Temozolomide

1 INDICATIONS AND USAGE TEMODAR is an alkylating drug indicated for the treatment of adults with: Newly diagnosed glioblastoma concomitantly with radiotherapy and then as maintenance treatment. ( 1.1 ) Anaplastic astrocytoma. ( 1.2 ) Adjuvant treatment of adults with newly diagnosed anaplastic astrocytoma. ( 1.2 ) Treatment of adults with refractory anaplastic astrocytoma. ( 1.2 ) 1.1 Newly Diagnosed Glioblastoma TEMODAR is indicated for the treatment of adults with newly diagnosed glioblastoma, concomitantly with radiotherapy and then as maintenance treatment. 1.2 Anaplastic Astrocytoma TEMODAR is indicated for the: adjuvant treatment of adults with newly diagnosed anaplastic astrocytoma; treatment of adults with refractory anaplastic astrocytoma.

2 DOSAGE AND ADMINISTRATION Administer either orally or intravenously. ( 2.4 ) Newly Diagnosed Glioblastoma : 75 mg/m 2 once daily for 42 to 49 days concomitant with focal radiotherapy followed by initial maintenance dose of 150 mg/m 2 once daily for Days 1 to 5 of each 28-day cycle for 6 cycles. May increase maintenance dose to 200 mg/m 2 for Cycles 2 to 6 based on toxicity. ( 2.1 ) Provide Pneumocystis pneumonia (PCP) prophylaxis during concomitant phase and continue in patients who develop lymphopenia until resolution to Grade 1 or less. ( 2.1 ) Adjuvant Treatment of Newly Diagnosed Anaplastic Astrocytoma: Beginning 4 weeks after the end of radiotherapy, administer TEMODAR orally in a single dose on days 1-5 of a 28-day cycle for 12 cycles. The recommended dosage for Cycle 1 is 150 mg/m 2 per day and for Cycles 2 to 12 is 200 mg/m 2 if patient experienced no or minimal toxicity in Cycle 1. ( 2.2 ) Refractory Anaplastic Astrocytoma: Initial dose of 150 mg/m 2 once daily on Days 1 to 5 of each 28-day cycle. ( 2.2 ) 2.1 Monitoring to Inform Dosage and Administration Prior to dosing, withhold TEMODAR until patients have an absolute neutrophil count (ANC) of 1.5 x 10 9 /L or greater and a platelet count of 100 x 10 9 /L or greater. For concomitant radiotherapy, obtain a complete blood count prior to initiation of treatment and weekly during treatment. For the 28-day treatment cycles, obtain a complete blood count prior to treatment on Day 1 and on Day 22 of each cycle. Perform complete blood counts weekly until recovery if the ANC falls below 1.5 x 10 9 /L and the platelet count falls below 100 x 10 9 /L. For concomitant use with focal radiotherapy, obtain a complete blood count weekly and as clinically indicated. 2.2 Recommended Dosage and Dosage Modifications for Newly Diagnosed Glioblastoma Administer TEMODAR either orally or intravenously once daily for 42 to 49 consecutive days during the concomitant use phase with focal radiotherapy, and then once daily on Days 1 to 5 of each 28-day cycle for 6 cycles during the maintenance use phase. Provide Pneumocystis pneumonia (PCP) prophylaxis during the concomitant use phase and continue in patients who develop lymphopenia until resolution to Grade 1 or less [see Warnings and Precautions (5.3) ] . Concomitant Use Phase: The recommended dosage of TEMODAR is 75 mg/m 2 either orally or intravenously once daily for 42 to 49 days in combination with focal radiotherapy. Focal radiotherapy includes the tumor bed or resection site with a 2 to 3 cm margin. Other administration schedules have been used. Obtain a complete blood count weekly. The recommended dosage modifications due to adverse reactions during concomitant use phase are provided in Table 1 . TABLE 1: Dosage Modifications Due to Adverse Reactions During Concomitant Use Phase Adverse Reaction Interruption Discontinuation Absolute Neutrophil Count Withhold TEMODAR if ANC is greater than or equal to 0.5 × 10 9 /L and less than 1.5 × 10 9 /L. Discontinue TEMODAR if ANC is less than 0.5 × 10 9 /L. Resume TEMODAR at the same dose when ANC is greater than or equal to 1.5 × 10 9 /L. Platelet Count Withhold TEMODAR if platelet count is greater than or equal to 10 × 10 9 /L and less than 100 × 10 9 /L. Discontinue TEMODAR if platelet count is less than 10 × 10 9 /L. Resume TEMODAR at the same dose when platelet count is greater than or equal to 100 × 10 9 /L. Non-hematological Adverse Reaction (except for alopecia, nausea, vomiting) Withhold TEMODAR if Grade 2 adverse reaction occurs. Discontinue TEMODAR if Grade 3 or 4 adverse reaction occurs. Resume TEMODAR at the same dose when resolution to Grade 1 or less. Single Agent Maintenance Use Phase: Beginning 4 