Long-term results of thalidomide in refractory and relapsed multiple myeloma with emphasis on response duration

Mutant p53, the Mevalonate Pathway and the Tumor Microenvironment Regulate Tumor Response to Statin Therapy

Tumor cells have the ability to co-opt multiple metabolic pathways, enhance glucose uptake and utilize aerobic glycolysis to promote tumorigenesis, which are characteristics constituting an emerging hallmark of cancer. Mutated tumor suppressor and proto-oncogenes are frequently responsible for enhanced metabolic pathway signaling. The link between mutant p53 and the mevalonate (MVA) pathway has been implicated in the advancement of various malignancies, with tumor cells relying heavily on increased MVA signaling to fuel their rapid growth, metastatic spread and development of therapy resistance. Statin drugs inhibit HMG-CoA reductase, the pathway’s rate-limiting enzyme, and as such, have long been studied as a potential anti-cancer therapy. However, whether statins provide additional anti-cancer properties is worthy of debate. Here, we examine retrospective, prospective and pre-clinical studies involving the use of statins in various cancer types, as well as potential issues with statins’ lack of efficacy observed in clinical trials and future considerations for upcoming clinical trials.

Analysis of the Efficacy of Thalidomide Plus Dexamethasone-Based Regimens in Patients With Relapsed/Refractory Multiple Myeloma Who Received Prior Chemotherapy, Including Bortezomib and Lenalidomide: KMM-166 Study

BACKGROUND

For patients with multiple myeloma (MM) that relapsed after treatment with bortezomib- and lenalidomide-based regimens, there were no other treatment options in Korea until 2016. We aimed to determine the efficacy of thalidomide plus dexamethasone-based regimens in patients with relapsed/refractory MM (RRMM).

PATIENTS AND METHODS

We conducted a multicenter retrospective analysis in Korea for patients with RRMM treated with thalidomide-based regimens who previously received bortezomib and immunomodulatory agents (IMiDs), including thalidomide and lenalidomide.

RESULTS

In 47 patients with RRMM, the median age was 64 years and the median number of previous treatment lines, including bortezomib and IMiDs, was 3. Primary resistance to bortezomib and lenalidomide was observed in 12 (26%) and 8 (17%) patients, respectively. The most common regimen was a combination of thalidomide, cyclophosphamide, and dexamethasone. The overall response rate was 38%; 2 patients (4%) experienced a complete response, and 2 patients (4%) experienced a very good partial response. The overall response rate of patients previously exposed to thalidomide was 53%. The median progression-free survival was 5.9 months, and overall survival was 9.2 months. Patients with disease that responded to the thalidomide-based regimen had better progression-free survival compared to those who did not (median, 8.8 vs. 2.5 months; P = .008). The most common adverse events were anemia (51%) for hematologic toxicities and peripheral neuropathy (30%) for nonhematologic toxicities.

CONCLUSION

Thalidomide-based regimens are potential salvage treatment options for patients with RRMM, even those with disease with prior resistance to IMiDs.

Efficacy and toxicity of the combination chemotherapy of thalidomide, alkylating agent, and steroid for relapsed/refractory myeloma patients: a report from the Korean Multiple Myeloma Working Party (KMMWP) retrospective study

We analyzed the treatment responses, toxicities, and survival outcomes of patients with relapsed or refractory multiple myeloma who received daily thalidomide, cyclophosphamide, and dexamethasone (CTD) or daily thalidomide, melphalan, and prednisolone (MTP) at 17 medical centers in Korea. Three‐hundred and seventy‐six patients were enrolled. The combined chemotherapy of thalidomide, corticosteroid, and an alkylating agent (TAS) was second‐line chemotherapy in 142 (37.8%) patients, and third‐line chemotherapy in 135 (35.9%) patients. The response rate overall was 69.4%. Patients who were not treated with bortezomib and lenalidomide before TAS showed a higher response rate compared to those who were exposed to these agents. The estimated median progression‐free survival and overall survival times were 10.4 months and 28.0 months, respectively. The adverse events during TAS were generally tolerable, but 39 (10.4%) patients experienced severe infectious complications. There were no differences in terms of efficacy between CTD and MTP, but infectious complications were more common in CTD group. TAS is an effective treatment regimen which induces a high response rate in relapsed or refractory multiple myeloma patients. Due to the high incidence of grade 3 or 4 infection, proper management of infection is necessary during the TAS treatment, especially the CTD.

Activity of 129 single-agent drugs in 228 phase I and II clinical trials in multiple myeloma

BACKGROUND

More than 400 preclinical studies report ≥ 1 compound as cytotoxic to multiple myeloma (MM) cells; however, few of these agents became relevant in the clinic. Thus, the utility of such assays in predicting future clinical value is debatable.

