Cladribine

Q: Is Cladribine available over the counter?

Cladribine is a prescription medication. You will need a valid prescription from a licensed healthcare provider.

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Tên thương mại: Cladribine

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Tablet

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ORAL

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Apotex Corp.

About This Medication

11 DESCRIPTION Cladribine tablets contains the nucleoside metabolic inhibitor cladribine, which is a white to off-white crystalline powder with the molecular formula C 10 H 12 ClN 5 O 3 and molecular weight 285.69 g/mol. It differs in structure from the naturally occurring nucleoside, deoxyadenosine, by the substitution of chlorine for hydrogen in the 2-position of the purine ring. The chemical name of cladribine is 2-chloro-2′-deoxy-adenosine. The structural formula is shown below: Cladribine is stable at slightly basic and at neutral pH. The main degradation pathway is hydrolysis and at acidic pH significant decomposition occurs with time. The ionization behavior of the molecule over the pH range 0 to 12 is characterized by a single pKa of approximately 1.21. Cladribine tablets are provided as 10 mg tablet for oral use. Each 10 mg tablet contains cladribine as an active ingredient and magnesium stearate and sorbitol as inactive ingredients. Cladribine tablets also contain hydroxypropyl betadex.

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Thành phần	Hàm lượng
Cladribine	-

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1 INDICATIONS AND USAGE Cladribine tablets are indicated for the treatment of relapsing form of multiple sclerosis (MS), to include relapsing-remitting disease in adults. Because of its safety profile, use of cladribine tablets is generally recommended for patients who have had an inadequate response to, or are unable to tolerate, an alternate drug indicated for the treatment of MS [ see Warnings and Precautions (5) ]. Limitations of Use Cladribine tablets are not recommended for use in patients with clinically isolated syndrome (CIS) because of its safety profile [ see Warnings and Precautions (5) ]. Cladribine tablets are purine antimetabolite indicated for the treatment of relapsing form of multiple sclerosis (MS), to include relapsing-remitting disease in adults. Because of its safety profile, use of cladribine tablets are generally recommended for patients who have had an inadequate response to, or are unable to tolerate, an alternate drug indicated for the treatment of MS. ( 1 , 5 ) Limitations of Use Cladribine tablets are not recommended for use in patients with clinically isolated syndrome (CIS) because of its safety profile. ( 1 , 5 )

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12.1 Mechanism of Action The mechanism by which cladribine exerts its therapeutic effects in patients with multiple sclerosis has not been fully elucidated but is thought to involve cytotoxic effects on B and T lymphocytes through impairment of DNA synthesis, resulting in depletion of lymphocytes.