weeks after concomitant use phase completion, administer TEMODAR either orally or intravenously once daily on Days 1 to 5 of each 28-day cycle for 6 cycles. The recommended dosage of TEMODAR in the maintenance use phase is: Cycle 1: 150 mg/m 2 per day on days 1 to 5. Cycles 2 to 6: May increase to 200 mg/m 2 per day on days 1 to 5 before starting Cycle 2 if no dosage interruptions or discontinuations are required (Table 1). If the dose is not escalated at the onset of Cycle 2, do not increase the dose for Cycles 3 to 6. Obtain a complete blood count on Day 22 and then weekly until the ANC is above 1.5 × 10 9 /L and the platelet count is above 100 × 10 9 /L. Do not start the next cycle until the ANC and platelet count exceed these levels. The recommended dosage modifications due to adverse reactions during the maintenance use phase are provided in Table 2 . If TEMODAR is withheld, reduce the dose for the next cycle by 50 mg/m 2 per day. Permanently discontinue TEMODAR in patients who are unable to tolerate a dose of 100 mg/m 2 per day. TABLE 2: Dosage Modifications Due to Adverse Reactions During Maintenance and Adjuvant Treatment Adverse Reactions Interruption and Dose Reduction Discontinuation Absolute Neutrophil Count Withhold TEMODAR if ANC less than 1 × 10 9 /L. Discontinue TEMODAR if unable to tolerate a dose of 100 mg/m 2 per day. When ANC is above 1.5 × 10 9 /L, resume TEMODAR at reduced dose for the next cycle. Platelet Count Withhold TEMODAR if platelet less than 50 × 10 9 /L. Discontinue TEMODAR if unable to tolerate a dose of 100 mg/m 2 per day. When platelet count is above 100 × 10 9 /L, resume TEMODAR at reduced dose for the next cycle. Nonhematological Adverse Reactions (except for alopecia, nausea, vomiting) Withhold TEMODAR if Grade 3 adverse reaction occurs. Discontinue TEMODAR if recurrent Grade 3 adverse reaction occurs after dose reduction, if Grade 4 adverse reaction occurs, or if unable to tolerate a dose of 100 mg/m 2 per day. When resolved to Grade 1 or less, resume TEMODAR at reduced dose for the next cycle. 2.3 Recommended Dosage and Dosage Modifications for Anaplastic Astrocytoma Adjuvant Treatment of Newly Diagnosed Anaplastic Astrocytoma Beginning 4 weeks after the end of radiotherapy, administer TEMODAR orally in a single dose on days 1 to 5 of a 28-day cycle for 12 cycles. The recommended dosage of TEMODAR is: Cycle 1: 150 mg/m 2 per day on days 1 to 5. Cycles 2 to 12: 200 mg/m 2 per day on days 1 to 5 if patient experienced no or minimal toxicity in Cycle 1. If the dose was not escalated at the onset of Cycle 2, do not increase the dose during Cycles 3 to 6. The recommended complete blood count testing and dosage modifications due to adverse reactions during adjuvant treatment are provided above and in Table 2 [see Dosage and Administration (2.2) ] . Refractory Anaplastic Astrocytoma The recommended initial dosage of TEMODAR is 150 mg/m 2 once daily on Days 1 to 5 of each 28-day cycle. Increase the TEMODAR dose to 200 mg/m 2 per day if the following conditions are met at the nadir and on Day 1 of the next cycle: ANC is greater than or equal to 1.5 × 10 9 /L, and Platelet count is greater than or equal to 100 × 10 9 /L. Continue TEMODAR until disease progression or unacceptable toxicity. Obtain a complete blood count on Day 22 and then weekly until the ANC is above 1.5 x 10 9 /L and the platelet count is above 100 x 10 9 /L. Do not start the next cycle until the ANC and platelet count exceed these levels. If the ANC is less than 1 × 10 9 /L or the platelet count is less than 50 × 10 9 /L during any cycle, reduce the TEMODAR dose for the next cycle by 50 mg/m 2 per day. Permanently discontinue TEMODAR in patients who are unable to tolerate a dose of 100 mg/m 2 per day. 2.4 Preparation and Administration TEMODAR is a hazardous drug. Follow applicable special handling and disposal procedures. 1 TEMODAR capsules Take TEMODAR at the same time each day. Administer TEMODAR consistently with respect to food (fasting vs. nonfasting) [see Clinical Pharmacology (12.3) ] . To reduce nausea and vomiting, take TEMODAR on an empty stomach or at bedtime and consider antiemetic therapy prior to and following TEMODAR administration. Swallow TEMODAR capsules whole with water. Advise patients not to open, chew, or dissolve the contents of the capsules [see Warnings and Precautions (5.6) ] . If capsules are accidentally opened or damaged, take precautions to avoid inhalation or contact with the skin or mucous membranes . In case of powder contact, wash the affected area with water immediately. TEMODAR for injection Bring the vial to room temperature prior to reconstitution with Sterile Water for Injection. Reconstitute the vial with 41 mL of Sterile Water for Injection to yield a TEMODAR solution with a concentration of 2.5 mg/mL temozolomide. Reconstituted TEMODAR is a clear solution and essentially free of visible particles. Gently swirl vial. Do not shake. