Dose Modifications

Gemcitabine for injection dosage adjustment for hematological toxicity within a cycle of treatment is based on the granulocyte and platelet counts taken on Day 8 of therapy. If marrow suppression is detected, gemcitabine for injection dosage should be modified according to guidelines in Table 1.

In general, for severe (Grade 3 or 4) non-hematological toxicity, except nausea/vomiting, therapy with gemcitabine for injection should be held or decreased by 50% depending on the judgment of the treating physician. For carboplatin dosage adjustment, see manufacturer's prescribing information.

Dose adjustment for gemcitabine for injection in combination with carboplatin for subsequent cycles is based upon observed toxicity. The dose of gemcitabine for injection in subsequent cycles should be reduced to 800 mg/m2 on Days 1 and 8 in case of any of the following hematologic toxicities:

• Absolute granulocyte count <500 x 106/L for more than 5 days
• Absolute granulocyte count <100 x 106/L for more than 3 days
• Febrile neutropenia
• Platelets <25,000 x 106/L
• Cycle delay of more than one week due to toxicity

If any of the above toxicities recur after the initial dose reduction, for the subsequent cycle, gemcitabine for injection should be given on Day 1 only at 800 mg/m2.

Dose Modifications

Gemcitabine for injection dosage adjustment for hematological toxicity is based on the granulocyte and platelet counts taken on Day 8 of therapy. If marrow suppression is detected, gemcitabine for injection dosage should be modified according to the guidelines in Table 2.

In general, for severe (Grade 3 or 4) non-hematological toxicity, except alopecia and nausea/vomiting, therapy with gemcitabine for injection should be held or decreased by 50% depending on the judgment of the treating physician. For paclitaxel dosage adjustment, see manufacturer's prescribing information.

Dose Modifications

Dosage adjustments for hematologic toxicity may be required for gemcitabine for injection and for cisplatin. Gemcitabine for injection dosage adjustment for hematological toxicity is based on the granulocyte and platelet counts taken on the day of therapy. Patients receiving gemcitabine for injection should be monitored prior to each dose with a complete blood count (CBC), including differential and platelet counts. If marrow suppression is detected, therapy should be modified or suspended according to the guidelines in Table 3. For cisplatin dosage adjustment, see manufacturer's prescribing information.

In general, for severe (Grade 3 or 4) non-hematological toxicity, except alopecia and nausea/vomiting, therapy with gemcitabine for injection plus cisplatin should be held or decreased by 50% depending on the judgment of the treating physician. During combination therapy with cisplatin, serum creatinine, serum potassium, serum calcium, and serum magnesium should be carefully monitored (Grade 3/4 serum creatinine toxicity for gemcitabine for injection plus cisplatin was 5% versus 2% for cisplatin alone).

Dose Modifications

Dosage adjustment is based upon the degree of hematologic toxicity experienced by the patient [see Warnings and Precautions (5.2)]. Clearance in women and the elderly is reduced and women were somewhat less able to progress to subsequent cycles [see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)].

Patients receiving gemcitabine for injection should be monitored prior to each dose with a complete blood count (CBC), including differential and platelet count. If marrow suppression is detected, therapy should be modified or suspended according to the guidelines in Table 3.

Laboratory evaluation of renal and hepatic function, including transaminases and serum creatinine, should be performed prior to initiation of therapy and periodically thereafter. Gemcitabine for injection should be administered with caution in patients with evidence of significant renal or hepatic impairment as there is insufficient information from clinical studies to allow clear dose recommendation for these patient populations.

Patients treated with gemcitabine for injection who complete an entire cycle of therapy may have the dose for subsequent cycles increased by 25%, provided that the absolute granulocyte count (AGC) and platelet nadirs exceed 1500 x 106/L and 100,000 x 106/L, respectively, and if non-hematologic toxicity has not been greater than WHO Grade 1. If patients tolerate the subsequent course of gemcitabine for injection at the increased dose, the dose for the next cycle can be further increased by 20%, provided again that the AGC and platelet nadirs exceed 1500 x 106/L and 100,000 x 106/L, respectively, and that non-hematologic toxicity has not been greater than WHO Grade 1.