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2 DOSAGE AND ADMINISTRATION Assessments are required prior to starting each cladribine treatment course. (2.1) Cumulative dosage of 3.5 mg/kg administered orally and divided into 2 treatment courses (1.75 mg/kg per treatment course). Each treatment course is divided into 2 treatment cycles. (2.2) Cladribine tablets are a cytotoxic drug. (2.4) Separate administration from any other oral drug by at least 3 hours. (2.4) 2.1 Assessments Prior to Starting Each Cladribine Treatment Course Cancer Screening Follow standard cancer screening guidelines because of the risk of malignancies [ see Boxed Warning and Warnings and Precautions (5.1) ]. Pregnancy Exclude pregnancy prior to treatment with cladribine tablets in females of reproductive potential [ see Contraindications (4) , Warnings and Precautions (5.2) , and Use in Specific Populations (8.1, 8.3) ]. Complete Blood Count (CBC) Obtain a CBC with differential including lymphocyte count [ see Dosage and Administration (2.5) and Warnings and Precautions (5.3) ]. Lymphocytes must be: within normal limits before initiating the first treatment course at least 800 cells per microliter before initiating the second treatment course If necessary, delay the second treatment course for up to 6 months to allow for recovery of lymphocytes to at least 800 cells per microliter. If this recovery takes more than 6 months, the patient should not receive further treatment with cladribine tablets. Infections [ see Warnings and Precautions (5.4) ] Exclude HIV infection. Perform tuberculosis screening. Screen for hepatitis B and C. Evaluate for acute infection. Consider a delay in cladribine treatment until any acute infection is fully controlled. Vaccination of patients who are seronegative for VZV is recommended prior to initiation of cladribine tablets. Vaccination of patients who are seropositive to VZV is recommended with zoster vaccine recombinant, adjuvanted. Patients may be administered zoster vaccine recombinant, adjuvanted at any time prior to or during the year 1 or year 2 course of cladribine treatment. These patients may also be administered the vaccine if their lymphocyte counts are ≤ 500 cells per microliter. Administer all immunizations (except as noted for VZV) according to immunization guidelines prior to starting cladribine tablets. Administer live-attenuated or live vaccines at least 4 to 6 weeks prior to starting cladribine tablets. Obtain a baseline (within 3 months) magnetic resonance imaging prior to the first treatment course because of the risk of progressive multifocal leukoencephalopathy (PML). Liver Injury Obtain serum aminotransferase, alkaline phosphatase, and total bilirubin levels prior to each treatment cycle and course [ see Warnings and Precautions (5.7) ]. 2.2 Recommended Dosage The recommended cumulative dosage of cladribine tablets is 3.5 mg per kg body weight administered orally and divided into 2 yearly treatment courses (1.75 mg per kg per treatment course) (see Table 1). Each treatment course is divided into 2 treatment cycles: Administration of First Treatment Course First Course/First Cycle: start any time. First Course/Second Cycle: administer 23 to 27 days after the last dose of First Course/First Cycle. Administration of Second Treatment Course Second Course/First Cycle: administer at least 43 weeks after the last dose of First Course/Second Cycle. Second Course/Second Cycle: administer 23 to 27 days after the last dose of Second Course/First Cycle. Table 1 Dose of Cladribine tablets per Cycle by Patient Weight in Each Treatment Course Weight Range Dose in mg (Number of 10 mg Tablets) per Cycle kg First Cycle Second Cycle 40* to less than 50 40 mg (4 tablets) 40 mg (4 tablets) 50 to less than 60 50 mg (5 tablets) 50 mg (5 tablets) 60 to less than 70 60 mg (6 tablets) 60 mg (6 tablets) 70 to less than 80 70 mg (7 tablets) 70 mg (7 tablets) 80 to less than 90 80 mg (8 tablets) 70 mg (7 tablets) 90 to less than 100 90 mg (9 tablets) 80 mg (8 tablets) 100 to less than 110 100 mg (10 tablets) 90 mg (9 tablets) 110 and above 100 mg (10 tablets) 100 mg (10 tablets) *The use of cladribine tablets in patients weighing less than 40 kg has not been investigated. Administer the cycle dosage as 1 or 2 tablets once daily over 4 or 5 consecutive days [ see How Supplied/Storage and Handling (16.1) ]. Do not administer more than 2 tablets daily. Following the administration of 2 treatment courses, do not administer additional cladribine treatment during the next 2 years. Treatment during these 2 years may further increase the risk of malignancy [ see Warnings and Precautions (5.1) ]. The safety and efficacy of reinitiating cladribine tablets more than 2 years after completing 2 treatment courses has not been studied. 2.3 Missed Dose If a dose is missed, patients should not take double or extra doses. If a dose is not taken on the scheduled day, then the patient must take the missed dose on the following day and extend the number of days in that treatment cycle. If two consecutive doses are missed, the treatment cycle is extended by 2 days. 2.4 Administration Cladribine tablets are taken orally, with water, and swallowed whole without chewing. Cladribine tablets can be taken with or without food. Separate administration of cladribine tablets and any other oral drugs by at least 3 hours during the 4 to 5 day cladribine treatment cycles [ see Clinical Pharmacology (12.6) ]. Cladribine tablets are a cytotoxic drug. Follow applicable special handling and disposal procedures [ see References (15) ]. Cladribine tablets are an uncoated tablet and must be swallowed immediately once removed from the blister. If a tablet is left on a surface, or if a broken or fragmented tablet is released from the blister, the area must be thoroughly washed with water. The patient’s hands must be dry when handling the tablets and washed thoroughly afterwards. Avoid prolonged contact with skin. 2.5 Laboratory Testing and Monitoring to Assess Safety Cancer Screening Follow standard cancer screening guidelines in patients treated with cladribine tablets [see Dosage and Administration ( 2.1 ) and Warnings and Precautions ( 5.1 )]. Complete Blood Count Obtain complete blood count (CBC) with differential including lymphocyte count: before initiating the first treatment course of cladribine tablets before initiating the second treatment course of cladribine tablets 2 and 6 months after start of treatment in each treatment course; if the lymphocyte count at month 2 is below 200 cells per microliter, monitor monthly until month 6. See Warnings and Precautions ( 5.3, 5.4 ) for instructions based on the patient’s lymphocyte counts and clinical status (e.g., infections). Hold cladribine tablets therapy if the lymphocyte count is below 200 cells per microliter periodically thereafter and when clinically indicated [ see Warnings and Precautions (5.5) ] 2.6 Recommended Concomitant Medication Herpes Prophylaxis Administer anti-herpes prophylaxis in patients with lymphocyte counts less than 200 cells per microliter [ see Warnings and Precautions (5.4) ].

