Effective treatment of advanced multiple myeloma refractory to alkylating agents

Biology and treatment of multiple myeloma

The uniformly fatal plasma cell malignancy, multiple myeloma (MM), currently represents 10-15% of hematologic neoplasms in the USA and has been steadily increasing in incidence for several decades. Therapeutic alternatives have lagged significantly behind insights into the biology and pathogenesis of this entity. Traditionally felt to be a neoplasm of fully differentiated plasma cells, evidence has been mounting that the self renewing population consist of cells derived from a much earlier compartment; perhaps prior to B-cell lineage commitment or even at the level of an earlier 'stem cell'. Bcl-2 protein overexpression has been almost uniformly seen in both clinical myeloma specimens as well as in myeloma cell lines. The failure to consistently identify the t(14;18) translocation, normally found in follicular lymphomas and characteristically associated with overexpression of bcl-2, implies a unique mechanism in MM. A number of cytokines, including TNF alpha, IL-1 and IL-6 have been found to play a central role not only in the biology of the malignant clone but also in the bony and other systemic manifestations of this disease. Since both IL-6 and bcl-2 protein have been shown to prevent programmed cell death, this may be the unifying event in MM. Standard therapy for MM has been an alkylating agent and corticosteroid. Combination chemotherapy provides more prompt palliation but no clear survival advantage. In advanced stages, adriamycin may offer some survival advantage. High dose chemotherapy with or without stem cell support offers a potentially curative therapeutic approach. New interventions directed at the complex cytokine networks pertinent to the pathogenesis of MM are an exciting new area of investigation. Identification of new prognostic parameters as well as new active agents remains the central theme in clinical myeloma research.

Recombinant human erythropoietin and the anemia of multiple myeloma

The anemia of multiple myeloma (MM) is multifactorial, including physical replacement of normal hemopoiesis by tumor cells, renal failure and cytokines which contribute to the blunted erythropoietin (EPO) response observed in anemias of chronic disease. Recombinant EPO has been evaluated in anemic patients with stable multiple myeloma (< or = 10g% hemoglobin). Responses (> or = 2g% hemoglobin increase) were observed in 78% of 41 patients in two separate studies. Responses were associated with an increase in bone marrow erythropoietic cell compartment and reticulocytosis. Evaluation of potential parameters affecting response identified prolonged cytotoxic therapy for > 12 months, especially with alkylating agents and pre-treatment EPO levels > 100 U/L, both of which seemed to decrease the likelihood of EPO response. EPO is a safe and effective treatment for the anemia associated with MM.

Cyclophosphamide and etoposide therapy with GM-CSF for VAD-resistant multiple myeloma

Few effective regimens are available for patients with advanced multiple myeloma resistant to or relapsing after both alkylating agents and VAD. We treated 52 patients with advanced and refractory multiple myeloma with the combination of cyclophosphamide (3.0 g/m2) and etoposide (900 mg/m2) followed by GM-CSF at a daily dose of 0.125 mg/m2 until recovery of granulocytes. 42% of patients responded with a median time of 19 d for recovery of granulocytes to 0.5 x 10(9)/l and a 4% mortality rate. Eight responding patients received a second myeloablative treatment supported by either autologous bone marrow (six patients) or blood stem cells (two patients). The median survival time for all patients was 11 months and the median remission time for responding patients was 8 months. The combination of cyclophosphamide and etoposide provided an effective rescue treatment for many patients with advanced multiple myeloma resistant to conventional therapies. This programme also allowed early marrow or blood stem cell collection in support of subsequent myeloablative therapy for selected patients.

Treatment of melphalan-resistant multiple myeloma with vincristine, BCNU, doxorubicin, and high-dose dexamethasone (VBAD)

A total of 65 patients (35 male/30 female) with multiple myeloma primarily (33) or secondarily (32) resistant to melphalan and prednisone were treated with vincristine, carmustine (BCNU), doxorubicin, and high-dose dexamethasone (VBAD) at 4-week intervals. Among 60 evaluable patients the overall response was 36.6% (21.6% objective response plus 15% improvements). The response rate was significantly higher in primarily resistant patients than in those becoming resistant after a prior response (48.4 vs. 24.1%, P < 0.05). The median duration of response was 17.5 months. When survival of responders and non-responders were compared by the conventional method, a highly significant difference was observed (P < 0.001). However, using the Mantel and Byar procedure and the landmark method, only a trend for longer survival in the responders was registered. These results indicate that although VBAD is effective in at least one third of patients with advanced multiple myeloma resistant to melphalan, its impact on survival is limited.

