Bortezomib and dexamethasone for Japanese patients with relapsed and refractory multiple myeloma: a single center experience

Bortezomib therapy in a real-world setting in patients with relapsed or refractory multiple myeloma

Bortezomib is a proteasome inhibitor, approved for treating newly diagnosed and relapsed multiple myeloma (MM). This realworld, multicenter, observational, non-interventional study of bortezomib was designed to collect and analyze prospective data in Taiwanese patients with relapsed or refractory MM. The primary endpoints included clinical effectiveness outcomes (disease response, disease progression [PD], time-to-response, time-toprogression, response duration, and overall survival [OS]). Secondary endpoints were safety and healthcare resource utilization.

Total 100 patients (median [range] age 64.9 [37.0-85.5] years) were enrolled; 47 patients completed the study. Of the withdrawn patients (n=53), there were 48 deaths (PD-related death: n=35, adverse events [AEs]-related: n=12, other reason: n=1), and 5 due to loss to follow-up. Four patients in Cycle 1, 6 patients each in Cycle 2 and 5, 7 in Cycle 3, 10 patients in Cycle 4, 5 patients in Cycle 6, and 3 patients each in Cycle 7 and 8 achieved overall response during the study. Time-to-response was 4.68 months (95%CI: 3.2, NE) and response duration was 10.08 months (95%CI: 2.3, 28.6). Median OS was 9.8 months (95%CI: 3.8, 13.7), and median time-to-progression was 11.3 months (95%CI: 6.2, 20.2). Most common non-hematological AEs were diarrhea (n=32) and hypoesthesia (n=25); most common hematological AE was thrombocytopenia (n=18).

Efficacy and safety profile of bortezomib in Taiwanese patients with MM was similar to global and other Asian population. Study provides a critical insight on use of bortezomib in realworld clinical practice, which can be helpful for Taiwanese healthcare providers’ decision-making processes.

Bortezomib-based therapy for transplant-ineligible East Asian patients with newly diagnosed mantle-cell lymphoma

Introduction

This subgroup analysis of the LYM-3002 Phase III study (NCT00722137) investigated whether substituting bortezomib for vincristine in frontline R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) therapy could improve outcomes in East Asian patients with newly diagnosed mantle-cell lymphoma (MCL).

Materials and methods

A total of 121 East Asian patients from China, Taiwan, Japan, and the Republic of Korea with stage II–IV MCL who were ineligible or not considered for stem-cell transplantation were enrolled to six to eight 21-day cycles of R-CHOP or VR-CAP (R-CHOP with bortezomib replacing vincristine).

Results

The primary end point was progression-free survival. After a median follow-up of 42.4 months, median progression-free survival in East Asian patients was 13.9 (R-CHOP) versus 28.6 (VR-CAP) months (HR 0.7, P=0.157; 43% improvement with VR-CAP). Secondary end points (R-CHOP vs VR-CAP), including complete response rate (47% vs 63%), duration of complete response (median 16.6 vs 46.7 months), and treatment-free interval (median 21 vs 46.5 months), were improved with VR-CAP. VR-CAP was associated with increased but manageable toxicity. The most frequent adverse events were hematologic toxicities.

Conclusion

VR-CAP was effective in East Asian patients with newly diagnosed MCL, and could be considered for patients in whom stem-cell transplantation is not an option.

The addition of dexamethasone to bortezomib for patients with relapsed multiple myeloma improves outcome but ongoing maintenance therapy has minimal benefit

