Monotherapy with low-dose thalidomide for relapsed or refractory multiple myeloma: better response rate with earlier treatment

BACKGROUND: Thalidomide is an immunomodulatory drug used in the treatment of relapsed or refractory multiple myeloma (MM). The optimal dosing regimen of thalidomide is not known. PATIENTS AND METHODS: We retrospectively analysed the overall response rate and response duration of 53 patients with relapsed MM who received thalidomide in a median dose of 100 mg daily. The aim of the study was to compare the response rates of thalidomide given as the second-line treatment to those of thalidomide given as the third-line therapy. RESULTS: Of 33 patients receiving thalidomide as second line, 13 (39%) had overall treatment response. Of 20 patients treated with thalidomide monotherapy as the third-line treatment, there were three treatment responses (15%) (P = 0.039). The median duration of treatment response in the second-line thalidomide group (12 months, range 6-60 months) was twice as long as that in the third-line thalidomide group (6 months, range 3-57 months), although the difference was not statistically significant, probably due to low number of patients. Only 6% of patients (3/53) had to stop the treatment because of toxicity. CONCLUSIONS: Monotherapy with low-dose thalidomide results in treatment responses in approximately 30% of patients with advanced MM. The response rate appears to be higher if thalidomide treatment is started after the first relapse or progression in comparison with the second relapse or progression. Treatment toxicity is acceptable even with prolonged exposure to the drug.     

A systematic review of phase-II trials of thalidomide monotherapy in patients with relapsed or refractory multiple myeloma

The activity of thalidomide in relapsed or refractory multiple myeloma is widely accepted but not yet demonstrated in a randomised-controlled trial. A systematic review of the published clinical trials of these patients could reduce the possible bias of single phase-II studies. A systematic search identified 42 communications reporting on 1674 patients. Thirty-two trials used an escalating dosing regimen and four a fixed dose regimen (one dose with 50 mg/d, three doses with 200 mg/d). The target dose in the dose escalating trials was 800 mg/d in 17 trials, 400-600 mg/d in 10 and 200 mg/d in one trial. The intention-to-treat population for efficacy was 1629 patients with a median age of 62 years. The complete and partial (>50% reduction in monoclonal protein) response rate was 29.4% (95%-confidence interval, 27-32%). The rates for minor responses or stable disease were 13.8% (12-16%) and 11.0% (9-13%). Progressive disease was reported in 9.9% (8-11%). The median overall survival from all trials was reported at 14 months. Severe adverse events (grade III-IV) included somnolence 11%, constipation 16%, neuropathy 6%, rash 3%, thrombo-embolism 3%, cardiac 2%. In conclusion, thalidomide monotherapy achieved complete and partial responses in 29.4% of patients with relapsed or refractory multiple myeloma.     

Therapy with thalidomide in refractory multiple myeloma patients - the revival of an old drug

We have treated 17 refractory or relapsed multiple myeloma patients resistant to chemotherapy with thalidomide at a dose of 200-800 mg/day. Eleven patients responded, five of whom had a very good partial response (> 75% decline in M protein) and another five exhibited a partial response (> 50% decline in M protein). Except for one patient, treatment was well tolerated with only mild side-effects. Thalidomide should be included in the therapeutic options for refractory myeloma.     

Intravenous melphalan, thalidomide and prednisone in refractory and relapsed multiple myeloma

