Raman Desikan

Antitumor Activity of Thalidomide in Refractory Multiple Myeloma

BACKGROUND Patients with myeloma who relapse after high-dose chemotherapy have few therapeutic options. Since increased bone marrow vascularity imparts a poor prognosis in myeloma, we evaluated the efficacy of thalidomide, which has antiangiogenic properties, in patients with refractory disease. METHODS Eighty-four previously treated patients with refractory myeloma (76 with a relapse after high-dose chemotherapy) received oral thalidomide as a single agent for a median of 80 days (range, 2 to 465). The starting dose was 200 mg daily, and the dose was increased by 200 mg every two weeks until it reached 800 mg per day. Response was assessed on the basis of a reduction of the myeloma protein in serum or Bence Jones protein in urine that lasted for at least six weeks. RESULTS The serum or urine levels of paraprotein were reduced by at least 90 percent in eight patients (two had a complete remission), at least 75 percent in six patients, at least 50 percent in seven patients, and at least 25 percent in six patients, for a total rate of response of 32 percent. Reductions in the paraprotein levels were apparent within two months in 78 percent of the patients with a response and were associated with decreased numbers of plasma cells in bone marrow and increased hemoglobin levels. The microvascular density of bone marrow did not change significantly in patients with a response. At least one third of the patients had mild or moderate constipation, weakness or fatigue, or somnolence. More severe adverse effects were infrequent (occurring in less than 10 percent of patients), and hematologic effects were rare. As of the most recent follow-up, 36 patients had died (30 with no response and 6 with a response). After 12 months of follow-up, Kaplan-Meier estimates of the mean (+/-SE) rates of event-free survival and overall survival for all patients were 22+/-5 percent and 58+/-5 percent, respectively. CONCLUSIONS Thalidomide is active against advanced myeloma. It can induce marked and durable responses in some patients with multiple myeloma, including those who relapse after high-dose chemotherapy.

Results of autologous stem cell transplant in multiple myeloma patients with renal failure

Data are presented on 81 multiple myeloma (MM) patients with renal failure (creatinine > 176·8 μmol/l) at the time of autologous stem cell transplantation (auto‐SCT), including 38 patients on dialysis. The median age was 53 years (range: 29–69) and 26% had received more than 12 months of prior chemotherapy. CD34+ cells were mobilized with granulocyte colony‐stimulating factor (G‐CSF) alone (n = 51) or chemotherapy plus G‐CSF (n = 27), yielding medians of 10 and 16 × 106 CD34+ cells/kg respectively (P = 0·003). Sixty patients (27 on dialysis) received melphalan 200 mg/m2 (MEL‐200). Because of excessive toxicity, the subsequent 21 patients (11 on dialysis) received MEL 140 mg/m2 (MEL‐140). Thirty‐one patients (38%) completed tandem auto‐SCT, including 11 on dialysis. Treatment‐related mortality (TRM) was 6% and 13% after the first and second auto‐SCT. Median times to absolute neutrophil count (ANC) > 0·5 × 109/l and to platelets > 50 × 109/l were 11 and 41 d respectively. Non‐haematological toxicities included mucositis, pneumonitis, dysrhythmias and encephalopathy. At a median follow up of 31 months, 30 patients have died. Complete remission (CR) was achieved in 21 patients (26%) after first SCT and 31 patients (38%) after tandem SCT. Two patients discontinued dialysis after SCT. Median durations of complete remission (CR) and overall survival (OS) have not been reached; probabilities of event‐free survival (EFS) and OS at 3 years were 48% and 55% respectively. Dialysis dependence and MEL dose did not affect EFS or OS. Sensitive disease prior to SCT, normal albumin level and younger age were independent prognostic factors for better OS. In conclusion, renal failure had no impact on the quality of stem cell collections and did not affect engraftment. MEL‐140 had an acceptable toxicity and appeared equally effective as MEL‐200. In the setting of renal failure, the role of auto‐SCT early in the disease course and benefits of tandem SCT require further evaluation.

Autologous stem cell transplantation in elderly multiple myeloma patients over the age of 70 years

The feasibility and efficacy of autologous stem cell transplantation (auto‐SCT) in patients aged ≥ 70 years was analysed. Newly diagnosed (n = 34) and refractory multiple myeloma (n = 36) patients were studied. The median age was 72 years (range: 70–82·6). CD34+ cells were mobilized with chemotherapy and granulocyte colony‐stimulating factor (G‐CSF) (n = 35) or G‐CSF alone (n = 35), yielding medians of 11·8 × 106 versus 8 × 106cells/kg respectively (P = 0·007). Because of excessive mortality (16%) in the first 25 patients who received melphalan 200 mg/m2 (MEL‐200), the dose was subsequently decreased to 140 mg/m2 (MEL‐140). Median times to absolute neutrophil count (ANC) > 0·5 × 109/l and to platelets > 20 × 109/l were 11 and 13 d respectively. Thirty‐one patients (44%) received tandem auto‐SCT. Complete remission (CR) was 20% after the first SCT and 27% after tandem SCT. Median CR duration was 1·5 years and was significantly longer for patients with ≤ 12 months of prior chemotherapy (2·6 versus 1·0 years, P = 0·0008). The 3‐year event‐free survival (EFS) and overall survival (OS) (+ standard error, SE) were projected at 20% + 9% and 31% + 10% respectively. Tandem SCTs positively affected EFS (4·0 versus 0·7 years; P = 0·003) and OS (4·0 versus 1·4 years; P = 0·02) compared with single auto‐SCT. In conclusion, MEL‐140 is less toxic and appears equally as efficacious as MEL‐200 in elderly patients. The benefits of tandem SCT in this patient population need further evaluation in a randomized trial.