Non-concurrent (given >7 days apart) — Analysis of the data does not indicate enhanced toxicity when gemcitabine for injection is administered more than 7 days before or after radiation, other than radiation recall. Data suggest that gemcitabine for injection can be started after the acute effects of radiation have resolved or at least one week after radiation.

Concurrent (given together or ≤7 days apart) — Preclinical and clinical studies have shown that gemcitabine for injection has radiosensitizing activity. Toxicity associated with this multimodality therapy is dependent on many different factors, including dose of gemcitabine for injection, frequency of gemcitabine for injection administration, dose of radiation, radiotherapy planning technique, the target tissue, and target volume. In a single trial, where gemcitabine for injection at a dose of 1000 mg/m2 was administered concurrently for up to 6 consecutive weeks with therapeutic thoracic radiation to patients with non-small cell lung cancer, significant toxicity in the form of severe, and potentially life-threatening mucositis, especially esophagitis and pneumonitis was observed, particularly in patients receiving large volumes of radiotherapy [median treatment volumes 4795 cm3]. Subsequent studies have been reported and suggest that gemcitabine for injection administered at lower doses with concurrent radiotherapy has predictable and less severe toxicity. However, the optimum regimen for safe administration of gemcitabine for injection with therapeutic doses of radiation has not yet been determined in all tumor types.

Single-Agent Use:

Myelosuppression is the principal dose-limiting toxicity with gemcitabine for injection therapy. Dosage adjustments for hematologic toxicity are frequently needed [see Dosage and Administration (2.1, 2.2, 2.3, and 2.4)].

The data in Table 4 are based on 979 patients receiving gemcitabine for injection as a single-agent administered weekly as a 30-minute infusion for treatment of a wide variety of malignancies. The gemcitabine for injection starting doses ranged from 800 to 1250 mg/m2. Data are also shown for the subset of patients with pancreatic cancer treated in 5 clinical studies. The frequency of all grades and severe (WHO Grade 3 or 4) adverse reactions were generally similar in the single-agent safety database of 979 patients and the subset of patients with pancreatic cancer. Adverse reactions reported in the single-agent safety database resulted in discontinuation of gemcitabine for injection therapy in about 10% of patients. In the comparative trial in pancreatic cancer, the discontinuation rate for adverse reactions was 14.3% for the gemcitabine for injection arm and 4.8% for the 5-FU arm. All WHO-graded laboratory adverse reactions are listed in Table 4, regardless of causality. Non-laboratory adverse reactions listed in Table 4 or discussed below were those reported, regardless of causality, for at least 10% of all patients, except the categories of Extravasation, Allergic, and Cardiovascular and certain specific adverse reactions under the Renal, Pulmonary, and Infection categories.

Hematologic — In studies in pancreatic cancer myelosuppression is the dose-limiting toxicity with gemcitabine for injection, but <1% of patients discontinued therapy for either anemia, leukopenia, or thrombocytopenia. Red blood cell transfusions were required by 19% of patients. The incidence of sepsis was less than 1%. Petechiae or mild blood loss (hemorrhage), from any cause, was reported in 16% of patients; less than 1% of patients required platelet transfusions. Patients should be monitored for myelosuppression during gemcitabine for injection therapy and dosage modified or suspended according to the degree of hematologic toxicity [see Dosage and Administration (2.1, 2.2, 2.3, and 2.4)].

Gastrointestinal — Nausea and vomiting were commonly reported (69%) but were usually of mild to moderate severity. Severe nausea and vomiting (WHO Grade 3/4) occurred in <15% of patients. Diarrhea was reported by 19% of patients, and stomatitis by 11% of patients.

Hepatic — In clinical trials, gemcitabine for injection was associated with transient elevations of one or both serum transaminases in approximately 70% of patients, but there was no evidence of increasing hepatic toxicity with either longer duration of exposure to gemcitabine for injection or with greater total cumulative dose. Serious hepatotoxicity, including liver failure and death, has been reported very rarely in patients receiving gemcitabine for injection alone or in combination with other potentially hepatotoxic drugs [see Adverse Reactions (6.2)].

