Thalidomide for the treatment of multiple myeloma

Intracranial Involvement in Multiple Myeloma Presenting as a Cranial Nerve Palsy

Multiple myeloma (MM) is characterized by the neoplastic proliferation of plasma cells producing a monoclonal immunoglobulin. Neurological complications in MM most frequently occur due to spinal cord compression by bony lesions, paraprotein-related neuropathy, hypercalcemia, hyperviscosity, or amyloidosis. Intracranial involvement is a rare complication of MM occurring in only 1% of patients. It can manifest as a solitary cerebral lesion, intra-parenchymal infiltration, or diffuse leptomeningeal disease. We present a case of a leptomeningeal myeloma in a 71-year-old woman with known relapsed MM presenting with a right sixth nerve palsy. Our patient was receiving spinal irradiation for a paraspinal plasmacytoma when she complained of double vision. Clinical exam revealed a right sixth nerve palsy. MRI revealed diffuse abnormal leptomeningeal thickening and enhancement typical for diffuse leptomeningeal infiltration. She was treated with whole brain irradiation and intrathecal methotrexate combined with a lenalidomide and dexamethasone chemotherapeutic regimen but unfortunately she passed away 5 weeks after onset of visual symptoms. MM involving the central nervous system (CNS) is a rare complication of MM and carries a poor prognosis with an average survival of 3 months. Due to its rarity, treatment of CNS MM is very heterogeneous. Thus case reporting is important to accumulate data on this rare presentation.

Mechanism of immunomodulatory drugs' action in the treatment of multiple myeloma

Although immunomodulatory drugs (IMiDs), such as thalidomide, lenalidomide, and pomalidomide, are widely used in the treatment of multiple myeloma (MM), the molecular mechanism of IMiDs' action is largely unknown. In this review, we will summarize recent advances in the application of IMiDs in MM cancer treatment as well as their effects on immunomodulatory activities, anti-angiogenic activities, intervention of cell surface adhesion molecules between myeloma cells and bone marrow stromal cells, anti-inflammatory activities, anti-proliferation, pro-apoptotic effects, cell cycle arrest, and inhibition of cell migration and metastasis. In addition, the potential IMiDs' target protein, IMiDs' target protein's functional role, and the potential molecular mechanisms of IMiDs resistance will be discussed. We wish, by presentation of our naive discussion, that this review article will facilitate further investigation in these fields.

[Comparison of dissolution profile and plasma concentration-time profile of the thalidomide formulations made by Japanese, Mexican and British companies]

Thalidomide is an important advance in the treatment of multiple myeloma. In Japan thalidomide is now on the approval step for the treatment of multiple myeloma. The drug has some bothersome side effects such as defect of organogenesis, neuropathy, constipation and fatigue, but is likely more effective than standard chemotherapy and is changing multiple myeloma treatment. At this moment, Japanese patients must import the thalidomide preparations from Mexico, Britain and elsewhere, but after approval, they patients will be able to get the new Japanese thalidomide capsules. In order to determine appropriate amounts of Japanese thalidomide capsules in the treatment of multiple myeloma, we compared the dissolution profile and plasma thalidomide concentrations of Japanese and British capsules and Mexican tablets. The dissolution test was performed according to the Japanese and the United States Pharmacopoeia. The pharmacokinetic data for Japanese capsules were obtained from the clinical trial in Japanese subjects and compared with those data published for other formulations. The dissolution rate of the Japanese capsule was the fastest, followed by British and Mexican formulations. The pharmacokinetic profiles of Japanese and British capsules were similar, while the 100 mg Japanese thalidomide capsule demonstrated a 1.6-fold higher maximum plasma concentration than the 200 mg Mexican thalidomide tablet (1.7 vs. 1.1 microg/ml), greatly shortened t(max) (4.5 vs. 6.2 h), and the apparent half life was only one-third of the Mexican tablet (4.8 vs. 13.5 h). A comparison of the dissolution and the pharmacokinetic absorption profiles demonstrated a rank-order correlation. Physicians and pharmacists should be aware of the probable alteration in plasma thalidomide concentration when switching to the Japanese capsule, especially from the Mexican tablet, and should monitor clinical response carefully.

