Modified adriamycin-vincristine-dexamethasone (m-VAD) in primary refractory and relapsed plasma cell myeloma: an NCI (Canada) pilot study. The National Cancer Institute of Canada Clinical Trials Group

Emerging therapies for the treatment of relapsed or refractory multiple myeloma

Encouraging progress has been made in the treatment of patients with relapsed/refractory multiple myeloma (MM). The rapidly evolving understanding of key pathways responsible for tumor growth and survival has led to the development of novel agents (including immunomodulatory drugs, proteasome inhibitors, histone deacetylase inhibitors, and other targeted agents) with the potential to provide significant improvements in response and survival, and influence treatment guidelines. This review summarizes recent advances in understanding of the biology of relapsed/refractory MM and clinical trials with novel targeted agents that are currently under investigation for patients with this disease.

Lenalidomide, adriamycin, and dexamethasone (RAD) in patients with relapsed and refractory multiple myeloma: a report from the German Myeloma Study Group DSMM (Deutsche Studiengruppe Multiples Myelom)

We conducted a phase 1/2 trial combining lenalidomide (R) with adriamycin (A) and dexamethasone (D) for relapsed and relapsed-refractory myeloma to determine tolerability and efficacy of this novel regimen, RAD, delivered for six 28-day cycles. A total of 69 intensively pretreated patients with a median age of 65 years (range, 46-77 years) were enrolled. Using pegfilgrastim (G), the maximum tolerated dose (MTD) was formally not reached at the highest dose level (R, 25 mg on days 1-21; A, 9 mg/m(2) intravenously on days 1-4; and D, 40 mg on days 1-4 and 17-20; dose level 5+G), which was then used to determine efficacy. Grades 3/4 neutropenia and thrombocytopenia were seen in 48% and 38% of patients, respectively. Thromboembolic events occurred in 4.5% and severe infections in 10.5% of patients. On an intent-to treat analysis, overall response rate (ORR) was 73% for the whole study and 77% including 74% complete response (CR) plus very good partial response (VGPR) for dose level 5+G. Response rates and progression-free survival did not differ between relapsed and relapsed-refractory patients. Deletion of chromosome 17p and elevated beta(2)-microglobulin were associated with significantly inferior response and shortened time to progression. In conclusion, RAD induces substantial and durable remission with an acceptable toxicity profile in patients with relapsed and relapsed-refractory myeloma. This trial was registered at www.ClinicalTrials.gov as no. NCT00306813.

Induction therapy before transplantation in multiple myeloma: new strategies to achieve complete response

The application of high-dose therapy combined with stem cell support has greatly improved the outcome of treatment in patients with multiple myeloma. However, induction treatments are rapidly changing, and it has now become possible to achieve complete responses in 30%-40% of newly diagnosed patients before high-dose therapy. The effect of the improved induction regimens on the results of the whole treatment strategy and the long-term outcome will have to be evaluated in prospective randomized trials. The introduction of new drugs such as thalidomide and bortezomib have contributed significantly to this changed remission status and may ultimately lead to a change of concept about the value of remission-induction therapy. In this article, we review various regimens that are used for induction therapy in preparation for stem cell transplantation and describe the impact these novel agents could have on patient remission status.

Bortezomib or high-dose dexamethasone for relapsed multiple myeloma

BACKGROUND

This study compared bortezomib with high-dose dexamethasone in patients with relapsed multiple myeloma who had received one to three previous therapies.

METHODS

We randomly assigned 669 patients with relapsed myeloma to receive either an intravenous bolus of bortezomib (1.3 mg per square meter of body-surface area) on days 1, 4, 8, and 11 for eight three-week cycles, followed by treatment on days 1, 8, 15, and 22 for three five-week cycles, or high-dose dexamethasone (40 mg orally) on days 1 through 4, 9 through 12, and 17 through 20 for four five-week cycles, followed by treatment on days 1 through 4 for five four-week cycles. Patients who were assigned to receive dexamethasone were permitted to cross over to receive bortezomib in a companion study after disease progression.