Side Effects Overview

6 ADVERSE REACTIONS The following serious adverse reactions and potential risks are discussed, or discussed in greater detail, in other sections of the labeling: Malignancies [ see Warnings and Precautions (5.1) ] Risk of Teratogenicity [ see Warnings and Precautions (5.2) ] Lymphopenia [ see Warnings and Precautions (5.3)] Infections [ see Warnings and Precautions (5.4) ] Hematologic Toxicity [ see Warnings and Precautions (5.5) ] Graft-Versus-Host Disease With Blood Transfusion [ see Warnings and Precautions (5.6) ] Liver Injury [ see Warnings and Precautions (5.7) ] Hypersensitivity [ see Warnings and Precautions (5.8) ] Cardiac Failure [ see Warnings and Precautions (5.9) ] Most common adverse reactions (incidence > 20%) are upper respiratory tract infection, headache, and lymphopenia. (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Apotex Corp. at 1-800-706-5575 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice. In the clinical trial program of cladribine in MS, 1,976 patients received cladribine for a total of 9,509 patient years. The mean time on study including follow-up was approximately 4.8 years, and approximately 24% of cladribine-treated patients had approximately 8 years of time on study including follow-up. Of these, 923 patients aged 18 to 66 years received cladribine as monotherapy at a cumulative dose of 3.5 mg per kg. Table 2 shows adverse reactions in Study 1 [ see Clinical Studies (14) ] with an incidence of at least 5% for cladribine and higher than placebo. The most common (> 20%) adverse reactions reported in Study 1 are upper respiratory tract infection, headache, and lymphopenia. Table 2 Adverse Reactions in Study 1 with an Incidence of at Least 5% for Cladribine tablets and Higher than Placebo Cladribine (N=440) % Placebo (N=435) % Upper respiratory tract infection 38 32 Headache 25 19 Lymphopenia 24 2 Nausea 10 9 Back pain 8 6 Arthralgia and arthritis 7 5 Insomnia 6 4 Bronchitis 5 3 Hypertension 5 3 Fever 5 3 Depression 5 3 Hypersensitivity In clinical studies, 11% of cladribine patients had hypersensitivity adverse reactions, compared to 7% of placebo patients [see Warnings and Precautions ( 5.8 )]. Alopecia Alopecia occurred in 3% of cladribine-treated patients compared to 1% of placebo patients. Myelodysplastic Syndrome Cases of myelodysplastic syndrome have been reported in patients that had received parenteral cladribine at a higher dosage than that approved for cladribine. These cases occurred several years after treatment. Herpes Meningoencephalitis Fatal herpes meningoencephalitis occurred in one cladribine-treated patient, at a higher dosage and longer duration of therapy than the approved cladribine dosage and in combination with interferon beta-1a treatment. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) SJS and TEN are identified risks of parenteral cladribine for the treatment of oncologic indications. Seizures In clinical studies, serious events of seizure occurred in 0.3% of cladribine-treated patients compared to 0 placebo patients. Serious events included generalized tonic-clonic seizures and status epilepticus. It is unknown whether these events were related to the effects of multiple sclerosis alone, to cladribine, or to a combination of both. 6.2 Postmarketing Experience The following adverse reactions have been identified during postapproval use of cladribine. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Infections and Infestations: nocardiosis, varicella zoster, histoplasmosis, cryptococcosis, and toxoplasmosis [see Warnings and Precautions ( 5.4 )]. Hepatobiliary Disorders: liver injury [see Warnings and Precautions ( 5.7 )]