Dexamethasone reverses glucocorticoid receptor RNA depression in multi-drug resistant (MDR) myeloma cell lines

Glucocorticoid receptors and glucocorticoid receptor RNA (GR RNA) were measured in doxorubicin resistant myeloma cell lines to investigate the relationship between multi-drug resistance and glucocorticoid sensitivity. Glucocorticoid binding sites and GR RNA were found to be lowered in all the tested doxorubicin resistant cell lines: R10, R40 and R60 compared to the untreated wild type RPMI 8226 cells (Dalton, et al., 1984). The least resistant cell line, R10, maintained a down regulation of GR RNA after 48 hours of dexamethasone (10(-6) M) treatment of the cells. Interestingly, the R10 cell line has been reported to be very sensitive to dexamethasone treatment. However, the GR RNA levels increased in presence of dexamethasone in the most resistant cell line, R40, R60 by comparison to the wild type. Thus, the reduction of GR RNA by doxorubicin treatment appears to be overcome by dexamethasone in the most resistant cell lines. Steroids may be helpful in reversing resistance and maintaining drug sensitive human tumor populations that will continue to respond to cancer chemotherapeutic agents.

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

The purpose of this single arm phase II study was to test a modified version of the three drug combination vincristine, adriamycin and dexamethasone (m-VAD), in which intravenous vincristine (0.4 mg/d) and adriamycin (9 mg/m2 per day) infusions are administered for only 2 h on days 1-4 of each 28 d cycle, in patients with refractory multiple myeloma. In addition, only two 4 d courses of dexamethasone 40 mg/d was given during each cycle. The entry criteria for 44 patients included plasma cell myeloma and a measurable monoclonal peak, either refractory to initial treatment with melphalan and prednisone, or resistant to melphalan and prednisone after initially responding (resistant relapsed disease, 27 patients). Patients treated previously with chemotherapy other than melphalan and prednisone were excluded. There were no complete responses. Of the 41 evaluable patients who completed at least one course of therapy 11 had a partial response (27%, 95% C.I. 14-40%). The response rates were 19% for primary refractory disease patients, and 32% for those with resistant relapsed disease. The median duration of response was 4 months. The median survival for all 44 patients was 7.6 months (5.5 months for primary refractory patients, and 10 months for relapsed resistant disease patients). Episodes of documented bacterial infection occurred in 12 patients, and 10 patients had minor viral infection. The dexamethasone dose was reduced in 12 patients. The median neutrophil nadir was 1.2 x 10(9)/l, and median platelet nadir was 147 x 10(9)/l. Five deaths were judged as treatment related and occurred during marrow cytopenia. The results of this modified form of VAD are inferior to that reported previously for 4 d continuous infusions of vincristine and doxorubicin. This could be related to either patient selection factors, or to a reduction of the efficacy of the drug combination produced by either the shortened intravenous infusions and/or omission of one 4 d course of dexamethasone.

Multiple myeloma and chronic lymphocytic leukemia: parallels and contrasts

Multiple myeloma (MM) and chronic lymphocytic leukemia (CLL) are closely related B-cell cancers. Parallel and divergent features of these diseases are reviewed. In MM, expression of multiple hemopoietic lineage-associated antigens on the malignant cells and the substantial likelihood of progression to acute myelogenous leukemia suggest transformation of a pluripotent stem cell. In CLL, transformation more likely involves a committed B-cell progenitor. Another difference is that clonal evolution with associated cytogenetic progression is common in MM but not CLL. Other data, including studies of proto-oncogenes and tumor suppressor genes, suggest that MM results both from increased proliferation and accumulation of tumor cells, whereas tumor cell accumulation is the predominant feature of CLL. These differences may be reflected in the seemingly greater role of cytokine abnormalities in MM progression. For example, osteoclast-activating properties of some cytokines account for bone involvement in MM but not in CLL. MM and CLL share common features such as stage-dependent anemia and immune deficiency. Both diseases respond to alkylating agents but vary markedly in their sensitivity to fludarabine (CLL greater than MM) and glucocorticoids (MM greater than CLL). Differences between these diseases in progression-free interval and survival may reflect different definitions of premalignant and malignant phases rather than biologic differences. Detailed comparisons between MM and CLL may provide additional insights into these and related B-cell cancers.

