Stem cell mobilization and autologous stem cell transplantation after pretreatment with bendamustine, prednisone and bortezomib (BPV) in newly diagnosed multiple myeloma

Revisiting the Role of Alkylating Agents in Multiple Myeloma: Up-to-Date Evidence and Future Perspectives

From the 1960s to the early 2000s, alkylating agents (e.g., melphalan, cyclophosphamide, and bendamustine) remained a key component of standard therapy for newly-diagnosed or relapsed/refractory multiple myeloma (MM). Later on, their associated toxicities (including second primary malignancies) and the unprecedented efficacy of novel therapies have led clinicians to increasingly consider alkylator-free approaches. Meanwhile, new alkylating agents (e.g., melflufen) and new applications of old alkylators (e.g., lymphodepletion before chimeric antigen receptor T-cell [CAR-T] therapy) have emerged in recent years. Given the expanding use of antigen-directed modalities (e.g., monoclonal antibodies, bispecific antibodies, and CAR-T therapy), this review explores the current and future role of alkylating agents in different treatment settings (e.g., induction, consolidation, stem cell mobilization, pre-transplant conditioning, salvage, bridging, and lymphodepleting chemotherapy) to ellucidate the role of alkylator-based regimens in modern-day MM management.

Impact of the changing landscape of induction therapy prior to autologous stem cell transplantation in 540 newly diagnosed myeloma patients: a retrospective real-world study

Introduction

Autologous stem cell transplantation (ASCT) is the standard treatment for younger patients with newly diagnosed multiple myeloma (MM). However, due to restrictive exclusion criteria, more than half of eligible patients are usually excluded from transplant studies.

Methods

This retrospective monocentric analysis included 540 patients with MM who received an ASCT between 1996 and 2019.

Results

Up to 2005, induction therapy consisted mainly of conventional chemotherapies, e.g. vincristine/doxorubicin/dexamethasone (VAD). In the following years, the triple-combinations based on bortezomib coupled with doxorubicin/dexamethasone (PAD), melphalan/prednisolone (VMP), cyclophposphamide/dexamethasone (VCD) or bendamustine/prednisolone (BPV) became the most popular treatment options. A progressive improvement in PFS was observed in patients treated with the two current induction therapies BPV (47 months) or VCD (54 months) compared to VAD (35 months, p < 0.03), PAD (39 months, p < 0.01 and VMP (36 months, p < 0.01). However, there was no significant difference in median OS (VAD 78, PAD 74, VMP 72, BPV 80 months and VCD not reached). In our analysis, we also included 139 patients who do fulfill at least one of the exclusion criteria for most phase 3 transplant studies (POEMS/amyloidosis/plasma cell leukemia, eGFR < 40 mL/min, severe cardiac dysfunction or poor general condition). Outcome for these patients was not significantly inferior compared to patients who met the inclusion criteria for most of the transplant studies with PFS of 36 vs 41 months (p = 0.78) and OS of 78 vs 79 months (p = 0.34).

Conclusions

Our real-world data in unselected pts also stress the substantial value of ASCT during the first-line treatment of younger MM pts.

Prognostic impact of rapid reduction of involved free light chains in multiple myeloma patients under first-line treatment with Bendamustine, Prednisone, and Bortezomib (BPV)

Introduction

Light chain involvement is observed in almost every patient (pt) with newly diagnosed multiple myeloma (MM). Owing to a relatively short half-life, rapid reduction in the involved free light chain (iFLC) is of potential prognostic value.

Methods

This retrospective analysis included 92 pts with newly diagnosed MM treated with bendamustine, prednisone, and bortezomib (BPV).

Results

After a median number of two (range 1–5) BPV cycles, the majority of pts (n = 86; 93%) responded with either sCR (n = 21), CR (n = 1), nCR (n = 25), VGPR (n = 20), or PR (n = 19). PFS and OS at 48 months were 39% and 67%, respectively. At baseline, 79 out of 92 pts (86%) had iFLC levels above the upper standard level and an abnormal ratio of involved to uninvolved free light chain ≥ 8. In a subgroup analysis of these pts, we evaluated the prognostic importance of an early reduction of the iFLC during the first two BPV cycles. A reduction ≥ 50% of the iFLC on day 8 of the first cycle was observed in 31 of 69 pts. These pts had a significantly better median PFS of 49 months as compared to 20 months in 38 pts with a lower iFLC reduction (p = 0.002). In contrast, OS did not differ significantly with a 48 months survival of 77% vs 69% (p > 0.05).

Conclusion

These results indicate that a rapid decrease in the iFLC on day 8 is an early prognostic marker for newly diagnosed MM pts undergoing BPV treatment.

Treatment with brentuximab vedotin plus bendamustine in unselected patients with CD30-positive aggressive lymphomas

OBJECTIVES

A treatment regimen consisting of bendamustine and brentuximab vedotin (BV) has been described as a highly potent salvage therapy and as an effective induction therapy leading to high response rates before autologous stem cell transplantation (ASCT) in patients with classical Hodgkin lymphoma (cHL). In this retrospective analysis, we aimed to assess this therapy's efficacy in unselected patients with cHL and CD30+ peripheral T-cell lymphoma (PTCL).

