitro data and theoretical considerations, the following potential interactions should be considered:

Importantly, in vitro studies have shown that lusutrombopag does not significantly inhibit or induce major CYP enzymes (CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, or CYP3A4) at clinically relevant concentrations. This means that lusutrombopag is unlikely to affect the metabolism of other drugs that are substrates of these enzymes, which includes the vast majority of commonly prescribed medications.

Similarly, lusutrombopag has not been shown to significantly inhibit or induce UGT enzymes other than being a substrate for UGT1A1 and UGT1A3. It does not inhibit the major drug transporters OATP1B1, OATP1B3, OAT1, OAT3, OCT1, OCT2, MATE1, or MATE2-K at clinically relevant concentrations.

Patients with chronic liver disease often take multiple medications for the management of their liver disease and its complications, including diuretics (spironolactone, furosemide), lactulose, rifaximin, beta-blockers (propranolol, carvedilol), and proton pump inhibitors. In the L-PLUS trials, concomitant use of these medications was common and no significant interactions were observed. However, as with all prescription medications, you should always inform your doctor about all medications, herbal supplements, vitamins, and over-the-counter products you are currently taking before starting Mulpleo treatment.

What Is the Correct Dosage of Mulpleo?

Mulpleo should always be used exactly as your doctor has prescribed. The treatment regimen is standardized and straightforward: one 3 mg film-coated tablet taken once daily by mouth for 7 consecutive days. The tablet can be taken with or without food, as food does not significantly affect the absorption of lusutrombopag. It should be swallowed whole with water and should not be crushed, split, or chewed.

Adults

The timing of treatment initiation is critical for optimal outcomes. The invasive procedure should be planned for approximately 2 to 7 days after the last dose of Mulpleo (i.e., days 9 to 14 after the first dose). This timing coincides with the expected peak platelet count response. Your doctor should check your platelet count on the day of the scheduled procedure to confirm that it has risen to an adequate level. If the platelet count has not risen sufficiently, your doctor may decide to administer platelet transfusion or postpone the procedure.

The 3 mg dose was selected based on dose-finding studies (phase II trials) that evaluated doses of 0.25 mg, 0.5 mg, 1 mg, 2 mg, 3 mg, and 4 mg once daily for 7 days. The 3 mg dose provided the optimal balance between efficacy (achieving a clinically meaningful increase in platelet counts) and safety (minimizing the risk of excessive platelet elevation and thromboembolic events). Higher doses did not provide significantly greater efficacy but were associated with a higher incidence of platelet counts exceeding the normal range.

Elderly Patients

No dose adjustment is required for elderly patients (65 years and older). In the L-PLUS clinical trials, approximately 30% of patients were aged 65 years or older. No clinically meaningful differences in safety or efficacy were observed between older and younger patients. As with all medications in elderly patients, careful monitoring is advisable, particularly given the potential for comorbidities and polypharmacy.

Renal and Hepatic Impairment

No dose adjustment is necessary for patients with any degree of renal impairment, including those with end-stage renal disease. Population pharmacokinetic analyses did not identify renal function as a significant covariate for lusutrombopag clearance, which is consistent with the drug's primarily hepatic/biliary elimination pathway.

Regarding hepatic impairment, it is important to note that Mulpleo is specifically designed for use in patients with chronic liver disease. The pivotal clinical trials enrolled patients with varying degrees of hepatic impairment (Child-Pugh Class A and B). Pharmacokinetic studies showed that exposure to lusutrombopag was modestly increased (approximately 1.2- to 2.8-fold) in patients with hepatic impairment compared to healthy subjects. However, despite this increased exposure, no dose adjustment was required, as the 3 mg dose remained safe and effective across the range of hepatic impairment studied. Data in patients with Child-Pugh Class C cirrhosis are limited; use in this population should be undertaken with caution and close monitoring.

Missed Dose

If you miss a dose of Mulpleo, take it as soon as you remember on the same day. If the entire day has passed, skip the missed dose and take your next dose at the usual time on the following day. Do not take a double dose to make up for a forgotten dose. If you miss multiple doses, contact your healthcare provider for guidance, as the timing of the invasive procedure may need to be adjusted to account for the potentially delayed or diminished platelet count response.

Overdose

There is limited experience with overdose of lusutrombopag. In dose-escalation studies, single doses of up to 50 mg were administered without dose-limiting toxicity. However, excessively high doses may lead to an excessive increase in platelet counts, which could increase the risk of thromboembolic complications. There is no specific antidote for lusutrombopag. In the event of an overdose, standard supportive measures should be initiated. Platelet counts should be monitored frequently, and antiplatelet or anticoagulant therapy should be considered if counts rise to dangerously high levels. Given the elimination half-life of approximately 27 hours, monitoring should continue for several days after an overdose.

What Are the Side Effects of Mulpleo?