RESULTS

Patients treated with bortezomib had higher response rates, a longer time to progression (the primary end point), and a longer survival than patients treated with dexamethasone. The combined complete and partial response rates were 38 percent for bortezomib and 18 percent for dexamethasone (P<0.001), and the complete response rates were 6 percent and less than 1 percent, respectively (P<0.001). Median times to progression in the bortezomib and dexamethasone groups were 6.22 months (189 days) and 3.49 months (106 days), respectively (hazard ratio, 0.55; P<0.001). The one-year survival rate was 80 percent among patients taking bortezomib and 66 percent among patients taking dexamethasone (P=0.003), and the hazard ratio for overall survival with bortezomib was 0.57 (P=0.001). Grade 3 or 4 adverse events were reported in 75 percent of patients treated with bortezomib and in 60 percent of those treated with dexamethasone.

CONCLUSIONS

Bortezomib is superior to high-dose dexamethasone for the treatment of patients with multiple myeloma who have had a relapse after one to three previous therapies.

Role of liposomal anthracyclines in the treatment of multiple myeloma

Patients with multiple myeloma (MM) typically respond to initial chemotherapy, but almost all patients relapse with a median survival of approximately 5 years. Combining vincristine and conventional doxorubicin with oral dexamethasone (VAD) or reduced-dose dexamethasone (VAd) provides rapid response in many patients, but its use is limited by toxicity concerns and the inconvenience of continuous infusions in each cycle. Use of pegylated liposomal doxorubicin (Doxil/Caelyx [PLD]) and vincristine intravenous injection with oral dexamethasone (DVD) or reduced-dose dexamethasone (DVd) is safe and effective for the management of newly diagnosed or relapsed/refractory MM. Controlled trials showed that DVD/DVd is at least as effective as VAD/VAd for the treatment of MM, but DVd is associated with less neutropenia and alopecia in addition to requiring fewer days in the hospital or clinic for drug administration. DVd therapy has also been reported to be associated with an antiangiogenic effect not observed with VAD. Another liposomal anthracycline, liposomal daunorubicin (DaunoXome [DNX]), has been investigated in MM and preliminary data suggest that it is safe and effective, but studies comparing it with other regimens have not been reported. Early results from ongoing trials suggest that adding thalidomide, bortezomib, or other immune modulators to PLD-based chemotherapy may improve efficacy.

New treatment strategies for multiple myeloma

Multiple myeloma remains an incurable disease despite aggressive, high-dose therapy and intensive supportive care. Newer therapies with good safety profiles are needed for patients with multiple myeloma to improve the quality of responses and prolong survival. Novel treatment strategies for multiple myeloma include replacing conventional doxorubicin with pegylated liposomal doxorubicin and reducing the dexamethasone dose (DVd) in the widely accepted VAD (vincristine, conventional doxorubicin, dexamethasone) regimen to improve the safety profile. Because of its antiangiogenic and immunomodulatory effects, thalidomide has also been explored for use in the treatment of multiple myeloma and has demonstrated increased response rates when used in combination with dexamethasone. These findings subsequently led to the evaluation of the role of thalidomide in combination with pegylated liposomal doxorubicin, vincristine, and reduced-dose dexamethasone (the DVd-T regimen). This regimen was associated with response rates greater than 80% in patients with both newly diagnosed and relapsed/refractory multiple myeloma. Future applications of this and similar regimens for the treatment of multiple myeloma are currently being explored.

Vincristine, Doxorubicin and Dexamethasone (VAD) Regimen for Multiple Myeloma

The increasing complexity of cancer chemotherapy makes it mandatory that pharmacists be familiar with these highly toxic agents. This column focuses on the commercially available and investigational agents used to treat malignant diseases and reviews issues related to the preparation, dispensing, and administration of cancer chemotherapy.

