A Tumor Growth Inhibition Model Based on M-Protein Levels in Subjects With Relapsed/Refractory Multiple Myeloma Following Single-Agent Carfilzomib Use

Change in tumor size estimated using longitudinal tumor growth inhibition (TGI) modeling is an early predictive biomarker of clinical outcomes for multiple cancer types. We present the application of TGI modeling for subjects with multiple myeloma (MM). Longitudinal time course changes in M‐protein data from relapsed and/or refractory MM subjects who received single‐agent carfilzomib in phase II studies (n = 456) were fit to a TGI model. The tumor growth rate estimate was similar to that of other anti‐myeloma agents, indicating that the model is robust and treatment‐independent. An overall survival model was subsequently developed, which showed that early change in tumor size (ECTS) at week 4, Eastern Cooperative Oncology Group performance status (ECOG PS), hemoglobin, sex, percent bone marrow cell involvement, and number of prior regimens were significant independent predictors for overall survival (P < 0.001). ECTS based on M‐protein modeling could be an early biomarker for survival in MM following exposure to single‐agent carfilzomib.

Phase II trial of combination of bortezomib and rituximab in relapsed and/or refractory Waldenstrom macroglobulinemia

8535

Background: This phase II study aimed to determine safety and activity of weekly bortezomib in combination with rituximab in patients with relapsed/refractory Waldenstrom macroglobulinemia (WM). Methods: Patients who had at least one previous therapy for WM and who had relapsed or refractory disease were eligible. NCI CTCAE v3.0 was used for toxicity assessment. All patients received bortezomib IV weekly at 1.6mg/m2 on days 1, 8, 15, q 28 days × 6 cycles, and rituximab 375 mg/m2 at days 1, 8, 15, 22, on cycles 1 and 4. Results: 37 pts (26 men and 11 women, median age 62 years, range 42 - 73) have been treated to date. The median number of lines of prior treatment was 3 (range 1 - 5). All patients had received prior rituximab and 5 pts received prior bortezomib. The median IgM at baseline was 3540 mg/dL (range 700-10,800). The median follow up is 12 months (range 5 - 26 months). Thirty-five pts are evaluable for response. Complete remission and near complete remission occurred in 2 (6%), partial remission in 17 (48%), and minimal response in 10 (29%). Progressive disease occurred in 1 (3%) and stable disease occurred in 5 (14%). Most patients achieved response rapidly within 3 months of therapy (2–7 months). Rituximab flare occurred only in 6 patients (20%). At 24 months of follow up, 8/35 pts have shown relapsed disease. The median time to progression and duration of response has not been reached. Patients tolerated therapy well without significant toxicities: grade 3 peripheral neuropathy occurred in only 2 pts. Grade 1 and 2 neuropathy occurred in 10 pts (26%). Other grade 3 and 4 toxicities included neutropenia in 5 patients, and anemia and thrombocytopenia in 4 patients. Grade 5 pneumonia and viral infection occurred in 1 patient who was within the first cycle of therapy and did not receive herpes zoster prophylaxis. Attributable toxicities otherwise proved manageable with appropriate supportive care and the combination was generally well tolerated. Conclusions: The combination of weekly bortezomib and rituximab has been well tolerated and demonstrates encouraging activity, with CR+ PR + MR in 83% of evaluable patients with relapsed WM. No significant peripheral neuropathy has been observed to date with this regimen.

[Table: see text]

Update of melphalan 280 mg/m2 plus amifostine cytoprotection before autologous stem cell transplantation as part of initial therapy in multiple myeloma patients

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Background: Autologous stem cell transplantation (ASCT) using melphalan 200 mg/m2 is a standard part of inital therapy in younger multiple myeloma (MM) patients (pts). We have previously reported an augmented regimen of melphalan 280 mg/m2 with the cytoprotectant agent amifostine (AF) to try to improve the anti-tumor response without increased mucosal toxicity (The Hematol J 2003; 4[suppl]: S207). We now update our experience with this regimen. Methods: Pts without disease progression and adequate organ function (creatinine clearance at least 60 cc/min) were eligible. Pts were treated as part of phase I-II trials approved by each center’s institutional review board. AF 740 mg/m2 was given IV over 5–15 min 24 hr and 15 min prior to melphalan 280 mg/m2 (infused over 15 min). Blood stem cells were reinfused 24 hrs later. The primary endpoint was response rate at day 100. Regimen-related toxicity using the Seattle criteria, progression-free (PFS) and overall survival (OS) were also assessed. Results: 24 pts were transplanted between 5/99–7/02. Median age was 50 (32–65) yrs; 1 pt had primary amyloidosis; median beta2-microglobulin level at diagnosis was 1.98 (0.88–11.80) mg/L. Prior therapy included VAD in 14, dexamethasone alone in 7 plus other regimens in 7. Day 100 responses compared with with pre-ASCT values included CR in 11, near CR (immunofixation positivity only) in 1, VGPR (greater than 90% reduction in serum M protein) in 3, PR in 5 and stable disease in 3. Maximum grade of mucositis was 2 (5 pts); no grade 3 or 4 toxicity was seen. The median day of ANC recovery to 0.5 x 109/L and median day of last platelet transfusion were 11 (6–16) and 10 (7–32), respectively. 4 received thalidomide (1 briefly), while 1 was treated with maintenance alpha interferon after day 100. Median follow-up is 52 (9–72) mos. 7 pts are alive without progression, including 5 in CR and 2 in PR. 16 have progressed at a median of 15 (7–36) mos post-ASCT. 8 have died from MM (7) or lung cancer (1). The 4 yr actuarial PFS is 28% (95% C.I. 34–76%) and OS 58% (95% C.I.11–47%). Conclusions: 1) Melphalan 280 mg/m2 with AF is well-tolerated; 2) the CR + nCR + VGPR rate of 62% warrants further evaluation, perhaps as part of tandem transplants or in conjuction with novel agents.