Renal — In clinical trials, mild proteinuria and hematuria were commonly reported. Clinical findings consistent with the Hemolytic Uremic Syndrome (HUS) were reported in 6 of 2429 patients (0.25%) receiving gemcitabine for injection in clinical trials. Four patients developed HUS on gemcitabine for injection therapy, 2 immediately posttherapy. The diagnosis of HUS should be considered if the patient develops anemia with evidence of microangiopathic hemolysis, elevation of bilirubin or LDH, reticulocytosis, severe thrombocytopenia, and/or evidence of renal failure (elevation of serum creatinine or BUN). Gemcitabine for injection therapy should be discontinued immediately. Renal failure may not be reversible even with discontinuation of therapy and dialysis may be required [see Adverse Reactions (6.2)].

Fever — The overall incidence of fever was 41%. This is in contrast to the incidence of infection (16%) and indicates that gemcitabine for injection may cause fever in the absence of clinical infection. Fever was frequently associated with other flu-like symptoms and was usually mild and clinically manageable.

Rash — Rash was reported in 30% of patients. The rash was typically a macular or finely granular maculopapular pruritic eruption of mild to moderate severity involving the trunk and extremities. Pruritus was reported for 13% of patients.

Pulmonary — In clinical trials, dyspnea, unrelated to underlying disease, has been reported in association with gemcitabine for injection therapy. Dyspnea was occasionally accompanied by bronchospasm. Pulmonary toxicity has been reported with the use of gemcitabine for injection [see Adverse Reactions (6.2)]. The etiology of these effects is unknown. If such effects develop, gemcitabine for injection should be discontinued. Early use of supportive care measures may help ameliorate these conditions.

Edema — Edema (13%), peripheral edema (20%), and generalized edema (<1%) were reported. Less than 1% of patients discontinued due to edema.

Flu-like Symptoms — “Flu syndrome” was reported for 19% of patients. Individual symptoms of fever, asthenia, anorexia, headache, cough, chills, and myalgia were commonly reported. Fever and asthenia were also reported frequently as isolated symptoms. Insomnia, rhinitis, sweating, and malaise were reported infrequently. Less than 1% of patients discontinued due to flu-like symptoms.

Infection — Infections were reported for 16% of patients. Sepsis was rarely reported (<1%).

Alopecia — Hair loss, usually minimal, was reported by 15% of patients.

Neurotoxicity — There was a 10% incidence of mild paresthesias and a <1% rate of severe paresthesias.

Extravasation — Injection-site related events were reported for 4% of patients. There were no reports of injection site necrosis. Gemcitabine for injection is not a vesicant.

Allergic — Bronchospasm was reported for less than 2% of patients. Anaphylactoid reaction has been reported rarely. Gemcitabine for injection should not be administered to patients with a known hypersensitivity to this drug [see Contraindications (4)].

Cardiovascular — During clinical trials, 2% of patients discontinued therapy with gemcitabine for injection due to cardiovascular events such as myocardial infarction, cerebrovascular accident, arrhythmia, and hypertension. Many of these patients had a prior history of cardiovascular disease [see Adverse Reactions (6.2)].

Combination Use in Non-Small Cell Lung Cancer:

In the gemcitabine for injection plus cisplatin versus cisplatin study, dose adjustments occurred with 35% of gemcitabine for injection injections and 17% of cisplatin injections on the combination arm, versus 6% on the cisplatin-only arm. Dose adjustments were required in greater than 90% of patients on the combination, versus 16% on cisplatin. Study discontinuations for possibly drug-related adverse reactions occurred in 15% of patients on the combination arm and 8% of patients on the cisplatin arm. With a median of 4 cycles of gemcitabine for injection plus cisplatin treatment, 94 of 262 patients (36%) experienced a total of 149 hospitalizations due to possibly treatment-related adverse reactions. With a median of 2 cycles of cisplatin treatment, 61 of 260 patients (23%) experienced 78 hospitalizations due to possibly treatment-related adverse reactions.