Pegylated liposomal doxorubicin, vincristine, and reduced-dose dexamethasone as first-line therapy for multiple myeloma

In patients with multiple myeloma (MM) who may ultimately receive active therapy, the combination of VAD (vincristine, doxorubicin, and dexamethasone) has been shown to be effective. However, the use of VAD is complicated by inherent risks that result from the use of central venous catheters, steroid toxicity, and by doxorubicin-associated adverse events such as cardiotoxicity and alopecia. To address these issues, a phase II trial investigating the combination of vincristine, pegylated liposomal doxorubicin, and reduced-schedule oral dexamethasone in the first-line treatment of patients with MM has been conducted. Patients with symptomatic, newly diagnosed MM were treated with intravenous (i.v.) pegylated liposomal doxorubicin 40 mg/m2 and vincristine 2 mg on day 1, along with dexamethasone 40 mg/day given either i.v. or orally for 4 days, every 4 weeks for a minimum of 6 cycles. Responses were reported in 29 patients (88%), and an additional 3 patients achieved stable disease. The median time to maximal response was 5.8 months (range, 0.7-13.6 months), and median overall survival time is estimated to be 60 months. This treatment regimen was well tolerated, and the most common grade 3/4 adverse events included hand-foot syndrome (21%), neutropenia (30%), anemia (21%), and mucositis (12%). Based on these results, the vincristine/liposomal doxorubicin/dexamethasone regimen appears to be effective and well tolerated in the first-line treatment of MM.

Modifications to Therapy for Multiple Myeloma: Pegylated Liposomal Doxorubicin in Combination With Vincristine, Reduced‐Dose Dexamethasone, and Thalidomide

The combination of vincristine, doxorubicin, and dexamethasone is an effective treatment for multiple myeloma that produces a more rapid response than other regimens, probably a function of the high-dose, intense steroid schedule. However, vincristine/doxorubicin/dexamethasone administration requires a 96-hour continuous infusion delivered via a central venous catheter, which necessitates hospitalization in a large number of patients and may increase the risk for infection. Moreover, the high dosages of corticosteroids required with this regimen can cause substantial toxicity. Therefore, a number of modifications to the regimen have been evaluated in an effort to improve its tolerability and efficacy. These include replacing doxorubicin with pegylated liposomal doxorubicin and using a reduced frequency of dexamethasone, and, later, the addition of thalidomide. The results of an ongoing study demonstrated that this latest regimen (including thalidomide) is associated with an improved response rate and a higher quality of response compared with previous regimens in patients with relapsed/refractory multiple myeloma. This modified regimen is well tolerated when prophylactic and supportive measures are incorporated. Although additional follow-up is required to determine the effect on survival, this modified regimen has significant potential in the management of advanced myeloma.

A Phase II trial of pegylated liposomal doxorubicin, vincristine, and reduced-dose dexamethasone combination therapy in newly diagnosed multiple myeloma patients

BACKGROUND

Patients with multiple myeloma (MM) have increased bone marrow angiogenesis, a low plasma cell labeling index, and multidrug resistance (the primary cause of chemotherapy failure). MM patients receiving the vincristine, doxorubicin, and dexamethasone (VAD) regimen develop resistance and cardiac and steroid toxicity. Pegylated liposomal doxorubicin (Doxil/CAELYX) could potentially extend the duration of malignant plasma cell exposure to therapeutic levels of doxorubicin. This Phase II study evaluates combination pegylated liposomal doxorubicin, vincristine, and reduced-dose dexamethasone in MM patients.

METHODS

Thirty-three newly diagnosed patients with MM received intravenous pegylated liposomal doxorubicin (40 mg/m(2)), vincristine (2.0 mg, Day 1), and oral or intravenous dexamethasone (40 mg per day for 4 days) every 4 weeks for six or more cycles and/or for two cycles after the best response.

RESULTS

The overall response rate was 88%: 4 (12%) patients achieved a complete response, 18 (55%) a major response, and 7 (21%) a minor response. Three patients (9%) had stable and one (3%) had progressive disease. The median time to progression was 23.1 months, with 2-year and 3-year progression-free survival rates of 42% and 23%, respectively. The patient survival rate at 3 years was 67%. No patients discontinued treatment due to adverse events. Myelosuppression was manageable. The most common toxicities were Grade 3 palmar-plantar erythrodysesthesia, mucositis, and neutropenia. Only one patient experienced cardiotoxicity.

CONCLUSIONS

Substituting pegylated liposomal doxorubicin for doxorubicin in the VAD regimen and reducing the dose of dexamethasone in patients with MM improve the safety profile and convenience of the treatment regimen without compromising efficacy.