Modulation of multidrug-resistant multiple myeloma by cyclosporin. The Leukaemia Group of the EORTC and the HOVON

Resistance to chemotherapy in refractory multiple myeloma is frequently associated with expression of multidrug resistance (MDR). In resistant cells, intracellular accumulation of doxorubicin and vincristine does not occur because the MDR-1 gene product, a membrane glycoprotein (PgP), is an energy-dependent efflux pump. Cyclosporin is one of several non-cytotoxic drugs that can block the function of PgP. In a prospective study, we assessed the possibility that cyclosporin could be used clinically to modulate MDR. We studied 21 patients with multiple myeloma; disease had progressed during primary chemotherapy in 6 and was resistant to VAD (vincristine, doxorubicin, dexamethasone) in 15. The patients received cyclosporin by continuous infusion during VAD treatment; there were three cyclosporin dosage groups (5, 7.5, 10 mg/kg daily). Serum cyclosporin concentrations adequate for MDR modulation were reached in all patients receiving 7.5 or 10 mg/kg daily. 47% (7) of the VAD-refractory patients and 48% (10) of the whole group responded to VAD. Before treatment, MDR-1 expression was present in 12 patients. After VAD plus cyclosporin, no MDR-1-positive plasma cells were present in 6 of 8 patients tested. The response rate in MDR-1-positive patients was 58% compared with 33% in all our patients. Toxic effects were mild and reversible and did not include nephrotoxic or serious cardiovascular side-effects. 12 months after the start of treatment, survival was 85%, and disease-free survival at a median of 9 months after the response was 65%. Thus, in multiple myeloma clinical resistance to VAD can be circumvented by cyclosporin, which enables the cytotoxic drugs to eliminate resistant myeloma cells.

Continuous-infusion cyclophosphamide in combination with teniposide and dexamethasone in refractory myeloma

Forty-three consecutive patients with refractory myeloma, median age 60, received monthly courses of teniposide 30 mg/m2 i.v. on days 1-2, dexamethasone 40 mg i.v. on days 1-7 and cyclophosphamide 200 mg/m2 by continuous i.v. infusion for seven days. Major response (decrease > 50% of M-protein) was achieved in 18 of 37 evaluable patients and minor response in 9, with an overall response rate of 73%. Response was irrespective of disease status, time from diagnosis and previous treatments, while beta 2 microglobulin > 6 mg/l was a powerful prognostic factor. All patients experienced transient granulocytopenia but extramedullary toxicity was negligible. Median survival of the whole group is 20 months, with 74% of responding patients projected to be alive at 30 months. In refractory myeloma cyclophosphamide appears to be more active when given by continuous infusion.

Ifosfamide in plasma cell leukemia: a report of two cases and review of the literature

We report two patients with primary plasma cell leukemia (PLC) treated with a single agent, ifosfamide. One patient had a total disappearance of plasma cells (PC) from the peripheral blood and the bone marrow and disappearance of the myeloma protein, is disease free 8 months after completion of treatment, and alive 14 months after diagnosis. The second patient had a partial response with persistence of plasma cells in the bone marrow lasting 7 months, after which she had a frank relapse of the disease. We suggest that ifosfamide may be an active agent in plasma cell malignancies and needs further evaluation in multiple myeloma.

Levels of expression of the mdr1 gene and glutathione S-transferase genes 2 and 3 and response to chemotherapy in multiple myeloma

We have quantitated the levels of mRNAs in bone marrow samples from patients with multiple myeloma of the mdr1 gene (responsible for the Multidrug Resistance phenotype) and for two of the glutathione S-transferase gene, GST-2 and GST-3 (which can also inactivate a wide variety of cytotoxic drugs) and examined the relationship between the levels of expression of these genes and response to subsequent chemotherapy. From a total of 47 patients, 37 were treated with chemotherapy with 34 evaluable for response. Twenty-nine of the patients treated had not received any treatment prior to the marrow sampling while eight had previously received chemotherapy. Patients who failed to respond to initial chemotherapy had significantly higher levels of mdr1 than patients who responded (P = 0.01). In the total myeloma patient data set, mRNA levels for mdr1 and GST-2 were significantly correlated (Spearman rank correlation coefficient (r) = 0.54, P = 0.0004) as were expression levels of GST-2 with GST-3 (r = 0.43, P = 0.017). GST-3 and mdr1 levels were more weekly associated (r = 0.16, P = 0.4). These data would suggest a significant relationship between failure of chemotherapy in multiple myeloma patients and increases in expression of the mdr1 gene together with other genes whose products will generate additional mechanisms of resistance to chemotherapeutic agents.