Like all medicines, Mulpleo can cause side effects, although not everybody gets them. The safety of lusutrombopag has been evaluated in clinical trials involving over 300 patients with chronic liver disease and thrombocytopenia. The overall incidence of adverse events was similar between the lusutrombopag and placebo groups, reflecting the generally well-tolerated nature of the medication. Most adverse reactions were mild to moderate in severity and resolved without intervention.

The following side effects have been reported in clinical trials and post-marketing experience, organized by frequency category according to the Medical Dictionary for Regulatory Activities (MedDRA) system organ class classification:

Thromboembolic Events – Important Safety Information

The most clinically significant safety concern with Mulpleo and other TPO receptor agonists in patients with chronic liver disease is the risk of thromboembolic events. Patients with chronic liver disease, particularly those with advanced cirrhosis and portal hypertension, have a complex coagulation balance that includes both bleeding and thrombotic tendencies. By increasing platelet counts, TPO receptor agonists may shift this balance toward a prothrombotic state in some patients.

In the L-PLUS 2 trial, portal vein thrombosis was reported in 1.4% of lusutrombopag-treated patients (2 out of 140 patients), compared to 0% in the placebo group. In post-marketing surveillance, additional cases of portal vein thrombosis, deep vein thrombosis, pulmonary embolism, and hepatic vein thrombosis have been reported. Most thromboembolic events occurred in patients with additional risk factors, such as advanced cirrhosis, history of thrombosis, or hepatocellular carcinoma.

To minimize the risk of thromboembolic complications, clinicians should conduct a thorough risk-benefit assessment before prescribing Mulpleo, monitor platelet counts during and after the treatment course, plan procedures when platelet counts reach adequate but not excessive levels, and watch for signs and symptoms of thromboembolism, including abdominal pain, nausea, leg swelling, chest pain, or shortness of breath. Patients should seek immediate medical attention if they experience any of these symptoms.

Reporting Side Effects

If you experience any side effects, including those not listed above, talk to your doctor, pharmacist, or nurse. You can also report side effects directly to your national pharmacovigilance authority (e.g., the FDA MedWatch program in the United States, the Yellow Card Scheme in the United Kingdom, or the EMA EudraVigilance system in the European Union). By reporting side effects, you help provide more information on the safety of this medicine.

How Should You Store Mulpleo?

Proper storage of Mulpleo is important to ensure that the medication remains effective and safe throughout its shelf life. The following storage guidelines apply:

• Temperature: Store at or below 30°C (86°F). Do not freeze. No special temperature storage conditions are required beyond avoiding excessive heat.
• Light protection: Store in the original blister packaging to protect from light. Lusutrombopag is sensitive to light degradation, and prolonged exposure to direct sunlight or strong artificial light may reduce the potency of the medication.
• Moisture: Store in the original packaging to protect from moisture. Do not store the tablets in humid environments such as bathrooms.
• Expiration date: Do not use Mulpleo after the expiration date printed on the blister pack and outer carton. The expiration date refers to the last day of that month. Once the blister pack is opened, use the tablet promptly.
• Children: Keep this medicine out of the sight and reach of children. Store in a secure location.
• Disposal: Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures help to protect the environment.

Mulpleo tablets are available in aluminum/aluminum blister packs containing 7 film-coated tablets (a complete treatment course). Each tablet is light pink to pink, round, biconvex, approximately 7.2 mm in diameter, and debossed with the Shionogi logo on one side. Before taking a tablet, visually inspect it to confirm it is intact, undamaged, and has not changed color significantly. If you notice any abnormalities in the appearance of the tablets, do not take them and consult your pharmacist for a replacement.

What Does Mulpleo Contain?

Understanding the full composition of Mulpleo is important, particularly for patients with known allergies or intolerances to specific excipients. Each film-coated tablet contains the following:

Active Ingredient

Inactive Ingredients (Excipients)

Tablet core: D-mannitol (E421), microcrystalline cellulose, magnesium oxide, sodium lauryl sulfate, hydroxypropylcellulose, carmellose calcium, and magnesium stearate.

Film coating: Hypromellose, titanium dioxide (E171), red iron oxide (E172), yellow iron oxide (E172), and macrogol 8000.

Mulpleo tablets contain a small amount of sodium (from sodium lauryl sulfate). Each tablet contains less than 1 mmol (23 mg) of sodium, meaning it is essentially sodium-free. This is relevant for patients on a strictly controlled sodium diet. The tablet does not contain lactose, gluten, sucrose, or any animal-derived ingredients.

Lusutrombopag (chemical name: (E)-3-{2,6-dichloro-4-[(4-{3-[(1S)-1-(hexanoyloxy)ethyl]-2-{(Z)-2-[3-methoxy-4-(pyridin-2-ylmethoxy)phenyl]vinyl}phenyl}butanoyl)amino]phenoxy}acrylic acid) has a molecular weight of approximately 764.7 g/mol. It is a synthetic, non-peptide compound that is structurally distinct from endogenous thrombopoietin and from other TPO receptor agonists such as eltrombopag, romiplostim, and avatrombopag.