In the gemcitabine for injection plus cisplatin versus etoposide plus cisplatin study, dose adjustments occurred with 20% of gemcitabine for injection injections and 16% of cisplatin injections in the gemcitabine for injection plus cisplatin arm compared with 20% of etoposide injections and 15% of cisplatin injections in the etoposide plus cisplatin arm. With a median of 5 cycles of gemcitabine for injection plus cisplatin treatment, 15 of 69 patients (22%) experienced 15 hospitalizations due to possibly treatment-related adverse reactions. With a median of 4 cycles of etoposide plus cisplatin treatment, 18 of 66 patients (27%) experienced 22 hospitalizations due to possibly treatment-related adverse reactions. In patients who completed more than one cycle, dose adjustments were reported in 81% of the gemcitabine for injection plus cisplatin patients, compared with 68% on the etoposide plus cisplatin arm. Study discontinuations for possibly drug-related adverse reactions occurred in 14% of patients on the gemcitabine for injection plus cisplatin arm and in 8% of patients on the etoposide plus cisplatin arm. The incidence of myelosuppression was increased in frequency with gemcitabine for injection plus cisplatin treatment (~90%) compared to that with the gemcitabine for injection monotherapy (~60%). With combination therapy gemcitabine for injection dosage adjustments for hematologic toxicity were required more often while cisplatin dose adjustments were less frequently required.

Table 5 presents the safety data from the gemcitabine for injection plus cisplatin versus cisplatin study in non-small cell lung cancer. The NCI Common Toxicity Criteria (CTC) were used. The two-drug combination was more myelosuppressive with 4 (1.5%) possibly treatment-related deaths, including 3 resulting from myelosuppression with infection and one case of renal failure associated with pancytopenia and infection. No deaths due to treatment were reported on the cisplatin arm. Nine cases of febrile neutropenia were reported on the combination therapy arm compared to 2 on the cisplatin arm. More patients required RBC and platelet transfusions on the gemcitabine for injection plus cisplatin arm.

Myelosuppression occurred more frequently on the combination arm, and in 4 possibly treatment-related deaths myelosuppression was observed. Sepsis was reported in 4% of patients on the gemcitabine for injection plus cisplatin arm compared to 1% on the cisplatin arm. Platelet transfusions were required in 21% of patients on the combination arm and <1% of patients on the cisplatin arm. Hemorrhagic events occurred in 14% of patients on the combination arm and 4% on the cisplatin arm. However, severe hemorrhagic events were rare. Red blood cell transfusions were required in 39% of the patients on the gemcitabine for injection plus cisplatin arm, versus 13% on the cisplatin arm. The data suggest cumulative anemia with continued gemcitabine for injection plus cisplatin use.

Nausea and vomiting despite the use of antiemetics occurred more often with gemcitabine for injection plus cisplatin therapy (78%) than with cisplatin alone (71%). In studies with single-agent gemcitabine for injection, a lower incidence of nausea and vomiting (58% to 69%) was reported. Renal function abnormalities, hypomagnesemia, neuromotor, neurocortical, and neurocerebellar toxicity occurred more often with gemcitabine for injection plus cisplatin than with cisplatin monotherapy. Neurohearing toxicity was similar on both arms.

Cardiac dysrrhythmias of Grade 3 or greater were reported in 7 (3%) patients treated with gemcitabine for injection plus cisplatin compared to one (<1%) Grade 3 dysrrhythmia reported with cisplatin therapy. Hypomagnesemia and hypokalemia were associated with one Grade 4 arrhythmia on the gemcitabine for injection plus cisplatin combination arm.

