Components:
Method of action:
Treatment option:
Medically reviewed by Oliinyk Elizabeth Ivanovna, PharmD. Last updated on 04.04.2022
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Gemcitabine is indicated for the treatment of locally advanced or metastatic bladder cancer in combination with cisplatin.
Gemcitabine is indicated for treatment of patients with locally advanced or metastatic adenocarcinoma of the pancreas.
Gemcitabine, in combination with cisplatin, is indicated as first-line treatment of patients with locally advanced or metastatic non-small cell lung cancer (NSCLC). Gemcitabine monotherapy can be considered in elderly patients or those with performance status 2.
Gemcitabine is indicated for the treatment of patients with locally advanced or metastatic epithelial ovarian carcinoma, in combination with carboplatin, in patients with relapsed disease following a recurrence-free interval of at least 6 months after platinum-based, first-line therapy.
Gemcitabine, in combination with paclitaxel, is indicated for the treatment of patients with unresectable, locally recurrent or metastatic breast cancer who have relapsed following adjuvant/neoadjuvant chemotherapy. Prior chemotherapy should have included an anthracycline unless clinically contraindicated.
Gemcitabine should only be prescribed by a physician qualified in the use of anti-cancer chemotherapy.
Recommended posology:
Bladder cancer
Combination use
The recommended dose for gemcitabine is 1,000 mg/m2, given by 30-minute infusion. The dose should be given on Days 1, 8 and 15 of each 28-day cycle in combination with cisplatin. Cisplatin is given at a recommended dose of 70 mg/m2 on Day 1 following gemcitabine or Day 2 of each 28-day cycle. This 4-week cycle is then repeated. Dosage reduction with each cycle or within a cycle may be applied based upon the grade of toxicity experienced by the patient.
Pancreatic cancer
The recommended dose of gemcitabine is 1,000 mg/m2, given by 30-minute intravenous infusion. This should be repeated once weekly for up to 7 weeks followed by a week of rest. Subsequent cycles should consist of injections once weekly for 3 consecutive weeks out of every 4 weeks. Dosage reduction with each cycle or within a cycle may be applied based upon the grade of toxicity experienced by the patient.
Non-small cell lung cancer
Monotherapy
The recommended dose of gemcitabine is 1,000 mg/m2, given by 30-minute intravenous infusion. This should be repeated once weekly for 3 weeks, followed by a 1-week rest period. This 4-week cycle is then repeated. Dosage reduction with each cycle or within a cycle may be applied based upon the grade of toxicity experienced by the patient.
Combination use
The recommended dose for gemcitabine is 1,250 mg/m2 body surface area given as a 30-minute intravenous infusion on Days 1 and 8 of the treatment cycle (21 days). Dosage reduction with each cycle or within a cycle may be applied based upon the grade of toxicity experienced by the patient.
Cisplatin has been used at doses between 75-100 mg/m2 once every 3 weeks.
Breast cancer
Combination use
Gemcitabine, in combination with paclitaxel, is recommended using paclitaxel (175 mg/m2) administered on Day 1 over approximately 3 hours as an intravenous infusion, followed by gemcitabine (1,250 mg/m2) as a 30-minute intravenous infusion on Days 1 and 8 of each 21-day cycle. Dose reduction with each cycle or within a cycle may be applied based upon the grade of toxicity experienced by the patient. Patients should have an absolute granulocyte count of at least 1,500 (x 106/l) prior to initiation of gemcitabine + paclitaxel combination.
Ovarian cancer
Combination use
Gemcitabine, in combination with carboplatin, is recommended using gemcitabine 1,000 mg/m2 administered on Days 1 and 8 of each 21-day cycle as a 30-minute intravenous infusion. After gemcitabine, carboplatin will be given on Day 1 consistent with a target area under curve (AUC) of 4.0 mg/ ml-min. Dosage reduction with each cycle or within a cycle may be applied based upon the grade of toxicity experienced by the patient.
