Treatment of multiple myeloma

Maintenance treatment of multiple myeloma

In multiple myeloma (MM), low-cost maintenance treatment has some attractions, since maintenance of a small tumor is usually compatible with a fairly healthy state. However, the great majority of the studies of maintenance treatment have failed to show any clinical benefit. Based on simple theoretical consideration, it is shown that in MM response duration and survival are affected primarily by the residual tumor mass after primary treatment, and by the kinetics of the tumor. Continuation of maintenance treatment is likely to have a moderate effect. The main cause of that is identified in the presence or in the development of a substantial proportion of drug-resistant cells. Preliminary data suggest that only alpha-interferon can be useful for maintenance, and that it can act by slowing down the kinetics of the tumor.

Multiple myeloma and renal failure: one center's experience

Renal involvement remains a major complication of multiple myeloma, particularly in advanced disease. A retrospective analysis was performed of the modes of presentation, treatment and outcome of all patients with multiple myeloma treated in our renal unit between 1987 and 1996. Thirty-four patients were identified: in 26 (76%) the diagnosis of myeloma was made only after referral. Light chains were the most common paraprotein in both serum and urine. Twenty-one (62%) patients underwent renal biopsy: myeloma cast nephropathy was the predominant histological finding in 16 cases. Thirty-one (91%) patients had severe renal failure (GFR < 20 mL/min), with 28 (82%) requiring dialysis within 2 weeks of admission. Despite treatment of presumed precipitaing causes of acute deterioration in renal function, only 1 of these 28 patients subsequently became independent of dialysis. Most had advanced stage myeloma: 29 (85%) were Durie-Salmon stage II or III. Hypercalcemia, sepsis and pathological fractures were the principal complications. Median survival overall was 5 months. The main causes of death were withdrawal of renal replacement therapy (overwhelming myeloma, severe debilitation) and sepsis. Nineteen (56%) patients received long-term (> 1 month) renal replacement therapy with a median survival of 8 months. However, five of these (26%) have survived for more than 12 months on dialysis and report a good quality of life.

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.

Alpha-2a-interferon/melphalan/prednisone versus melphalan/prednisone in previously untreated patients with multiple myeloma

Alpha-2a-interferon (IFN) has demonstrable activity in advance and refractory multiple myeloma (MM), because of the in vitro synergism between IFNs and cytotoxic agents we report the preliminary results of a therapeutic trial of 50 patients with MM. Twenty-eight patients were randomized to receive melphalan plus prednisone (MP) and 22 were randomized to receive IFN plus MP (IFN-MP). Criteria for response, progression and relapse were those of the Southwestern Oncology Group. 95% of the patients receiving IFN-MP responded to therapy as opposed to 68% of the patients receiving MP (P less than 0.05). Response was independent of M-component immunoglobulin class but in stage III it was higher in the IFN-MP group than in the MP group (P less than 0.05). The combination IFN-MP was well tolerated without unusual or unexpected toxic effects. The response duration time was longer in the IFN-MP group than in the MP group (P less than 0.025). The median survival was 80 weeks in the MP group and in the IFN-MP group the 93% of patients were still alive after 90 weeks (P less than 0.025). Our results show that the use of the IFN as an adjuvant to MP improves the percentage of responders, the response duration time and the median survival of untreated patients with MM.

Oral dosage of melphalan and response to treatment in multiple myeloma

Forty-nine consecutive patients with multiple myeloma were analysed for treatment response in relation to dose of orally administered melphalan (induction therapy). All patients were given at least six courses of melphalan-prednisone. Treatment response, defined as a reduction of the myeloma protein of greater than 50%, was seen in 26 patients while 23 were non-responders. When treatment response was related to the dosage of melphalan given by mg/kg of body weight, the numbers of responding and non-responding patients were similar in the group of patients without dose reduction as well as in that with dose reduction. Drug-induced suppression of white blood cell and platelet count was similar in the responding as well as in the non-responding group indicating that the reason for non-response is not simply explained by deficient drug absorption. When the cumulative dose of melphalan given during the induction therapy was analysed, however, a positive correlation (r = 0.47, P less than 0.001) was seen between the cumulative dose and the degree of response. Thus, the cumulative dose of melphalan given during induction therapy seems to be of importance for the response, but other factors as intrinsic differences in cell sensitivity may also explain the individual responsiveness.