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. Discard if particulate matter or discoloration is observed. Do not further dilute the reconstituted solution. Store reconstituted solution at room temperature (25°C [77°F]). Discard reconstituted solution if not used within 14 hours, including infusion time. Withdraw up to 40 mL from each vial to make up the total dose and discard any unused portion. Transfer reconstituted solution from each vial into an empty 250 mL infusion bag. Administer reconstituted solution using a pump over a period of 90 minutes. Administer TEMODAR by intravenous infusion only. Infusion over a shorter or longer period of time may result in suboptimal dosing. Flush the lines before and after each infusion. TEMODAR for injection may be administered in the same intravenous line with 0.9% Sodium Chloride injection only. Because no data are available on the compatibility of TEMODAR for injection with other intravenous substances or additives, do not infuse other medications simultaneously through the same intravenous line.

6 ADVERSE REACTIONS The following clinically significant adverse reactions are described elsewhere in the labeling: Myelosuppression [see Warnings and Precautions (5.1) ] Hepatotoxicity [see Warnings and Precautions (5.2) ] Pneumocystis Pneumonia [see Warnings and Precautions (5.3) ] Secondary Malignancies [see Warnings and Precautions (5.4) ] The most common adverse reactions (≥20%) are: alopecia, fatigue, nausea, vomiting, headache, constipation, anorexia, and convulsions. ( 6.1 ) The most common Grade 3 to 4 hematologic laboratory abnormalities (≥10%) in patients with anaplastic astrocytoma are: decreased lymphocytes, decreased platelets, decreased neutrophils, and decreased leukocytes. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Merck Sharp & Dohme LLC at 1-877-888-4231 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials 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 trials of another drug and may not reflect the rates observed in practice. Newly Diagnosed Glioblastoma The safety of TEMODAR was evaluated in study MK-7365-051 [see Clinical Studies (14.1) ]. Severe or life-threatening adverse reactions occurred in 49% of patients treated with TEMODAR; the most common were fatigue (13%), convulsions (6%), headache (5%), and thrombocytopenia (5%). The most common adverse reactions (≥20%) in patients treated with TEMODAR were alopecia, fatigue, nausea, anorexia, headache, constipation, and vomiting. Table 3 summarizes the adverse reactions in MK-7365-051. TABLE 3: Adverse Reactions (≥10%) in Patients with Newly Diagnosed Glioblastoma Adverse Reactions Concomitant Use Phase Maintenance Use Phase Radiation Therapy and TEMODAR N=288 One patient who was randomized to radiation therapy-only arm received radiation therapy and TEMODAR. Radiation Therapy Alone N=285 TEMODAR N=224 All Grades (%) Grade ≥3 (%) All Grades (%) Grades ≥3 (%) All Grades (%) Grade ≥3 (%) Note: Grade 5 (fatal) adverse reactions are included in the Grade ≥3 column. Skin and Subcutaneous Tissue Alopecia 69 0 63 0 55 0 Rash 19 1 15 0 13 1 General Fatigue 54 7 49 5 61 9 Anorexia 19 1 9 <1 27 1 Headache 19 2 17 4 23 4 Gastrointestinal System Nausea 36 1 16 <1 49 1 Vomiting 20 <1 6 <1 29 2 Constipation 18 1 6 0 22 0 Diarrhea 6 0 3 0 10 1 Central and Peripheral Nervous System Convulsions 6 3 7 3 11 3 Clinically relevant adverse reactions in <10% of patients are presented below: Central & Peripheral Nervous System: memory impairment, confusion Eye: v ision blurred Gastrointestinal System: stomatitis, abdominal pain General: weakness, dizziness Immune System: allergic reaction Injury: radiation injury not otherwise specified Musculoskeletal System: arthralgia Platelet, Bleeding, & Clotting: thrombocytopenia Psychiatric: insomnia Respiratory System: coughing, dyspnea Special Senses Other: taste perversion Skin & Subcutaneous Tissue: dry skin, pruritus, erythema When laboratory abnormalities and adverse reactions were