Treatment of myeloma: recent developments

Melphalan was the first described treatment for patients with multiple myeloma in the 1960s and is still being used in clinical practice. However, the use of melphalan in combination with prednisone resulted in a median survival of only 2-3 years. Therefore, the dose of melphalan has been intensified since then (140-200 mg/m(2)). In order to diminish treatment-related morbidity and mortality due to severe myelosuppression induced by these regimens, high-dose melphalan is currently supported with autologous stem cells. Indications for high-dose therapy and the role of further intensification by performing second or allogeneic transplantations are discussed. Furthermore, new therapeutic modalities, such as inhibitors of angiogenesis, also showing direct antiproliferative, cytokine-related and immunomodulatory effects on plasma cells (thalidomide and its newer derivatives), inhibitors of the transcription factor NF-kappa B (proteasome inhibitors) and immunotherapy are described.

OPP-EBV-CAD regimen as salvage treatment in advanced refractory or resistant multiple myeloma

With the aim of developing an effective therapy for heavily pretreated refractory MM outpatients, we evaluated the OPPEBVCAD regimen, a Hodgkin's disease-derived protocol that includes many drugs effective in MM administered in a sequential schedule. Twenty-two pts aged 42-72 years, with symptomatic highly-pretreated refractory (18 cases), or primary resistant MM (four cases. including two pts with plasma cell leukemia-PCL) received this therapy every 28 days (2-4 cycles, followed by a maintenance program). Therapeutic response (Chronic Leukemia-Myeloma Task Force criteria) and performance status (PS) and pain (W.H.O.) were evaluated. All of the pts were evaluable for response. There were 9 (40%) objective responses (OR: stabilization of blood counts and bone lesions, serum calcium normalization, 50% or more reduction in the concentration of serum monoclonal component (MC), 90% reduction in Bence-Jones proteinuria), 8 (36%) partial responses (PR: 25-50% reduction in serum MC), 1 no response or stable disease (NR), and 4 (18%) cases of progressive disease (PD). OR plus PR were 77%. Of the 4 primary resistant tumors (2 PCL and 2 MM), 2 achieved PR, 1 OR (a PCL case) and 1 progressed. Median survival was 15 months for responding pts (OR plus PR) and 4.5 months for non-responders (NR plus PD). PS and pain improved in 15 pts and did not change in 9. The most frequent side effects were cytopenias, with one drug related infective death. The OPPEBVCAD regimen proved to be an effective therapy for refractory relapsing or primary resistant MM: in responders (two-thirds of the pts), survival was prolonged by about 10 months. Its efficacy in anthracycline-treated pts, as well as the feasibility of using it on an outpatient basis without any continuous drug infusions, make this regimen a promising third line salvage therapy.

Cyclophosphamide, etoposide, vincristine, adriamycin, and dexamethasone (CEVAD) regimen in refractory multiple myeloma: an International Oncology Study Group (IOSG) phase II protocol

A 4- day continuous intravenous (CIV) infusion of vincristine and doxorubicin with high-dose dexamethasone (VAD) regimen is a standard refractory multiple myeloma (MM) regimen. A Phase II study of a CEVAD regimen, i.e., VAD plus etoposide administered as a 96-hr continuous infusion, was carried out with IV bolus cyclophosphamide. Thirty-six patients were treated on study and received a total of 114 cycles of CEVAD: median 2 cycles (range 1-8). No patient achieved a CR. The overall rate of PR was 15/36 (42%). Patients achieved maximal response after a median of 4 (range 3-6) courses. PR rates were 40% (4/10) in patients with primary refractory disease, 48% (11/23) in patients with secondary refractory disease, 31% (6/19) in patients who had failed previous VAD therapy, and 50% (7/14) in patients receiving 2nd or subsequent relapse therapy. Three patients died during their initial cycle of therapy from rapidly progressive disease and sepsis. Overall median survival was 24 weeks with a 1-year survival of 33.3% ¿95% confidence interval of 20-46%¿. Myelosuppression was the most frequent adverse event with NCI grade 2 neutropenia and/or thrombocytopenia in 15% of first cycles, grade 3 in 20%, and grade 4 in 65%. Two-thirds of patients had at least one episode of grade 3 or 4 sepsis. In 15% of septic episodes positive blood cultures were obtained. Overt cardiotoxicity was seen in two patients. CEVAD as used in this study was not more effective than VAD in terms of overall response rate or survival.