Arterial thrombosis and thalidomide

Arterial emboli are largely a reflection of cardiac disease. Thalidomide is an antiangiogenic drug used in cancer therapy. Venous thrombosis incidence increased during treatment with thalidomide. We reported arterial thrombosis in two cases with multiple myeloma implemented in thalidomide treatment. Standard emergency intervention was applied. In the postoperative period, enoxiparine was given to all the patients. Warfarin treatment was started in the level of INR 2-2,5. ASA with a dose of 100 mg/day was added to the treatment. In conclusion, this side effect of the use of thalidomide should be taken into consideration while doing examinations with respect to the etiology in arterial thromboembolism and because of this vascular complication that threatens life; we suggest stopping the thalidomide treatment.

Single-institute phase 2 study of thalidomide treatment for refractory or relapsed multiple myeloma: prognostic factors and unique toxicity profile

We previously reported a pilot study of thalidomide monotherapy for Japanese patients with refractory or relapsed multiple myeloma. In the present work, we have extended this clinical trial to a single-institute phase 2 study with a larger number of patients and longer follow-up time. New information on the optimal dose and prognostic factors as well as the correlation of toxicities with treatment schedule was obtained. Fifteen of 56 (27%) patients achieved a partial response, including three cases with near-complete remission. Most patients suffered toxicities at a dose of 400 mg per day, but there was no clear dose-response relationship. Thus, a lower dose such as 200 mg per day or less is considered optimal. Multivariate analyses identified only lack of response to therapy as an adverse prognostic factor for progression-free survival. Chromosomal abnormality, C-reactive protein >10 mg/L, and more than six previous courses of chemotherapy were significantly associated with shorter overall survival. Grade 3 or 4 neutropenia and thrombocytopenia were observed in 23 and 11% of patients, respectively. Grade 4 interstitial pneumonia and grade 5 pulmonary hypertension were observed; however, no patient suffered deep vein thrombosis, which has frequently been observed in other studies. Duration of therapy was closely related to the development of peripheral neuropathy. The efficacy and prognostic factors of this treatment were confirmed in long-term observation. However, special attention should be paid to toxicities such as hematological and pulmonary complications as well as peripheral neuropathy in long-term users.

The pharmacokinetics of low-dose thalidomide in Japanese patients with refractory multiple myeloma

Thalidomide has been used for the treatment of refractory multiple myeloma, the dosage in Japan is lower than in other countries; however, there is little information on the pharmacokinetics and their relationship with the drug response. The aim of this study was to characterize the pharmacokinetics of low-dose thalidomide in Japanese patients with refractory multiple myeloma, and to examine the relationship between pharmacokinetics and adverse events. On the first and second days, a 100 mg capsule was administered to 8 Japanese patients after breakfast and blood samples were obtained. The plasma concentrations were measured using HPLC and analyzed based on a one-compartment model. If intolerable adverse events were not observed for 14 d, the dose was increased to 200 mg. The average apparent volume of distribution (Vd/F), apparent total clearance (CL/F) and area under the plasma concentration-time curve from 0 to infinity (AUC0-infinity), which were 45.3 l, 5.5 l/h and 21.7 microg.h/ml, respectively, with smaller Vd/F and CL/F and larger AUC0-infinity than in Caucasian populations. This pharmacokinetic difference may explain the dose difference between Japan and other countries. Adverse events were associated with AUC0-infinity, which was best correlated with plasma concentration at 12 h after administration. The 12-h time point was suggested to be a capable indicator for "safety-oriented" therapeutic drug monitoring of thalidomide.

Vascular-specific quantification in an in vivo Matrigel chamber angiogenesis assay

The study of angiogenesis as a therapeutic target requires reliable in vivo assays that can provide physiologically relevant data. A murine in vivo Matrigel-based angiogenesis assay is presented here which includes the quantitative assessment of vascular-specific indicators of neovascularization. Matrigel containing 175 ng/ml bFGF is encapsulated in synthetic chambers which are implanted subcutaneously in C57/B16J mice. Ex vivo implants can be imaged to qualitatively view perfused vasculature within the chambers, or histologically processed to confirm the presence of vascular-specific tissue within the Matrigel. Viable cells are recovered from the excised chambers and quantified cytometrically using endothelial cell-specific markers CD34 and CD144, and for a marker of nucleated cells, Hoechst 33342. Thalidomide, 200 mg/kg/day, was tested using the assay and was found to inhibit angiogenesis by 46%. Angiogenesis inhibitors secreted by LL/M27 tumors were also characterized, where tumor-bearing mice showed a 73% inhibition of angiogenesis compared to tumor-free controls. Analysis of the number of nucleated cells in these samples failed to show a strong correlation with the number of endothelial cells, indicating that quantification of nonvascular-specific tissue in in vivo angiogenesis assays may not be sufficient. This new assay provides an objective, comprehensive determination of the vasculature-specific response of both endogenous and exogenous angiogenesis inhibitors in vivo, and also creates new opportunities for obtaining primary murine endothelial cells.