Despite the common practice of combining dexamethasone (Dex) with bortezomib (Bz) in patients with multiple myeloma (MM), until now there has been few prospective trials undertaken. We undertook a trial that recapitulated the original APEX study except that dexamethasone was incorporated from cycle 1. We also incorporated an exploratory maintenance component to the study. Twenty sites enrolled 100 relapsed/or refractory MM patients utilizing eight 21 day cycles of IV Bz [1.3 mg/m(2) ; Day (D) 1, 4, 8, 11] and three 35 day cycles; Bz (1.3 mg/m(2) ; Day (D) 1, 8, 15, 22). Our study was registered at www.clinicaltrials.gov (NCT00335348). Patients with stable disease or better received maintenance Bz (1.3 mg/m(2) ) every 14 days until progression. Dexamethasone (20 mg) was given for 2 days with each Bz dose. A prospectively defined matched-analysis of primary (overall response rate; ORR) and secondary endpoints [Complete Response (CR) and time to progression (TTP)] compared our cohort to those on the Bz arm of the APEX trial. The addition of Dex improved ORR by 20% (56% vs. 36%) [odds ratio 0.44 (0.24-0.80)]. The median TTP was also significantly longer (10.1 vs. 5.1 months) (hazard ratio 0.50, 95% CI: 0.35-0.72, P = 0.0002) and our landmark analysis demonstrated that this was largely due to the early use of dexamethasone, as we were unable to demonstrate any benefit of bortezomib/dexamethasone maintenance therapy.

The protective effects of lafutidine for bortezomib induced peripheral neuropathy

Peripheral neuropathy (PN) caused by bortezomib is an important complication of multiple myeloma. Subcutaneous injection of bortezomib reduced PN, but 24% of cases were grade 2 PN and 6% of cases were grade 3 PN. PN higher than grade 2 was not resolved by subcutaneous injection. PN higher than grade 3 has serious dose limiting toxicity and is the cause of discontinuing bortezomib treatment. Lafutidine is an H2-blocker with gastroprotective activity and is thought to function by increasing mucosal blood flow via capsaicin sensitive neurons. The same activity of lafutidine is considered to improve glossodynia and taxane induced PN. We hypothesized that lafutidine prevents or improves PN that is caused by bortezomib. In the current study, bortezomib was administered in the usual manner (intravenous administration of bortezomib 1.3 mg/m², twice a week for 2 weeks, followed by 1 week without treatment) for up to four cycles to compare our data with other studies. Lafutidine was administered orally at a dose of 10 mg twice daily. In our eight evaluated cases, the total occurrence of PN was four out of eight patients (50%). There were only grade 1 PN (4 out of 8) cases, and no cases higher than grade 2. We conclude that (1) the total occurrence of PN was not improved, (2) there was no PN after the first course, (3) there were only grade 1 cases and there were no cases higher than grade 2, and (4) no cases discontinued bortezomib treatment because of PN. This is the first report showing that lafutidine is useful for the amelioration of bortezomib induced PN.

Monosomy 13 in metaphase spreads is a predictor of poor long-term outcome after bortezomib plus dexamethasone treatment for relapsed/refractory multiple myeloma

We retrospectively investigated the prognostic impact of high-risk cytogenetic abnormalities (CAs) on the outcome of treatment with bortezomib plus dexamethasone (BD) in 43 relapsed/refractory (Rel/Ref) multiple myeloma patients. Fluorescence in situ hybridization (FISH) analysis identified del(13q) in 25 patients, t(4;14) in 14, t(14;16) in 4, 1q21 abnormality in 12 and del(17p) in 2, while G-banding also detected chromosome 13 monosomy (-13) in metaphase spreads from 7 patients. Eighteen of 25 patients with FISH-detected chromosome 13 abnormalities also exhibited other abnormalities. Median observation period was 510 days, and median overall survival (OS) and progression-free survival (PFS) were 912 days and 162 days, respectively. Detection of del(13q), t(4;14), t(14;16) or 1q21 abnormalities by FISH and co-occurrence of chromosome 13 abnormality with other abnormalities were not associated with poorer outcomes. In contrast, detection of -13 by G-banding in metaphase spreads showed significant association with shorter OS, although the overall response rate and PFS were not inferior to those for patients without -13 detected by G-banding. BD therapy may be a potent weapon for overcoming most classical high-risk CAs, while the detection of -13 in metaphase spreads may serve as a predictor of highly progressive disease, even when treated with BD.