Monitoring for toxicity and dose modification due to toxicity
Dose modification due to non-haematological toxicity
Periodic physical examination and checks of renal and hepatic function should be made to detect non-haematological toxicity. Dosage reduction with each cycle or within a cycle may be applied based upon the grade of toxicity experienced by the patient. In general, for severe (Grade 3 or 4) non-haematological toxicity, except nausea/vomiting, therapy with gemcitabine should be withheld or decreased depending on the judgement of the treating physician. Doses should be withheld until toxicity has resolved, in the opinion of the physician.
For cisplatin, carboplatin, and paclitaxel dosage adjustment in combination therapy, please refer to the corresponding Summary of Product Characteristics.
Dose modification due to haematological toxicity
Initiation of a cycle
For all indications, the patient must be monitored before each dose for platelet and granulocyte counts. Patients should have an absolute granulocyte count of at least 1,500 (x 106/l) and platelet count of 100,000 (x 106/l) prior to the initiation of a cycle.
Within a cycle
Dose modifications of gemcitabine within a cycle should be performed according to the following tables:
Dose modification of gemcitabine within a cycle for bladder cancer, NSCLC and pancreatic cancer, given in monotherapy or in combination with cisplatin | |||
Absolute granulocyte count (x 106/l) | Platelet count (x 106/l) | Percentage of standard dose of Demozar (%) | |
> 1,000 | and | > 100,000 | 100 |
500-1,000 | or | 50,000-100,000 | 75 |
< 500 | or | < 50,000 | Omit dose * |
*Treatment omitted will not be reinstated within a cycle before the absolute granulocyte count reaches at least 500 (x106/l) and the platelet count reaches 50,000 (x106/l).
Dose modification of gemcitabine within a cycle for breast cancer, given in combination with paclitaxel | |||
Absolute granulocyte count (x 106/l) | Platelet count (x 106/l) | Percentage of standard dose of Demozar (%) | |
> 1,200 | and | > 75,000 | 100 |
1,000- < 1,200 | or | 50,000-75,000 | 75 |
700- < 1,000 | and | > 50,000 | 50 |
< 700 | or | < 50,000 | Omit dose* |
*Treatment omitted will not be reinstated within a cycle. Treatment will start on Day 1 of the next cycle once the absolute granulocyte count reaches at least 1,500 (x106/l) and the platelet count reaches 100,000 (x106/l).
Dose modification of gemcitabine within a cycle for ovarian cancer, given in combination with carboplatin | |||
Absolute granulocyte count (x 106/l) | Platelet count (x 106/l) | Percentage of standard dose of Demozar (%) | |
> 1,500 | and | > 100,000 | 100 |
1,000-1,500 | or | 75,000-100,000 | 50 |
< 1,000 | or | < 75,000 | Omit dose* |
*Treatment omitted will not be reinstated within a cycle. Treatment will start on Day 1 of the next cycle once the absolute granulocyte count reaches at least 1,500 (x106/l) and the platelet count reaches 100,000 (x106/l).
Dose modifications due to haematological toxicity in subsequent cycles, for all indications
The gemcitabine dose should be reduced to 75% of the original cycle initiation dose, in the case of the following haematological 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 1 week due to toxicity
Method of administration
Demozar is tolerated well during infusion and may be administered ambulant. If extravasation occurs, generally the infusion must be stopped immediately and started again in another blood vessel. The patient should be monitored carefully after the administration.
Special populations
Patients with renal or hepatic impairment
Gemcitabine should be used with caution in patients with hepatic or renal impairment as there is insufficient information from clinical studies to allow for clear dose recommendations for these patient populations.
Older people (> 65 years)
Gemcitabine has been well tolerated in patients over the age of 65. There is no evidence to suggest that dose adjustments, other than those already recommended for all patients, are necessary in older people (see section 5.2).
Paediatric population (< 18 years)
Gemcitabine is not recommended for use in children under 18 years of age due to insufficient data on safety and efficacy.
Hypersensitivity to the active substance or to any of the excipients.
Breast-feeding.
Prolongation of the infusion time and increased dosing frequency have been shown to increase toxicity.
Haematological toxicity
Gemcitabine can suppress bone marrow function as manifested by leucopenia, thrombocytopenia and anaemia.
Patients receiving gemcitabine should be monitored prior to each dose for platelet, leucocyte and granulocyte counts. Suspension or modification of therapy should be considered when drug-induced bone marrow depression is detected. However, myelosuppression is short-lived and usually does not result in dose reduction and rarely in discontinuation.