Table 6 presents data from the randomized study of gemcitabine for injection plus cisplatin versus etoposide plus cisplatin in 135 patients with NSCLC. One death (1.5%) was reported on the gemcitabine for injection plus cisplatin arm due to febrile neutropenia associated with renal failure which was possibly treatment-related. No deaths related to treatment occurred on the etoposide plus cisplatin arm. The overall incidence of Grade 4 neutropenia on the gemcitabine for injection plus cisplatin arm was less than on the etoposide plus cisplatin arm (28% versus 56%). Sepsis was experienced by 2% of patients on both treatment arms. Grade 3 anemia and Grade 3/4 thrombocytopenia were more common on the gemcitabine for injection plus cisplatin arm. RBC transfusions were given to 29% of the patients who received gemcitabine for injection plus cisplatin versus 21% of patients who received etoposide plus cisplatin. Platelet transfusions were given to 3% of the patients who received gemcitabine for injection plus cisplatin versus 8% of patients who received etoposide plus cisplatin. Grade 3/4 nausea and vomiting were also more common on the gemcitabine for injection plus cisplatin arm. On the gemcitabine for injection plus cisplatin arm, 7% of participants were hospitalized due to febrile neutropenia compared to 12% on the etoposide plus cisplatin arm. More than twice as many patients had dose reductions or omissions of a scheduled dose of gemcitabine for injection as compared to etoposide, which may explain the differences in the incidence of neutropenia and febrile neutropenia between treatment arms. Flu syndrome was reported by 3% of patients on the gemcitabine for injection plus cisplatin arm with none reported on the comparator arm. Eight patients (12%) on the gemcitabine for injection plus cisplatin arm reported edema compared to one patient (2%) on the etoposide plus cisplatin arm.

Combination Use in Breast Cancer:

In the gemcitabine for injection plus paclitaxel versus paclitaxel study, dose reductions occurred with 8% of gemcitabine for injection injections and 5% of paclitaxel injections on the combination arm, versus 2% on the paclitaxel arm. On the combination arm, 7% of gemcitabine for injection doses were omitted and <1% of paclitaxel doses were omitted, compared to <1% of paclitaxel doses on the paclitaxel arm. A total of 18 patients (7%) on the gemcitabine for injection plus paclitaxel arm and 12 (5%) on the paclitaxel arm discontinued the study because of adverse reactions. There were two deaths on study or within 30 days after study drug discontinuation that were possibly drug-related, one on each arm.

Table 7 presents the safety data occurrences of ≥10% (all grades) from the gemcitabine for injection plus paclitaxel versus paclitaxel study in breast cancer.

The following are the clinically relevant adverse reactions that occurred in >1% and <10% (all grades) of patients on either arm. In parentheses are the incidences of Grade 3 and 4 adverse reactions (gemcitabine for injection plus paclitaxel versus paclitaxel): febrile neutropenia (5.0% versus 1.2%), infection (0.8% versus 0.8%), dyspnea (1.9% versus 0), and allergic reaction/hypersensitivity (0 versus 0.8%).

No differences in the incidence of laboratory and non-laboratory events were observed in patients 65 years or older, as compared to patients younger than 65.

Combination Use in Ovarian Cancer:

In the gemcitabine for injection plus carboplatin versus carboplatin study, dose reductions occurred with 10.4% of gemcitabine for injection injections and 1.8% of carboplatin injections on the combination arm, versus 3.8% on the carboplatin alone arm. On the combination arm, 13.7% of gemcitabine for injection doses were omitted and 0.2% of carboplatin doses were omitted, compared to 0% of carboplatin doses on the carboplatin alone arm. There were no differences in discontinuations due to adverse reactions between arms (10.9% versus 9.8%, respectively).

Table 8 presents the adverse reactions (all grades) occurring in ≥10% of patients in the ovarian cancer study.

In addition to blood product transfusions as listed in Table 8, myelosuppression was also managed with hematopoietic agents. These agents were administered more frequently with combination therapy than with monotherapy (granulocyte growth factors: 23.6% and 10.1%, respectively; erythropoietic agents: 7.3% and 3.9%, respectively).

The following are the clinically relevant adverse reactions, regardless of causality, that occurred in >1% and <10% (all grades) of patients on either arm. In parentheses are the incidences of Grade 3 and 4 adverse reactions (gemcitabine for injection plus carboplatin versus carboplatin): AST or ALT elevation (0 versus 1.2%), dyspnea (3.4% versus 2.9%), febrile neutropenia (1.1% versus 0), hemorrhagic event (2.3% versus 1.1%), hypersensitivity reaction (2.3% versus 2.9%), motor neuropathy (1.1% versus 0.6%), and rash/desquamation (0.6% versus 0).