PATIENTS AND METHODS

We examined the application of early-phase trial experiences to predict future clinical adoption. We identified 129 drugs explored as single agents in 228 trials involving 7421 patients between 1961 and 2013.

RESULTS

All drugs in common use in MM (melphalan, dexamethasone, prednisone, cyclophosphamide, bendamustine, thalidomide, lenalidomide, pomalidomide, bortezomib, carfilzomib, and doxorubicin) demonstrated a best reported response rate of ≥ 22%. Older agents, including teniposide, fotemustine, paclitaxel, and interferon, also appear active by this criterion; however, if mean response rates from all reported trials for an agent are considered, then only drugs with a mean response rate of 15% partial response are in clinical use.

CONCLUSION

Our analysis suggests that thresholds of 20% for best or 15% for mean response are highly predictive of future clinical success. Below these thresholds, no drug has yet reached regulatory approval or widespread use in the clinic. Thus, this benchmark provides 1 element of the framework for guiding choice of drugs for late-stage clinical testing.

Superiority of the Triple Combination of Bortezomib-Thalidomide-Dexamethasone Over the Dual Combination of Thalidomide-Dexamethasone in Patients With Multiple Myeloma Progressing or Relapsing After Autologous Transplantation: The MMVAR/IFM 2005-04 Randomized Phase III Trial From the Chronic Leukemia Working Party of the European Group for Blood and Marrow Transplantation

Purpose

This prospective multicenter phase III study compared the efficacy and safety of a triple combination (bortezomib-thalidomide-dexamethasone [VTD]) versus a dual combination (thalidomide-dexamethasone [TD]) in patients with multiple myeloma (MM) progressing or relapsing after autologous stem-cell transplantation (ASCT).

Patients and Methods

Overall, 269 patients were randomly assigned to receive bortezomib (1.3 mg/m2 intravenous bolus) or no bortezomib for 1 year, in combination with thalidomide (200 mg per day orally) and dexamethasone (40 mg orally once a day on 4 days once every 3 weeks). Bortezomib was administered on days 1, 4, 8, and 11 with a 10-day rest period (day 12 to day 21) for eight cycles (6 months), and then on days 1, 8, 15, and 22 with a 20-day rest period (day 23 to day 42) for four cycles (6 months).

Results

Median time to progression (primary end point) was significantly longer with VTD than TD (19.5 v 13.8 months; hazard ratio, 0.59; 95% CI, 0.44 to 0.80; P = .001), the complete response plus near-complete response rate was higher (45% v 21%; P = .001), and the median duration of response was longer (17.9 v 13.4 months; P = .04). The 24-month survival rate was in favor of VTD (71% v 65%; P = .093). Grade 3 peripheral neuropathy was more frequent with VTD (29% v 12%; P = .001) as were the rates of grades 3 and 4 infection and thrombocytopenia.

Conclusion

VTD was more effective than TD in the treatment of patients with MM with progressive or relapsing disease post-ASCT but was associated with a higher incidence of grade 3 neurotoxicity.

Thalidomide, dexamethasone and lovastatin with autologous stem cell transplantation as a salvage immunomodulatory therapy in patients with relapsed and refractory multiple myeloma

The treatment of patients with multiple myeloma usually includes many drugs including thalidomide, lenalidomide and bortezomib. Lovastatin and other inhibitors of HMG-CoA reductase demonstrated to exhibit antineoplasmatic and proapoptotic properties in numerous in vitro studies involving myeloma cell lines. We treated 91 patients with relapsed or refractory multiple myeloma with thalidomide, dexamethasone and lovastatin (TDL group, 49 patients) or thalidomide and dexamethasone (TD group, 42 patients). A clinical response defined of at least 50% reduction of monoclonal band has been observed in 32% of TD patients and 44% of TDL patients. Prolongation of overall survival and progression-free survival in the TDL group as compared with the TD group has been documented. The TDL regimen was safe and well tolerated. The incidence of side effects was comparable in both groups. Plasma cells have been cultured in vitro with thalidomide and lovastatin to assess the impact of both drugs on the apoptosis rate of plasma cells. In vitro experiments revealed that the combination of thalidomide and lovastatin induced higher apoptosis rate than apoptosis induced by each drug alone. Our results suggest that the addition of lovastatin to the TD regimen may improve the response rate in patients with relapsed or refractory myeloma.

Impact on response and survival of DNA repair single nucleotide polymorphisms in relapsed or refractory multiple myeloma patients treated with thalidomide

Single nucleotide polymorphisms (SNPs) in 12 genes involving multidrug resistance, drug metabolic pathways, DNA repair systems and cytokines were examined in 28 patients with relapsed/refractory multiple myeloma (MM) treated with single agent thalidomide and the results were correlated with response, toxicity and overall survival (OS). The response rate was higher in patients with SNPs in ERCC1 (rs735482) (p=0.006), ERCC5 (rs17655) (p=0.04) or XRCC5 (rs1051685) (p=0.013). Longer OS was associated with the SNP in ERCC1 (rs735482) (p=0.005) and XRCC5 (rs1051685) (p=0.02). Finally, polymorphism in GSTT1 (rs4630) was associated with a lower frequency of thalidomide-induced peripheral neuropathy (p=0.04).

