1.1 Newly Diagnosed Glioblastoma Multiforme

Temozolomide is indicated for the treatment of adult patients with newly diagnosed glioblastoma multiforme concomitantly with radiotherapy and then as maintenance treatment.

1.2 Refractory Anaplastic Astrocytoma

Temozolomide is indicated for the treatment of adult patients with refractory anaplastic astrocytoma, i.e., patients who have experienced disease progression on a drug regimen containing nitrosourea and procarbazine.

2.1 Recommended Dosing and Dose Modification Guidelines

The recommended dose for temozolomide as an intravenous infusion over 90 minutes is the same as the dose for the oral capsule formulation. Bioequivalence has been established only when temozolomide for Injection was given over 90 minutes [see Clinical Pharmacology (12.3)]. Dosage of temozolomide must be adjusted according to nadir neutrophil and platelet counts in the previous cycle and the neutrophil and platelet counts at the time of initiating the next cycle. For temozolomide dosage calculations based on body surface area (BSA) see Table 5. For suggested capsule combinations on a daily dose see Table 6. 

Patients with Newly Diagnosed High Grade Glioma: Concomitant Phase: Temozolomide is administered at 75 mg/m2 daily for 42 days concomitant with focal radiotherapy (60 Gy administered in 30 fractions) followed by maintenance temozolomide for 6 cycles. Focal RT includes the tumor bed or resection site with a 2- to 3-cm margin. No dose reductions are recommended during the concomitant phase; however, dose interruptions or discontinuation may occur based on toxicity. The temozolomide dose should be continued throughout the 42-day concomitant period up to 49 days if all of the following conditions are met: absolute neutrophil count greater than or equal to 1.5 x 109/L, platelet count greater than or equal to 100 x 109/L, common toxicity criteria (CTC) nonhematological toxicity less than or equal to Grade 1 (except for alopecia, nausea, and vomiting). During treatment a complete blood count should be obtained weekly. Temozolomide dosing should be interrupted or discontinued during concomitant phase according to the hematological and nonhematological toxicity criteria as noted in Table 1. Pneumocystis pneumonia (PCP) prophylaxis is required during the concomitant administration of temozolomide and radiotherapy, and should be continued in patients who develop lymphocytopenia until recovery from lymphocytopenia (CTC Grade less than or equal to 1).

*Treatment with concomitant TMZ could be continued when all of the following conditions were met: absolute neutrophil count greater than or equal to 1.5 x 109/L; platelet count greater than or equal to 100 x 109/L; CTC nonhematological toxicity less than or equal to Grade 1 (except for alopecia, nausea, vomiting).
TMZ=temozolomide; CTC=Common Toxicity Criteria.

Maintenance Phase:

Cycle 1: Four weeks after completing the temozolomide+RT phase, temozolomide is administered for an additional 6 cycles of maintenance treatment. Dosage in Cycle 1 (maintenance) is 150 mg/m2 once daily for 5 days followed by 23 days without treatment.

Cycles 2-6: At the start of Cycle 2, the dose can be escalated to 200 mg/m2, if the CTC nonhematologic toxicity for Cycle 1 is Grade less than or equal to 2 (except for alopecia, nausea, and vomiting), absolute neutrophil count (ANC) is greater than or equal to 1.5 x 109/L, and the platelet count is greater than or equal to 100 x 109/L. The dose remains at 200 mg/m2 per day for the first 5 days of each subsequent cycle except if toxicity occurs. If the dose was not escalated at Cycle 2, escalation should not be done in subsequent cycles.

Dose Reduction or Discontinuation During Maintenance: Dose reductions during the maintenance phase should be applied according to Tables 2 and 3.

During treatment, a complete blood count should be obtained on Day 22 (21 days after the first dose of temozolomide) or within 48 hours of that day, and weekly until the ANC is above 1.5 x 109/L (1500/µL) and the platelet count exceeds 100 x 109/L (100,000/µL). The next cycle of temozolomide should not be started until the ANC and platelet count exceed these levels. Dose reductions during the next cycle should be based on the lowest blood counts and worst nonhematologic toxicity during the previous cycle. Dose reductions or discontinuations during the maintenance phase should be applied according to Tables 2 and 3.

*TMZ dose levels are listed in Table 2.
†TMZ is to be discontinued if dose reduction to less than 100 mg/m2 is required or if the same Grade 3 nonhematological toxicity (except for alopecia, nausea, vomiting) recurs after dose reduction.
TMZ=temozolomide; CTC=Common Toxicity Criteria.

Patients with Refractory Anaplastic Astrocytoma: For adults the initial dose is 150 mg/m2 once daily for 5 consecutive days per 28-day treatment cycle. For adult patients, if both the nadir and day of dosing (Day 29, Day 1 of next cycle) ANC are greater than or equal to 1.5 x 109/L (1500/µL) and both the nadir and Day 29, Day 1 of next cycle platelet counts are greater than or equal to 100 x 109/L (100,000/µL), the temozolomide dose may be increased to 200 mg/m2/day for 5 consecutive days per 28-day treatment cycle. During treatment, a complete blood count should be obtained on Day 22 (21 days after the first dose) or within 48 hours of that day, and weekly until the ANC is above 1.5 x 109/L (1500/µL) and the platelet count exceeds 100 x 109/L (100,000/µL). The next cycle of temozolomide should not be started until the ANC and platelet count exceed these levels. If the ANC falls to less than 1 x 109/L (1000/µL) or the platelet count is less than 50 x 109/L (50,000/µL) during any cycle, the next cycle should be reduced by 50 mg/m2, but not below 100 mg/m2, the lowest recommended dose (see Table 4). Temozolomide therapy can be continued until disease progression. In the clinical trial, treatment could be continued for a maximum of 2 years, but the optimum duration of therapy is not known.