Long-term outcome results of the first tandem autotransplant trial for multiple myeloma.

Total Therapy 1, the first tandem autotransplant trial for newly diagnosed patients with multiple myeloma, was designed to increase the frequency of complete response (CR) and thereby extend survival. With a median follow‐up of 12 years, 62 of 231 initially enrolled patients are alive (17% at 15 years); 31 remain event free (7% at 15 years) including 16 of 94 (41%) that initially achieved CR. Currently alive patients less frequently had cytogenetic abnormalities (CAs) at baseline (P = 0·002), postenrolment (P < 0·001) and at relapse (P = 0·004); elevations of serum C‐reactive protein (CRP) (P = 0·003) and lactate dehydrogenase (P = 0·029), anaemia (P = 0·029) and they more often completed two transplants within 12 months (P = 0·019). Postenrolment overall survival (OS) and event‐free survival (EFS) were superior in the absence of CA of the hypodiploidy or deletion 13 variety (P < 0·001 and 0·037 respectively) and in the presence of low CRP at baseline (P = 0·001 and 0·017 respectively). Postrelapse survival was longer in the absence of CA at relapse (P < 0·001), IgA isotype (P = 0·002), International Staging System stage 3 (P = 0·014), and when patients had two protocol transplants prior to relapse (P = 0·038). Ten‐year EFS and OS could be accomplished in 15% and 33% of patients, respectively, when all agents available in 1989, especially high‐dose melphalan, were applied together upfront for the management of myeloma.

Clinical activity of arsenic trioxide for the treatment of multiple myeloma

Arsenic has been used since ancient times as a therapeutic agent. However, until recently its use in modern medicine has been restricted to the treatment of a limited number of parasitic infections. In the early 1990s, reports from China described impressive results with arsenic trioxide in patients with de novo, relapsed, and refractory acute promyelocytic leukemia (APL). Other investigators subsequently confirmed these results leading to approval of its use for relapsed or refractory APL in the United States. Investigations of this agent have demonstrated that its efficacy in APL and preclinical tumor models is dependent upon a number of mechanisms, including induction of apoptosis, effects on cellular differentiation, cell cycling, and tumor angiogenesis. Subsequent preclinical studies showed significant activity of arsenic trioxide in multiple myeloma (MM). Based on this, in a phase II trial, we have evaluated the activity of arsenic trioxide in 14 patients with relapsed MM, refractory to conventional salvage therapy. With the dose and schedule used, treatment with arsenic trioxide produced responses in three patients and prolonged stable disease in a fourth patient, with the longest response lasting 6 weeks. Although treatment was reasonably well tolerated, in these patients with extensive prior therapy, 11 developed cytopenia, five associated with infectious complications and three developed deep vein thromboses. The results of this small trial support further investigation of this novel drug for the treatment of patients with relapsed or refractory MM.

Myeloma of the central nervous system: association with high-risk chromosomal abnormalities, plasmablastic morphology and extramedullary manifestations.

Summary.  Involvement of the central nervous system (CNS) by multiple myeloma, as defined by the detection of malignant plasma cells in the cerebrospinal fluid in the presence of suggestive symptoms, is considered extremely rare. We report on the characteristics of 18 such patients diagnosed and treated at the University of Arkansas over the last 10 years for an overall incidence of approximately 1%. Their evaluation revealed association of CNS involvement with unfavourable cytogenetic abnormalities (especially translocations and deletion of the chromosome 13), high tumour mass, plasmablastic morphology, additional extramedullary myeloma manifestations and circulating plasma cells. The presence of these features should alert clinicians to the possibility of CNS involvement. The outcome of these patients was extremely poor despite the use of aggressive local and systemic treatment including autologous stem cell transplants. Given this universally poor prognosis, the application of allogeneic transplants should be studied in this clinical setting.