Lenalidomide, melphalan, prednisone and thalidomide (RMPT) for relapsed/refractory multiple myeloma

This multicenter, open-label, non-comparative phase II trial evaluated the safety and efficacy of salvage therapy with lenalidomide, melphalan, prednisone and thalidomide (RMPT) in patients with relapsed/refractory multiple myeloma (MM). Oral lenalidomide (10 mg/day) was administered on days 1-21, and oral melphalan (0.18 mg/kg) and oral prednisone (2 mg/kg) on days 1-4 of each 28-day cycle. Thalidomide was administered at 50 mg/day or 100 mg/day on days 1-28; six cycles were administered in total. Maintenance included lenalidomide 10 mg/day on days 1-21, until unacceptable adverse events or disease progression. Aspirin (100 mg/day) was given as thromboprophylaxis. A total of 44 patients with relapsed/refractory MM were enrolled and 75% achieved at least a partial response (PR), including 32% very good PR (VGPR) and 2% complete response (CR). The 1-year progression-free survival (PFS) was 51% and the 1-year overall survival (OS) from study entry was 72%. Grade 4 hematologic adverse events included neutropenia (18%), thrombocytopenia (7%) and anemia (2%). Grade 3 non-hematologic adverse events were infections (14%), neurological toxicity (4.5%) and fatigue (7%). No grade 3/4 thromboembolic events or peripheral neuropathy were reported. In conclusion, RMPT is an active salvage therapy with good efficacy and manageable side effects. This study represents the basis for larger phase III randomized trials.

Pulsed cyclophosphamide, thalidomide and dexamethasone regimen for previously treated patients with multiple myeloma: Long term follow up and disease control after subsequent treatments

There are limited data regarding the long term follow up after thalidomide based regimen and the outcome of patients when they progress and they receive further treatment. We reassessed our original series of 43 patients with previously treated multiple myeloma who had received a pulsed cyclophosphamide, thalidomide, dexamethasone (CTD) regimen. Among the 43 patients, 14 did not respond to pulsed CTD and 29 (67%) achieved at least a partial response. The median PFS for all patients was 10 months. After a median follow up of 24 months (range 1 - 62), the 3 year PFS is 14% and 3 patients remain off treatment and without progression for 55+, 55+ and 56+ months respectively. Moreover, 28% of patients who progressed after CTD achieved a partial response after subsequent treatment which included thalidomide, bortezomib or lenalidomide. The median PFS of these patients was 5 months and the 1 year PFS was 20%. Furthermore, 31% of patients who had responded to CTD and then progressed (CTD sensitive) responded to subsequent treatment. We conclude that some patients enjoy long responses after CTD and that several patients who progress after CTD may respond to treatment with a novel agent-based regimen.

Long-term outcome in relapsed and refractory multiple myeloma treated with thalidomide. Balancing efficacy and side-effects

A total of 303 MM patients were retrospectively reviewed to evaluate long-term efficacy and toxicity of thalidomide alone or in combination with steroids. Overall response rate was 57% (CR/VGPR 12%). Median TTP, PFS and OS were 13.4 months, 20.6 months, and 26.2 months, respectively. PFS and OS were significantly different according to response (p < 0.0001), with better outcome in patients achieving CR/VGPR (PFS and OS 35.4 months and 63 months, respectively). PFS and OS of patients achieving SD or PR were overlapping (p = 0.3). The addition of steroids significantly increased the response rate (p = 0.01). The most clinically relevant complications were neuropathy (40%), constipation (26%), thromboembolic events (7%). Thalidomide was reduced for toxicity in 68 patients (24%) and permanently discontinued in 36 (12%). In conclusion, thalidomide produces high response rate in relapsed/refractory MM. The best outcome is observed in patients with good quality response, but even patients with suboptimal response may obtain durable survival.

Plasma cell leukemia: a highly aggressive monoclonal gammopathy with a very poor prognosis

Plasma cell leukemia (PCL) is an aggressive variant of multiple myeloma and is characterized by the presence of >20% and/or an absolute number of greater 2 x 10(9)/L plasma cells circulating in the peripheral blood. PCL represents approximately 2-4% of all MM diagnosis and exists in two forms: primary PCL (PPCL, 60% of cases) presents de novo, whereas secondary PCL (SPCL, accounts for the remaining 40%) consists of a leukemic transformation in patients with a previously diagnosed MM. Because the mechanisms contributing to the pathogenesis of PCL are not fully understood, immunophenotyping, genetic evaluation (conventional karyotype, FISH, GEP and array-CGH), and immunohistochemistry are really important tools to investigate why plasma cells escape from bone marrow and become highly aggressive. Since treatment with standard agents and steroids is poorly effective, a combination of new drugs as part of the induction regimens and bone marrow transplant (autologous and allogeneic approaches) could nearly overcome the poor prognosis exhibited by PCL patients.