combined, Grade 3 or Grade 4 neutrophil abnormalities including neutropenic reactions were observed in 8% of patients, and Grade 3 or Grade 4 platelet abnormalities including thrombocytopenic reactions were observed in 14% of patients. Newly Diagnosed Anaplastic Astrocytoma The safety of TEMODAR for the adjuvant treatment of adults with newly diagnosed anaplastic astrocytoma was derived from published literature [see Clinical Studies (14.2) ]. The safety of TEMODAR for the adjuvant treatment of patients with newly diagnosed anaplastic astrocytoma was consistent with the known safety profile of TEMODAR. Refractory Anaplastic Astrocytoma The safety of TEMODAR was evaluated in study MK-7365-006 [see Clinical Studies (14.2) ]. The most common adverse reactions (≥20%) were nausea, vomiting, headache, fatigue, constipation, and convulsions. Tables 4 and 5 summarize the adverse reactions and hematological laboratory abnormalities in MK-7365-006. TABLE 4: Adverse Reactions (≥10%) in Patients with Refractory Anaplastic Astrocytoma Adverse Reactions TEMODAR N=158 All Reactions (%) Grades 3-4 (%) Gastrointestinal System Nausea 53 10 Vomiting 42 6 Constipation 33 1 Diarrhea 16 2 General Headache 41 6 Fatigue 34 4 Asthenia 13 6 Fever 13 2 Central and Peripheral Nervous System Convulsions 23 5 Hemiparesis 18 6 Dizziness 12 1 Coordination abnormal 11 1 Amnesia 10 4 Insomnia 10 0 Cardiovascular Edema peripheral 11 1 Resistance Mechanism Infection viral 11 0 Clinically relevant adverse reactions in <10% of patients are presented below: Central and Peripheral Nervous System: paresthesia, somnolence, paresis, urinary incontinence, ataxia, dysphasia, convulsions local, gait abnormal, confusion Endocrine: adrenal hypercorticism Gastrointestinal System: abdominal pain, anorexia General: back pain Metabolic: weight increase Musculoskeletal System: myalgia Psychiatric : anxiety, depression Reproductive Disorders: breast pain female Respiratory System: upper respiratory tract infection, pharyngitis, sinusitis, coughing Skin & Appendages: rash, pruritus Urinary System: urinary tract infection, micturition increased frequency Vision: diplopia, vision abnormal This term includes blurred vision; visual deficit; vision changes; and vision troubles. TABLE 5: Grade 3 to 4 Hematologic Laboratory Abnormalities That Worsened from Baseline in Patients with Refractory Anaplastic Astrocytoma TEMODAR Change from Grade 0 to 2 at baseline to Grade 3 or 4 during treatment. , Denominator range= 142, 158 (%) Decreased lymphocytes 55 Decreased platelets 19 Decreased neutrophils 14 Decreased leukocytes 11 Decreased hemoglobin 4 Hematological Toxicities for Advanced Gliomas In clinical trial experience with 110 to 111 females and 169 to 174 males (depending on measurements), females experienced higher rates of Grade 4 neutropenia (ANC <0.5 × 10 9 /L) and thrombocytopenia (<20 × 10 9 /L) than males in the first cycle of therapy (12% vs. 5% and 9% vs. 3%, respectively). In the entire safety database for which hematologic data exist (N=932), 7% (4/61) and 10% (6/63) of patients >70 years experienced Grade 4 neutropenia or thrombocytopenia in the first cycle, respectively. For patients ≤70 years, 7% (62/871) and 6% (48/879) experienced Grade 4 neutropenia or thrombocytopenia in the first cycle, respectively. Pancytopenia, leukopenia, and anemia also occurred. Injection Site Reactions Adverse reactions that were reported in 35 patients who received TEMODAR for injection were pain, irritation, pruritus, warmth, swelling, and erythema at infusion site; petechiae; and hematoma. 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of TEMODAR. 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 the drug exposure. Dermatologic : Toxic epidermal necrolysis and Stevens-Johnson syndrome. Immune System : Hypersensitivity reactions, including anaphylaxis. Erythema multiforme, which resolved after discontinuation of TEMODAR and, in some cases, recurred upon rechallenge. Hematopoietic : Prolonged pancytopenia, which may result in aplastic anemia and fatal outcomes. Hepatobiliary : Fatal and severe hepatotoxicity, elevation of liver enzymes, hyperbilirubinemia, cholestasis, and hepatitis. Infections : Serious opportunistic infections, including some cases with fatal outcomes, with bacterial, viral (primary and reactivated), fungal, and protozoan organisms. Pulmonary : Interstitial pneumonitis, pneumonitis, alveolitis, and pulmonary fibrosis. Endocrine : Diabetes insipidus.