TABLE 4: Dosing Modification Table

150 mg/m2/d x 5d (Starting Dose) or 200 mg/m2/d x 5d				Measure Day 22 ANC and platelets
Measure ANC and platelets on Day 29 (Day 1 of next cycle)
Based on lowest counts at either Day 22 or Day 29
ANC less than 1000/µL or platelets less than 50,000/µL		ANC 1000/µL – 1500/µL or platelets 50,000/µL – 100,000/µL		ANC greater than 1500/µL and platelets greater than 100,000/µL
Postpone therapy until ANC greater than 1500/µL and platelets greater than 100,000/µL; reduce dose by 50 mg/m2/d for subsequent cycle		Postpone therapy until ANC greater than 1500/µL and platelets greater than 100,000/µL; maintain initial dose		Increase dose to, or maintain dose at, 200 mg/m2/d x 5d for subsequent cycle

2.2 Preparation and Administration

Temozolomide Capsules: In clinical trials, temozolomide was administered under both fasting and nonfasting conditions; however, absorption is affected by food [see Clinical Pharmacology (12.3)], and consistency of administration with respect to food is recommended. There are no dietary restrictions with temozolomide. To reduce nausea and vomiting, temozolomide should be taken on an empty stomach. Bedtime administration may be advised. Antiemetic therapy may be administered prior to and/or following administration of temozolomide.

Temozolomide capsules should not be opened or chewed. They should be swallowed whole with a glass of water. If capsules are accidentally opened or damaged, precautions should be taken to avoid inhalation or contact with the skin or mucous membranes [see How Supplied/Storage and Handling (16.1)].

4.1 Hypersensitivity

Temozolomide is contraindicated in patients who have a history of hypersensitivity reaction (such as urticaria, allergic reaction including anaphylaxis, toxic epidermal necrolysis, and Stevens-Johnson syndrome) to any of its components. Temozolomide is also contraindicated in patients who have a history of hypersensitivity to dacarbazine (DTIC), since both drugs are metabolized to 5-(3-methyltriazen-1-yl)-imidazole-4-carboxamide (MTIC).

5.1 Myelosuppression

Patients treated with temozolomide may experience myelosuppression, including prolonged pancytopenia, which may result in aplastic anemia, which in some cases has resulted in a fatal outcome. In some cases, exposure to concomitant medications associated with aplastic anemia, including carbamazepine, phenytoin, and sulfamethoxazole/trimethoprim, complicates assessment. Prior to dosing, patients must have an absolute neutrophil count (ANC) greater than or equal to 1.5 x 109/L and a platelet count greater than or equal to 100 x 109/L. A complete blood count should be obtained on Day 22 (21 days after the first dose) or within 48 hours of that day, and weekly until the ANC is above 1.5 x 109/L and platelet count exceeds 100 x 109/L. Geriatric patients and women have been shown in clinical trials to have a higher risk of developing myelosuppression.

5.2 Myelodysplastic Syndrome

Cases of myelodysplastic syndrome and secondary malignancies, including myeloid leukemia, have been observed.

5.3 Pneumocystis Pneumonia

For treatment of newly diagnosed glioblastoma multiforme: Prophylaxis against Pneumocystis pneumonia (PCP) is required for all patients receiving concomitant temozolomide and radiotherapy for the 42-day regimen.

There may be a higher occurrence of PCP when temozolomide is administered during a longer dosing regimen. However, all patients receiving temozolomide, particularly patients receiving steroids, should be observed closely for the development of PCP regardless of the regimen. 

5.4 Laboratory Tests

For the concomitant treatment phase with RT, a complete blood count should be obtained prior to initiation of treatment and weekly during treatment.

For the 28-day treatment cycles, a complete blood count should be obtained prior to treatment on Day 1 and on Day 22 (21 days after the first dose) of each cycle. Blood counts should be performed weekly until recovery if the ANC falls below 1.5 x 109/L and the platelet count falls below 100 x 109/L [see Recommended Dosing and Dose Modification Guidelines (2.1)].

5.5 Hepatotoxicity

Fatal and severe hepatotoxicity have been reported in patients receiving temozolomide. Perform liver function tests at baseline, midway through the first cycle, prior to each subsequent cycle, and approximately two to four weeks after the last dose of temozolomide.

5.6 Use in Pregnancy

Temozolomide can cause fetal harm when administered to a pregnant woman. Administration of temozolomide to rats and rabbits during organogenesis at 0.38 and 0.75 times the maximum recommended human dose (75 and 150 mg/m2), respectively, caused numerous fetal malformations of the external organs, soft tissues, and skeleton in both species [see Use in Specific Populations (8.1)].