Peripheral blood counts may continue to deteriorate after gemcitabine administration has been stopped. In patients with impaired bone marrow function, the treatment should be started with caution. As with other cytotoxic treatments, the risk of cumulative bone-marrow suppression must be considered when gemcitabine treatment is given together with other chemotherapy.
Hepatic and renal impairment
Gemcitabine should be used with caution in patients with hepatic or renal function impairment as there is insufficient information from clinical studies to allow clear dose recommendation for this patient population.
Administration of gemcitabine in patients with concurrent liver metastases or a pre-existing medical history of hepatitis, alcoholism or liver cirrhosis may lead to exacerbation of the underlying hepatic impairment.
Laboratory evaluation of renal and hepatic function (including virological tests) should be performed periodically.
Concomitant radiotherapy
Live vaccinations
Yellow fever vaccine and other live attenuated vaccines are not recommended in patients treated with gemcitabine.
Posterior reversible encephalopathy syndrome
Reports of posterior reversible encephalopathy syndrome (PRES) with potentially severe consequences have been reported in patients receiving gemcitabine as single agent or in combination with other chemotherapeutic agents. Acute hypertension and seizure activity were reported in most gemcitabine patients experiencing PRES, but other symptoms such as headache, lethargy, confusion and blindness could also be present. Diagnosis is optimally confirmed by magnetic resonance imaging (MRI). PRES was typically reversible with appropriate supportive measures. Gemcitabine should be permanently discontinued and supportive measures implemented, including blood pressure control and anti-seizure therapy, if PRES develops during therapy.
Cardiovascular
Due to the risk of cardiac and/or vascular disorders with gemcitabine, particular caution must be exercised with patients presenting a history of cardiovascular events.
Capillary leak syndrome
Capillary leak syndrome has been reported in patients receiving gemcitabine as single agent or in combination with other chemotherapeutic agents. The condition is usually treatable if recognised early and managed appropriately, but fatal cases have been reported. The condition involves systemic capillary hyperpermeability during which fluid and proteins from the intravascular space leak into the interstitium. The clinical features include generalised oedema, weight gain, hypoalbuminaemia, severe hypotension, acute renal impairment and pulmonary oedema. Gemcitabine should be discontinued and supportive measures implemented if capillary leak syndrome develops during therapy. Capillary leak syndrome can occur in later cycles and has been associated in the literature with adult respiratory distress syndrome.
Pulmonary
Pulmonary effects, sometimes severe (such as pulmonary oedema, interstitial pneumonitis or adult respiratory distress syndrome (ARDS)) have been reported in association with gemcitabine therapy. If such effects develop, consideration should be made to discontinuing gemcitabine therapy. Early use of supportive care measure may help ameliorate the condition.
Renal
Haemolytic uraemic syndrome
Clinical findings consistent with the haemolytic uraemic syndrome (HUS) were rarely reported (post-marketing data)in patients receiving gemcitabine. HUS is a potentially life-threatening disorder. Gemcitabine should be discontinued at the first signs of any evidence of microangiopathic haemolytic anaemia, such as rapidly falling haemoglobin with concomitant thrombocytopenia, elevation of serum bilirubin, serum creatinine, blood urea nitrogen, or LDH. Renal failure may not be reversible with discontinuation of therapy and dialysis may be required.
Fertility
In fertility studies, gemcitabine caused hypospermatogenesis in male mice. Therefore, men being treated with gemcitabine are advised not to father a child during and up to 6 months after treatment and to seek further advice regarding cryoconservation of sperm prior to treatment because of the possibility of infertility due to therapy with gemcitabine.
Sodium
Demozar 200 mg contains 3.5 mg (<1 mmol) sodium per vial, i.e., essentially sodium free.
Demozar 1000 mg contains 17.5 mg (<1 mmol) sodium per vial, i.e., essentially sodium free.
No studies on the effects on the ability to drive and use machines have been performed. However, gemcitabine has been reported to cause mild to moderate somnolence, especially in combination with alcohol consumption. Patients should be cautioned against driving or operating machinery until it is established that they do not become somnolent.