Bolus therapy with mitoxantrone and vincristine in combination with high-dose prednisone (NOP-bolus) in resistant multiple myeloma. Nordic Myeloma Study Group (NMSG)

In a phase II study, 58 patients with resistant multiple myeloma (MM) were treated with a combination chemotherapy (NOP-bolus regimen) consisting of mitoxantrone (16 mg/m2 for the first 25 patients and 12 mg/m2 for the subsequent 33), vincristine (2 mg), both as bolus injections on day 1 and prednisone (250 mg/d on d 1-4 and 17-20). In patients greater than 70 years of age, the mitoxantrone dose was reduced to 12 mg/m2 or 8 mg/m2, respectively. The treatment was repeated every 4 weeks. A response (greater than 50% reduction in M component) was obtained in 26% of the patients and a minor response (clinical improvement but less than 50% reduction in M component) in another 21%. Median response duration was 27 wk and median survival for all patients was 25 wk. There were no differences in response rate or duration between patients receiving the high or low mitoxantrone dose, but patients in the low-dose group had fewer serious infections.

Serum osteocalcin concentrations in patients with multiple myeloma--correlation with disease stage and survival

Multiple myeloma affects bone, and enhanced bone resorption is a characteristic finding. In the present study the serum concentration of osteocalcin, serum bone gla-protein, which is a protein specific for bone turnover and reflects osteoblast activity, was analysed at diagnosis in 48 patients with multiple myeloma. At that time there was a significant relationship between disease stage (Durie-Salmon) and osteocalcin levels, lower levels being found in patients with more advanced disease. No relationship was found between osteocalcin and serum calcium levels. To date, 33 patients have died. There was a significant correlation between initial osteocalcin levels and patient survival. These findings suggest that serum osteocalcin could be a marker of prognostic significance for survival in multiple myeloma.

Glucocorticoids in cancer therapy

Glucocorticoids are often included with other agents in cancer treatment although the mode of action is not clear. They are useful in the primary combination chemotherapy of both acute and chronic lymphocytic leukaemias, Hodgkin's and non-Hodgkin's lymphomas, multiple myeloma and breast cancer. Other uses for glucocorticoids in cancer patients include an anti-inflammatory action for the oedema of cranial and spinal metastases, a weak antihypercalcaemic effect and the ability to suppress tumour-related fever.

Has the incidence of multiple myeloma in old age been underestimated? The myeloma project of health region I in Norway. I

All patients in the region with newly discovered M components were registered from 15 Aug. 1984-31 Dec. 1986. Among a total of 393 patients enrolled, 162 had multiple myeloma (MM). The incidence rate was 6.6 per 100,000 population per year (age-adjusted to the European standard population), which is somewhat higher than previous reports based on hospital and autopsy records. In particular, the incidence rate was higher in the greater than 70 age group. Thus, the median age was 72 yr, which is the highest reported. As many as 71 (44%) of the 162 MM patients were asymptomatic; these asymptomatic patients had the same age distribution as the symptomatic ones. The stage distribution, occurrence of risk factors, response to chemotherapy, response duration and survival were similar in the age groups below and above the median and, in multivariate survival analysis, age was not an independent risk factor.

The clinical pharmacology and use of antimicrotubule agents in cancer chemotherapeutics

Although there has been a rapid expansion of the number of classes of compounds with antineoplastic activity, few have played a more vital role in the curative and palliative treatment of cancers than the antimicrotubule agents. Although the vinca alkaloids have been the only subclass of antimicrotubule agents that have had broad experimental and clinical applications in oncologic therapeutics over the last several decades, the taxanes, led by the prototypic agent taxol, are emerging as another very active class of antimicrotubule agents. After briefly reviewing the mechanisms of antineoplastic action and resistance, this article comprehensively reviews the clinical pharmacology, therapeutic applications, and clinical toxicities of selected antimicrotubule agents.

