Effective treatment of advanced multiple myeloma refractory to alkylating agents

Peptichemio in pretreated patients with plasmacell neoplasms

Twenty-one patients with alkylator-resistant plasmacell neoplasms were treated with Peptichemio (PTC) at a dose of 40 mg/m2 for 3 days every 3 weeks or, in the case of persistent leukopenia and/or thrombocytopenia, at the single dose of 70 mg/m2 every 2-3 weeks according to haematological recovery. Seventeen patients, 10 with multiple myeloma and seven with extramedullary plasmacytoma (EMP), were fully evaluable. Six of 17 patients (35%) responded: three of seven EMP patients had a complete remission and 3 of 10 multiple myeloma patients had an objective response greater than 50%. The median duration of response was 8.5 months. An EMP patient obtained a complete response lasting for 16 months. The most frequent toxic effect were phlebosclerosis, occurring in all the patients, and myelosuppression, which was severe in only one case. PTC appears to be an active drug in patients with plasmacell neoplasms even if resistant to alkylating agents.

Biclonal and hypodiploid multiple myeloma

Plasma cell DNA and RNA content was measured by flow cytometry of acridine orange-stained bone marrow cells from 72 untreated patients with multiple myeloma. Biclonal or hypodiploid DNA stemlines were identified in 10 patients, nine of whom had a low RNA content and did not have response to chemotherapy. Biclonal tumors often showed atypical myeloma protein changes with chemotherapy, suggesting that one clone was reduced whereas the other remained unchanged. These findings suggest a genetic basis for the resistance of low RNA tumors to chemotherapy.

Beta 2 microglobulin in multiple myeloma

Serum beta 2 microglobulin levels (B2M) were evaluated before and during chemotherapy in 97 previously untreated patients with multiple myeloma. Pretreatment values were useful in confirming tumor mass grade, and marked reductions following chemotherapy correlated well with the onset of remission. No gain was evident from correcting the B2M for the level of serum creatinine. A pretreatment B2M value greater than 6 mg/L correlated with a low response rate and was the most important variable that predicted a short survival time.

Malignant plasmacytic ascites. A report of two cases and a review of the literature

Two patients with ascites due to peritoneal involvement by multiple myeloma are reported and seven previously described cases of plasmacytic ascites are reviewed. In all nine cases, ascitic fluid contained large numbers of bizzare, immature plasma cells. Although the cells were often difficult to characterize by light microscopy, they could be rapidly identified as malignant plasma cells by immunofluorescent demonstration of monoclonal, intracellular immunoglobulin as performed in one of the patients. This rare extramedullary complication of plasma cell neoplasia has been unresponsive to therapy and rapidly fatal, with a median survival of 2 months.

Objective evaluation of the role of vincristine in induction and maintenance therapy for myelomatosis. Medical Research Council Working Party on Leukaemia in Adults

In the Medical Research Council's IVth trial in Myelomatosis the possible benefit of adding vincristine to first line treatment with intermittent melphalan and prednisone has been assessed. This was analysed in 530 patients who were randomly allocated to receive vincristine or not. Survival was not improved by the addition of vincristine. A total of 268 patients reached plateau phase on first line therapy. Of these 226 patients were rerandomised either to continue receiving first line therapy for a further year or to cease therapy. At the present time there is a slight but not significant survival advantage in the group which received no further treatment on reaching plateau.

[Extrahepatic biliary obstruction caused by infiltration of the pancreas by plasmacytoma]

This is a report about a 61 year old male suffering from IgG-Kappa plasmocytoma. 12 months after the initial diagnosis, he developed an intrathoracal plasma cell tumour, primarily affecting the pleura. One year later obstructive jaundice was caused by a mass of the head of the pancreas, diagnosed by ultrasound. Percutaneous fine needle aspiration biopsy revealed homogeneous plasma cell infiltration of the gland.

Cytoplasmic immunoglobulin content in multiple myeloma

Bone marrow cells of 82 patients with multiple myeloma were subjected to flow cytometric analysis of DNA and cytoplasmic immunoglobulin (CIg) content using propidium iodide and direct immunofluorescence assays. Except for two patients with nonsecretory myeloma, there was conformity in the immunoglobulin type derived from immunoelectrophoresis and plasma cell CIg staining. One patient with nonsecretory myeloma exhibited monotypic CIg staining, while the second showed no reaction. In eight patients with IgG lambda myeloma, the same tumor cells contained both lambda and kappa light chains, suggesting the productive rearrangement of both light chain genes. 14 patients with previously unrecognized plasma cells of low RNA content, all of whom were resistant to chemotherapy, were identified by CIg staining. By revealing previously unrecognized plasma cells with low RNA content, CIg analysis identified more patients with treatment-refractory myeloma.