The most commonly reported adverse drug reactions associated with Demozar treatment include: nausea with or without vomiting, raised liver transaminases (AST/ALT) and alkaline phosphatase, reported in approximately 60% of patients; proteinuria and haematuria reported in approximately 50% of patients; dyspnoea reported in 10-40% of patients (highest incidence in lung cancer patients); allergic skin rashes occur in approximately 25% of patients and are associated with itching in 10% of patients.
The frequency and severity of the adverse reactions are affected by the dose, infusion rate and intervals between doses. Dose-limiting adverse reactions are reductions in thrombocyte, leucocyte and granulocyte counts.
Clinical trial data
Frequencies are defined as: Very common (>1/10), Common (>1/100 to <1/10), Uncommon (>1/1,000 to <1/100), Rare (>1/10,000 to <1/1,000), Very Rare (<1/10,000).
The following table of undesirable effects and frequencies is based on data from clinical trials. Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness.
System Organ Class | Frequency grouping |
Blood and lymphatic system disorders | Very common - Leucopenia (Neutropenia Grade 3 = 19.3 %; Grade 4 = 6 %). Bone-marrow suppression is usually mild to moderate and mostly affects the granulocyte count - Thrombocytopenia - Anaemia Common - Febrile neutropenia Very rare - Thrombocytosis |
Immune system disorders | Very Rare - Anaphylactoid reaction |
Metabolism and nutrition disorders | Common - Anorexia |
Nervous system disorders | Common - Headache - Insomnia - Somnolence Uncommon - Cerebrovascular accident Very rare - Posterior reversible encephalopathy syndrome |
Cardiac disorders | Uncommon - Arrhythmias, predominantly supraventricular in nature - Heart failure Rare - Myocardial infarct |
Vascular disorders | Rare - Clinical signs of peripheral vasculitis and gangrene - Hypotension Very rare - Capillary leak syndrome |
Respiratory, thoracic and mediastinal disorders | Very common - Dyspnoea -usually mild and passes rapidly without treatment Common - Cough - Rhinitis Uncommon - Interstitial pneumonitis - Bronchospasm -usually mild and transient but may require parenteral treatment Rare - Pulmonary oedema - Adult respiratory distress syndrome |
Gastrointestinal disorders | Very common - Vomiting - Nausea Common - Diarrhoea - Stomatitis and ulceration of the mouth - Constipation Very rare - Ischaemic colitis |
Hepatobiliary disorders | Very common - Elevation of liver transaminases (AST and ALT) and alkaline phosphatase Common - Increased bilirubin Uncommon - Serious hepatotoxicity, including liver failure and death Rare - Increased gamma-glutamyl transferase (GGT) |
Skin and subcutaneous tissue disorders | Very common - Allergic skin rash frequently associated with pruritus - Alopecia Common - Itching - Sweating Rare - Severe skin reactions, including desquamation and bullous skin eruptions - Ulceration - Vesicle and sore formation - Scaling Very rare - Toxic epidermal necrolysis - Stevens-Johnson Syndrome |
Musculoskeletal and connective tissue disorders | Common - Back pain - Myalgia |
Renal and urinary disorders | Very common - Haematuria - Mild proteinuria Uncommon - Renal failure - Haemolytic uraemic syndrome |
General disorders and administration site conditions | Very common - Influenza-like symptoms - the most common symptoms are fever, headache, chills, myalgia, asthenia and anorexia. Cough, rhinitis, malaise, perspiration and sleeping difficulties have also been reported. - Oedema/peripheral oedema-including facial oedema. Oedema is usually reversible after stopping treatment. Common - Fever - Asthenia - Chills Rare - Injection site reactions - mainly mild in nature |
| Injury, poisoning, and procedural complications | Rare - Radiation toxicity - Radiation recall |
Combination use in breast cancer
The frequency of Grade 3 and 4 haematological toxicities, particularly neutropenia, increases when gemcitabine is used in combination with paclitaxel. However, the increase in these adverse reactions is not associated with an increased incidence of infections or haemorrhagic events. Fatigue and febrile neutropenia occur more frequently when gemcitabine is used in combination with paclitaxel. Fatigue, which is not associated with anaemia, usually resolves after the first cycle.