12.3 Pharmacokinetics Following a single oral dose of 150 mg/m 2 , the mean C max is 7.5 mcg/mL for temozolomide and 282 ng/mL for MTIC. The mean AUC is 23.4 mcg∙hr/mL for temozolomide and 864 ng∙hr/mL for MTIC. Following a single 90-minute intravenous infusion of 150 mg/m 2 , the mean C max is 7.3 mcg/mL for temozolomide and 276 ng/mL for MTIC. The mean AUC is 24.6 mcg∙hr/mL for temozolomide and 891 ng∙hr/mL for MTIC. Temozolomide exhibits linear kinetics over the therapeutic dosing range of 75 mg/m 2 /day to 250 mg/m 2 /day. Absorption The median T max is 1 hour. Effect of Food The mean temozolomide C max and AUC decreased by 32% and 9%, respectively, and median T max increased by 2-fold (from 1 to 2.25 hours) when TEMODAR capsules were administered after a modified high-fat breakfast (587 calories comprised of 1 fried egg, 2 strips of bacon, 2 slices of toast, 2 pats of butter, and 8 oz whole milk). Distribution Temozolomide has a mean (CV%) apparent volume of distribution of 0.4 L/kg (13%). The mean percent bound of drug-related total radioactivity is 15%. Elimination Clearance of temozolomide is approximately 5.5 L/hr/m 2 and the mean elimination half-life is 1.8 hours. Metabolism Temozolomide is spontaneously hydrolyzed at physiologic pH to the active species, MTIC and to temozolomide acid metabolite. MTIC is further hydrolyzed to 5-amino-imidazole-4-carboxamide (AIC), which is known to be an intermediate in purine and nucleic acid biosynthesis, and to methylhydrazine, which is believed to be the active alkylating species. Cytochrome P450 enzymes play a minor role in the metabolism of temozolomide and MTIC. Relative to the AUC of temozolomide, the exposure to MTIC and AIC is 2.4% and 23%, respectively. Excretion Approximately 38% of the administered temozolomide total radioactive dose is recovered over 7 days: 38% in urine and 0.8% in feces. The majority of the recovered radioactivity in urine is unchanged temozolomide (6%), AIC (12%), temozolomide acid metabolite (2.3%), and unidentified polar metabolite(s) (17%). Specific Populations No clinically significant differences in the pharmacokinetics of temozolomide were observed based on age (range: 19 to 78 years), gender, smoking status (smoker vs. non-smoker), creatinine clearance (CLcr) of 36 to 130 mL/min/m 2 , or mild to moderate hepatic impairment (Child Pugh class A and B). The pharmacokinetics of temozolomide has not been studied in patients with CLcr <36 mL/min/m 2 , end-stage renal disease on dialysis, or severe hepatic impairment (Child-Pugh class C). Drug Interaction Studies Clinical Studies and Model-Informed Approaches No clinically significant differences in the pharmacokinetics of temozolomide or MTIC were observed when co-administered with ranitidine. No clinically significant differences in the clearance of temozolomide or MTIC were predicted when co-administered with the following drugs: valproic acid, dexamethasone, prochlorperazine, phenytoin, carbamazepine, ondansetron, histamine-2-receptor antagonists, or phenobarbital.