Controlled plasma exchange trial in acute renal failure due to multiple myeloma

We studied 29 patients affected by acute renal failure due to multiple myeloma with Bence-Jones proteinuria greater than 1 g/day to evaluate the effectiveness of plasma exchange in the treatment of severe myeloma nephropathy. Renal failure was severe enough to require dialysis in 24 cases, while the remaining 5 patients showed serum creatinine levels greater than 5 mg/dl. The patients were randomly allocated to Group I (15 patients undergoing plasma exchange together with corticosteroids, cytotoxic drug, hemodialysis only when needed) or to Group II (14 patients undergoing peritoneal dialysis together with corticosteroids and cytotoxic drug). In Group I Bence-Jones proteinuria decreased dramatically (P less than 0.01) with a significant increase in urine output (P less than 0.001), while Group II presented a slight reduction in Bence-Jones proteinuria without a significant increase in daily diuresis. Thirteen out the 15 Group I patients recovered renal function reaching serum creatinine levels less than or equal to 2.5 mg/dl in most cases. Only two patients in Group II improved renal failure well enough to stop dialysis. The one-year survival rate was significantly higher in Group I (66%) than in Group II (28%, P less than 0.01). We conclude that plasma exchange associated to chemotherapy rapidly removes large amounts of light chains, improves both renal function and long-term survival expectancies.

Weekly low-dose cyclophosphamide and alternate-day prednisone: an effective low toxicity regimen for advanced myeloma

10 of 20 patients with advanced myeloma treated with a simple regimen consisting of weekly low-dose cyclophosphamide (C; 150-300 mg/m2; maximum weekly dose = 500 mg) given intravenously or orally, and alternate-day oral prednisone (P; 50-100 mg) responded clinically and with a fall in serum M protein greater than 50% or urine M protein greater than 90%. 3 of these responders were previous primary treatment failures, all having received cyclophosphamide in combination with other drugs given at 3- to 4-wk intervals. 2 patients treated with this regimen as primary therapy also responded. Although the median survival for the 10 responders was reached at 24.5 months, 3 patients remain alive and well 50+ months from the start of CP therapy. An additional 5 patients had disease stabilization or major improvement in bone pain and/or pancytopenia for over 12 months despite failure to meet strict criteria for response. The data suggest that disease control may be achieved by the more frequent scheduling of known active drugs such as cyclophosphamide (although it alone or in combination with other drugs may be ineffective when given at standard 3- to 4-wk intervals) in combination with prednisone or a more continuous basis. This is an effective yet simple therapeutic approach to myeloma with the distinct advantage of less toxicity than the multiple drug regimens in current use. It may have particular applicability to patients who are elderly or debilitated or in patients in whom cytopenia is present initially or develops on standard melphalan/prednisone regimens.

Multiple myeloma treated with high dose intravenous melphalan

High dose melphalan (HDM, 140 mg/m2 i.v.) has been evaluated in 58 patients under 63 years with multiple myeloma. Among previously untreated patients 11/41 (27%) entered a complete remission (CR: no measurable myeloma protein and a normal bone marrow) and 21 (51%) entered a partial remission (more than 50% reduction in myeloma protein and improvement in all other features). Median duration of remission is 19 months. Two patients who had responded to previous conventional treatment entered CR after HDM. Among 15 patients who had failed on previous chemotherapy the response rate was 66% including two CRs. However, in this group all patients have relapsed within 1 year. Profound myelosuppression, moderate nausea, vomiting, mucositis and diarrhoea with reversible alopecia occurred in all patients. There were 10 deaths within 2 months of treatment mainly due to sepsis and haemorrhage. In a subsequent study, high dose methyl prednisolone (1 g/m2 daily for 5 d) has been added to HDM. Response rates are similar with 6/22 (27%) CR, 13/22 (59%) PR and 2/22 NR but there was only one early death, reflecting improvements in medical management. The high CR rate is an encouraging feature of this approach which is now to be the basis of a prospective trial sponsored by the Medical Research Council in which HDM, with and without steroids, is compared to the best available conventional therapy (the MRC VI Myelomatosis trial).

Interferons in the treatment of multiple myeloma

A review of the clinical studies in which interferons have been involved has shown that they may have a role in the treatment of multiple myeloma. Twelve studies, each of which involved at least 10 evaluable cases (352 in total) with various dose schedules involving leukocyte, lymphoblastoid and recombinant alpha-IFNs, reported 8-33% objective responses. The response duration was rather short but, in a few cases, it lasted for more than a year. In addition to a decrease in the levels of M-protein and/or urine Bence-Jones protein, a decrease in the number of plasma cells in the bone marrow, disappearance of bone pain, healing of bone lesions, increase of hemoglobin and/or restoration of normal immunoglobulins were observed. Higher doses of recombinant alpha-interferons seemed to exert a stronger effect. No clear difference in response rate was observed between myeloma which had been previously treated and that which was not treated. At least clinically, therefore, there seems to be no cross-resistance between alpha-interferons and conventional anti-tumor drugs. A randomized study comparing low-dose leukocyte interferon with intermittent high-dose melphalan-prednisone has given a lower response rate for interferon. Beta- and gamma-interferons have not yet been extensively studied. They have been used at low doses producing an objective response in 7% of 68 and 2% of 45 evaluable cases, respectively. Since the myelosuppression of interferons is transient and, after discontinuation of interferon therapy, peripheral blood cells usually recover within a week, it may be possible to use interferon in combination with agents that have strong myelosuppressive effects provided there is no synergism.