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5 WARNINGS AND PRECAUTIONS Lymphopenia: Monitor lymphocyte counts before, during and after treatment. (5.3) Infections: Serious, including life-threatening and fatal infections, have occurred. Screen patients for active and latent infections; delay treatment until infection is fully resolved or controlled. Vaccination of patients seronegative to varicella zoster virus (VZV) is recommended prior to treatment. Vaccination of patients seropositive to VZV with zoster vaccine recombinant, adjuvanted, is recommended prior to or during treatment. Administer anti-herpes prophylaxis in patients with lymphocyte counts less than 200 cells per microliter. Monitor for infections. (5.4) Hematologic toxicity: Monitor complete blood count before, during and after treatment. (5.5) Graft-versus-host-disease with blood transfusion: Irradiation of cellular blood components is recommended. (5.6) Liver injury: Clinically significant liver injury has occurred. Obtain tests prior to treatment. Discontinue if clinically significant injury is suspected. (5.7) 5.1 Malignancies Treatment with cladribine tablets may increase the risk of malignancy. In controlled and extension clinical studies worldwide, malignancies occurred more frequently in cladribine-treated patients [10 events in 3,754 patient-years (0.27 events per 100 patient-years)], compared to placebo patients [3 events in 2,275 patient-years (0.13 events per 100 patient-years)]. Malignancy cases in cladribine patients included metastatic pancreatic carcinoma, malignant melanoma (2 cases), ovarian cancer, compared to malignancy cases in placebo patients, all of which were curable by surgical resection [basal cell carcinoma, cervical carcinoma in situ (2 cases)]. The incidence of malignancies in United States cladribine clinical study patients was higher than the rest of the world [4 events in 189 patient-years (2.21 events per 100 patient-years) compared to 0 events in United States placebo patients]; however, the United States results were based on a limited amount of patient data. After the completion of 2 treatment courses, do not administer additional cladribine treatment during the next 2 years [ see Dosage and Administration (2.2) ]. In clinical studies, patients who received additional cladribine treatment within 2 years after the first 2 treatment courses had an increased incidence of malignancy [7 events in 790 patient-years (0.91 events per 100 patient-years) calculated from the start of cladribine treatment in Year 3]. The risk of malignancy with reinitiating cladribine tablets more than 2 years after the completion of 2 treatment courses has not been studied. Cladribine tablets are contraindicated in patients with current malignancy. In patients with prior malignancy or with increased risk of malignancy, evaluate the benefits and risks of the use of cladribine tablets on an individual patient basis. Follow standard cancer screening guidelines in patients treated with cladribine tablets. 5.2 Risk of Teratogenicity Cladribine tablets may cause fetal harm when administered to pregnant women. Malformations and embryolethality occurred in animals [ see Use in Specific Populations (8.1) ] . Advise women of the potential risk to a fetus during cladribine tablets dosing and for 6 months after the last dose in each treatment course. In females of reproductive potential, pregnancy should be excluded before initiation of each treatment course of cladribine tablets and prevented by the use of effective contraception during cladribine tablets dosing and for at least 6 months after the last dose of each treatment course. Women who become pregnant during treatment with cladribine tablets should discontinue treatment [ see Use in Specific Populations (8.1 , 8.3) ] . Cladribine tablets are contraindicated for use in pregnant women and in women and men of reproductive potential who do not plan to use effective contraception. 5.3 Lymphopenia Cladribine tablets cause a dose-dependent reduction in lymphocyte count. In clinical studies, 87% of cladribine-treated patients experienced lymphopenia. The lowest absolute lymphocyte counts occurred approximately 2 to 3 months after the start of each treatment course and were lower with each additional treatment course. In patients treated with a cumulative dose of cladribine tablets 3.5 mg per kg over 2 courses as monotherapy, 26% and 1% had nadir absolute lymphocyte counts less than 500 and less than 200 cells per microliter, respectively. At the end of the second treatment course, 2% of clinical study patients had lymphocyte counts less than 500 cells per microliter; median time to recovery to at least 800 cells per microliter was approximately 28 weeks. Additive hematological adverse reactions may be expected if cladribine tablets are administered prior to or concomitantly with other drugs that affect the hematological profile [ see Drug Interactions (7.3) ]. The incidence of lymphopenia less than 500 cells per microliter was higher in patients who had used drugs to treat relapsing forms of MS prior to study entry (32.1%), compared to those with no prior use of these drugs (23.8%). Obtain complete blood count (CBC) with differential including lymphocyte count prior to, during, and after treatment with cladribine tablets. See Dosage and Administration (2.1, 2.5) and Warnings and Precautions (5.4) for timing of CBC measurements and additional instructions based on the patient’s lymphocyte counts and clinical status (e.g., infections). 5.4 Infections Serious, including life-threatening or fatal, bacterial, viral, parasitic, and fungal infections have been reported in patients receiving cladribine tablets. Cladribine tablets reduces the body's immune defense, and an increased risk of infections has been observed in patients receiving cladribine tablets. Infections occurred in 49% of cladribine-treated patients compared to 44% of placebo patients in clinical studies; serious or severe infections occurred in 2.4% of cladribine-treated patients and 2% of placebo-treated patients. The most frequent serious infections in cladribine-treated patients included herpes zoster and pyelonephritis ( see Herpes Virus Infections ). Fungal infections were observed, including cases of coccidioidomycosis. In the postmarketing setting, serious infections have been reported, including nocardiosis, varicella zoster, histoplasmosis, cryptococcosis, and toxoplasmosis. The majority of patients with these infections who had an available absolute lymphocyte count at the time of the event had concurrent lymphopenia, consistent with the mechanism of action of cladribine tablets [see Warnings and Precautions ( 5.3 )]. HIV infection, active tuberculosis, and active hepatitis must be excluded before initiation of each treatment course of cladribine tablets [ see Contraindications (4) ]. Delay initiation of cladribine tablets in patients with an acute infection until the infection is fully resolved or controlled. Initiation of cladribine tablets in patients currently receiving immunosuppressive or myelosuppressive therapy is not recommended [see Drug Interactions ( 7.1 )] . Concomitant use of cladribine tablets with these therapies could increase the risk of immunosuppression. Tuberculosis Three of 1,976 (0.2%) cladribine-treated patients in the clinical program developed tuberculosis. All three cases occurred in regions where tuberculosis is endemic. One case of tuberculosis was fatal, and two cases resolved with treatment. Perform tuberculosis screening prior to initiation of the first and second treatment course of cladribine tablets. Latent tuberculosis infections may be activated with use of cladribine tablets. In patients with tuberculosis infection, delay initiation of cladribine tablets until the infection has been adequately treated. Hepatitis One clinical study patient died from fulminant hepatitis B infection. Perform screening for hepatitis B and C prior to initiation of the first and second treatment course of cladribine tablets. Latent hepatitis infections may be activated with use of cladribine tablets. Patients who are carriers of hepatitis B or C virus may be at risk of irreversible liver damage caused by