Suppression of Urokinase Receptor Expression by Thalidomide Is Associated with Inhibition of Nuclear Factor κB Activation and Subsequently Suppressed Ovarian Cancer Dissemination

Thalidomide has been used to treat a variety of diseases ranging from alleviation of autoimmune disorders to prevention of metastasis of cancers. It has been shown previously that increased levels of urokinase-type plasminogen activator receptor (uPAR) correlate well with higher invasive phenotype. We examined whether thalidomide is able to suppress the expression of uPAR mRNA and protein in human ovarian cancer cell line HRA and human chondrosarcoma cell line HCS-2/8. Here, we show that: (a) thalidomide suppresses the expression of constitutive and transforming growth factor-beta1 (TGF-beta1)-induced uPAR mRNA and protein; (b) a nuclear factor kappaB (NF-kappaB) activation system (phosphorylation of IkappaB-alpha and degradation of IkappaB-alpha) is necessary for the TGF-beta1-induced increase in uPAR expression, because L-1-tosylamido-2-phenylethyl chloromethyl ketone, a NF-kappaB inhibitor, reduced the uPAR production as well as mRNA expression; (c) thalidomide failed to further strengthen L-1-tosylamido-2-phenylethyl chloromethyl ketone's action; (d) the once-daily i.p. administration of thalidomide (400 microg/g body weight/d) decreased progressive growth of HRA tumors and ascites formation in an in vivo animal model; and (e) the once-daily i.p. administration of thalidomide in combination with paclitaxel (i.p., 100 microg/20 g at days 2 and 5) significantly decreased progressive growth of HRA cells in a synergistic fashion. We conclude that thalidomide down-regulates constitutive and TGF-beta1-stimulated uPAR mRNA and protein expression possibly through suppression of NF-kappaB activation. Furthermore, combination therapy with thalidomide plus paclitaxel may be an effective way to markedly reduce i.p. tumor growth and ascites in ovarian cancer dissemination.

Thalidomide-Associated Thrombocytopenia

OBJECTIVE

To report thrombocytopenia in a patient prescribed thalidomide for multiple myeloma (MM).

CASE SUMMARY

A 70-year-old woman was diagnosed in 2003 with MM. At diagnosis, melphalan 0.25 mg/kg/day and prednisolone 2 mg/kg/day were started; however, the patient became refractory to therapy. Melphalan and prednisolone were discontinued, and monotherapy with dexamethasone 40 mg for 12 days per month was started. The patient's hematologic condition deteriorated again after about one year; dexamethasone was discontinued, and treatment with oral thalidomide 200 mg/day was initiated. About 2 weeks after thalidomide administration, the woman developed disabling adverse effects (flu-like symptoms, swollen fingers, rash and hematoma on her legs, shortness of breath, dry mouth, multiple petechiae). Laboratory testing showed neutropenia (neutrophils 0.4 × 109/L) and thrombocytopenia (platelets 58 × 109/L). Thalidomide was promptly discontinued; within 3 weeks, the laboratory values returned to pretreatment levels (1.3 × 109/L and 267 × 109/L, respectively) and her symptoms disappeared.

DISCUSSION

Thrombocytopenia is a rarely reported hematologic adverse consequence of thalidomide therapy. A recent report identified 5 patients who developed thrombocytopenia while undergoing monotherapy with thalidomide for MM. According to the Naranjo probability scale, thalidomide was classified as the probable cause of thrombocytopenia in our patient.

CONCLUSIONS

Unlike other antineoplastic drugs, thalidomide is rarely reported to cause severe hematologic toxicity. We present this case to increase clinicians’ awareness for the potential of thalidomide to adversely affect platelet counts, particularly because its effectiveness in MM will likely result in expansion of its clinical use.