No differences in the incidence of laboratory and non-laboratory events were observed in patients 65 years or older, as compared to patients younger than 65.

Cardiovascular — Congestive heart failure and myocardial infarction have been reported very rarely with the use of gemcitabine for injection. Arrhythmias, predominantly supraventricular in nature, have been reported very rarely.

Vascular Disorders — Clinical signs of peripheral vasculitis and gangrene have been reported very rarely.

Skin — Cellulitis and non-serious injection site reactions in the absence of extravasation have been rarely reported. Severe skin reactions, including desquamation and bullous skin eruptions, have been reported very rarely.

Hepatic — Increased liver function tests including elevations in aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT), alkaline phosphatase, and bilirubin levels have been reported rarely. Serious hepatotoxicity including liver failure and death has been reported very rarely in patients receiving gemcitabine for injection alone or in combination with other potentially hepatotoxic drugs. Hepatic veno-occlusive disease has been reported.

Pulmonary — Parenchymal toxicity, including interstitial pneumonitis, pulmonary fibrosis, pulmonary edema, and adult respiratory distress syndrome (ARDS), has been reported rarely following one or more doses of gemcitabine for injection administered to patients with various malignancies. Some patients experienced the onset of pulmonary symptoms up to 2 weeks after the last gemcitabine for injection dose. Respiratory failure and death occurred very rarely in some patients despite discontinuation of therapy.

Renal — Hemolytic Uremic Syndrome (HUS) and/or renal failure have been reported following one or more doses of gemcitabine for injection. Renal failure leading to death or requiring dialysis, despite discontinuation of therapy, has been rarely reported. The majority of the cases of renal failure leading to death were due to HUS.

Injury, Poisoning, and Procedural Complications — Radiation recall reactions have been reported [see Warnings and Precautions (5.8)].

Pregnancy Category D. See 'Warnings and Precautions' section.

Gemcitabine for injection can cause fetal harm when administered to a pregnant woman. Based on its mechanism of action, gemcitabine for injection is expected to result in adverse reproductive effects. There are no adequate and well-controlled studies of gemcitabine for injection in pregnant women. Gemcitabine is embryotoxic causing fetal malformations (cleft palate, incomplete ossification) at doses of 1.5 mg/kg/day in mice (about 1/200 the recommended human dose on a mg/m2 basis). Gemcitabine is fetotoxic causing fetal malformations (fused pulmonary artery, absence of gall bladder) at doses of 0.1 mg/kg/day in rabbits (about 1/600 the recommended human dose on a mg/m2 basis). Embryotoxicity was characterized by decreased fetal viability, reduced live litter sizes, and developmental delays. 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 the fetus [see Warnings and Precautions (5.6)].

Absorption and Distribution

The pharmacokinetics of gemcitabine were examined in 353 patients, with various solid tumors. Pharmacokinetic parameters were derived using data from patients treated for varying durations of therapy given weekly with periodic rest weeks and using both short infusions (<70 minutes) and long infusions (70 to 285 minutes). The total gemcitabine for injection dose varied from 500 to 3600 mg/m2.

The volume of distribution was increased with infusion length. Volume of distribution of gemcitabine was 50 L/m2 following infusions lasting <70 minutes. For long infusions, the volume of distribution rose to 370 L/m2.

Gemcitabine pharmacokinetics are linear and are described by a 2-compartment model. Population pharmacokinetic analyses of combined single and multiple dose studies showed that the volume of distribution of gemcitabine was significantly influenced by duration of infusion and gender. Gemcitabine plasma protein binding is negligible.

Metabolism

Gemcitabine disposition was studied in 5 patients who received a single 1000 mg/m2/30 minute infusion of radiolabeled drug. Within one (1) week, 92% to 98% of the dose was recovered, almost entirely in the urine. Gemcitabine (<10%) and the inactive uracil metabolite, 2′-deoxy-2′,2′-difluorouridine (dFdU), accounted for 99% of the excreted dose. The metabolite dFdU is also found in plasma.

The active metabolite, gemcitabine triphosphate, can be extracted from peripheral blood mononuclear cells. The half-life of the terminal phase for gemcitabine triphosphate from mononuclear cells ranges from 1.7 to 19.4 hours.

