No abstract

Pyridazine scaffolds are considered privileged structures pertaining to its novelty, chemical stability, and synthetic feasibility. In our quest towards the development of novel scaffolds for effective vascular endothelial growth 2 (VEGFR-2) inhibition with antiangiogenic activity, four novel series of pyridazines were designed and synthesised. Five of the synthesised compounds; namely (8c, 8f, 15, 18b, and 18c) exhibited potent VEGFR-2 inhibitory potency (>80%); with IC50 values ranging from low micromolar to nanomolar range; namely compounds 8c, 8f, 15, 18c with (1.8 µM, 1.3 µM, 1.4 µM, 107 nM), respectively. Moreover, 3-[4-{(6-oxo-1,6-dihydropyridazin-3-yl)oxy}phenyl]urea derivative (18b) exhibited nanomolar potency towards VEGFR-2 (60.7 nM). In cellular assay, the above compounds showed excellent inhibition of VEGF-stimulated proliferation of human umbilical vein endothelial cells at 10 μM concentration. Finally, an extensive molecular simulation study was performed to investigate the probable interaction with VEGFR-2.

Prasugrel and ticagrelor exhibit greater platelet inhibition and superior efficacy compared with clopidogrel, at the expense of higher bleeding risk. Prasugrel and ticagrelor should be preferred over clopidogrel in patients who are at a high risk of thrombotic events with low risk of bleeding. Additionally, these two agents may offer advantage over clopidogrel in those patients who might have risk for drug resistance due to CYP2C19 polymorphism. In selecting the ideal agent for patients, clinicians should tailor the antiplatelet regimen by considering individual risk factors and medication characteristics.

Management of Malignant Gliomas continues to be a challenge. We prospectively studied the role of adding weekly Paclitaxel to Fractionated Stereotactic Radiation Therapy (FSRT) in the treatment of Malignant Gliomas. Twenty-three Glioblastoma Multiforme and two Anaplastic Astrocytoma were studied. Patients received 46 Gy at 2 Gy/fraction followed by a boost utilizing FSRT at a fraction of 2.5 Gy for 8 fractions. Paclitaxel is delivered concomitantly at 150 mg/m(2) weekly for six cycles. Eighteen patients had pharmacokinetic assays of Paclitaxel levels. All patients were followed until death or for a maximum of 36 months. The overall survival of the whole group was 14 months. The median survival for RPA prognostic classes III, IV, V, and VI were 20, 14, 12, and 11 months. Higher survival (14 months) was noted in the subtherapeutic phenytoin level group compared to 10 months in the therapeutic group (P=0.271). No grade 4 CTCAE (version 3.0) toxicities were observed. Enhanced survival was demonstrated with gross tumor resection (20.8 months), KPS > or =80 (18.7 months) and age < or =60 years (27 months) as compared to subtotal resection or biopsy (12.1 months, P< 0.005), KPS < or =70 (10.8 months, P=0. 005) and older age > 60 (10.46 months, P=0.006), respectively. Our study suggests that: i) the use of weekly Paclitaxel and FSRT in Gliomas is well tolerated with a survival of 14 months; ii) the regimen resulted in improvement of survival of RPA classes IV, V, VI; and iii) the use of FSRT boost may be studied with other chemotherapeutic agents to see if superior results can be attained.