Commercially available pentostatin powder for injection should be stored at 2-8 °C. ... When stored at 2-8 °C, the manufacturer states that currently available pentostatin powder for injection is stable for 18 mo after the date of manufacture when stored as directed. ... Pentostatin is compatible with 5% dextrose injection, 0.9% sodium chloride injection, and lactated Ringer's. When reconstituted with 0.9% sodium chloride injection to a final concentration of 2 mg/ml, pentostatin solutions are physically and chemically stable for at least 72 hr at room temperature (22-25 °C). When diluted to a final concentration of 20 ug/ml, the drug is chemically compatible at room temperature with 0.9% sodium chloride or lactated Ringer's injection for at least 48 hr and with 5% dextrose injection for at least 24 hr. Up to an 8-10% loss in potency has been reported to occur within 48 hr in such solutions diluted in 5% dextrose, However, because such reconstituted and/or diluted pentostatin solutions contain no preservatives, the manufacturer recommends that they be used within 8 hr when stored at room temperature in ambient light, and that unused portions be discarded.
旋光度:
Specific optical rotation: + 76.4 deg at 25 °C/D (concentration by volume = 1 g 100 ml water); specific optical rotation: + 73.0 deg at 23 °C/D (concentration by volume = 1 g in 100 ml water pH 7 buffer)
Limited data suggest that concomitant therapy with pentostatin (4 mg/sq m every 2 weeks) and fludarabine (principally 10 mg/sq m daily for 4 days at 28 day intervals), a synthetic purine nucleoside, may be associated with severe and/or fatal pulmonary toxicity (eg, pneumonitis). In one study, 4 of 6 patients receiving the drugs concomitantly for treatment of refractory chronic lymphocytic leukemia reportedly developed such toxicity.
Although therapy with either pentostatin or allopurinol alone has been associated with the development of skin rash, limited evidence suggests that concomitant use of the drugs, compared with pentostatin therapy alone, in patients with refractory hairy cell leukemia is not associated with an increased incidence of rash. However, other toxicities, including abnormalities in renal or hepatic function, have been observed in a few patients receiving concomitant pentostatin and allopurinol. ... One patient reportedly developed a fatal hypersensitivity vasculitis while receiving pentostatin and allopurinol concurrently; however, a causal relationship to the drugs has not been established.
Pentostatin inhibits the degradation of vidarabine and enhances its cytotoxicity in cell culture and in animals with experimentally induced leukemia. In addition, limited data in patients with acute leukemia suggest that combined therapy with the drugs may be associated with increased plasma vidarabine concentrations and/or half-life and greater toxicity compared with pentostatin therapy alone. Although improvement and/or remission has been reported in a few patients with acute T cell lymphoblastic leukemia who received vidarabine and pentostatin concomitantly.
No specific antidote for pentostatin overdosage is known. Administration of pentostatin in dosages higher than those currently recommended (20-50 mg/sq m over 5 days as compared with 4 mg/sq m every other week, respectively) has been associated with severe renal, hepatic, pulmonary, and CNS toxicity, which was unpredictable and occasionally fatal. In case of overdosage, management should include discontinuance of the drug and initiation of supportive measures appropriate to the type of toxicity observed.
Plasma concentrations of pentostatin following direct iv injection of 0.25 mg/kg daily for 4 or 5 days in a limited number of patients with advanced, refractory cancer ranged from approximately 3.2-9.7 ng/ml. Plasma concentrations appear to increase linearly with dose; in a study in patients with leukemia, plasma pentostatin concentrations determined 1 hour after administration of 0.25 or 1 mg/kg of the drug as a 30 min iv infusion averaged approximately 0.4 or 1.26 ug/ml, respectively.
No apparent correlation has been documented between mean or absolute plasma adenosine or deoxyadenosine concentrations and therapeutic or toxic responses to pentostatin; however, limited data suggest that there may be a correlation between response to the drug and the ratio of deoxyadenosine triphosphate to adenosine triphosphate in lymphoblasts. In addition, increases in plasma deoxyadenosine reportedly parallel the accumulation of deoxyadenosine triphosphate in erythrocytes and lymphoblasts, and there appears to be a correlation between toxicity and the ratio of deoxyadenosine triphosphate to adenosine triphosphate in erythrocytes.
Studies in animals indicate that pentostatin distributes rapidly to all body tissues, but the extent of drug accumulation in different tissues appears to vary among species. Following intraperitoneal injection in mice, the highest concentrations of the drug were found in the kidneys, liver, and spleen. In dogs, pentostatin tissue concentrations following iv administration were proportional to tissue adenosine deaminase activity, with the highest concentrations in the lungs, spleen, pancreas, heart, liver, and jejunum. Pentostatin reportedly enters erythrocytes via a facilitated transport system common to other nucleosides or by simple diffusion; efflux of the drug from cells has not been characterized, although the time course of pentostatin's effects (eg, adenosine deaminase inhibition) varies among different types of cells (eg, lymphocytes, erythrocytes).
Limited data in animals and humans indicate that pentostatin distributes relatively poorly into CSF, with peak CSF concentrations averaging approximately 10% of concurrent plasma concentrations. In a 6 yr old leukemia patient receiving pentostatin 0.25 mg/kg daily for 3 successive days by direct iv injection, serum and CSF (via lumbar puncture) pentostatin concentrations 4 hr after the initial dose were approximately 147 and 19 ng/ml, respectively, using an enzyme-inhibition titration assay; one hour after the third dose, corresponding serum and CSF concentrations were approximately 241 and 35 ng/ml, respectively.
The combination of an IGF-1R antagonist such as a humanized antibody and an anti-proliferative drug is described. In a preferred embodiment, the present invention describes the combination of an IGF-1R antibody and an anti-proliferative drug belonging to the EGFR-inhibitor class, which is preferably erlotinib. The combination according to the present invention is useful for the treatment of tumours, including IGF-1R and/or EGFR mediated or dependent tumours.
The present invention provides methods for preventing or treating a medical disorder in a subject comprising administering to the subject an effective amount of a stable pharmaceutical formulation comprising an antibody or antigen-binding fragment thereof.
The present invention provides, for example, methods for conveniently determining if a cancerous condition in a subject will be responsive to an IGF1R inhibitor. The invention includes patient selection methods and methods of treatment.
This invention relates to methods for evaluating the efficacy of an IGF1R inhibitor, such as an anti-IGF1R antibody, for the treatment of an Ewing's sarcoma tumor by determining the level of tumoral glucose metabolism. Tumoral glucose metabolism is determining at an early point in the treatment regimen by any of several methods known in the art including FDG-PET/CT scan.
The present invention provides method for quickly and conveniently determining if a given treatment regimen of IGF1R inhibitor is sufficient, e.g., to saturate IGF1R receptors in the body of a subject. Several clinically relevant determinations may be made based on this point, including, for example, whether the dosage of the regimen is sufficient or should be increased.