OBJECTIVES: Thalidomide combined with conventional chemotherapies including oral melphalan shows significant anti-myeloma activity. To address this issue, feasibility and efficacy of a three drug combination consisting of intravenous (i.v.) melphalan, thalidomide and prednisone [M(i.v.)PT] was evaluated in advanced myeloma patients. PATIENTS AND METHODS: Twenty-four advanced myeloma patients were treated with multiple cycles of a regimen consisting of low dose i.v. melphalan (20 mg/m2) at d 1, thalidomide at the dose of 50-100 mg/d given continuously and oral prednisone at the planned dose of 50 mg/d every other day. Intravenous melphalan was administered every fourth month. Median time from diagnosis was 40 months (range: 8-144 months). Fifteen patients (66%) had previously been treated with a combination of thalidomide and dexamethasone or with thalidomide alone. RESULTS: Overall, on an intent-to treat basis, 14 patients responded: three achieved near complete remission (nCR), seven achieved partial response (PR), four minimal response (MR). Six patients showed stable disease (SD) and four-disease progression. Interestingly, of five patients who had previously progressed while on thalidomide and prednisone, one reached nCR, two PR and one MR. After a median follow up of 14 months, median progression free survival was 9 months. Response duration was longer than that induced by the previous line of treatment in eight patients (33%). Thalidomide-associated toxicity mainly consisted of constipation, tingling and sedation. CONCLUSIONS: M(i.v.)PT is an effective regimen, which can overcome resistance to thalidomide plus prednisone in advanced myeloma with acceptable toxicity.     

Frequent good partial remissions from thalidomide including best response ever in patients with advanced refractory and relapsed myeloma

Twenty-three patients with advanced and heavily pretreated myeloma were treated with thalidomide. Starting dose was 200 mg/d, and 20 patients had dose escalations up to 400 (n = 5), 600 (n = 12) or 800 mg/d (n = 3), usually in divided doses. Nineteen patients were refractory to recent chemotherapy, and four had untreated relapse after prior intensive therapy. Ten out of 23 patients (43%) achieved partial response (PR; nine with refractory and one with relapsed disease), six patients had minor response or stabilization of the disease and four had disease progression. Another three patients died early from advanced myeloma at less than 3 weeks of thalidomide therapy. Of the 10 patients with PR, seven had a better response than after any prior therapy, despite vincristine-doxorubicin-dexamethasone (VAD)-based treatment in all but one and high-dose melphalan with autologous stem cell support in four. Time to achieve PR was rapid in patients receiving thalidomide in divided doses (median 31 d). Responses also included reduced bone marrow plasma cell infiltration and improved general status. Normalized polyclonal gammaglobulin levels were seen in four cases. Six out of 10 patients with PR remained in remission with a median time on treatment of 23 weeks (range 15-50 weeks). Sedation was common but usually tolerable, and some patients continued full- or part-time work. Four patients had skin problems, three patients had pneumonia, one hypothyrosis, one sinus bradycardia and one minor sensory neuropathy. Thalidomide may induce good partial remissions in advanced refractory myeloma with tolerable toxicity, and should be evaluated in other settings for myeloma patients. Divided thalidomide doses seem to reduce time to achieve remission and may improve response rate.     

Hyperfractionated cyclophosphamide in combination with pulsed dexamethasone and thalidomide (HyperCDT) in primary refractory or relapsed multiple myeloma

Sixty patients with advanced multiple myeloma received 2-6 monthly treatment courses combining hyperfractionated cyclophosphamide (300 mg/m2 i.v. over 3 h q 12 h x 6, d 1-3) with pulsed dexamethasone (20 mg/m2/d p.o., d 1-4, 9-12, 17-20) and once daily thalidomide at individually escalating doses (100-400 mg/d) depending on tolerability (HyperCDT). Responding patients were maintained on daily thalidomide and monthly dexamethasone pulses. Complete, partial and minor response rates were 4%, 68% and 12% respectively; overall response rate was 84% (efficacy analysis). Median event-free and overall survival was 11 and 19 months respectively. During at least one treatment cycle, 67% of patients experienced grade 4 neutropenia resulting in 17% grade 3 and 9% grade 4 infections. Side-effects, presumably related to thalidomide, included neuropathy (40% grade 2, 16% grade 3), constipation (17%), oedema (5%), bradycardia (5%), skin reactions (3%), cerebrovascular events (5%) and deep vein thromboses (8%). Thromboses were not related to known thrombophilic risk factors. Four patients with prior myeloma therapy > 50 months developed myelodysplastic syndrome or secondary acute myeloid leukaemia 2-4 months after study entry. HyperCDT is a highly active and reasonably well-tolerated salvage regimen in advanced or refractory multiple myeloma.     