virus reactivation. In patients with hepatitis infection, delay initiation of cladribine tablets until the infection has been adequately treated. Herpes Virus Infections In controlled clinical studies, 6% of cladribine-treated patients developed a herpes viral infection compared to 2% of placebo patients. The most frequent types of herpes viral infections were herpes zoster infections (2.0% vs. 0.2%) and oral herpes (2.6% vs. 1.2%). Serious herpes zoster infections occurred in 0.2% of cladribine-treated patients. Vaccination of patients who are seronegative for varicella zoster virus is recommended prior to initiation of cladribine tablets. Administer live-attenuated or live vaccines at least 4 to 6 weeks prior to starting cladribine tablets. Vaccination with zoster vaccine recombinant, adjuvanted is recommended for patients who are seropositive to VZV, either prior to or during cladribine treatment, including when their lymphocyte counts are less than or equal to 500 cells per microliter. The incidence of herpes zoster was higher during the period of absolute lymphocyte count less than 500 cells per microliter, compared to the time when the patients were not experiencing this degree of lymphopenia. Administer anti-herpes prophylaxis in patients with lymphocyte counts less than 200 cells per microliter. Patients with lymphocyte counts below 500 cells per microliter should be monitored for signs and symptoms suggestive of infections, including herpes infections. If such signs and symptoms occur, initiate treatment as clinically indicated. Consider interruption or delay of cladribine tablets until resolution of the infection. Progressive Multifocal Leukoencephalopathy Progressive multifocal leukoencephalopathy (PML) is an opportunistic viral infection of the brain caused by the JC virus (JCV) that typically only occurs in patients who are immunocompromised, and that usually leads to death or severe disability. Typical symptoms associated with PML are diverse, progress over days to weeks, and include progressive weakness on one side of the body or clumsiness of limbs, disturbance of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes. No case of PML has been reported in clinical studies of cladribine in patients with multiple sclerosis. In patients treated with parenteral cladribine for oncologic indications, cases of PML have been reported in the postmarketing setting. Obtain a baseline (within 3 months) magnetic resonance imaging (MRI) before initiating the first treatment course of cladribine tablets. At the first sign or symptom suggestive of PML, withhold cladribine tablets and perform an appropriate diagnostic evaluation. MRI findings may be apparent before clinical signs or symptoms. Vaccinations Administer all immunizations (except as noted for VZV) according to immunization guidelines prior to starting cladribine tablets. Administer live-attenuated or live vaccines at least 4 to 6 weeks prior to starting cladribine tablets, because of a risk of active vaccine infection (see Herpes Virus Infections) . Avoid vaccination with live-attenuated or live vaccines during and after cladribine treatment while the patient’s white blood cell counts are not within normal limits. 5.5 Hematologic Toxicity In addition to lymphopenia [see Warnings and Precautions ( 5.3 )] , decreases in other blood cells and hematological parameters have been reported with cladribine in clinical studies. Mild to moderate decreases in neutrophil counts (cell count between 1,000 cells per microliter and < lower limit of normal (LLN)) were observed in 27% of cladribine-treated patients, compared to 13% of placebo patients whereas severe decreases in neutrophil counts (cell count below 1,000 cells per microliter) were observed in 3.6% of cladribine-treated patients, compared to 2.8% of placebo patients. Decreases in hemoglobin levels, in general mild to moderate (hemoglobin 8 g per dL to < LLN), were observed in 26% of cladribine-treated patients, compared to 19% of placebo patients. Decreases in platelet counts were generally mild (cell count 75,000 cells per microliter to < LLN) and were observed in 11% of cladribine- treated patients, compared to 4% of placebo patients. In clinical studies at dosages similar to or higher than the approved cladribine dosage, serious cases of thrombocytopenia, neutropenia, and pancytopenia (some with documented bone marrow hypoplasia) requiring transfusion and granulocyte-colony stimulating factor treatment have been reported [ see Warnings and Precautions (5.6) for information regarding graft-versus- host disease with blood transfusion ]. Obtain complete blood count (CBC) with differential prior to, during, and after treatment with cladribine tablets [ see Dosage and Administration (2.1, 2.5) ]. 5.6 Risk of Graft-Versus-Host Disease With Blood Transfusion Transfusion-associated graft-versus-host disease has been observed rarely after transfusion of nonirradiated blood in patients treated with cladribine for non-MS treatment indications. In patients who require blood transfusion, irradiation of cellular blood components is recommended prior to administration to decrease the risk of transfusion-related graft-versus-host disease. Consultation with a hematologist is advised. 5.7 Liver Injury Cladribine tablets can cause liver injury. In clinical studies, 0.3% of cladribine-treated patients had liver injury (serious or causing treatment discontinuation) considered related to treatment, compared to 0 placebo patients. Onset ranged from a few weeks to several months after initiation of treatment with cladribine. Signs and symptoms of liver injury, including elevation of serum aminotransferases to greater than 20-fold the upper limit of normal, were observed. These abnormalities resolved upon treatment discontinuation. Clinically significant and life-threatening liver injury has been reported in patients treated with cladribine tablets in the postmarketing setting. Patients with pre-existing liver disease and patients taking other hepatotoxic drugs may be at increased risk for developing liver injury when taking cladribine tablets. Most reported cases of liver injury associated with cladribine tablets occurred approximately 30 days after initiation (i.e., course 1, cycle 1) of treatment. Cladribine tablets are not recommended in patients with moderate to severe hepatic impairment (Child-Pugh score greater than 6) [see Use in Specific Populations ( 8.7 ), Clinical Pharmacology ( 12.3 )]. Obtain serum aminotransferase, alkaline phosphatase, and total bilirubin levels prior to each treatment cycle and course [ see Dosage and Administration (2.1) ]. If a patient develops clinical signs, including unexplained liver enzyme elevations, or symptoms suggestive of hepatic dysfunction (e.g., unexplained nausea, vomiting, abdominal pain, fatigue, anorexia, or jaundice and/or dark urine), promptly measure serum transaminases and total bilirubin and interrupt or discontinue treatment with cladribine tablets, as appropriate. 5.8 Hypersensitivity In clinical studies, 11% of cladribine-treated patients had hypersensitivity reactions, compared to 7% of placebo patients. Hypersensitivity reactions that were serious and/or led to discontinuation of cladribine tablets (e.g., dermatitis, pruritis) occurred in 0.5% of cladribine-treated patients, compared to 0.1% of placebo patients. One patient had a serious hypersensitivity reaction with rash, mucous membrane ulceration, throat swelling, vertigo, diplopia, and headache after the first dose of cladribine tablets. If a hypersensitivity reaction is suspected, discontinue cladribine therapy. Do not use cladribine tablets in patients with a history of hypersensitivity to cladribine [ see Contraindications (4) ]. 5.9 Cardiac Failure In clinical studies, one cladribine-treated patient experienced life-threatening acute cardiac failure with myocarditis, which improved after approximately one week. Cases of cardiac failure have also been reported with parenteral cladribine used for treatment indications other than multiple sclerosis. Instruct patients to seek medical advice if they experience symptoms of cardiac failure (e.g., shortness of breath, rapid or irregular heartbeat, swelling).

