[Treatment of AL amyloidosis in 2012; the benefit of new drugs (bortezomib, thalidomide, and lenalidomide). Summary of published clinical trials]. / Lécba AL-amyloidózy v roce 2012, prínos nových léku (bortezomibu, thalidomidu a lenalidomidu). Prehled publikovaných klinických studií

ABSTRACT

Until 2011, the gold standard of treatment for patients with AL amyloidosis was the combination of alkylating cytostatics (melphalan or cyclophosphamide) and dexamethasone. For a selected group of patients under 65 years of age with only moderate damage to their body caused by amyloid and with good cardiac function (EF> 40%), high-dose chemotherapy with autologous hematopoietic cell transplantation seems to be optimal. Patients with AL amyloidosis and low bone marrow plasma cell count generally undergo the harvest of hematopoietic cells from peripheral blood, followed by high-dose chemotherapy immediately after they are diagnosed. In contrast to multiple myeloma, high-dose chemotherapy is not preceded by several months of conventional treatment. The year 2012 witnessed a release of reports about extensive experience with new drugs that were used in Phase I and Phase II clinical trials, and in isolated cases also in Phase III, for the treatment of patients with AL amyloidosis. Based on these studies it can be concluded that among the new available drugs (bortezomib, thalidomide and lenalidomide) bortezomib is the drug with the greatest curative effect in patients with AL amyloidosis; it achieved 24-37% of complete remissions in monotherapy. The greatest number of treatment responses was reported during the treatment that combined bortezomib, alkylating cytostatics and dexamethasone. This treatment showed significantly more treatment responses during the first-line drug therapy than during therapies that followed. Clinical trials with lenalidomide combined with other drugs saw a lower number of treatment responses than the number described in treatment with bortezomib combined with other drugs. That is the reason why lenalidomide combinations are not considered the optimal first-line therapy, with the exception of AL amyloidosis with bortezomib contraindication (severe neuropathy caused by AL amyloidosis). It was confirmed that lenalidomide combined with other drugs could cause remission in patients whose disease was resistant to the initial bortezomib therapy. Lenalidomide (or alternatively also thalidomide) can therefore be used as second-line therapy if bortezomib therapy proves unsuccessful, with the possibility of achieving a complete remission. The increase in the number of complete remissions brought about by bortezomib therapies in patients with AL amyloidosis poses a question about which treatment should be used for younger patients with only moderate damage to their body, i.e. high-dose chemotherapy with autologous hematopoietic cell transplantation or combined treatment with bortezomib. Additional comparative studies are required to be able to answer that question and determine which of the aforesaid therapy modalities is optimal. A question still remains whether the increase in the number of complete remissions due to bortezomib will also bring about longer survival comparable to the results of high-dose chemotherapy treatment with autologous hematopoietic cell transplantation.