5.7 Infusion Time

As bioequivalence has been established only when temozolomide for Injection was given over 90 minutes, infusion over a shorter or longer period of time may result in suboptimal dosing. Additionally, the possibility of an increase in infusion-related adverse reactions cannot be ruled out.

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 Multiforme: During the concomitant phase (temozolomide+radiotherapy), adverse reactions including thrombocytopenia, nausea, vomiting, anorexia, and constipation were more frequent in the temozolomide+RT arm. The incidence of other adverse reactions was comparable in the two arms. The most common adverse reactions across the cumulative temozolomide experience were alopecia, nausea, vomiting, anorexia, headache, and constipation (see Table 7). Forty-nine percent (49%) of patients treated with temozolomide reported one or more severe or life-threatening reactions, most commonly fatigue (13%), convulsions (6%), headache (5%), and thrombocytopenia (5%). Overall, the pattern of reactions during the maintenance phase was consistent with the known safety profile of temozolomide.

*One patient who was randomized to RT only arm received RT+temozolomide.
RT+TMZ=radiotherapy plus temozolomide; NOS=not otherwise specified.
Note: Grade 5 (fatal) adverse reactions are included in the Grade ≥3 column.

Myelosuppression (neutropenia and thrombocytopenia), which is a known dose-limiting toxicity for most cytotoxic agents, including temozolomide, was observed. When laboratory abnormalities and adverse reactions were combined, Grade 3 or Grade 4 neutrophil abnormalities including neutropenic reactions were observed in 8% of the patients, and Grade 3 or Grade 4 platelet abnormalities, including thrombocytopenic reactions, were observed in 14% of the patients treated with temozolomide.

Refractory Anaplastic Astrocytoma: Tables 8 and 9 show the incidence of adverse reactions in the 158 patients in the anaplastic astrocytoma study for whom data are available. In the absence of a control group, it is not clear in many cases whether these reactions should be attributed to temozolomide or the patients’ underlying conditions, but nausea, vomiting, fatigue, and hematologic effects appear to be clearly drug-related. The most frequently occurring adverse reactions were nausea, vomiting, headache, and fatigue. The adverse reactions were usually NCI Common Toxicity Criteria (CTC) Grade 1 or 2 (mild to moderate in severity) and were self-limiting, with nausea and vomiting readily controlled with antiemetics. The incidence of severe nausea and vomiting (CTC Grade 3 or 4) was 10% and 6%, respectively. Myelosuppression (thrombocytopenia and neutropenia) was the dose-limiting adverse reaction. It usually occurred within the first few cycles of therapy and was not cumulative.

Myelosuppression occurred late in the treatment cycle and returned to normal, on average, within 14 days of nadir counts. The median nadirs occurred at 26 days for platelets (range: 21-40 days) and 28 days for neutrophils (range: 1-44 days). Only 14% (22/158) of patients had a neutrophil nadir and 20% (32/158) of patients had a platelet nadir, which may have delayed the start of the next cycle. Less than 10% of patients required hospitalization, blood transfusion, or discontinuation of therapy due to myelosuppression.

In clinical trial experience with 110 to 111 women and 169 to 174 men (depending on measurements), there were higher rates of Grade 4 neutropenia (ANC less than 500 cells/µL) and thrombocytopenia (less than 20,000 cells/µL) in women than men 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 9.5% (6/63) of patients over age 70 experienced Grade 4 neutropenia or thrombocytopenia in the first cycle, respectively. For patients less than or equal to age 70, 7% (62/871) and 5.5% (48/879) experienced Grade 4 neutropenia or thrombocytopenia in the first cycle, respectively. Pancytopenia, leukopenia, and anemia have also been reported.

*Blurred vision; visual deficit; vision changes; vision troubles

*Change from Grade 0 to 2 at baseline to Grade 3 or 4 during treatment.

Temozolomide for injection delivers equivalent temozolomide dose and exposure to both temozolomide and 5-(3-methyltriazen-1-yl)-imidazole-4-carboxamide (MTIC) as the corresponding temozolomide capsules. Adverse reactions probably related to treatment that were reported from the 2 studies with the intravenous formulation (n=35) that were not reported in studies using the temozolomide capsules were: pain, irritation, pruritus, warmth, swelling, and erythema at infusion site as well as the following adverse reactions: petechiae and hematoma.

6.2 Postmarketing Experience

The following adverse reactions have been identified during postapproval use of temozolomide. 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 disorders: Toxic epidermal necrolysis and Stevens-Johnson syndrome 

Immune system disorders: Allergic reactions, including anaphylaxis. Erythema multiforme, which resolved after discontinuation of temozolomide and, in some cases, recurred upon rechallenge. 

Hematopoietic disorders:  Prolonged pancytopenia, which may result in aplastic anemia and fatal outcomes [see Warnings and Precautions (5.1)]. 

Hepatobiliary disorders: Fatal and severe hepatotoxicity, elevation of liver enzymes, hyperbilirubinemia, cholestasis, and hepatitis [see Warnings and Precautions (5.5)]. 

Infections and infestations: Opportunistic infections including Pneumocystis pneumonia (PCP) [see Warnings and Precautions (5.3)], primary and reactivated cytomegalovirus (CMV), and reactivation of hepatitis B infections including some cases with fatal outcomes. 