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4 CONTRAINDICATIONS Cladribine tablets are contraindicated: in patients with current malignancy [ see Warnings and Precautions (5.1) ] . in pregnant women and in women and men of reproductive potential who do not plan to use effective contraception during cladribine tablets dosing and for 6 months after the last dose in each treatment course. May cause fetal harm [ see Warnings and Precautions (5.2) and Use in Specific Populations (8.1, 8.3 )]. in patients infected with the human immunodeficiency virus (HIV) [ see Warnings and Precautions (5.4) ]. in patients with active chronic infections (e.g., hepatitis or tuberculosis) [ see Warnings and Precautions (5.4) ]. in patients with a history of hypersensitivity to cladribine [ see Warnings and Precautions (5.8) ]. in women intending to breastfeed on a cladribine treatment day and for 10 days after the last dose [ see Use in Specific Populations (8.2) ]. Patients with current malignancy. (4) Pregnant women, and women and men of reproductive potential who do not plan to use effective contraception during cladribine tablets dosing and for 6 months after the last dose in each treatment course. (4, 8.3) HIV infection. (4) Active chronic infections (e.g., hepatitis or tuberculosis). (4) History of hypersensitivity to cladribine. (4, 5.8) Women intending to breastfeed on a cladribine treatment day and for 10 days after the last dose. (4, 8.2)