| Grade 3 and 4 Adverse Events Paclitaxel versus Gemcitabine plus paclitaxel | ||||
Number (%) of Patients | ||||
| Paclitaxel arm (N=259) | Gemcitabine plus paclitaxel arm (N=262) | |||
| Grade 3 | Grade 4 | Grade 3 | Grade 4 | |
| Laboratory | ||||
| Anaemia | 5 (1.9) | 1 (0.4) | 15 (5.7) | 3 (1.1) |
| Thrombocytopenia | 0 | 0 | 14 (5.3) | 1 (0.4) |
| Neutropenia | 11 (4.2) | 17 (6.6)* | 82 (31.3) | 45 (17.2)* |
| Non-laboratory | ||||
| Febrile neutropenia | 3 (1.2) | 0 | 12 (4.6) | 1(0.4) |
| Fatigue | 3 (1.2) | 1 (0.4) | 15 (5.7) | 2 (0.8) |
| Diarrhoea | 5 (1.9) | 0 | 8 (3.1) | 0 |
| Motor neuropathy | 2(0.8) | 0 | 6(2.3) | 1(0.4) |
| Sensory neuropathy | 9(3.5) | 0 | 14(5.3) | 1(0.4) |
*Grade 4 neutropenia lasting for more than 7 days occurred in 12.6% of patients in the combination arm and 5.0% of patients in the paclitaxel arm.
Combination use in bladder cancer
| Grade 3 and 4 Adverse Events MVAC versus Gemcitabine plus cisplatin | ||||
| Number (%) of Patients | ||||
| MVAC (methotrexate, vinblastine, doxorubicin and cisplatin) arm (N=196) | Gemcitabine plus cisplatin arm (N=200) | |||
| Grade 3 | Grade 4 | Grade 3 | Grade 4 | |
| Laboratory | ||||
| Anaemia | 30(16) | 4(2) | 47(24) | 7(4) |
| Thrombocytopenia | 15(8) | 25(13) | 57(29) | 57(29) |
| Non-laboratory | ||||
| Nausea and vomiting | 37(19) | 3(2) | 44(22) | 0(0) |
| Diarrhoea | 15(8) | 1(1) | 6(3) | 0(0) |
| Infection | 19(10) | 10(5) | 4(2) | 1(1) |
| Stomatitis | 34(18) | 8(4) | 2(1) | 0(0) |
Combination use in ovarian cancer
| Grade 3 and 4 Adverse Events Carboplatin versus Gemcitabine plus carboplatin | ||||
| Number (%) of Patients | ||||
| Carboplatin arm (N=174) | Gemcitabine plus carboplatin arm (N=175) | |||
| Grade 3 | Grade 4 | Grade 3 | Grade 4 | |
| Laboratory | ||||
| Anaemia | 10(5.7) | 4(2.3) | 39(22.3) | 9(5.1) |
| Neutropenia | 19(10.9) | 2(1.1) | 73(41.7) | 50(28.6) |
| Thrombocytopenia | 18(10.3) | 2(1.1) | 53(30.3) | 8(4.6) |
| Leucopenia | 11(6.3) | 1(0.6) | 84(48.0) | 9(5.1) |
| Non-laboratory | ||||
| Haemorrhage | 0(0.0) | 0(0.0) | 3(1.8) | (0.0) |
| Febrile neutropenia | 0(0.0) | 0(0.0) | 2(1.1) | (0.0) |
| Infection without neutropenia | 0(0) | 0(0.0) | (0.0) | 1(0.6) |
Sensory neuropathy was also more frequent in the combination arm than with single-agent carboplatin.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the
Yellow Card Scheme, www.mhra.gov.uk/yellowcard
There is no known antidote for overdose of gemcitabine. Doses as high as 5,700 mg/m2 have been administered by intravenous infusion over 30 minutes every 2 weeks with clinically acceptable toxicity. In the event of suspected overdose, the patient should be monitored with appropriate blood counts and receive supportive therapy, as necessary.