Pulmonary disorders: Interstitial pneumonitis, pneumonitis, alveolitis, and pulmonary fibrosis. 

Endocrine disorders: Diabetes insipidus

7.1 Valproic Acid

Administration of valproic acid decreases oral clearance of temozolomide by about 5%. The clinical implication of this effect is not known [see Clinical Pharmacology (12.3)].

8.1 Pregnancy

Pregnancy Category D. See Warnings and Precautions section.

Temozolomide can cause fetal harm when administered to a pregnant woman. Five consecutive days of oral temozolomide administration of 0.38 and 0.75 times the highest recommended human dose (75 and 150 mg/m2) in rats and rabbits, respectively, during the period of organogenesis caused numerous malformations of the external and internal soft tissues and skeleton in both species. Doses equivalent to 0.75 times the highest recommended human dose (150 mg/m2) caused embryolethality in rats and rabbits as indicated by increased resorptions. There are no adequate and well-controlled studies in pregnant women. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus. Women of childbearing potential should be advised to avoid becoming pregnant during therapy with temozolomide.

8.3 Nursing Mothers

It is not known whether this drug is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants and tumorigenicity shown for temozolomide in animal studies, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of temozolomide to the mother.

8.4 Pediatric Use

Safety and effectiveness in pediatric patients have not been established. Temozolomide capsules have been studied in 2 open-label studies in pediatric patients (aged 3-18 years) at a dose of 160 to 200 mg/m2 daily for 5 days every 28 days. In one trial, 29 patients with recurrent brain stem glioma and 34 patients with recurrent high grade astrocytoma were enrolled. All patients had recurrence following surgery and radiation therapy, while 31% also had disease progression following chemotherapy. In a second study conducted by the Children’s Oncology Group (COG), 122 patients were enrolled, including patients with medulloblastoma/PNET (29), high grade astrocytoma (23), low grade astrocytoma (22), brain stem glioma (16), ependymoma (14), other CNS tumors (9), and non-CNS tumors (9). The temozolomide toxicity profile in pediatric patients is similar to adults. Table 10 shows the adverse reactions in 122 children in the COG study.

*These various tumors included the following: PNET-medulloblastoma, glioblastoma, low grade astrocytoma, brain stem tumor, ependymoma, mixed glioma, oligodendroglioma, neuroblastoma, Ewing’s sarcoma, pineoblastoma, alveolar soft part sarcoma, neurofibrosarcoma, optic glioma, and osteosarcoma.

8.5 Geriatric Use

Clinical studies of temozolomide did not include sufficient numbers of subjects aged 65 and over to determine whether they responded differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.

In the anaplastic astrocytoma study population, patients 70 years of age or older had a higher incidence of Grade 4 neutropenia and Grade 4 thrombocytopenia (2/8; 25%, P=0.31 and 2/10; 20%, P=0.09, respectively) in the first cycle of therapy than patients under 70 years of age [see Warnings and Precautions (5.1) and Adverse Reactions (6.1)].

In newly diagnosed patients with glioblastoma multiforme, the adverse reaction profile was similar in younger patients (less than 65 years) vs. older (greater than or equal to 65 years).

8.6 Renal Impairment

Caution should be exercised when temozolomide is administered to patients with severe renal impairment [see Clinical Pharmacology (12.3)].

8.7 Hepatic Impairment

Caution should be exercised when temozolomide is administered to patients with severe hepatic impairment [see Clinical Pharmacology (12.3)].

12.1 Mechanism of Action

Temozolomide is not directly active but undergoes rapid nonenzymatic conversion at physiologic pH to the reactive compound 5-(3-methyltriazen-1-yl)-imidazoIe-4-carboxamide (MTIC). The cytotoxicity of MTIC is thought to be primarily due to alkylation of DNA. Alkylation (methylation) occurs mainly at the O6 and N7 positions of guanine.

12.3 Pharmacokinetics

Absorption: Temozolomide is rapidly and completely absorbed after oral administration with a peak plasma concentration (Cmax) achieved in a median Tmax of 1 hour. Food reduces the rate and extent of temozolomide absorption. Mean peak plasma concentration and AUC decreased by 32% and 9%, respectively, and median Tmax increased by 2-fold (from 1-2.25 hours) when temozolomide was administered after a modified high-fat breakfast.

A pharmacokinetic study comparing oral and intravenous temozolomide in 19 patients with primary CNS malignancies showed that 150 mg/m2 temozolomide for injection administered over 90 minutes is bioequivalent to 150 mg/m2 temozolomide oral capsules with respect to both Cmax and AUC of temozolomide and MTIC. Following a single 90-minute intravenous infusion of 150 mg/m2, the geometric mean Cmax values for temozolomide and MTIC were 7.3 mcg/mL and 276 ng/mL, respectively. Following a single oral dose of 150 mg/m2, the geometric mean Cmax values for temozolomide and MTIC were 7.5 mcg/mL and 282 ng/mL, respectively. Following a single 90-minute intravenous infusion of 150 mg/m2, the geometric mean AUC values for temozolomide and MTIC were 24.6 mcg·hr/mL and 891 ng·hr/mL, respectively. Following a single oral dose of 150 mg/m2, the geometric mean AUC values for temozolomide and MTIC were 23.4 mcg·hr/mL and 864 ng·hr/mL, respectively.