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12.3 Pharmacokinetics Cladribine is a prodrug that becomes active upon phosphorylation to its 2-chlorodeoxyadenosine triphosphate (Cd-ATP) metabolite. The pharmacokinetic parameters presented below were assessed following oral administration of cladribine 10 mg, unless otherwise specified. The cladribine mean maximum concentration (C max ) was in the range of 22 to 29 ng/ mL and corresponding mean AUC was in the range of 80 to 101 ng·h/mL. The C max and AUC of cladribine increased proportionally across a dose range from 3 to 20 mg. No accumulation of cladribine concentration in plasma was observed after repeated dosing. Absorption The bioavailability of cladribine was approximately 40%. Following fasted administration of cladribine, the median time to maximum concentration (T max ) was 0.5 h (range 0.5 to 1.5 hours). Effect of Food Following administration of cladribine with a high fat meal, the geometric mean C max decreased by 29% and AUC was unchanged. The T max was prolonged to 1.5 hours (range 1 to 3 hours). This difference is not expected to be clinically significant. Distribution Cladribine mean apparent volume of distribution ranges from 480 to 490 liters. The plasma protein binding of cladribine is 20% and is independent of concentration, in vitro . Intracellular concentrations of cladribine and/or its metabolites in human lymphocytes were approximately 30 to 40 times extracellular, in vitro . Cladribine has the potential to penetrate the blood brain barrier. A cerebrospinal fluid/plasma concentration ratio of approximately 0.25 was observed in cancer patients. Elimination Cladribine estimated terminal half-life is approximately 1 day. The intracellular half-life of the cladribine phosphorylated metabolites cladribine monophosphate (Cd-AMP) is 15 hours and Cd- ATP is 10 hours. Cladribine estimated median apparent renal clearance is 22.2 liter per hour and non-renal clearance is 23.4 liter per hour. Metabolism Cladribine is a prodrug that is phosphorylated to Cd-AMP by deoxycytidine kinase (and also by deoxyguanosine kinase in the mitochondria) in lymphocytes. Cd-AMP is further phosphorylated to cladribine diphosphate (Cd-ADP) and the active moiety Cd-ATP. The dephosphorylation and deactivation of Cd-AMP is catalyzed by cytoplasmic 5’-nucleotidase (5’-Ntase). The metabolism of cladribine in whole blood has not been fully characterized. However, extensive whole blood and negligible hepatic enzyme metabolism was observed, in vitro. Excretion After administration of 10 mg oral cladribine in MS patients, 28.5 [20] (mean [SD]) percent of the dose was excreted unchanged via the renal route. Renal clearance exceeded the glomerular filtration rate, indicating active renal secretion of cladribine. Specific Populations No studies have been conducted to evaluate the pharmacokinetics of cladribine in elderly or in patients with renal or hepatic impairment. There were no clinically significant differences in the pharmacokinetics of cladribine based on age (range 18 to 65 years) or gender. The effect of hepatic impairment on the pharmacokinetics of cladribine is unknown. Patients with Renal Impairment Renal clearance of cladribine was shown to be dependent on creatinine clearance (CL CR ). No dedicated studies have been conducted in patients with renal impairment, however patients with mild renal impairment (CL CR of 60 mL to below 90 mL per minute) were included in Study 1. A pooled pharmacokinetic analysis estimated a decrease of 18% in total clearance in a typical subject with a CL CR of 65 mL per minute leading to an increase in cladribine exposure of 25%. Clinical experience in patients with moderate to severe renal impairment (i.e., CL CR below 60 mL per minute) is limited [ see Use in Specific Populations (8.6) ]. Drug Interaction Studies Clinical Studies No clinically significant differences in cladribine pharmacokinetics were observed when used concomitantly with pantoprazole or interferon beta-1a. No clinically significant differences in ethinyl estradiol and levonorgestrel pharmacokinetics were observed when a combined oral hormonal contraceptive (containing 150 mcg levonorgestrel and 30 mcg ethinyl estradiol) was used concomitantly with cladribine. In Vitro Studies It has been reported that lamivudine can inhibit the phosphorylation of cladribine intracellularly. Potential competition for intracellular phosphorylation exists between cladribine and compounds that require intracellular phosphorylation to become active (e.g., lamivudine, zalcitabine, ribavirin, stavudine, and zidovudine). Cytochrome P450 (CYP) Enzymes: Cladribine is not a substrate of cytochrome P450 enzymes and does not show significant potential to act as inhibitor of CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1 and CYP3A4. Cladribine has no clinically meaningful inductive effect on CYP1A2, CYP2B6 and CYP3A4 enzymes. Transporter Systems: Cladribine is a substrate of P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), equilibrative nucleoside transporter 1 (ENT1) and concentrative nucleoside transporter 3 (CNT3). Inhibition of BCRP in the gastrointestinal tract may increase the oral bioavailability and systemic exposure of cladribine. Intracellular distribution and renal elimination of cladribine may be altered by potent ENT1, CNT3 transporter inhibitors.