Pharmacotherapeutic group: Pyrimidine analogues. ATC code: L01BC05
Cytotoxic activity in cell cultures
Gemcitabine shows significant cytotoxic effects against a variety of cultured murine and human tumour cells. Its action is phase-specific such that gemcitabine primarily kills cells that are undergoing DNA synthesis (S-phase) and, under certain circumstances, blocks the progression of cells at the junction of the G1/S phase boundary. In vitro, the cytotoxic effect of gemcitabine is dependent on both concentration and time.
Anti-tumoural activity in preclinical models
In animal tumour models, anti-tumoural activity of gemcitabine is schedule-dependent. When gemcitabine is administered daily, high mortality among the animals, but minimal anti-tumoural activity, is observed. If, however, gemcitabine is given every third or fourth day, it can be administered in non-lethal doses with substantial anti-tumoural activity against a broad spectrum of mouse tumours.
Mechanism of action
Cellular metabolism and mechanism of action: Gemcitabine (dFdC), which is a pyrimidine antimetabolite, is metabolised intracellularly by nucleoside kinase to the active diphosphate (dFdCDP) and triphosphate (dFdCTP) nucleosides. The cytotoxic effect of gemcitabine is due to inhibition of DNA synthesis by two mechanisms of action by dFdCDP and dFdCTP. First, dFdCDP inhibits ribonucleotide reductase, which is uniquely responsible for catalysing the reactions that produce deoxynucleoside triphosphates (dCTP) for DNA synthesis. Inhibition of this enzyme by dFdCDP reduces the concentration of deoxynucleosides in general and, in particular, dCTP. Second, dFdCTP competes with dCTP for incorporation into DNA (self-potentiation).
Likewise, a small amount of gemcitabine may also be incorporated into RNA. Thus, the reduced intracellular concentration of dCTP potentiates the incorporation of dFdCTP into DNA. DNA polymerase epsilon lacks the ability to eliminate gemcitabine and to repair the growing DNA strands. After gemcitabine is incorporated into DNA, one additional nucleotide is added to the growing DNA strands. After this addition there is essentially a complete inhibition in further DNA synthesis (masked chain termination). After incorporation into DNA, gemcitabine appears to induce the programmed cell death process known as apoptosis.
Clinical data
Bladder cancer
A randomised phase III study of 405 patients with advanced or metastatic urothelial transitional cell carcinoma showed no difference between the two treatment arms, gemcitabine/cisplatin versus methotrexate/vinblastine/adriamycin/cisplatin (MVAC), in terms of median survival (12.8 and 14.8 months respectively, p=0.547), time to disease progression (7.4 and 7.6 months respectively, p=0.842) and response rate (49.4% and 45.7% respectively, p=0.512). However, the combination of gemcitabine and cisplatin had a better toxicity profile than MVAC.
Pancreatic cancer
In a randomised phase III study of 126 patients with advanced or metastatic pancreatic cancer, gemcitabine showed a statistically significant higher clinical benefit response rate than 5-fluorouracil (23.8% and 4.8% respectively, p=0.0022). Also, a statistically significant prolongation of the time to progression from 0.9 to 2.3 months (log-rank p<0.0002) and a statistically significant prolongation of median survival from 4.4 to 5.7 months (log-rank p<0.0024) was observed in patients treated with gemcitabine compared to patients treated with 5-fluorouracil.
Non-small cell lung cancer
In a randomised phase III study of 522 patients with inoperable, locally advanced or metastatic NSCLC, gemcitabine in combination with cisplatin showed a statistically significant higher response rate than cisplatin alone (31.0% and 12.0%, respectively, p<0.0001). A statistically significant prolongation of the time to progression, from 3.7 to 5.6 months (log-rank p<0.0012) and a statistically significant prolongation of median survival from 7.6 months to 9.1 months (log-rank p<0.004) was observed in patients treated with gemcitabine/cisplatin compared to patients treated with cisplatin.
In another randomised phase III study of 135 patients with stage IIIB or IV NSCLC, a combination of gemcitabine and cisplatin showed a statistically significant higher response rate than a combination of cisplatin and etoposide (40.6% and 21.2%, respectively, p=0.025). A statistically significant prolongation of the time to progression, from 4.3 to 6.9 months (p=0.014) was observed in patients treated with gemcitabine/cisplatin compared to patients treated with etoposide/cisplatin. In both studies it was found that tolerability was similar in the two treatment arms.