Distribution: Temozolomide has a mean apparent volume of distribution of 0.4 L/kg (%CV=13%). It is weakly bound to human plasma proteins; the mean percent bound of drug-related total radioactivity is 15%.

Metabolism and Elimination: 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 only 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: About 38% of the administered temozolomide total radioactive dose is recovered over 7 days: 37.7% in urine and 0.8% in feces. The majority of the recovery of radioactivity in urine is unchanged temozolomide (5.6%), AIC (12%), temozolomide acid metabolite (2.3%), and unidentified polar metabolite(s) (17%). Overall clearance of temozolomide is about 5.5 L/hr/m2. Temozolomide is rapidly eliminated, with a mean elimination half-life of 1.8 hours, and exhibits linear kinetics over the therapeutic dosing range of 75 to 250 mg/m2/day.

Effect of Age: A population pharmacokinetic analysis indicated that age (range: 19-78 years) has no influence on the pharmacokinetics of temozolomide.

Effect of Gender: A population pharmacokinetic analysis indicated that women have an approximately 5% lower clearance (adjusted for body surface area) for temozolomide than men.

Effect of Race: The effect of race on the pharmacokinetics of temozolomide has not been studied.

Tobacco Use: A population pharmacokinetic analysis indicated that the oral clearance of temozolomide is similar in smokers and nonsmokers.

Effect of Renal Impairment: A population pharmacokinetic analysis indicated that creatinine clearance over the range of 36 to 130 mL/min/m2 has no effect on the clearance of temozolomide after oral administration. The pharmacokinetics of temozolomide have not been studied in patients with severely impaired renal function (CLcr less than 36 mL/min/m2). Caution should be exercised when temozolomide is administered to patients with severe renal impairment [see Use in Special Populations (8.6)]. Temozolomide has not been studied in patients on dialysis.

Effect of Hepatic Impairment: A study showed that the pharmacokinetics of temozolomide in patients with mild-to-moderate hepatic impairment (Child-Pugh Class I - II) were similar to those observed in patients with normal hepatic function. Caution should be exercised when temozolomide is administered to patients with severe hepatic impairment [see Use in Specific Populations (8.7)].

Effect of Other Drugs on Temozolomide Pharmacokinetics: In a multiple-dose study, administration of temozolomide capsules with ranitidine did not change the Cmax or AUC values for temozolomide or MTIC.

A population analysis indicated that administration of valproic acid decreases the clearance of temozolomide by about 5% [see Drug Interactions (7.1)].

A population analysis did not demonstrate any influence of coadministered dexamethasone, prochlorperazine, phenytoin, carbamazepine, ondansetron, H2-receptor antagonists, or phenobarbital on the clearance of orally administered temozolomide.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Temozolomide is carcinogenic in rats at doses less than the maximum recommended human dose. Temozolomide induced mammary carcinomas in both males and females at doses 0.13 to 0.63 times the maximum human dose (25-125 mg/m2) when administered orally on 5 consecutive days every 28 days for 6 cycles. Temozolomide also induced fibrosarcomas of the heart, eye, seminal vesicles, salivary glands, abdominal cavity, uterus, and prostate, carcinomas of the seminal vesicles, schwannomas of the heart, optic nerve, and harderian gland, and adenomas of the skin, lung, pituitary, and thyroid at doses 0.5 times the maximum daily dose. Mammary tumors were also induced following 3 cycles of temozolomide at the maximum recommended daily dose.

Temozolomide is a mutagen and a clastogen. In a reverse bacterial mutagenesis assay (Ames assay), temozolomide increased revertant frequency in the absence and presence of metabolic activation. Temozolomide was clastogenic in human lymphocytes in the presence and absence of metabolic activation.

Temozolomide impairs male fertility. Temozolomide caused syncytial cells/immature sperm formation at 0.25 and 0.63 times the maximum recommended human dose (50 and 125 mg/m2) in rats and dogs, respectively, and testicular atrophy in dogs at 0.63 times the maximum recommended human dose (125 mg/m2).

13.2 Animal Toxicology and/or Pharmacology

Toxicology studies in rats and dogs identified a low incidence of hemorrhage, degeneration, and necrosis of the retina at temozolomide doses equal to or greater than 0.63 times the maximum recommended human dose (125 mg/m2). These changes were most commonly seen at doses where mortality was observed.

14.1 Newly Diagnosed Glioblastoma Multiforme

Five hundred and seventy-three patients were randomized to receive either temozolomide (TMZ)+Radiotherapy (RT) (n=287) or RT alone (n=286). Patients in the temozolomide+RT arm received concomitant temozolomide (75 mg/m2) once daily, starting the first day of RT until the last day of RT, for 42 days (with a maximum of 49 days). This was followed by 6 cycles of temozolomide alone (150 or 200 mg/m2) on Days 1 to 5 of every 28-day cycle, starting 4 weeks after the end of RT. Patients in the control arm received RT only. In both arms, focal radiation therapy was delivered as 60 Gy/30 fractions. Focal RT includes the tumor bed or resection site with a 2- to 3- cm margin. Pneumocystis pneumonia (PCP) prophylaxis was required during the TMZ+RT, regardless of lymphocyte count, and was to continue until recovery of lymphocyte count to less than or equal to Grade 1.