[New therapeutic strategies for multiple myeloma. Efficacy and cost-effectiveness analyses]

The objective of the present article is the review of the most important therapeutic innovations in the treatment of multiple myeloma in terms of efficacy and cost-effectiveness. Besides autologous transplant with peripheral-blood stem-cell, thalidomide establishes as one of the most powerful therapeutic tools in induction and maintenance treatment and together with lenalidomide and bortezomib as therapy for relapsing/refractory multiple myeloma. Considering, the last named situation thalidomide can be an adequate therapeutical option in combination with dexamethasone. Under a strictly pharmacoeconomic point of view, lenalidomide and bortezomib seem to be additional alternatives in patients previously treated with thalidomide.

Thalidomide for treatment of multiple myeloma: 10 years later

Thalidomide, bortezomib, and lenalidomide have recently changed the treatment paradigm of myeloma. In young, newly diagnosed patients, the combination of thalidomide and dexamethasone has been widely used as induction treatment before autologous stem cell transplantation (ASCT). In 2 randomized studies, consolidation or maintenance with low-dose thalidomide has extended both progression-free and overall survival in patients who underwent ASCT at diagnosis. In elderly, newly diagnosed patients, 3 independent randomized studies have reported that the oral combination of melphalan and prednisone plus thalidomide (MPT) is better than the standard melphalan and prednisone (MP). These studies have shown better progression-free survival, and 2 have shown improved overall survival for patients assigned to MPT. In refractory-relapsed disease, combinations including thalidomide with dexamethasone, melphalan, doxorubicin, or cyclophosphamide have been extensively investigated. The risks of side effects are greater when thalidomide is used in combination with other drugs. Thromboembolism and peripheral neuropathy are the major concern. The introduction of anticoagulant prophylaxis has reduced the rate of thromboembolism to less than 10%. Immediate thalidomide dose reduction or discontinuation when paresthesia is complicated by pain or motor deficit has decreased the severity of neuropathy. Future studies will define the most effective or the best sequence of combinations which could improve life expectancy.

Complications of multiple myeloma

Multiple myeloma, also known as myeloma or plasma cell myeloma, is a progressive hematologic disease. Complications of multiple myeloma include renal insufficiency, hematologic complications (anemia, bone marrow failure, bleeding disorders), infections, bone complications (pathologic fractures, spinal cord compression, hyercalcemia), and neurologic complications (spinal cord and nerve root compression, intracranial plasmacytomas, leptomeningeal involvement, among others). This article reviews these various complications connected to multiple myeloma, examining their various causes and possible treatment.

Low-dose thalidomide plus low-dose dexamethasone therapy in patients with refractory multiple myeloma

We report the results of a non-randomized phase II study of low-dose thalidomide plus low-dose dexamethasone therapy in 66 patients with refractory multiple myeloma. The overall response rate (near complete, partial and minimal response) was 63.6%, and progression-free and overall survival periods were 6.2 and 25.4 months. In adverse events, the incidence of peripheral neuropathy and deep vein thrombosis was lower than the data reported in USA and Europe. On the other hand, leukopenia was observed in 41% of patients, including 11% of those with Grade 3. Leukopenia was closely related to pretreatment pancytopenia, especially thrombocytopenia. The incidence of adverse events related to dexamethasone was low. In conclusion, low-dose thalidomide plus low-dose dexamethasone therapy was as effective as high-dose thalidomide plus high-dose dexamethasone therapy in patients with refractory multiple myeloma. Leukopenia is one of the most serious adverse events in Japanese patients, especially in patients with pretreatment pancytopenia.

Angiogenesis and antiangiogenic therapy in hematologic malignancies

Angiogenesis, the generation of new blood capillaries from preexisting blood vessels, is tightly regulated in the adult organism. Although many of the initial studies were performed on solid tumors, increasing evidence indicates that angiogenesis also plays an important role in hematologic malignancies. Overexpression of angiogenic factors in particular VEGF and bFGF in most hematologic malignancies may explain the increased angiogenesis found in these malignancies and correlate with poor prognosis as well as decreased overall survival. In this review, we focus on the current literature of angiogenesis and antiangiogenic therapy in hematologic malignancies, and finally describe advances and potential challenges in antiangiogenic treatment in hematologic malignancies.