Ovarian carcinoma
In a randomised phase III study, 356 patients with advanced epithelial ovarian carcinoma who had relapsed at least 6 months after completing platinum-based therapy were randomised to therapy with gemcitabine and carboplatin (GCb), or carboplatin (Cb). A statistically significant prolongation of the time to progression of disease, from 5.8 to 8.6 months (log-rank p=0.0038) was observed in the patients treated with GCb compared to patients treated with Cb. Differences in response rate of 47.2% in the GCb arm versus 30.9% in the Cb arm (p=0.0016) and median survival 18 months (GCb) versus 17.3 (Cb) (p=0.73) favoured the GCb arm.
Breast cancer
In a randomised phase III study of 529 patients with inoperable, locally recurrent or metastatic breast cancer with relapse after adjuvant/neoadjuvant chemotherapy, gemcitabine in combination with paclitaxel showed a statistically significant prolongation of time to documented disease progression from 3.98 to 6.14 months (log-rank p=0.0002) in patients treated with gemcitabine/paclitaxel compared to patients treated with paclitaxel. After 377 deaths, the overall survival was 18.6 months versus 15.8 months (log-rank p=0.0489, HR 0.82) in patients treated with gemcitabine/paclitaxel compared to patients treated with paclitaxel, and the overall response rate was 41.4% and 26.2% respectively (p= 0.0002).
The pharmacokinetics of gemcitabine have been examined in 353 patients in seven studies. The 121 women and 232 men ranged in age from 29 to 79 years. Of these patients, approximately 45% had non-small cell lung cancer and 35% were diagnosed with pancreatic cancer. The following pharmacokinetic parameters were obtained for doses ranging from 500 to 2,592 mg/m2 that were infused from 0.4 to 1.2 hours.
Peak plasma concentrations (obtained within 5 minutes of the end of the infusion) were 3.2 to 45.5 µg/ml. Plasma concentrations of the parent compound following a dose of 1,000 mg/m2/30 minutes are greater than 5 µg/ml for approximately 30 minutes after the end of the infusion, and greater than 0.4 µg/ml for an additional hour.
Distribution
The volume of distribution of the central compartment was 12.4 l/m2 for women and 17.5 l/m2 for men (inter-individual variability was 91.9%). The volume of distribution of the peripheral compartment was 47.4 l/m2. The volume of the peripheral compartment was not sensitive to gender.
The plasma protein binding was considered to be negligible.
Half-life: This ranged from 42 to 94 minutes depending on age and gender. For the recommended dosing schedule, gemcitabine elimination should be virtually complete within 5 to 11 hours of the start of the infusion. Gemcitabine does not accumulate when administered once weekly.
Metabolism
Gemcitabine is rapidly metabolised by cytidine deaminase in the liver, kidney, blood and other tissues. Intracellular metabolism of gemcitabine produces the gemcitabine mono, di and triphosphates (dFdCMP, dFdCDP and dFdCTP) of which dFdCDP and dFdCTP are considered active. These intracellular metabolites have not been detected in plasma or urine. The primary metabolite, 2'-deoxy-2', 2'-difluorouridine (dFdU), is not active and is found in plasma and urine.
Excretion
Systemic clearance ranged from 29.2 l/hr/m2 to 92.2 l/hr/m2 depending on gender and age (inter-individual variability was 52.2%). Clearance for women is approximately 25% lower than the values for men. Although rapid, clearance for both men and women appears to decrease with age. For the recommended gemcitabine dose of 1,000 mg/m2 given as a 30-minute infusion, lower clearance values for women and men should not necessitate a decrease in the gemcitabine dose.
Urinary excretion: Less than 10% is excreted as unchanged drug.
Renal clearance was 2 to 7 l/hr/m2.