At the time of disease progression, temozolomide was administered as salvage therapy in 161 patients of the 282 (57%) in the RT alone arm, and 62 patients of the 277 (22%) in the temozolomide+RT arm.

The addition of concomitant and maintenance temozolomide to radiotherapy in the treatment of patients with newly diagnosed GBM showed a statistically significant improvement in overall survival compared to radiotherapy alone (Figure 1). The hazard ratio (HR) for overall survival was 0.63 (95% CI for HR=0.52-0.75) with a log-rank P<0.0001 in favor of the temozolomide arm. The median survival was increased by 2.5 months in the temozolomide arm.

FIGURE 1: Kaplan-Meier Curves for Overall Survival (ITT Population)

14.2 Refractory Anaplastic Astrocytoma

A single-arm, multicenter study was conducted in 162 patients who had anaplastic astrocytoma at first relapse and who had a baseline Karnofsky performance status of 70 or greater. Patients had previously received radiation therapy and may also have previously received a nitrosourea with or without other chemotherapy. Fifty-four patients had disease progression on prior therapy with both a nitrosourea and procarbazine, and their malignancy was considered refractory to chemotherapy (refractory anaplastic astrocytoma population). Median age of this subgroup of 54 patients was 42 years (19-76). Sixty-five percent were male. Seventy-two percent of patients had a KPS of greater than 80. Sixty-three percent of patients had surgery other than a biopsy at the time of initial diagnosis. Of those patients undergoing resection, 73% underwent a subtotal resection and 27% underwent a gross total resection. Eighteen percent of patients had surgery at the time of first relapse. The median time from initial diagnosis to first relapse was 13.8 months (4.2-75.4).

Temozolomide capsules were given for the first 5 consecutive days of a 28-day cycle at a starting dose of 150 mg/m2/day. If the nadir and day of dosing (Day 29, Day 1 of next cycle) absolute neutrophil count was greater than or equal to 1.5 x 109/L (1500/µL) and the nadir and Day 29, Day 1 of next cycle platelet count was greater than or equal to 100 x 109/L (100,000/µL), the temozolomide dose was increased to 200 mg/m2/day for the first 5 consecutive days of a 28-day cycle.

In the refractory anaplastic astrocytoma population, the overall tumor response rate (CR+PR) was 22% (12/54 patients) and the complete response rate was 9% (5/54 patients). The median duration of all responses was 50 weeks (range: 16-114 weeks) and the median duration of complete responses was 64 weeks (range: 52-114 weeks). In this population, progression-free survival at 6 months was 45% (95% CI: 31%-58%) and progression-free survival at 12 months was 29% (95% CI: 16%-42%). Median progression-free survival was 4.4 months. Overall survival at 6 months was 74% (95% CI: 62%-86%) and 12-month overall survival was 65% (95% CI: 52%-78%). Median overall survival was 15.9 months.

16.1 Safe Handling and Disposal

Care should be exercised in the handling and preparation of temozolomide. Capsules should not be opened. If capsules are accidentally opened or damaged, rigorous precautions should be taken with the contents to avoid inhalation or contact with the skin or mucous membranes. The use of gloves and safety glasses is recommended to avoid exposure in case of breakage of the capsules. Procedures for proper handling and disposal of anticancer drugs should be considered {1-4}. Several guidelines on this subject have been published.

16.2 How Supplied

Temozolomide Capsules: Temozolomide capsules are supplied in amber glass bottles with child-resistant polypropylene caps containing the following capsule strengths:

Temozolomide Capsules 5 mg: have an olive opaque cap and white opaque body.  They are imprinted with “Lannett” on the cap and “1777” over “5 mg” on the body and are supplied in:
Bottles of 5 (NDC 0527-1777-55)
Bottles of 14 (NDC 0527-1777-14)

Temozolomide Capsules 20 mg: have an orange opaque cap and white opaque body.  They are imprinted with “Lannett” on the cap and “1778” over “20 mg” on the body and are supplied in:
Bottles of 5 (NDC 0527-1778-55)
Bottles of 14 (NDC 0527-1778-14)

Temozolomide Capsules 100 mg: have a flesh opaque cap and white opaque body.  They are imprinted with “Lannett” on the cap and “1779” over “100 mg” on the body and are supplied in:
Bottles of 5 (NDC 0527-1779-55)
Bottles of 14 (NDC 0527-1779-14)

Temozolomide Capsules 140 mg: have an aqua blue opaque cap and white opaque body.  They are imprinted with “Lannett” on the cap and “1780” over “140 mg” on the body and are supplied in:
Bottles of 5 (NDC 0527-1780-55)
Bottles of 14 (NDC 0527-1780-14)

Temozolomide Capsules 180 mg: have a swedish orange opaque cap and white opaque body.  They are imprinted with “Lannett” on the cap and “1781” over “180 mg” on the body and are supplied in:
Bottles of 5 (NDC 0527-1781-55)
Bottles of 14 (NDC 0527-1781-14)

Temozolomide Capsules 250 mg: have a white opaque cap and white opaque body.  They are imprinted with “Lannett” on the cap and “1782” over “250 mg” on the body and are supplied in:
Bottles of 5 (NDC 0527-1782-55)

16.3 Storage

Store temozolomide capsules at 25°C (77°F); excursions permitted to 15-30°C (59-86°F) [see USP Controlled Room Temperature].