Excretion

Clearance of gemcitabine was affected by age and gender. The lower clearance in women and the elderly results in higher concentrations of gemcitabine for any given dose. Differences in either clearance or volume of distribution based on patient characteristics or the duration of infusion result in changes in half-life and plasma concentrations. Table 9 shows plasma clearance and half-life of gemcitabine following short infusions for typical patients by age and gender.

Gemcitabine half-life for short infusions ranged from 42 to 94 minutes, and the value for long infusions varied from 245 to 638 minutes, depending on age and gender, reflecting a greatly increased volume of distribution with longer infusions.

Drug Interactions

When gemcitabine for injection (1250 mg/m2 on Days 1 and 8) and cisplatin (75 mg/m2 on Day 1) were administered in NSCLC patients, the clearance of gemcitabine on Day 1 was 128 L/hr/m2 and on Day 8 was 107 L/hr/m2. The clearance of cisplatin in the same study was reported to be 3.94 mL/min/m2 with a corresponding half-life of 134 hours [see Drug Interactions (7)]. Analysis of data from metastatic breast cancer patients shows that, on average, gemcitabine for injection has little or no effect on the pharmacokinetics (clearance and half-life) of paclitaxel and paclitaxel has little or no effect on the pharmacokinetics of gemcitabine for injection. Data from NSCLC patients demonstrate that gemcitabine for injection and carboplatin given in combination does not alter the pharmacokinetics of gemcitabine for injection or carboplatin compared to administration of either single-agent. However, due to wide confidence intervals and small sample size, interpatient variability may be observed.

Gemcitabine for injection plus cisplatin versus cisplatin: This study was conducted in Europe, the US, and Canada in 522 patients with inoperable Stage IIIA, IIIB, or IV NSCLC who had not received prior chemotherapy. Gemcitabine for injection 1000 mg/m2 was administered on Days 1, 8, and 15 of a 28-day cycle with cisplatin 100 mg/m2 administered on Day 1 of each cycle. Single-agent cisplatin 100 mg/m2 was administered on Day 1 of each 28-day cycle. The primary endpoint was survival. Patient demographics are shown in Table 13. An imbalance with regard to histology was observed with 48% of patients on the cisplatin arm and 37% of patients on the gemcitabine for injection plus cisplatin arm having adenocarcinoma.

The Kaplan-Meier survival curve is shown in Figure 3. Median survival time on the gemcitabine for injection plus cisplatin arm was 9.0 months compared to 7.6 months on the single-agent cisplatin arm (Log rank p=0.008, two-sided). Median time to disease progression was 5.2 months on the gemcitabine for injection plus cisplatin arm compared to 3.7 months on the cisplatin arm (Log rank p=0.009, two-sided). The objective response rate on the gemcitabine for injection plus cisplatin arm was 26% compared to 10% with cisplatin (Fisher's Exact p<0.0001, two-sided). No difference between treatment arms with regard to duration of response was observed.

Gemcitabine for injection plus cisplatin versus etoposide plus cisplatin: A second, multicenter, study in Stage IIIB or IV NSCLC randomized 135 patients to gemcitabine for injection 1250 mg/m2 on Days 1 and 8, and cisplatin 100 mg/m2 on Day 1 of a 21-day cycle or to etoposide 100 mg/m2 intravenous on Days 1, 2, and 3 and cisplatin 100 mg/m2 on Day 1 of a 21-day cycle (Table 13).

There was no significant difference in survival between the two treatment arms (Log rank p=0.18, two-sided). The median survival was 8.7 months for the gemcitabine for injection plus cisplatin arm versus 7.0 months for the etoposide plus cisplatin arm. Median time to disease progression for the gemcitabine for injection plus cisplatin arm was 5.0 months compared to 4.1 months on the etoposide plus cisplatin arm (Log rank p=0.015, two-sided). The objective response rate for the gemcitabine for injection plus cisplatin arm was 33% compared to 14% on the etoposide plus cisplatin arm (Fisher's Exact p=0.01, two-sided).