Thalidomide : mécanismes d'action et indications en hématologie

Thromboembolic events and thromboprophylaxis associated with immunomodulators in multiple myeloma patients: a real-life study

PURPOSE

The aim of this study is to assess international guidelines implementation concerning thromboprophylaxis strategy in myeloma patients treated with immunomodulatory drugs.

METHODS

This retrospective study includes multiple myeloma patients treated with immunomodulatory drugs between 2014 and 2017 in the Hematology department of a teaching hospital (Hospices Civils de Lyon, France) and followed by the multidisciplinary care plan for cancer outpatients ONCORAL (ONCological care for outpatients with ORAL anticancer drugs). Data from immunomodulatory drugs administration, thromboprophylaxis strategy and thrombotic events were collected from medical files. Adherence to 2010 International Myeloma Working Group (IMWG) guidelines was assessed.

RESULTS

213 patients received at least one immunomodulatory drug: lenalidomide (60.9%), pomalidomide (24.0%) and thalidomide (15.1%). About two third of treatment lines (66.2%) were in accordance with IMWG recommendations. Among the others, 30.5% and 69.5% had thromboprophylaxis, respectively, superior or inferior to IMWG recommendations. 37 venous thrombotic events and 4 arterial thromboembolisms (one patient experienced both a stroke and deep venous thrombosis simultaneously) were reported.

CONCLUSION

Thromboprophylaxis was systematically performed in myeloma patients treated with immunomodulatory drugs in this real-life retrospective cohort. However, the choice of anticoagulant or anti-platelet agent remains debatable, as adherence to existing guidelines was variable.

Thalidomide for the treatment of histiocytic sarcoma after hematopoietic stem cell transplant

Histiocytic sarcoma (HS) is a rare neoplasm of uncertain etiology. Most recently, the diagnostic criteria for this entity have been revised with inclusion of diagnostic modalities such as immunohistochemical and cytogentic techniques. HS tends to have an aggressive clinical course and presents with systemic symptoms of fever, weight loss, adenopathy, hepatosplenomegly, rash, and pancytopenia. Thalidomide is a promising agent that may exert a therapeutic benefit in HS. We report a case of a 48-year-old female with HS who presented with fever, weight loss, fatigue, generalized anasarca, and pancytopenia. She underwent multi-agent chemotherapy followed by matched unrelated hematopoietic stem cell transplant. Her disease recurred and thalidomide therapy was started, with her overall disease burden significantly reduced as measured radiographically.

Thalidomide attenuates nitric oxide mediated angiogenesis by blocking migration of endothelial cells

BACKGROUND

Thalidomide is an immunomodulatory agent, which arrests angiogenesis. The mechanism of anti-angiogenic activity of thalidomide is not fully understood. As nitric oxide is involved in angiogenesis, we speculate a cross-talk between thalidomide and nitric oxide signaling pathway to define angiogenesis. The aim of present study is to understand the mechanistic aspects of thalidomide-mediated attenuation of angiogenesis induced by nitric oxide at the cellular level.

METHODS

To study the cellular mechanism of thalidomide-mediated blocking of angiogenesis triggered by nitric oxide, we used two endothelial cell based models: 1) wound healing and 2) tube formation using ECV 304, an endothelial cell line. These cell-based models reflect pro-angiogenic events in vivo. We also studied the effects of thalidomide on nitric oxide mediated egg yolk angiogenesis. Thalidomide could block the formation of blood vessels both in absence and presence of nitric oxide. Thalidomide effects on migration of, and actin polymerization in, ECV 304 cells were studied at the single cell level using live cell imaging techniques and probes to detect nitric oxide.

RESULTS

Results demonstrate that thalidomide blocks nitric oxide-mediated angiogenesis in egg yolk model and also reduces the number of tubes formed in endothelial cell monolayers. We also observed that thalidomide arrests wound healing in presence and absence of nitric oxide in a dose-dependent fashion. Additionally, thalidomide promotes actin polymerization and antagonizes the formation of membrane extensions triggered by nitric oxide in endothelial cells. Experiments targeting single tube structure with thalidomide, followed by nitric oxide treatment, show that the tube structures are insensitive to thalidomide and nitric oxide. These observations suggest that thalidomide interferes with nitric oxide-induced migration of endothelial cells at the initial phase of angiogenesis before cells co-ordinate themselves to form organized tubes in endothelial cells and thereby inhibits angiogenesis.

CONCLUSION

Thalidomide exerts inhibitory effects on nitric oxide-mediated angiogenesis by altering sub-cellular actin polymerization pattern, which leads to inhibition of endothelial cell migration.