17.1 Information for the Patient

Physicians should discuss the following with their patients:

• Nausea and vomiting are the most frequently occurring adverse reactions. Nausea and vomiting are usually either self-limiting or readily controlled with standard antiemetic therapy. 
• Capsules should not be opened. If capsules are accidentally opened or damaged, rigorous precautions should be taken with the capsule contents to avoid inhalation or contact with the skin or mucous membranes. 
• The medication should be kept away from children and pets.

Manufactured by:
Lannett Company, Inc.
Philadelphia, PA 19136 

Made in the USA

Rev. 12/2015, Revision 4

10-605

What is temozolomide?

Temozolomide is an oral alkylating agent for the treatment of newly diagnosed glioblastoma multiforme and refractory anaplastic astrocytoma.

How is temozolomide dosed?

The daily dose of temozolomide capsules for a given patient is calculated by the physician, based on the patient’s body surface area (BSA). The resulting dose is then rounded off to the nearest 5 mg. An example of the dosing may be as follows: the initial daily dose of temozolomide in milligrams is the BSA multiplied by mg/m2/day, (a patient with a BSA of 1.84 is 1.84 x 75 mg = 138, or 140 mg/day). The dose for subsequent cycles may be adjusted according to nadir neutrophil and platelet counts in the previous cycle and at the time of initiating the next cycle.

How might the dose of temozolomide be modified for Refractory Anaplastic Astrocytoma?

Dosage of temozolomide must be adjusted according to nadir neutrophil and platelet counts in the previous cycle and neutrophil and platelet counts at the time of initiating the next cycle. The initial dose is 150 mg/m2 orally once daily for 5 consecutive days per 28-day treatment cycle. If both the nadir and day of dosing (Day 29, Day 1 of next cycle) absolute neutrophil counts (ANC) are greater than or equal to 1.5 x 109/L (1500/µL) and both the nadir and Day 29, Day 1 of next cycle platelet counts are greater than or equal to 100 x 109/L (100,000/µL), the temozolomide dose may be increased to 200 mg/m2/day for 5 consecutive days per 28-day treatment cycle. During treatment, a complete blood count should be obtained on Day 22 (21 days after the first dose) or within 48 hours of that day, and weekly until the ANC is above 1.5 x 109/L (1500/µL) and the platelet count exceeds 100 x 109/L (100,000/µL). The next cycle of temozolomide should not be started until the ANC and platelet count exceed these levels. If the ANC falls to less than 1 x 109/L (1000/µL) or the platelet count is less than 50 x 109/L (50,000/µL) during any cycle, the next cycle should be reduced by 50 mg/m2, but not below 100 mg/m2, the lowest recommended dose (see Table 1 below).

TABLE 1: Dosing Modification Table for Refractory Anaplastic Astrocytoma

150 mg/m2/d x 5d (Starting Dose) or 200 mg/m2/d x 5d				Measure Day 22 ANC and platelets
Measure ANC and platelets on Day 29 (Day 1 of next cycle)
Based on lowest counts at either Day 22 or Day 29
ANC less than 1000/µL or platelets less than 50,000/µL		ANC 1000/µL – 1500/µL or platelets 50,000/µL – 100,000/µL		ANC greater than 1500/µL and platelets greater than 100,000/µL
Postpone therapy until ANC greater than 1500/µL and platelets greater than 100,000/µL; reduce dose by 50 mg/m2/d for subsequent cycle		Postpone therapy until ANC greater than 1500/µL and platelets greater than 100,000/µL; maintain initial dose		Increase dose to, or maintain dose at, 200 mg/m2/d x 5d for subsequent cycle

What is the temozolomide capsules treatment regimen?

Temozolomide is given for 5 consecutive days on a 28-day cycle. Patients should continue taking temozolomide until their physician determines that their disease has progressed, up to 2 years, or until unacceptable side effects or toxicities occur. Physicians may alter the treatment regimen for a given patient.

Newly Diagnosed Concomitant Phase Treatment Schedule

Temozolomide is administered orally at 75 mg/m2 daily for 42 days concomitant with focal radiotherapy (60 Gy administered in 30 fractions), followed by maintenance temozolomide for 6 cycles. No dose reductions are recommended; however, dose interruptions may occur based on patient tolerance. The temozolomide dose can be continued throughout the 42-day concomitant period up to 49 days if all of the following conditions are met: absolute neutrophil count greater than or equal to 1.5 x 109/L, platelet count greater than or equal to 100 x 109/L, common toxicity criteria (CTC) nonhematological toxicity less than or equal to Grade 1 (except for alopecia, nausea and vomiting). During treatment a complete blood count should be obtained weekly. Temozolomide dosing should be interrupted or discontinued during concomitant phase according to the hematological and nonhematological toxicity criteria as noted in Table 2. Pneumocystis carinii pneumonia (PCP) prophylaxis is required during the concomitant administration of temozolomide and radiotherapy, and should be continued in patients who develop lymphocytopenia until recovery from lymphocytopenia (CTC grade less than or equal to 1).

