Short-course bortezomib-based retreatment for patients with multiple myeloma who had received bortezomib-thalidomide-dexamethasone (VTD) as an initial therapy: A single-center case series

Abstract

Studies have shown that the bortezomib-based retreatment of patients with multiple myeloma (MM) may prolong control of the disease. The optimal duration of bortezomib-based retreatment in relapsed or refractory MM is unknown. The present retrospective study evaluated the efficacy and safety of short-course bortezomib-based retreatment in patients who had received bortezomib-thalidomide-dexamethasone (VTD) treatment for the initial therapy of newly diagnosed MM. The clinical records of 20 patients who had received short-course bortezomib-based retreatment in a single center were reviewed. Patients received a median of two cycles of bortezomib as the retreatment and the overall response rate was 90%. Six (30%), eight (40%) and four (20%) patients achieved a complete response (CR), a very good partial response and a partial response, respectively. Of the 10 patients who had achieved a CR during the initial VTD treatment, six experienced a repeat CR during the retreatment. The median duration of the response was nine months and the median time to progression was 10.5 months. The most common grade I and II adverse events were thrombocytopenia and neutropenia. The short-course bortezomib-based retreatment was well tolerated and the favorable response rates observed suggest that it may be an effective and convenient treatment option for certain patients, particularly elderly patients.

Bortezomib retreatment for relapsed and refractory multiple myeloma in real‐world clinical practice

“…Over half of the retreated patients had advanced stage III MM at initial diagnosis, and the patient population, as a whole, was heavily pretreated before receiving bortezomib retreatment (median of four prior lines of therapy). Our findings compare favorably with those from the bortezomib pivotal phase 2 study, in which the ≥PR rate was 40% in 130 patients who had received a median of 2, rather than 4, prior lines of therapy, and are also in line with the results of other previous prospective and retrospective clinical studies …”

“…Consistent with previous prospective and retrospective studies, patient subgroup analyses showed that the response rate at retreatment was significantly higher in patients who achieved a deeper response with initial bortezomib. Yet, it is notable that 20% of patients with ≤MR to initial bortezomib achieved ≥PR following bortezomib retreatment, indicating that lack of a major response initially does not preclude a better response at a later stage.…”

“…Our findings compare favorably with those from the bortezomib pivotal phase 2 study, in which the ≥PR rate was 40% in 130 patients who had received a median of 2, rather than 4, prior lines of therapy, 32 and are also in line with the results of other previous prospective and retrospective clinical studies. [23][24][25][26][27]29,33,34 The majority (77%) of patients included in this analysis were enrolled at clinics in countries within the European Union. Most of these patients received bortezomib-dexamethasone or bortezomib monotherapy for initial bortezomib treatment, and bortezomib retreatment within eVOBS.…”

“…Retreatment with bortezomib is, therefore, a viable option for patients with progressive disease (PD), either as a subsequent or later line of therapy after initial bortezomib treatment. A number of retrospective studies, prospective clinical trials, and a recent meta‐analysis have demonstrated the viability of retreatment with bortezomib, all showing bortezomib‐based retreatment to be efficacious and tolerable . On the basis of the prospective clinical study by Petrucci et al, the indication for bortezomib in the US was expanded in late 2014 to include retreatment in patients who have previously responded to bortezomib and who have relapsed at least 6 months after completing prior bortezomib treatment…”