During the week following administration, 92 to 98% of the dose of gemcitabine administered is recovered, 99% in the urine, mainly in the form of dFdU and 1% of the dose is excreted in faeces.
dFdCTP kinetics
This metabolite can be found in peripheral blood mononuclear cells and the information below refers to these cells. Intracellular concentrations increase in proportion to gemcitabine doses of 35-350 mg/m2/ 30 minutes, which give steady-state concentrations of 0.4-5 µg/ml. At gemcitabine plasma concentrations above 5 µg/ml, dFdCTP levels do not increase, suggesting that the formation is saturable in these cells.
Half-life of terminal elimination: 0.7-12 hours.
dFdU kinetics
Peak plasma concentrations (3-15 minutes after end of 30-minute infusion, 1,000 mg/m2): 28-52 µg/ml. Trough concentration following once-weekly dosing: 0.07-1.12 µg/ml, with no apparent accumulation. Triphasic plasma concentration versus time curve, mean half-life of terminal phase - 65 hours (range 33-84 hr).
Formation of dFdU from parent compound: 91%-98%.
Mean volume of distribution of central compartment: 18 l/m2 (range 11-22 l/m2).
Mean steady-state volume of distribution (Vss): 150 l/m2 (range 96-228 l/m2).
Tissue distribution: Extensive.
Mean apparent clearance: 2.5 l/hr/m2 (range 1-4 l/hr/m2).
Urinary excretion: All.
Gemcitabine and paclitaxel combination therapy
Combination therapy did not alter the pharmacokinetics of either gemcitabine or paclitaxel.
Gemcitabine and carboplatin combination therapy
When given in combination with carboplatin the pharmacokinetics of gemcitabine were not altered.
Renal impairment
Mild to moderate renal insufficiency (GFR from 30 ml/min to 80 ml/min) has no consistent, significant effect on gemcitabine pharmacokinetics.
In repeat-dose studies of up to 6 months in duration in mice and dogs, the principal finding was schedule and dose-dependent haematopoietic suppression which was reversible.
Gemcitabine is mutagenic in an in vitro mutation test and an in vivo bone marrow micronucleus test. Long-term animal studies evaluating the carcinogenic potential have not been performed.
In fertility studies, gemcitabine caused reversible hypospermatogenesis in male mice. No effect on the fertility of females has been detected.
Evaluation of experimental animal studies has shown reproductive toxicity, e.g., birth defects and other effects on the development of the embryo or foetus, the course of gestation or perinatal and postnatal development.
Handling
The normal safety precautions for cytostatic agents must be observed when preparing and disposing of the infusion solution. Handling of the solution for infusion should be done in a safety box and protective coats and gloves should be used. If no safety box is available, the equipment should be supplemented with a mask and protective glasses.
If the preparation comes into contact with the eyes, this may cause serious irritation. The eyes should be rinsed immediately and thoroughly with water. If there is lasting irritation, a doctor should be consulted. If the solution is spilled on the skin, rinse thoroughly with water.
Instructions for reconstitution (and further dilution, if performed)
The only approved diluent for reconstitution of gemcitabine sterile powder is sodium chloride 9 mg/ml (0.9%) solution for injection (without preservative). Due to solubility considerations, the maximum concentration for gemcitabine upon reconstitution is 40 mg/ml. Reconstitution at concentrations greater than 40 mg/ml may result in incomplete dissolution and should be avoided.
1. Use aseptic technique during the reconstitution and any further dilution of gemcitabine for intravenous infusion administration.
2. To reconstitute, add 5 ml of sterile sodium chloride 9 mg/ml (0.9 %) solution for injection, without preservative, to the 200 mg vial or 25 ml sterile sodium chloride 9 mg/ml (0.9 %) solution for injection, without preservative, to the 1,000 mg vial. The total volume after reconstitution is 5.26 ml (200 mg vial) or 26.3 ml (1,000 mg vial) respectively. This yields a gemcitabine concentration of 38 mg/ml, which includes accounting for the displacement volume of the lyophilised powder. Shake to dissolve. Further dilution with sterile sodium chloride 9 mg/ml (0.9 %) solution for injection, without preservative, can be done. Reconstituted solution is a clear, colourless to light straw-coloured solution.
3. Parenteral medicinal products should be inspected visually for particulate matter and discolouration prior to administration. If particulate matter is observed, do not administer.
Any unused product or waste material should be disposed of in accordance with local requirements.
