Resistance of human tumors to anticancer drugs is most often ascribed to gene mutations, gene amplification, or epigenetic changes that influence the uptake, metabolism, or export of drugs from single cells. Another important yet little-appreciated cause of anticancer drug resistance is the limited ability of drugs to penetrate tumor tissue and to reach all of the tumor cells in a potentially lethal concentration. To reach all viable cells in the tumor, anticancer drugs must be delivered efficiently through the tumor vasculature, cross the vessel wall, and traverse the tumor tissue. In addition, heterogeneity within the tumor microenvironment leads to marked gradients in the rate of cell proliferation and to regions of hypoxia and acidity, all of which can influence the sensitivity of the tumor cells to drug treatment. In this review, we describe how the tumor microenvironment may be involved in the resistance of solid tumors to chemotherapy and discuss potential strategies to improve the effectiveness of drug treatment by modifying factors relating to the tumor microenvironment.

Rizatriptan (MAXALT(TM), Merck & Co., Inc.) is a selective 5-HT(1B/1D) receptor agonist with rapid oral absorption and early onset of action for the acute treatment of migraine. This randomized, double-masked, double-dummy, placebo-controlled study compared rizatriptan 10 mg to naratriptan (NARAMIG(TM), AMERGE(TM), both Glaxo Wellcome plc) 2.5 mg in 522 patients treating a single migraine attack. Rizatriptan was more effective than naratriptan. Rizatriptan provided earlier headache relief than naratriptan (hazard ratio 1.62, p < 0.001), acting as early as 30 min. More patients were pain free at 2 h on rizatriptan than on naratriptan (44.8 vs. 20.7%, p < 0.001). Rizatriptan also provided earlier relief of associated migraine symptoms within 2 h than naratriptan and more patients had normal function at 2 h (39.3 vs. 22.6%, p < 0. 001). Both active treatments were effective compared to placebo. Both active treatments were well tolerated. The most common side effects with rizatriptan were dizziness, asthenia/fatigue, nausea and somnolence, while the most common side effects with naratriptan were dizziness and asthenia/fatigue.

Immuno-oncology is a fast evolving field of cancer therapy and immune checkpoint inhibitors (ICIs) are clearly a breakthrough in this field. Cardiotoxicity with conventional anti-cancer therapies has been well studied in the past and clear guidelines for management of these side effects are available in the literature. However, cardiotoxicity with novel agents such as ICIs has been fairly under-reported and/or underestimated and we are yet to formulate clear guidelines for management of these rare side effects. In the last few years, there has been an overall increase in the number of cases of cardiotoxicity related to ICIs. In this literature review, we describe the mechanism of action of the most widely used ICIs and their related cardiotoxicities. The increase in number of case reports about the potential of cardiotoxicities with these novel agents clearly indicates the need for a new insight into the field of cardio-immuno-oncology.

No abstract

The efficacy and tolerability of rizatriptan (MAXALT) and zolmitriptan (ZOMIG) were compared in a randomized, double-blind, double-dummy, stratified (on prior use of rizatriptan and/or zolmitriptan), placebo-controlled, single attack study in 766 patients. Rizatriptan tended to provide freedom from pain sooner than zolmitriptan (hazard ratio 1.26, P = 0.075), acting within 60 min following dosing. More patients were pain free at 2 h on rizatriptan than on zolmitriptan (43.2% vs. 35.6%, P=0.041), while headache relief at 2 h was similar (70.5% vs. 66.8%). At 2 h, fewer patients on rizatriptan had symptoms of photophobia (35.6% vs. 43.5%, P = 0.029) and nausea (25.2% vs. 32.5%, P=0.046), and more patients on rizatriptan had normal function (45.4% vs. 37.0%, P=0.025) than zolmitriptan. Headache recurred in 28% of patients taking rizatriptan, 29% taking zolmitriptan and 26% taking placebo. Both active treatments were effective compared to placebo and were well tolerated. The most common side-effects with rizatriptan were asthenia/fatigue, somnolence and dizziness, while the most common side-effects with zolmitriptan were asthenia/fatigue and dizziness.