No correlation between response and survival in patients with multiple myeloma treated with vincristine, melphalan, cyclophosphamide, and prednisone

A vincristine, melphalan, cyclophosphamide, and prednisone (VMCP) multi-drug regimen was used in 85 previously untreated patients with multiple myeloma (MM) (symptomatic Durie Stages II and III) until they became refractory. The prognostic significance of various pretreatment characteristics was evaluated in terms of therapeutic response (according to Southwest Oncology Group [SWOG] and Chronic Leukemia-Myeloma Task Force [TF] criteria) and survival. Therapeutic responses, obtained in 31.2% (SWOG) and 68.7% (TF) of patients, had a significant inverse correlation with myeloma cell mass, serum calcium, and bone status. Median survival time of Stage II and Stage III patients was 39 and 34 months, respectively. Serum B2 microglobulin greater than or equal to 6 micrograms/ml was the only variable correlating unfavorably with survival duration after multi-variate analysis (increased risk = 2.79), although therapeutic response as a time-dependent variable had no effect on survival. These data suggest no correlation between response and survival, partially because of inadequate response assessment criteria and partially because no existing treatment is curative (although current therapeutic approaches may prevent death from complications).

Evolution of neuropathy and myopathy during intensive vincristine/corticosteroid chemotherapy for non-Hodgkin's lymphoma

Neuropathy and myopathy are common sequelae of intensive chemotherapy protocols that contain vincristine and corticosteroids. The authors prospectively monitored the evolution of neuropathy and myopathy during an intensive 12-week chemotherapy program for patients with intermediate and high-grade non-Hodgkin's lymphoma. In this study, vincristine was administered by bolus injection followed by a 3-day continuous intravenous (IV) infusion (total dose of 2.0 mg/m2 every other week); the maximum dose of vincristine was not arbitrarily limited. Cronassial, a mixture of four naturally occurring gangliosides, was administered in a randomized double-blind test to evaluate whether this agent could prevent vincristine-induced neuropathy. High doses of dexamethasone (50 mg/d for 3 days weekly or every other week) were also prescribed. Patients were monitored every 4 weeks with comprehensive physical and neurologic examinations and electrophysiologic studies of peripheral nerve function. Twenty-seven patients were fully evaluable. Weakness was a prominent adverse reaction in this study, and all patients had moderate to severe signs and symptoms of neuropathy and myopathy. Cronassial (100 mg) administered by intramuscular (IM) injection daily provided no protection against the development of neuropathic symptoms. Vincristine typically impaired fine-motor coordination initially, whereas corticosteroids were associated with delayed development of proximal muscle weakness. Results of electrodiagnostic studies did not add to the clinical examination results. The authors conclude that symptomatic weakness due to neuropathy or myopathy appears in a predictable manner during intensive vincristine/corticosteroid-based treatment protocols. Simple clinical tests can be used to rapidly distinguish between toxic effects due either to vincristine or corticosteroids, and routine implementation of these tests can prevent inappropriate dose attenuation of these agents.

High-dose dexamethasone for refractory or relapsing multiple myeloma

In order to assess the efficacy and toxicity of dexamethasone as a single agent without the concomitant infusion of Adriamycin and vincristine (VAD), an ECOG pilot study was initiated using 40 mg by mouth daily for 4 days every week for 8 weeks. Patients who responded were then maintained on the same treatment, but at 2 week intervals. Of the 32 patients evaluable for response, three were completely refractory to all prior therapy. All patients had advanced disease and 26 had received multiple prior treatments. There were 13/32 (40%) objective responses by ECOG criteria. Of the 28 patients evaluable for subjective response, i.e., significant decrease in performance status and/or bone pain, eight (28.5%) responded. Of the 34 patients evaluable for toxicity, 19 patients (55%) had moderate to severe side effects, including nine who had central nervous system effects, three who had gastrointestinal bleeding, two who had pulmonary emboli, one with psychosis, and four who had serious infections with one death. Median survival for the entire group was 19 weeks, with 31 weeks in the responders and 9 weeks in the non-responders. Although high-dose dexamethasone is capable of producing a significant number of partial responses (40%), it is associated with excessive toxicity. Less frequent administration of the dexamethasone at 2 week intervals was well tolerated in the maintenance of partial response, but has not been studied for efficacy in induction of remission.

Teniposide, dexamethasone and continuous-infusion cyclophosphamide in advanced refractory myeloma

Twenty-one patients with advanced refractory myeloma (nine primary unresponsive to melphalan, 12 relapsed and resistant to first-line salvage therapy) received monthly 7 d courses of cyclophosphamide by continuous infusion, associated with teniposide and dexamethasone. Six patients died within 2 months from start of treatment, before receiving an adequate trial. Among the 15 evaluable patients, there were eight objective responses and three improvements (decrease of monoclonal protein greater than 50% or greater than 30%, respectively). After a median follow-up of 10 months, all responding patients are alive and none of them is still relapsed. In heavily pretreated patients, ineligible for more aggressive approaches, cyclophosphamide by continuous-infusion exerted a good antineoplastic activity without increasing toxicity.

