vitamin-b-12 and taxane

The objective of this study was to assess the efficacy and safety of pemetrexed in pretreated patients with advanced-stage breast cancer.. Patients with advanced-stage or metastatic breast cancer, Eastern Cooperative Oncology Group performance status 0-2, and progressive or relapsed disease after treatment with regimens containing anthracyclines and taxanes were eligible. Pemetrexed 500 mg/m2 was administered as a 10-minute intravenous infusion on day 1 every 21 days.. Seventy-nine women were enrolled. After protocol amendment, 43 patients received folic acid and vitamin B12 supplementation to control pemetrexed-related toxicity. A median of 4 cycles (range, 1-23 cycles) was administered. Overall response rate was 9% (95% confidence interval, 3.7%-17.6%), median duration of response was 5.5 months, median progression-free survival was 3.1 months, and median survival was 10.5 months. Major grade 3/4 toxicities were lymphopenia (53.3%), neutropenia (36.4%), leukopenia (26.9%), and anemia (7.7%). In general, the toxicities were less frequent in patients who received vitamin supplementation than in those who did not receive vitamin supplementation.. The response to pemetrexed salvage treatment was low in this study of heavily pretreated patients with breast cancer. Pemetrexed was generally well tolerated in patients with previously treated breast cancer. Vitamin supplementation appeared to ameliorate toxicity.

Topics: Adult; Aged; Anthracyclines; Antineoplastic Agents; Breast Neoplasms; Bridged-Ring Compounds; Female; Folic Acid; Glutamates; Guanine; Humans; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Pemetrexed; Premedication; Salvage Therapy; Taxoids; Vitamin B 12; Vitamin B Complex

Herein, the use of red blood cells (RBCs) as carriers of cytoplasmically interned phototherapeutic agents is described. Photolysis promotes drug release from the RBC carrier thereby providing the means to target specific diseased sites. This strategy is realized with a vitamin B12-taxane conjugate (B12-TAX), in which the drug is linked to the vitamin via a photolabile CoC bond. The conjugate is introduced into mouse RBCs (mRBCs) via a pore-forming/pore-resealing procedure and is cytoplasmically retained due to the membrane impermeability of B12. Photolysis separates the taxane from the B12 cytoplasmic anchor, enabling the drug to exit the RBC carrier. A covalently appended Cy5 antenna sensitizes the conjugate (Cy5-B12-TAX) to far red light, thereby circumventing the intense light absorbing properties of hemoglobin (350-600 nm). Microscopy and imaging flow cytometry reveal that Cy5-B12-TAX-loaded mRBCs act as drug carriers. Furthermore, intravital imaging of mice furnish a real time assessment of circulating phototherapeutic-loaded mRBCs as well as evidence of the targeted photorelease of the taxane upon photolysis. Histopathology confirms that drug release occurs in a well resolved spatiotemporal fashion. Finally, acoustic angiography is employed to assess the consequences of taxane release at the tumor site in Nu/Nu-tumor-bearing mice.

Topics: Animals; Bridged-Ring Compounds; Drug Carriers; Drug Delivery Systems; Erythrocytes; Female; Flow Cytometry; Humans; Mice; Photolysis; Prodrugs; Taxoids; Vitamin B 12