Multiple myeloma: current therapy and a glimpse of the future

Patients with benign monoclonal gammopathy or smouldering multiple myeloma should not be treated. The plasma cell labelling index utilizing tritiated thymidine or a monoclonal antibody to 5-bromo-2-deoxyuridine is helpful in differentiating patients with benign monoclonal gammopathy or smouldering myeloma from those with overt myeloma. Although combinations of chemotherapeutic agents seem to produce a greater number of objective responses than does melphalan-prednisone, a significant difference in survival has not been proved. Possibilities for future treatment include chemotherapy with large intravenous doses of melphalan, very small doses of cyclophosphamide or melphalan, the administration of hydroxyurea before chemotherapy, combination of interferon with alkylating agents, autologous bone marrow transplantation, and improvement of the soft-agar colony-forming assay for myeloma cells. The therapeutic use of monoclonal antibodies to plasma cell antigens may be possible in the future. Much more needs to be learned about the biologic basis of myeloma before real progress can be made.

Immunoglobulin-producing tumors

Multiple myeloma and macroglobulinemia are the most common immunoglobulin-producing neoplasms seen in the dog. Treatment with the alkylating agents in combination with prednisone may significantly prolong survival. Supportive management of associated complications is imperative to ensure that the individual case receives optimal care. The use of clinical staging seems to be of value in establishing prognosis; however, response to therapy may be more significant, for many dogs present with advanced disease. In the high-risk patient, one should consider using investigational combination drug protocols which are available at a referral center. Although a "cure" is unlikely, the prospect of the animal having a fairly normal, healthy life for an extended period of time (over a year in the majority of cases) should encourage veterinarians to recommend evaluation for treatment in dogs with multiple myeloma and macroglobulinemia.

Response rate and survival in myeloma patients receiving prednisone alone

Thirty-two evaluable good risk patients with multiple myeloma received a 70-day tapering course of prednisone beginning at a dose of 1.2 mg/kg/day. Forty-four percent of the patients demonstrated objective evidence of response to this treatment. Although the median time to disease progression for the prednisone-treated group was shorter than for patients randomized to receive prednisone with alkylating agents or who were treated with alkylating agent alone, the results from this trial indicate that prednisone, by itself, may produce objective responses. Caution must be used interpreting trials of new agents in myeloma when such treatments are combined with corticosteroid administration.

Salvage treatment for patient with multiple myeloma refractory to alkylating agents

Sixteen patients with multiple myeloma refractory to alkylating agents were treated with vincristine 0.25 mg/m2 i.v. on days 1 to 4 and prednisone 1 gm/m2 on days 1 and 3. Chemotherapy was repeated every 2 weeks. Of 15 evaluable patients, five achieved a partial response and four stable disease. Three patients with partial response and three with stable disease relapsed at 6, 7, and 16 and at 5, 9, and 10 months, respectively. The median survival for all patients was 10 1/2 months and it ranged from 1 to 21 + months. The median survival in responders was not reached at 13 months. Onset of antitumor effect was observed within the first 2 weeks. Symptomatic relief of bone pain was noted within 48 hours in responders and nonresponders. Improvement in bone marrow cellularity and decrease in plasma cell infiltration was documented in more than one-half of the responders. Tolerance to the treatment was good. No hematologic or other significant toxicity was observed.

The hematologic malignancies. Leukemia, lymphoma, and myeloma

Many of the conceptual advances in the treatment of advanced cancer have resulted from studies of the hematologic malignancies: The signal importance of complete remission, the complete disappearance of evident disease, as the major contributor to significant palliation; the first studies of adjuvant therapy, that is chemotherapy given to patients free of disease, which demonstrated prolongation of disease-free periods; the first studies of intensification, including early, intermittent, and late; combination chemotherapy; and finally, the important observation that advanced metastatic malignancies can be cured were made in studies of these important diseases. Because of treatment advances that have occurred over the last 10 to 20 years, the majority of patients with adult hematologic malignancies that were once considered universally fatal can be either cured or have substantial palliation. Treatment for adult acute leukemia has advanced such that 15% to 20% of patients have prolonged disease and treatment-free survivorship; in Hodgkin's disease, over 70% of patients can be cured; and for the lymphomas, the majority or 50% to 60% of patients can be cured with available treatments. Major treatment advances in supportive treatment such as allogeneic transfusion and allogeneic and autologous bone marrow transplantation improve the perspective for control of the hematologic malignancies. In addition, the potential for biologic response modifiers or the biologic products of normal cells that are normally involved in the regulation of both proliferation and differentiation show enormous potential for the treatment of advanced disease. Studies of interferon have shown promising early results in chronic granulocytic leukemia and in hairy cell leukemia. A new class of drugs, the acridine analogs, of which AMSA (4'-[9-acridinylamino]methanesulfon-M-anisidide) is a member, has been introduced and has established activity against acute leukemia. VP-16 (etoposide) has just become commercially available and is an important drug both in leukemia and lymphoma. Finally, the discovery of new knowledge about the biochemical pharmacology of drugs such as arabinosyl cytosine has offered a major advance in salvage treatment and the potential for substantial further improvement in the frontline management of these diseases. The rapid advances in both palliative and curative treatment for the hematologic malignancies have generally found broad application to the management of advanced cancer arising from other organ systems.