Refractory myelomatosis treated with mitoxantrone in combination with vincristine and prednisone (NOP-regimen): a phase II study. The Nordic Myeloma Study Group (NMSG)

In a phase II study, patients with refractory myelomatosis were treated with a combination chemotherapy (NOP regimen): mitoxantrone (bolus injection of 4 mg/m2 on days 1-4), vincristine (continuous infusion of 0.4 mg/24 h on days 1-4) and prednisone (250 mg/d on days 1-4 and 17-20). The treatment was repeated every 4 weeks. Ninety-two patients were treated after they were found refractory to treatment with melphalan and prednisone (and occasionally vincristine) (n = 50) or more intensive treatment regimens (n = 42) including anthracyclines (n = 18). Response (greater than or equal to 50% reduction of M protein) was obtained in 23 patients and minor response (clinical improvement but less than 50% reduction in M protein) in 22 patients. The median duration of the response was 7.5 months. Equal response rates were observed irrespective of the type of previous treatment. The major toxicity was myelosuppression with severe granulocytopenia and infections. However, the frequency decreased throughout the cycles. The NOP treatment is recommended in refractory myelomatosis, especially in patients refractory to other intensive regimens. Patients in a poor clinical condition or with thrombocytopenia before treatment should have a reduced mitoxantrone dose in the first treatment cycles.

Bayesian estimation of doxorubicin pharmacokinetic parameters

Doxorubicin was given by brief i.v. infusion (doses ranging from 25 to 72 mg/m2) to 28 patients for 2-7 successive courses of chemotherapy (68 courses studied in all). A Bayesian approach was developed to determine the individual pharmacokinetic parameters of doxorubicin. Statistical characteristics of the population pharmacokinetic parameters were first evaluated for 19 patients and a total of 30 courses, which, when combined with 4 individual plasma concentrations of drug, led to a Bayesian estimation of individual pharmacokinetic parameters for the remaining 38 courses. The estimated parameters for the elimination phase (A3/V1 and t1/2 elimination) and the residual plasma level at 48 h as computed by Bayesian estimation on this reduced sub-optimal sampling protocol were compared with a maximal likelihood estimation of these parameters. No statistically significant differences were found. Performance of the developed methodology was evaluated by computing bias and precision. The mean errors were -0.0315 x 10(-4) l-1 for A3/V1, 0.0839 h for t1/2 elimination, and -0.22 ng/ml for c(48 h). The precision of the prediction of these three parameters (0.304 x 10(-5) l-1, 3.34 h, and 0.659 ng/ml, respectively) remained lower than the interindividual standard deviation (1.42 x 10(-4) l-1, 14.9 h, and 4.54 ng/ml, respectively). This procedure enables the estimation of individual pharmacokinetic parameters for doxorubicin at minimal cost and minimal disturbance of the patient.

Decrease in clonogenic tumour cells in bone marrow aspirates from multiple myeloma patients due to the incorporation of cyclophosphamide into treatment with vincristine, adriamycin and methyl prednisolone

A study of 32 patients receiving cyclophosphamide (CY) and verapamil (VER) in addition to the drug combination vincristine, adriamycin and methyl prednisolone (VAMP) was made in which the clinical response and growth of clonogenic myeloma cells (MY-CFUc) from bone marrow aspirates were compared. At presentation, MY-CFUc were grown from 72 per cent (23/32) of the patients. After treatment with CY-VAMP or VERCY-VAMP, MY-CFUc were grown from 25 per cent (8/32) of patients of whom only 50 per cent responded clinically. The overall clinical response rate for patients receiving CY-VAMP and VERCY-VAMP was 64 per cent (9/14) and 72 per cent (13/18) respectively of whom 14 per cent in each group achieved complete remission. There was no concomitant increase in normal tissue toxicity as measured by granulocyte-macrophage colony (GM-CFUc) formation. Comparison of these data with our previous study of patients receiving VAMP alone, suggests that the addition of CY to the regimen may increase the tumour cell kill. Further clinical studies will determine whether there is a significant increase in the complete remission rate.