Early response predicts thalidomide efficiency in patients with advanced multiple myeloma

Sixty-five patients who were primary or secondary refractory to melphalan/prednisone or other type of chemotherapy, or relapsed within 6 months after high dose chemotherapy with stem cell support, were given thalidomide at a dose of 200 mg/d escalating to 800 mg. The patients were followed for a median of 2 years and 22 weeks. Response was evaluated according to M-protein reduction combined with improvement of haemoglobin (Hb) concentration, renal function and pain. Altogether, 14% of patients had a minor response, 14% partial response and 6% complete response. Median survival was 12 months and 29% were alive at last contact. Decline of M protein started early and a minimum 25% reduction of M protein was detected in 14 of 20 responders (70%) after 3 weeks, and in 20 of 22 responders (91%) after 5 weeks of treatment. Reduction of M protein continued for 3 months and further decline was observed in only four patients. The Hb concentration showed a different time course, with a significant increase after 3 months and further increases continued for up to 12 months. Blood concentration levels of thalidomide from 40 patients were used to evaluate the pharmacokinetics of the drug. Rate of absorption, rate of elimination, volume of distribution, clearance and elimination half-life were calculated to be 0.200/h, 0.140/h, 0.886 l/kg, 0.126 l/h/kg and 4.98 h respectively. We found no relationship between thalidomide concentration and effect after 12 weeks.     

Low-dose thalidomide in combination with oral weekly cyclophosphamide and pulsed dexamethasone is a well tolerated and effective regimen in patients with relapsed and refractory multiple myeloma

The feasibility and efficacy of a triple regimen of oral weekly cyclophosphamide, monthly pulsed dexamethasone and low-dose Thalidomide (CDT) was studied in 52 patients with relapsed or refractory multiple myeloma (MM). All 52 patients were evaluable for response with a median follow up of 18 (4-29) months. About 17% achieved complete response (CR), 62% partial response (PR), 11% minimal response (MR), 6% stable disease (SD) and 4% progressive disease (PD), resulting in an objective response rate (>/=MR) of 90%. Subsequent to successful response, nine patients received high-dose therapy (HDT) followed by stem cell transplantation (SCT) and 34 received thalidomide monotherapy as maintenance. Response rate was not influenced by disease status, prior HDT or age. The regimen was successfully delivered to all patients except for one patient who developed abnormal liver function at 7 weeks. Infective complications were minimal and there were no infection-related deaths. The estimated overall and event-free survival (EFS) at 2 years was 73% and 34%, respectively, and the median time to progression has not been reached. We conclude that the CDT regimen is safe, well tolerated and effective in patients with relapsed and refractory myeloma.     

Efficacy of single-agent bortezomib vs. single-agent thalidomide in patients with relapsed or refractory multiple myeloma: a systematic comparison

OBJECTIVE: To conduct a systematic review of the efficacy of single-agent bortezomib vs. single-agent thalidomide in patients with relapsed/refractory multiple. METHODS: Publications in English from 1966 to June 2005 (MEDLINE, EMBASE, Cochrane library), publication reference lists, Janssen-Cilag data-on-file and abstracts from recent multiple myeloma conferences were reviewed. Prospective studies containing at least a single arm of either treatment group with n> or =30 were included. Studies adding dexamethasone for non-responders were excluded. Statistical pooling was performed for response rate and overallsurvival. RESULTS: One bortezomib study (n = 333, NEJM 2005, 352; 2487-98) and 15 thalidomide (n = 1007) studies met these criteria and were included. Patient baseline characteristics including age, gender, IgG : IgA, disease duration and beta-2 microglobulin were well matched except that 48% of bortezomib patients had received prior thalidomide. Response rate, defined as serum M-protein reduction > or =50%, was 53% for patients receiving bortezomib vs. 32% for thalidomide (P < 0.001, n = 10 studies). Response rate determined by European Group for Blood and Marrow Transplantation (EBMT) criteria was 41% for patients receiving bortezomib vs. 22% for thalidomide (P < 0.001, n = 4 studies). CONCLUSION: Bortezomib was associated with a significantly higher response rate and complete remission rate using both M-protein and EBMT criteria.     