Optimizing dendritic cell-based immunotherapy in multiple myeloma

Summary. Vaccination with idiotype protein‐pulsed dendritic cells (DCs) has been explored in multiple myeloma and the results have been disappointing. These studies used immature DCs, which are less potent at activating T cells and could differentiate to macrophages once the cytokines were withdrawn. After intravenous administration, DCs accumulate in the lungs and liver for up to 48 h, thus reducing their potential to migrate to lymphoid organs and interact with T cells. To improve the efficacy of DC vaccination in myeloma, we investigated the use of idiotype‐pulsed mature DCs administered subcutaneously. Five patients (three IgG and two IgA myeloma) with stable partial remission following high‐dose chemotherapy were enrolled. DC vaccines were administered three times at 2‐week intervals at least 4 months post transplantation. Idiotype‐specific T‐cell responses, detected using enzyme‐linked immunospot (ELISPOT) (four patients) and proliferation (two patients) assays, were elicited in four and anti‐idiotypic B‐cell responses in all five patients. The cytokine‐secretion profile of activated T cells demonstrated a type‐1 response. A 50% reduction in serum M‐component was observed in one immunologically responding patient that persisted for 6 months and stable disease (for 6 months) resulted in the other three patients. The remaining patient without an immune response to the vaccination relapsed. No major side‐effects were noted. Thus, subcutaneous administration of idiotype‐pulsed mature DCs induced idiotype‐specific T‐ and B‐cell responses. Current efforts are geared towards optimizing the conditions of DC generation and administration, and the development of in vitro assays to monitor the cytotoxicity of the T cells.

Predicting long-term (≥ 5 years) event-free survival in multiple myeloma patients following planned tandem autotransplants

Summary. Although outcome in multiple myeloma (MM) patients has improved significantly with the introduction of autotransplants (AT), the curability of this approach remained to be demonstrated. Therefore, we analysed outcome and prognostic factors using a logistic regression model in 515 consecutive newly diagnosed and previously treated patients intended to receive melphalan‐based tandem transplants with follow up of ≥ 5 years. One quarter ofpatients had event‐free survivals (EFS) ≥ 5 years with no further relapses seen after 7 years (46 patients on plateau). On multivariate analysis, factors associated with EFS ≥ 5 years were absence of chromosome 11 and 13 abnormalities (odds ratio: 6·1), ≤ 12 months of preceding standard‐dose therapy (SDT) (OR: 2·6) and β‐2 microglobulin (B2M) level ≤ 2·5 mg/l at time of first AT (OR: 1·7). Patients with only favourable variables (25%) had a 7‐year EFS in excess of 35%, compared with 15% and 10%, respectively, with one (43%) or two unfavourable variables (27%), and 0% for 5% of patients with three unfavourable variables (P < 0·0001). Using a 1‐year landmark analysis to allow for guaranteed time and thereby excluding early treatment failures, attaining a complete remission (CR) had no significant effect on long‐term survival. Our data are consistent with cure in MM patients with a CR duration ≥ 7 years and re‐establishment of a monoclonal gammopathy of undetermined significance (MGUS) phase in those with persistent evidence of disease post transplantation, but without disease progression ≥ 7 years.

High-dose therapy with autologous haemopoietic stem cell support for Waldenström's macroglobulinaemia.

Standard doses of alkylating agents or purine analogues effect response rates of up to 50% in Waldenströms macroglobulinaemia (WM); however, complete responses are infrequent and there are no cures. We have evaluated the feasibility, safety and efficacy of high‐dose chemotherapy with peripheral blood stem cell support in six patients aged 45–69 years (median 51.5) with WM; four patients relapsed after prior therapy inclusive of purine analogues and two patients proceeded with transplant after minimal therapy. Four patients mobilized adequate numbers of stem cells; however, two patients with more extensive fludarabine therapy failed to mobilize and required a second attempt at stem cell collection. Five patients were treated with melphalan 200 mg/m2, including one patient who received tandem transplants and one patient who received melphalan 140 mg/m2 with added total body irradiation (TBI). There was no treatment‐related mortality and non‐haematological toxicities were manageable. Engraftment was prompt except in one patient with extensive prior use of fludarabine. All the six patients achieved at least partial response (PR), including one who achieved complete response (CR). Five patients are alive and four are event‐free at 52+, 15+, 12+ and 2+ months post transplant. This pilot study suggests safety and efficacy of high‐dose therapy in WM and suggests that the peripheral blood stem cells should preferably be procured prior to extensive use of purine analogues.

Nephrotic proteinuria associated with high-dose pamidronate in multiple myeloma

Summary. Five patients receiving increased dose or frequency of pamidronate beyond the recommended dose (90 mg/monthly) exhibited nephrotic proteinuria (range 3·96–24 g/24 h). On dose reduction or discontinuation, three of these patients showed decreased proteinuria to normal levels (< 1 g/24 h), and proteinuria decreased to 4·5 g/24 h from a peak of 24 g/24 h in one patient. One patient on haemodialysis (hence not evaluable) had proteinuria of 2 g/24 h and elevated creatinine levels. One other patient continued to show elevated creatinine levels (272·8 µmol/l). Renal biopsies obtained in two patients revealed focal segmental glomerulosclerosis.