Clinical experience with thalidomide and lenalidomide in multiple myeloma

Thal has antiangiogenic and immunomodulatory activity. Clinical research provided clear evidence that Thal belongs to the most active drugs for the treatment of multiple myeloma e.g. leading to decrease of monoclonal protein of at least 50 % in 30 % of patients with relapsed or refractory multiple myeloma. Randomized trials that were designed based on a large body of evidence from phase II trials determined that Thal significantly increases total response rate, progression-free and in some studies overall survival in combination regimens (dexamethason and or chemotherapy) for relapsed as well as newly diagnosed patients and was therefore approved for first-line treatment of Multiple Myeloma. Strict guidelines apply due to the teratogenic effects of Thal and to monitor and prevent other potential adverse events as neuropathy and thrombosis has been recognized by leading organizations as part of the treatment concept for patients with relapsed or refractory disease. The success of Thal has sparked the development of Thal analogues with Lenalidomide (Len) the most advanced compound which was approved for relapsed multiple myeloma. As Len has a lower incidence of polyneuropathy, constipation and somnolence compared to Thalidomid but at least equal if not higher efficacy Len is meanwhile used more frequently in clinical routine and has advantages in combination therapies with Bortezomib. Additional randomized studies will now define the status of Thal and Len for maintenance therapy and their optimal integration in multi-agent treatment regimen.     

Treating chronic lymphocytic leukemia with thalidomide and lenalidomide

Introduction: Chronic lymphocytic leukemia (CLL) is biologically, as well as clinically, highly heterogeneous. In CLL patients, immunosuppression is a consequence of the disease, which plays a key role in effecting the quality of life and overall survival. Treatment modalities should ideally not only reduce tumor burden, but also augment immune function in CLL patients.

Areas covered: The current review summarizes biological and clinical data on thalidomide and lenalidomide in CLL.

Expert opinion: Immunomodulatory drugs such as thalidomide and lenalidomide show both antitumor activity and immunostimulation. Three main mechanisms of action seem to play a role in cancer, including i) anti-angiogenic, ii) immunomodulatory and iii) tumoricidal effects. The exact contributions of these effects seem to be unique for different diseases. The two representatives of this family of drugs studied in CLL include thalidomide and its analog lenalidomide. These drugs proved to be effective as single agents and in the combination setting in CLL. Toxicities have been identified but largely controlled by a low starting dose, with gradual dose escalation.     

Treating chronic lymphocytic leukemia with thalidomide and lenalidomide

INTRODUCTION: Chronic lymphocytic leukemia (CLL) is biologically, as well as clinically, highly heterogeneous. In CLL patients, immunosuppression is a consequence of the disease, which plays a key role in effecting the quality of life and overall survival. Treatment modalities should ideally not only reduce tumor burden, but also augment immune function in CLL patients. AREAS COVERED: The current review summarizes biological and clinical data on thalidomide and lenalidomide in CLL. EXPERT OPINION: Immunomodulatory drugs such as thalidomide and lenalidomide show both antitumor activity and immunostimulation. Three main mechanisms of action seem to play a role in cancer, including i) anti-angiogenic, ii) immunomodulatory and iii) tumoricidal effects. The exact contributions of these effects seem to be unique for different diseases. The two representatives of this family of drugs studied in CLL include thalidomide and its analog lenalidomide. These drugs proved to be effective as single agents and in the combination setting in CLL. Toxicities have been identified but largely controlled by a low starting dose, with gradual dose escalation.     

Binding of ethacrynic acid to hepatic glutathione S-transferases in vivo in the rat

Ethacrynic acid is a substrate for rat glutathione $\text{S}$-transferases $\text{in}$$\text{vitro}$ (1,2). In their study defining the importance of the glutathione $\text{S}$-transferases in the hepatic metabolism and biliary excretion of ethacrynic acid, Wallin $\text{et}$$\text{al}$. (3) suggested that a small but consistent portion of the administered drug was bound selectively and covalently to the transferases. Such an association would represent a unique example of covalent binding of a drug to the metabolizing enzyme without prior microsomal enzyme activation. We have undertaken these studies, therefore, to characterize the binding of ethacrynic acid to the glutathione $\text{S}$-transferases and to delineate the selectivity of this binding.     

Managing the teratogenic risk of thalidomide and lenalidomide: an industry perspective

Celgene has developed and operated pregnancy prevention programs since 1998 with the first approval of thalidomide in the US. With the development and marketing of lenalidomide, an analog of thalidomide, the company further advanced its risk management activities, which now cover several territories across the globe. To date, the program is a success in as much as it has minimized the risk of fetal exposure and subsequent development of fetal malformations. Nonetheless, the company understands the need to provide a mechanism for intervention and remediation when at-risk behaviors are identified, and this forms an integral part of the risk management processes. The implementation of the thalidomide and lenalidomide pregnancy prevention program partners patients, healthcare professionals, regulators and the company in a spirit of shared responsibility. This paper also presents the authors' experience and perspective on the challenges of managing a pregnancy prevention program, which at its core aims at ensuring that the product's benefits outweigh the risk of fetal exposure.     

Modulation of sulphobromophthalein excretion by ethacrynic acid.

1. Ethacrynic acid (EA), a phenoxyacetic acid diuretic, has similar effects to tienilic acid (TA) on rat liver glutathione S-transferase (GST) activity in vitro, using either 1-chloro-2,4-dinitrobenzene or sulphobromophthalein (BSP) as a substrate. EA inhibits the basic rat liver GST, with inhibition being greater with GST containing subunits 3 and 4 than with those containing subunits 1 and 2. 2. In vitro inhibitors of GST can inhibit biliary excretion of BSP in a perfused liver. 3. A single bolus dose of EA had no effect on BSP excretion from the isolated perfused rat liver, and this is most likely due to the rapid disappearance of EA from the perfusion media. Experiments using perfused rat liver indicated that a sustained high concentration of EA in the perfusion media has an inhibitory effect on the excretion of both unchanged and conjugated BSP. 4. A decrease in BSP excretion may not be an indicator of liver damage, but a consequence of GST inhibition.     