A systematic review of phase II trials of thalidomide/dexamethasone combination therapy in patients with relapsed or refractory multiple myeloma

Thalidomide monotherapy in relapsed/refractory multiple myeloma (MM) has a response rate of 30%. The combination of thalidomide with dexamethasone (Thal/Dex) is expected to improve responses, but it is unknown if the combination increases the rate of adverse events. Here, we conducted a systematic review of studies evaluating Thal/Dex in relapsed/refractory MM. Twelve studies were included, comprising 451 patients. The response rate (CR and PR) was 46% (95% CI 42-51%). Therapy-related toxicity was comparable to thalidomide monotherapy and included somnolence (26%, 95% CI 22-31%), constipation (37%, 95% CI 32-42%) and peripheral neuropathy (27%, 95% CI 23-32%). Only venous thromboembolism appeared to occur more often with Thal/Dex (5%, 95% CI 3-8%). Thus, using Thal/Dex results in an improved response rate in relapsed/refractory MM, with a toxicity rate comparable to thalidomide monotherapy.     

Clarithromycin with low dose dexamethasone and thalidomide is effective therapy in relapsed/refractory myeloma

A combination of clarithromycin, low dose of thalidomide and low dose dexamethasone was used in a phase II study to treat patients with relapsed and refractory myeloma. Thirty patients received clarithromycin 250 mg twice daily and thalidomide 50 mg at night on an ongoing basis with 4-d pulses of 10 mg dexamethasone given monthly. Eight patients had permitted escalation of thalidomide dosage up to 200 mg daily. The combination was well tolerated and could be given to elderly, infirm and severely cytopenic patients. Response rates were high, with 89% achieving at least 50% reduction in paraprotein and a 96% overall response rate. Although clarithromycin has only minimal anti-myeloma properties when used as a single agent, its combination with thalidomide and dexamethasone appears very effective, allowing these to be used in lower and more tolerable doses with good clinical effects.     

Bortezomib and thalidomide, a steroid free regimen in newly diagnosed patients with multiple myeloma

Despite their efficacy in myeloma, corticosteroids have acute and chronic toxicities. Newer agents with significant anti-myeloma activity permit the development of steroid-free regimens. We designed a Phase II clinical trial to study the toxicity and efficacy of a steroid-free combination of bortezomib and thalidomide as a first-line treatment in patients with symptomatic myeloma. Patients received bortezomib 1·3 mg/m(2) on days 1, 4, 8 and 11 every 21 d and thalidomide 150 mg/d for a maximum of eight cycles. Amongst 27 evaluable patients, the overall response was 81·5% with 25·8% near complete response or greater. The response rate was comparable to most other two drug combinations for upfront therapy but lower than that obtained with the use of three drugs. The most common grade 3 toxicities were peripheral neuropathy (22%), pneumonia (15%), fatigue (7%) and anaemia (7%). Peripheral neuropathy completely resolved in 80% of the patients upon completion of therapy, but not in the remaining 20% of patients. No venous thromboembolic events were observed even in the absence of prophylactic anticoagulation. The median progression-free survival was 16·8 months (95% confidence interval 8·7-21·6 months). Median overall survival has not yet been reached at a median follow up of 39 months. The 3-year overall survival was 74%. This study demonstrates: (i) the efficacy of a steroid-free regimen; (ii) mostly reversible treatment-related peripheral neuropathy; and (iii) the absence of venous thrombotic events.     