New treatment strategies for multiple myeloma

During the past 5 years, several new treatments and strategies have been developed for patients with multiple myeloma. For patients with disease resistant to standard therapies, these include the VAD regimen, dexamethasone alone, high-dose melphalan, and intensive chemoradiotherapy with bone marrow transplantation. Alpha interferon appears to have its greatest potential as part of early induction therapy or during remission maintenance. The role of hemopoietic growth factors or blood stem cells in support of high-dose therapy and drugs that may overcome multiple drug resistance continues under study. A sequence of non-cross resistant therapies early in the disease course seems worthy of investigation, especially in patients at high risk for early relapse.

Multiple myeloma of the bladder and vagina

A case is described of multiple myeloma with involvement of the urinary bladder and vagina. The patient was admitted with hematuria and postrenal obstruction. She was treated successfully with local radiotherapy and combination chemotherapy with vincristine, Adriamycin (doxorubicin), and dexamethasone (VAD).

Treatment of refractory multiple myeloma with the vincristine-adriamycin-dexamethasone (VAD) regimen

Seventeen patients with advanced refractory multiple myeloma were treated with a 4-day continuous infusion of vincristine and adriamycin in combination with 4-day intermittent high-dose dexamethasone (VAD). Ten patients entered a partial remission (59%). Complete remission was not achieved in any patients. The median response duration was 11 months and the median survival of the responding patients was 18 months versus 5 months for non-responders. Major complications during VAD treatment were infections probably due to a combination of myelosuppression and intensive corticosteroid therapy. The VAD regimen offers a useful chemotherapy that produces an overall high response rate even in intensively pretreated patients resistant to first line therapy. The treatment results in a clear tendency to longer survival in responding patients.

Myeloma

Myeloma is a malignancy of plasma cells that are terminally differentiated B-lymphocytes. The clinical spectrum varies from the incidental discovery of a pathologically raised monoclonal immunoglobulin on routine electrophoresis in asymptomatic patients to widespread skeletal involvement with incapacitating bone pain. Symptoms may result from a solitary tumor mass, described as an extramedullary plasmacytoma, in virtually any part of the body. Metabolic abnormalities commonly include hypercalcemia, elevated plasma urate levels, or the development of amyloidosis, all of which may disturb renal function. High paraprotein levels cause hyperviscosity, resulting in generalized debility and varying degrees of disturbed mental function. The natural history is determined by the mass of the tumor coupled with its unique biologic features. Median survival of unselected patients, without effective treatment but once symptoms are evident, is approximately 7 months; this period can be significantly prolonged with appropriate therapy. As a first step, urgent medical management is often necessary, centering on rehydration, correction of hyperviscosity, and reversal of metabolic defects, each of which may improve renal function. Over the longer term, specific antitumor drugs have extended median survival to approximately 30 months, and most regimens include a combination of melphalan and prednisone, with or without other cytotoxic drugs. Alternative forms of treatment include sequential hemibody irradiation, recombinant alpha interferon, and in suitably selected patients, high-dose chemoradiotherapy followed by bone marrow transplantation. The latter approaches offer promising management options and are currently the subject of evaluation in controlled clinical trials.

Evidence that multiple myeloma may be regulated by homeostatic control mechanisms: correlation of changes in the number of clonogenic myeloma cells in vitro with clinical response

Myeloma colonies (MY-CFUc) could be grown in vitro for 6 months (median time) after a group of 12 myeloma patients had reached complete remission (CR). In a second group of 25 patients MY-CFUc increased in 17/25 and GM-CFUc in 20/25 patients after cyclophosphamide even though 24/25 patients had a partial response to VAMP and one was in CR. These data suggest that cell killing by cyclophosphamide stimulates residual tumour cells into proliferation and adds further support to the idea that myeloma is under some degree of homeostatic control which may be analogous to that in normal bone marrow. Although lymphoplasmacytoid myeloma cells may be more drug resistant than plasmacytoid myeloma cells in vitro, it was not possible to conclude that the emergence of lymphoplasmacytoid cells at relapse was indicative of resistance to further treatment.