Frequently Asked Questions

1 INDICATIONS AND USAGE Cladribine tablets are indicated for the treatment of relapsing form of multiple sclerosis (MS), to include relapsing-remitting disease in adults. Because of its safety profile, use of cladribine tablets is generally recommended for patients who have had an inadequate response to, or are unable to tolerate, an alternate drug indicated for the treatment of MS [ see Warnings and Precautions (5) ]. Limitations of Use Cladribine tablets are not recommended for use in patients with clinically …

2 DOSAGE AND ADMINISTRATION Assessments are required prior to starting each cladribine treatment course. (2.1) Cumulative dosage of 3.5 mg/kg administered orally and divided into 2 treatment courses (1.75 mg/kg per treatment course). Each treatment course is divided into 2 treatment cycles. (2.2) Cladribine tablets are a cytotoxic drug. (2.4) Separate administration from any other oral drug by at least 3 hours. (2.4) 2.1 Assessments Prior to Starting Each Cladribine Treatment Course Cancer Screening Follow standard cancer screening guidelines because …

5 WARNINGS AND PRECAUTIONS Lymphopenia: Monitor lymphocyte counts before, during and after treatment. (5.3) Infections: Serious, including life-threatening and fatal infections, have occurred. Screen patients for active and latent infections; delay treatment until infection is fully resolved or controlled. Vaccination of patients seronegative to varicella zoster virus (VZV) is recommended prior to treatment. Vaccination of patients seropositive to VZV with zoster vaccine recombinant, adjuvanted, is recommended prior to or during treatment. Administer anti-herpes prophylaxis in patients with lymphocyte counts less …

4 CONTRAINDICATIONS Cladribine tablets are contraindicated: in patients with current malignancy [ see Warnings and Precautions (5.1) ] . in pregnant women and in women and men of reproductive potential who do not plan to use effective contraception during cladribine tablets dosing and for 6 months after the last dose in each treatment course. May cause fetal harm [ see Warnings and Precautions (5.2) and Use in Specific Populations (8.1, 8.3 )]. in patients infected with the human immunodeficiency virus …

Cladribine is a prescription medication. You will need a valid prescription from a licensed healthcare provider.

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References & Data Sources

• DailyMed — Cladribine drug label (National Library of Medicine)
• openFDA — Cladribine label data (U.S. Food & Drug Administration)
• RxNorm — RXCUI 2122634 (NLM Normalized Drug Names)
• NDC Directory — Cladribine (FDA National Drug Code)

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Nguồn dữ liệu: DailyMed (NLM), openFDA, MFDS