PATIENTS AND METHODS

Data of 28 patients with cHL and five patients with PTCL treated with a combination of bendamustine and BV at three Austrian tertiary cancer centers were analyzed.

RESULTS

In patients with cHL, the ORR was 100% (78.6% CR, 21.4% PR). After 17 months median follow-up, median survival times were not reached; 1-year PFS was 81.9%, and 1-year OS was 95.7%. Thirteen eligible patients (46.4%) successfully underwent planned ASCT after salvage therapy with bendamustine and BV and subsequent high-dose chemotherapy. Three of the five PTCL patients achieved CR, while two did not respond and died during or shortly after therapy.

CONCLUSION

A combination of bendamustine and BV is an effective salvage and induction therapy before ASCT in patients with relapsed/refractory cHL. Further research is warranted to evaluate the use in patients with PTCL.

Lenalidomide in combination with bendamustine and prednisolone in relapsed/refractory multiple myeloma: results of a phase 2 clinical trial (OSHO-#077)

INTRODUCTION

While lenalidomide monotherapy is established for relapsed and/or refractory multiple myeloma (MM) treatment, combination therapies including lenalidomide are still under investigation in a number of phase 2/3 studies. In the current study, a treatment regime of lenalidomide (Revlimid^®), bendamustine and prednisolone (RBP) was tested in patients with relapsed/refractory MM.

METHODS

In the previously completed phase 1 study RBP with a dose of 75 mg/m² bendamustine days 1-2, prednisolone 100 mg days 1-4 and 25 mg lenalidomide days 1-21 was well tolerated.

RESULTS

Between July 2011 and September 2013, 25 patients were included in this analysis. The median number of previous treatments was 1 (range 1-2). Twenty-two patients (88%) responded after at least two cycles of RBP (one sCR, five nCR, eight VGPR and eight PR). The median time to first haematological response was 28 days, and median time to best response was 56 days. Due to increased haematological toxicity a dose reduction in most patients required in subsequent cycles of therapy. The median progression-free and overall survival was 22 and 38 months, respectively. In conclusion RBP is a highly effective therapy for patients with relapsed/refractory MM. In contrast to our phase 1 study, dose reduction was necessary in many patients because of haematological toxicity.

Phase II study of bendamustine, bortezomib and dexamethasone (BBD) in the first-line treatment of patients with multiple myeloma who are not candidates for high dose chemotherapy

The combination of bendamustine, bortezomib and dexamethasone (BBD) was evaluated as a first-line therapy for multiple myeloma. The original treatment regimen of bendamustine 80 mg/m² , days 1, 4; bortezomib 1·3 mg/m² , days 1, 4, 8, 11; dexamethasone 40 mg, days 1, 2, 3, 4 on a 28-day cycle (up to 8 cycles) was efficacious but determined relatively toxic in an interim analysis. The regimen was amended to bendamustine 80 mg/m² , days 1, 2; bortezomib 1·3 mg/m² , days 1, 8, 15; dexamethasone 20 mg, days 1, 2, 8, 9, 15, 16 every 28 days (up to 8 cycles), then maintenance 1·3 mg/m² IV bortezomib every 2 weeks. Fifty-nine patients were enrolled. Primary endpoint was complete response (CR) rate. The original schema was given for a median of 7 cycles (range 1-8); modified schema was given for a median of 8 cycles (range 1-8) plus maintenance. Overall response was 91%, CR was 9%. Median follow-up was 19·1 months; median progression-free survival was 11·1 months and 18·9 months on the original and modified regimens, respectively. The most common Grade 3/4 adverse events were fatigue and neuropathy. The combination of BBD is tolerable and efficacious in this patient population. Modifications to decrease intensity but increase duration translated to better outcomes.

Bendamustine in multiple myeloma

The advent of high-dose melphalan with autologous stem-cell transplantation (ASCT), the availability of novel agents such as thalidomide, lenalidomide (immunomodulatory drugs or IMiDs) and bortezomib (proteasome inhibitor) and improvements in supportive care have allowed to increase overall survival in multiple myeloma (MM) patients; nevertheless, MM remains an incurable pathology. For this reason, newer agents are required for continued disease control. Bendamustine is an old drug rediscovered in the last decade. In fact, its unique mechanism of action with structural similarities to both alkylating agents and antimetabolities, but which is not cross-resistant to alkylating agents, has reawakened interest in the use of this drug in the treatment of MM. Studies have proven the safety and efficacy of bendamustine administered alone or in combination with new drugs in both upfront and relapse/refractory settings of MM patients, including those with renal impairment. Moreover, bendamustine has been successfully used as conditioning for autologous stem-cell transplantation. Finally, the use of bendamustine does not compromise peripheral blood stem-cell collection. This drug is generally well tolerated, with the majority of adverse events being due to myelosuppression. Non-haematological adverse events are infrequent and usually mild.