VAD-based regimens as primary treatment for multiple myeloma

An alternating VCAD-VAD regimen, combining vincristine-doxorubicin by continuous infusion with cyclophosphamide and pulse dexamethasone, or VAD alone, was given to 175 previously untreated patients with multiple myeloma. The response rate with primary VAD-based regimens of 55% was virtually identical to the 54% in comparable patients treated previously with similar programs by using bolus vincristine-doxorubicin. Despite responses to VAD that were more rapid in onset than any previous treatment, remission and survival times were similar. This may be due to major differences in drug sensitivity between progenitor and differentiated plasma cells. A VAD-based regimen seems better for newly diagnosed patients when rapid control of multiple myeloma is necessary.

Assessment of observer variation in measuring the Radiographic Vertebral Index in patients with multiple myeloma

The Radiographic Vertebral Index (RVI) was assessed as a possible outcome measure for bone disease in myeloma by evaluating within and between reader reproducibility. Four readers (2 radiologists and 2 clinical hematologists) independently scored, on two separate occasions, the RVI on 40 radiographs from patients with myeloma. Each vertebra from third thoracic (T3) to fifth lumbar (L5) received a score of "1" if normal, "2" if biconcave and "4" if crushed or fractured. RVI global scores, therefore, could vary from a minimum of 15, for no damage, to a potential maximum of 60 in which all vertebrae are collapsed. Agreement was determined for each vertebra using crude percentage agreement and the kappa statistic (which corrects for chance-expected agreement) for categorical data, and for global score using analysis of variance and calculating intra-class correlation. With increasing mean abnormality score on individual vertebrae there was a corresponding increase in kappa and reduction in crude percentage agreement. Within readers, the mean percentage agreement across all vertebrae varied from 85.6 to 90.3% and the observed differences just reach statistical significance (p = 0.048). Mean kappa values ranged from 0.48 to 0.63 and were similar across readers. Differences in intra-reader agreement were not related to subspecialty. When between reader percentage agreement and kappa scores were assessed for radiologists and non-radiologist clinicians, no difference could be detected. Agreement with respect to intra-reader mean global RVI scores was excellent as illustrated by the intra-class correlation coefficient which varied from 0.89 to 0.94. The mean intra-class correlation for radiologists was 0.92, compared with 0.91 for non-radiologists.(ABSTRACT TRUNCATED AT 250 WORDS)

Management of multiple myeloma

There has been little progress in the treatment of patients with multiple myeloma, and the average survival time is still only about 3 years. Although there have been significant therapeutic advances in recent years, clinical trials have only just begun. The major concern is, of course, the achievement of major disease control (which can be equated with a cure). The data available to date indicate that this is possible only with the use of allogeneic bone marrow transplantation, with which a survival plateau of around 30% can be attained. The trials should perhaps include the sequential use of all regimens with established efficacy in refractory myeloma. Immunoconjugate therapy with either radioisotopes or cytotoxic agents could also be envisioned, and expansion with suitable biological agents such as interleukin-2 could be considered. There is a plethora of promising treatment possibilities and novel concepts that may improve the dismal outlook for patients with multiple myeloma.

High levels of doxorubicin in the tissues of a patient experiencing extravasation during a 4-day infusion

A 56-year-old patient with multiple myeloma experienced an extravasation of doxorubicin (DOX) and vincristine administered as a 96-hour infusion. An unknown quantity of solution (2.1 mg/ml of DOX and 0.1 mg/ml of vincristine) extravasated into the medial aspect of the right upper arm. This was caused by the axillary blockage of a 14-inch, 18-gauge catheter that had been inserted through the antecubital fossa. The only physical complaint mentioned by the patient was a dull muscle ache. No local swelling or redness was apparent until 2 weeks after the extravasation occurred, at which time surgical debridement yielded a 9.2 x 4 x 2-cm section of fascia and thrombosed vein with a normal-appearing margin. A high performance liquid chromatography analysis of different tissue areas in the surgical specimen yielded DOX levels of 1.25 to 7.94 micrograms/g of wet tissue weight. These levels are approximately tenfold higher than those of any previous extravasation reports. Slightly lower levels of the DOX aglycone (but no doxorubicinol) were recovered from these tissues. An important finding was the DOX level of 2.7 micrograms/g in the margin of the specimen, predicting a need for further surgery. Indeed, a second debridement was performed 1 week later, followed by a split thickness skin graft. Although the myeloma remains in clinical remission, use of the effected right arm is limited primarily by skin contracture at the graft site. This case demonstrates that high DOX levels can be deposited in soft tissues during prolonged DOX infusions without producing severe acute symptomatology. Furthermore, an analysis of DOX content in excised tissues may help guide the surgical management of the patient experiencing an extravasation.