Managing the teratogenic risk of thalidomide and lenalidomide: an industry perspective

Celgene has developed and operated pregnancy prevention programs since 1998 with the first approval of thalidomide in the US. With the development and marketing of lenalidomide, an analog of thalidomide, the company further advanced its risk management activities, which now cover several territories across the globe. To date, the program is a success in as much as it has minimized the risk of fetal exposure and subsequent development of fetal malformations. Nonetheless, the company understands the need to provide a mechanism for intervention and remediation when at-risk behaviors are identified, and this forms an integral part of the risk management processes. The implementation of the thalidomide and lenalidomide pregnancy prevention program partners patients, healthcare professionals, regulators and the company in a spirit of shared responsibility. This paper also presents the authors' experience and perspective on the challenges of managing a pregnancy prevention program, which at its core aims at ensuring that the product's benefits outweigh the risk of fetal exposure.     

Inhibition of some polymorphonuclear leukocyte functions by ethacrynic acid

Ethacrynic acid (10(-4) M) inhibits exocytosis, phagocytosis and superoxide release in rabbit polymorphonuclear leukocytes (PMN's). Dihydroethacrynic acid is a much weaker inhibitor of these PMN functions. Though ethacrynic acid inhibits ATPase activity in the PMN, this occur at much higher concentrations than required for inhibition of exocytosis and superoxide release, thus a causal relationship seems unlikely. The same applies to inhibition of ATP generation by ethacrynic acid: the concentration required to decrease ATP level in PMN's is much higher than required for the inhibitory effect on exocytosis. Inhibition of exocytosis by ethacrynic acid can be prevented by dithiothreitol. It is concluded that vulnerable sulfhydryl groups are involved in the inhibition by ethacrynic acid.     

Immunomodulatory properties of thalidomide analogs: pomalidomide and lenalidomide, experimental and therapeutic applications

Thalidomide has a broad spectrum of anti-cancer activity. Antitumor activity of thalidomide may be related to a number of known properties, including anti-tumor necrosis factor (TNF)-α and T-cell costimulatory and antiangiogenic activities. The therapeutic potential of thalidomide provided motivation to develop more effective derivatives with considerably reduced toxicity. Thalidomide's immunomodulatory (IMiDs) analogs (lenalidomide, CC-5013; CC-4047, ACTIMID) represent a novel class of compounds with numerous effects on the immune system. Some of these analogs are thought to mediate the anticancer and anti-inflammatory effects observed in humans. Thalidomide is currently approved for the treatment of dermal reaction to leprosy and is currently in phase III trials for multiple myeloma (MM). IMiDs inhibit the cytokine's tumor necrosis factor-α (TNF-α), interleukins (IL) 1β, 6, 12, and granulocyte macrophage-colony stimulating factor (GM-CSF). The repression of the tumor necrosis factor-a (TNF-α) expression is the crucial factor of many of the anti-inflammatory properties of thalidomide. The mechanisms underlying many of the anti-inflammatory properties of thalidomide, including its ability to co-stimulate T cells, still remain unclear. Some recent patent are also summarized in this review.     

Exacerbation of acetaminophen hepatotoxicity by thalidomide and protection by nicotinic acid amide

• 1.1. The effects of racemic thalidomide (d[ + ]/l[ - ] α-phthalimido-glutarimide) on acetaminophen (AAP)-induced hepatitis were tested in male NMRI mice (n = 133) and quantified as serum activities of glutamate-oxaloacetate transaminase (GOT) and glutamate-pyruvate transaminase (GPT).
• 2.2. A 2.1-fold increase of GOT and a 1.9-fold increase of GPT activities (P < 0.001) were observed in mice treated perorally with 500 mg/kg of AAP plus 150 mg/kg of thalidomide (Tha1). In the absence of AAP, Thal did not display any detectable hepatotoxic effects.
• 3.3. The Thal-induced exacerbation of AAP hepatotoxicity was completely inhibited by nicotinic acid amide, a selective inhibitor of poly(ADP-ribose) polymerase (PARP) (P < 0.0001), suggesting a possible influence of Thal on the hepatic metabolism of NAD-adenoribosylation.
• 4.4. We see the main application of nicotinic acid amide as for the combinational use in pharmaceutical preparations of AAP in order to avoid hepatic damage in patients treated with AAP and Thal.

     

Toxicity of ethacrynic acid in isolated rat hepatocytes.

Ethacrynic acid, a loop diuretic drug, caused lipid peroxidation in isolated rat hepatocytes. The thiobarbituric acid reactive substances (TBARS) formation showed a good correlation with the leakage of glutamic-oxaloacetic acid transaminase (GOT) from the hepatocytes. The addition of antioxidants such as N, N'-diphenyl-p-phenylenediamine (DPPD) and promethazine to the isolated rat hepatocyte suspension containing ethacrynic acid prevented the lipid peroxidation and decreased the GOT leakage to some extent. SKF-525A inhibited the oxidative metabolism of ethacrynic acid and decreased the TBARS formation, suggesting that the lipid peroxidation was caused by the oxidative metabolism. The intracellular reduced glutathione markedly decreased in the hepatocyte suspension containing ethacrynic acid and the hepatocellular protein sulfhydryls were decreased, which was negatively correlated with the GOT leakage. Thus the ethacrynic acid-induced hepatotoxicity was found to be related to the lipid peroxidation and the decrease of cellular protein sulfhydryls.