Treatment of multiple myeloma with recombinant interferon alfa-2a

A Phase II study of interferon alfa-2a was conducted in 64 patients with multiple myeloma (42 IgG, 16 IgA, 5 Bence-Jones type, and 1 IgD) in a multi-institutional cooperative trial. Partial remission was obtained in 10 (21.3%) of 47 evaluable patients, and minor responses in 5 (10.6%) of 47. Remission was reached at 22 to 89 days (median, 29 days) after the initiation of interferon alfa-2a and lasted 4 to 55 weeks (median, 8 weeks). Side effects were noted in more than two-thirds of patients, and included fever (58%), malaise (20%), anorexia (52%), nausea-vomiting (26%), lethargy (2%), and myelosuppression (56%). They were all reversible on discontinuation of interferon alfa-2a. Antibody to interferon alfa-2a was detected in 1 of 20 patients tested during the course of treatment. Thus, interferon alfa-2a was effective in multiple myeloma, producing unequivocal response in 21.3% of patients without unacceptable side effects.

Melphalan-resistant multiple myeloma: results of treatment according to the M-2 protocol

A group of 46 patients with melphalan-resistant multiple myeloma was treated according to the M-2 protocol with melphalan, prednisolone, BCNU, cyclophosphamide, and vincristine. According to the Salmon and Durie classification, four patients had stage II A; 36, stage III A; and six, stage III B disease. Treatment resulted in five patients (11%) entering remission, while 21 (46%) had stable and 20 (43%) had progressive disease. The median survival for all patients was 12.5 months, patients in remission surviving longer (median 46 months) than those with stable disease (median 15.4 months) or progressive disease (median 6.9 months). Compared with other treatment regimens used in melphalan-resistant myeloma, the remission rate is low but the median survival exceeds that reported by most other authors.

Clinical staging and therapeutic results in multiple myeloma

The validity of the Durie and Salmon's clinical staging system for multiple myeloma has been tested in 81 consecutive patients studied at the Istituto Nazionale Tumori of Milan from January 1970 to June 1982. Median survival from diagnosis was 48 months for stage I, 41 months for stage II and 23 months for stage III (P = 0.02). Median survival of patients with normal renal function (A) was 35 months and of those with abnormal kidney function (B) 7 months. Almost all early deaths were observed in patients with stage III disease associated with renal failure. No statistically significant difference was found in the median survival in patients with kappa and those with lambda light chains. The analysis of survival according to the three main combinations of chemotherapy used in this study (melphalan-prednisone vs melphalan-procarbazine-prednisone vs adriamycin-prednisone) could not disclose any significant difference. Prognosis was, however, closely related to the response to combination chemotherapy: median survival was 72 months in responders, 36 months in patients with improvement and 25 months in non-responders (P less than 0.01). A lower incidence of response was obtained in patients with stage III myeloma compared to patients with stage I-II. The myeloma staging system used in this study is simple to employ and allows identification of truly comparable patient groups in the evaluation of therapeutic results. Our therapeutic results confirm the effectiveness of melphalan plus prednisone and fail to demonstrate any advantage in the administration of adriamycin as first-line therapy.

Treatment of multiple myeloma with M-2 protocol and without maintenance therapy

From September 1975 to December 1981, 63 consecutive untreated patients with multiple myeloma received the Lee M-2 protocol. We used the same drugs (melphalan, cyclophosphamide, vincristine, BCNU and prednisone) but employed the lowest suggested doses and recycled earlier, i.e. after 21-28 days. Thirty-five patients (62.5%) were in stage III, 16 (28.6%) in stage II and 5 (8.9%) in stage I. An objective response (reduction in paraprotein production rate greater than 50%) was obtained in 44 out of 56 cases (78%); 32 (57%) had a reduction greater than 75%. The median duration of response was 21.5 months. In responding patients the treatment was stopped after 1 yr and resumed only at relapse. Twenty-two out of 25 retreated patients are now evaluable. Eighteen of them (82%) responded again; in retreatment the degree of response was lower, but the duration of second response was only slightly lower than the first response (15.7 vs 21.5 months, NS). Of 7 patients receiving a third M-2 reinduction 4 responded again. The median survival for all the patients is 51 months. The high rate of second response to the M-2 regimen after an unmaintained remission brings into question the value of continuous therapy in responsive multiple myeloma.