*Treatment with concomitant TMZ could be continued when all of the following conditions were met: absolute neutrophil count greater than or equal to 1.5 x 109/L; platelet count greater than or equal to 100 x 109/L; CTC nonhematological toxicity less than or equal to Grade 1 (except for alopecia, nausea, vomiting). TMZ = temozolomide; CTC = Common Toxicity Criteria.

Maintenance Phase Treatment Schedule

Four weeks after completing the temozolomide + RT phase, temozolomide is administered for an additional 6 cycles of maintenance treatment. Dosage in Cycle 1 (maintenance) is 150 mg/m2 once daily for 5 days followed by 23 days without treatment. At the start of Cycle 2, the dose is escalated to 200 mg/m2, if the CTC nonhematologic toxicity for Cycle 1 is Grade less than or equal to 2 (except for alopecia, nausea and vomiting), absolute neutrophil count (ANC) is greater than or equal to 1.5 x 109/L, and the platelet count is greater than or equal to 100 x 109/L. If the dose was not escalated at Cycle 2, escalation should not be done in subsequent cycles. The dose remains at 200 mg/m2 per day for the first 5 days of each subsequent cycle except if toxicity occurs.

During treatment a complete blood count should be obtained on Day 22 (21 days after the first dose) or within 48 hours of that day, and weekly until the ANC is above 1.5 x 109/L (1500/µL) and the platelet count exceeds 100 x 109/L (100,000/µL). The next cycle of temozolomide capsules should not be started until the ANC and platelet count exceed these levels. Dose reductions during the next cycle should be based on the lowest blood counts and worst nonhematologic toxicity during the previous cycle. Dose reductions or discontinuations during the maintenance phase should be applied according to Tables 3 and 4.

*TMZ dose levels are listed in Table 3.

† TMZ is to be discontinued if dose reduction to less than 100 mg/m2 is required or if the same Grade 3 nonhematological toxicity (except for alopecia, nausea, vomiting) recurs after dose reduction.

TMZ = temozolomide; CTC = Common Toxicity Criteria.

How is temozolomide taken?

Patients should take each day’s dose with a full glass of water at the same time each day. Taking the medication on an empty stomach or at bedtime may help ease nausea. If patients are also taking antinausea or other medications to relieve the side effects associated with temozolomide, they should be advised to take these medications 30 minutes before they take temozolomide. Temozolomide causes the rapid appearance of malignant tumors in rats. Patients SHOULD NOT open or split the capsules. If capsules are accidentally opened or damaged, rigorous precautions should be taken with the capsule contents to avoid inhalation or contact with the skin or mucous membranes. The medication should be kept away from children and pets. The temozolomide capsules should be swallowed whole and NEVER CHEWED.

What should the patient avoid during treatment with temozolomide?

There are no dietary restrictions for patients taking temozolomide. Temozolomide may affect testicular function, so male patients should exercise adequate birth control measures. Temozolomide may cause birth defects. Female patients should avoid becoming pregnant while receiving this drug. Women who are nursing prior to receiving temozolomide should discontinue nursing. It is not known whether temozolomide is excreted into breast milk. Because many drugs are excreted in human milk, and because of the potential for serious adverse reactions in nursing infants and tumorigenicity shown for temozolomide in animal studies, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of temozolomide to the mother.

What are the side effects of temozolomide?

Nausea and vomiting are the most common side effects associated with temozolomide. Noncumulative myelosuppression is the dose-limiting toxicity. Patients should be evaluated periodically by their physician to monitor blood counts.

Other commonly reported side effects reported by patients taking temozolomide are fatigue, constipation, alopecia, anorexia, and headache.

How is temozolomide supplied?

Temozolomide capsules are available in 5-mg, 20-mg, 100-mg, 140-mg, 180-mg, and 250-mg strengths. The capsules contain a white capsule body with a color cap, and the colors vary based on the dosage strength.

The 5-mg, 20-mg, 100-mg, 140-mg, and 180-mg capsule strengths are available in 5-count and 14-count packages. The 250-mg capsule strength is available in a 5-count package.

How is temozolomide dispensed?

Each strength of temozolomide must be dispensed in its original package (one strength per one container). Follow the instructions below:

Based on the dose prescribed, determine the number of each strength of temozolomide capsules needed for the full 42- or 5-day cycle as prescribed by the physician. For example, in a 5-day cycle, 275 mg/day would be dispensed as five 250-mg capsules, five 20-mg capsules and five 5-mg capsules. Label each container with the appropriate number of capsules to be taken each day. Dispense to the patient, making sure each container lists the strength (mg) per capsule and that he or she understands to take the appropriate number of capsules of temozolomide from each package to equal the total daily dose prescribed by the physician.

How can temozolomide be ordered?

Temozolomide can be ordered from your wholesaler. It is important to understand if temozolomide is being used as part of a 42-day regimen or as part of a 5-day course. Remember to order enough temozolomide for the appropriate cycle.

For example:

• a 5-day course of 360 mg/day would require the following to be ordered: two 5-count packages of 180-mg capsules.
• a 42-day course of 140 mg/day would require the following to be ordered: three 14-count packages of 140-mg capsules.

For examples of other dosing regimens, please refer to the full Prescribing Information (Table 6). 

Manufactured by:
Lannett Company, Inc.
Philadelphia, PA 19136

Made in the USA

Rev. 12/2015

10-613