Treatment of multiple myeloma in elderly patients. New developments

The median of survival among patients with multiple myeloma (MM) is about 30 months from the onset of treatment. Tumour burden and a range of other parameters, such as C-reactive protein levels, the plasma cell labelling index and beta2-microglobulin levels, can be used to assign patients to favourable and unfavourable prognostic groups. Conventional chemotherapy consists of melphalan and prednisone, and is as effective as moderately intensive cytotoxic drug regimens. Although second-line chemotherapy is initially effective, all patients eventually die. Maintenance therapy will interferon-alpha prolongs the plateau phase of the disease, but its effects on overall survival are minimal. One of the promising developments in the treatment of MM has been the introduction of high dosage chemotherapy, which can now be safely administered when stem cells are used for haematological recovery. Autologous bone marrow transplantation has been shown to produce a significant improvement in survival compared with conventional therapy. Several studies are under way that are examining the effects of multiple courses of high dosage chemotherapy together with peripheral stem cell support. Purging of autologous stem cell harvests will be performed in the near future to minimise contamination with myeloma cells. It is now feasible to use high dosage chemotherapy, with the support of granulocyte colony-stimulating factor-stimulated whole blood, in selected elderly patients. Besides the promising development of intensive therapy, a number of other treatment strategies have emerged, including treatment with monoclonal antibodies against interleukin-6 and multidrug resistance-modulating agents. Better supportive care can be provided for some patients by using epoetin (recombinant human erythropoietin), and the sequelae of lytic bone lesions can be ameliorated through the use of bisphosphonates.

The role of chemotherapy in the treatment of multiple myeloma

Plasma cell neoplasms often present in an asymptomatic, stable phase. Treatment should not be started until manifestations, such as bone pain, increased susceptibility to infections, renal failure, anaemia and weight loss, announce that the disease has progressed to the MM phase. Conventional therapy with melphalan and prednisone results in objective improvement in about 50% of patients and improves median survival to about 32 months from the start of treatment. Induction therapy should be continued until the M-protein reaches a stable plateau that lasts for at least 4 months. Maintenance therapy with melphalan prolongs the duration of the initial response, but does not improve overall survival, in comparison with patients receiving no maintenance therapy, because survival following relapse is shortened in those receiving maintenance melphalan. In two randomized clinical trials, maintenance treatment with interferon alpha prolonged remissions durations and overall survival of MM patients who responded to induction chemotherapy. Second-line treatment for MM patients who are primary refractory to melphalan, and for those who respond initially and then relapse with refractory disease, is outlined. Although long-term control is possible for a minority of patients, it is unlikely that MM can be cured with currently available chemotherapeutic agents. We need to learn more about the basic biology of the disease.

VAD chemotherapy as remission induction for multiple myeloma

A total of 142 patients with multiple myeloma received VAD as remission induction therapy. Seventy-five were previously untreated and 67 had relapsed (31) or refractory disease (36). Vincristine (total dose 1.6 mg) was infused with doxorubicin 36 mg m-2 by continuous ambulatory pump over 4 days. In addition, oral dexamethasone 40 mg day-1 was given for 4 days. Intermittent dexamethasone was only given to 19 patients. Courses were repeated every 21 days. The overall response rate was 84% [27% complete response (CR)] in previously untreated patients and 61% (3% CR) in patients with relapsed and refractory disease. The median survival was 36 months for untreated patients and 10 months for those who had received prior therapy. VAD was well tolerated; however, despite prophylaxis, 54% patients received antibiotics at some time during therapy and 37% had dyspepsia. Twenty-three patients subsequently received a transplant (eight allografts, eight marrow autografts and seven peripheral blood stem cell transplants). Eight have died-four in the allogeneic group and four in the autologous group. The overall median survival of transplanted patients has not yet been reached. VAD is an effective, out-patient therapy for inducing remission in multiple myeloma. Post-remission therapy needs to be optimised, but it is likely that the needs of previously untreated patients may be different from those with relapsed and refractory disease.