Combined bendamustine, prednisolone and thalidomide for refractory or relapsed multiple myeloma after autologous stem-cell transplantation or conventional chemotherapy: results of a Phase I clinical trial

Thalidomide is an effective agent for advanced refractory or relapsed multiple myeloma (MM), although dose-limiting toxicity (DLT) may limit its use. This Phase I study found that a combination of low-dose thalidomide with bendamustine and prednisolone (BPT) maintained or increased efficacy, whilst avoiding DLT in 28 patients with MM that was refractory or that had relapsed after conventional chemotherapy or high-dose therapy with stem-cell support. BPT comprised fixed doses of bendamustine (60 mg/m(2)) and prednisolone (100 mg), and escalating doses of thalidomide (50, 100, 200 mg). Treatment cycles were repeated every 28 d until the occurrence of maximum response, DLT, or disease progression. Twenty-four patients responded after at least two cycles (four complete remission, six very good partial remission, 14 partial remission). Median progression-free and overall survival for all patients was 11 and 19 months respectively. Only mild/moderate non-haematological side effects were observed and no patient developed dose-limiting haematotoxicity. Transient grade 3-4 neutropenia was reported in 12 patients, and grade 3-4 thrombocytopenia occurred in two patients. We conclude that BPT therapy was well tolerated in patients with relapsed or refractory MM, with a response rate higher than 80%. The maximum tolerated dose of thalidomide was not reached in this study.     

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.     

Neurological toxicity of long-term (>1 yr) thalidomide therapy in patients with multiple myeloma

OBJECTIVE: Thalidomide is remarkably active in advanced relapsed and refractory multiple myeloma (MM), so that its use has been recently proposed either in newly diagnosed patients or as maintenance treatment after conventional or high-dose therapy. This latter therapeutic approach has risen the concern of side-effects of long-term therapy with this drug. METHODS: We analysed long-term toxicity of 40 patients (27 M, 13 F, median age = 61.5 yr) who received salvage therapy with thalidomide +/- dexamethasone for longer than 12 months (median 15, range 12-44) at our centre. All the patients had achieved at least a stable disease upon treatment with thalidomide alone (200-400 mg/d, n = 20) or thalidomide (200 mg/d) and dexamethasone (40 mg/d for 4 d every 4 wk) (n = 20). RESULTS AND CONCLUSIONS: Neurotoxicity was the most troublesome and frequent toxic effect that was observed after long-term treatment, the incidence averaging 75%. Among these 30 patients symptoms included paraesthesias, tremor and dizziness. Neurotoxicity was grade 1 in six patients (15%); grade 2 in 13 patients (32.5%), thus determining thalidomide dose reduction to 100 mg/d; and grade 3 in 11 patients (27.5%) who had subsequently to interrupt therapy despite their response. Electromyographic study, performed in patients with grade >/=2 neurotoxicity, revealed a symmetrical, mainly sensory peripheral neuropathy, with minor motor involvement. The severity of neurotoxicity was not related to cumulative or daily thalidomide dose, but only to the duration of the disease prior to thalidomide treatment, although no patients presented neurological symptoms at study entry. These results suggest that long-term thalidomide therapy in MM may be hampered by the remarkable neurotoxicity of the drug, and that a neurological evaluation should be mandatory prior to thalidomide treatment, in order to identify patients at risk of developing a peripheral neuropathy.     

Impact of prior therapies on the relative efficacy of bortezomib compared with dexamethasone in patients with relapsed/refractory multiple myeloma

This subgroup analysis of the phase III APEX (Assessment of Proteasome Inhibition for Extending Remissions) trial examined whether prior exposure to specific therapies affected the relative efficacy of bortezomib versus dexamethasone in relapsed/refractory myeloma. Time to progression and overall survival were superior with bortezomib in all subgroups, with no evidence of interaction between any prior therapies and assignment to study therapy. Patients with prior thalidomide exposure had worse outcomes overall, but neither prior thalidomide nor prior autologous stem cell transplantation affected the relative efficacy of bortezomib versus dexamethasone. These results confirm the superiority of bortezomib over dexamethasone, regardless of prior exposure to specific therapies (clinicaltrials.gov: NCT00048230).