[Table: see text]

Clonal cytogenetic changes and myeloma relapse after reduced intensity conditioning allogeneic transplantation

To identify a correlation between metaphase cytogenetics and relapse after reduced intensity conditioning (RIC) allotransplant for patients with multiple myeloma, data on 60 patients (median age 52) who received grafts from a sibling (n = 49) or unrelated donor (n = 11) were analyzed. Fifty-three patients (88%) showed chromosomal abnormalities (CA) before the allotransplant, including 42 with abnormalities involving 13q (CA13). Twenty-two patients (41%) relapsed post-allotransplant at a median of 165 days. Of these, 11 patients showed abnormal cytogenetics at the time of post-allotransplant relapse at a median of 167 days. Of 54 patients who developed graft-versus-host disease, relapse occurred in 19 of 48 patients (43%) with CA present before RCI allotransplant, versus 1 of 6 without CA (17%) (P = 0.06). Loss of CA before RIC allotransplant and disease status > PR after RIC allotransplant were significantly associated with a lower risk of post-allotransplant relapse with cytogenetic abnormalities; 5.2 vs 36%, and 18 vs 53%, (both P < 0.05), respectively. The current data suggests that myeloma associated with persistent clonal cytogenetic abnormalities is an entity which most likely escapes the effects of a graft versus myeloma activity, maybe because of acquisition of resistance to immunologic manipulations.

Autologous stem cell transplantation followed by consolidation chemotherapy for relapsed or refractory Hodgkin's lymphoma

Relapse remains a major cause of treatment failure after autotransplantation (auto-PBSCT) for Hodgkin's disease (HD). The administration of non-crossresistant therapies during the post-transplant period may delay or prevent relapse. We prospectively studied the role of consolidation chemotherapy (CC) after auto-PBSCT in 37 patients with relapsed or refractory HD. Patients received high-dose gemcitabine-BCNU-melphalan and auto-PBSCT followed by involved-field radiation and up to four cycles of the DCEP-G regimen, which consisted of dexamethasone, cyclophosphamide, etoposide, cisplatin, gemcitabine given at 3 and 9 months post transplant alternating with a second regimen (DPP) of dexamethasone, cisplatin, paclitaxel at 6 and 12 months post transplant. The probabilities of event-free survival (EFS) and overall survival (OS) at 2.5 years were 59% (95% CI=42-76%) and 86% (95% CI=71-99%), respectively. In all, 17 patients received 54 courses of CC and 15 were surviving event free (2.5 years, EFS=87%). There were no treatment-related deaths during or after the CC phase. Post-transplant CC is feasible and well tolerated. The impact of this approach on EFS should be evaluated in a larger, randomized study.

Molecular remission of CML after autotransplantation followed by adoptive transfer of costimulated autologous T cells

Four patients with chronic myelogenous leukemia (CML) that was refractory to interferon alpha (two patients) or imatinib mesylate (two patients), and who lacked donors for allogeneic stem cell transplantation, received autotransplants followed by infusions of ex vivo costimulated autologous T cells. At day +30 (about 14 days after T-cell infusion), the mean CD4+ cell count was 481 cells/microl (range 270-834) and the mean CD8+ count was 516 cells/microl (range 173-1261). One patient had a relative lymphocytosis at 3.5 months after T-cell infusion, with CD4 and CD8 levels of 750 and 1985 cells/microl, respectively. All the four patients had complete cytogenetic remissions early after transplantation, three of whom also became PCR negative for the bcr/abl fusion mRNA. One patient, who had experienced progressive CML while on interferon alpha therapy, became PCR- post transplant, and remained in a molecular CR at 3.0 years of follow-up. All the four patients survived at 6, 9, 40, and 44 months post transplant; the patient who remained PCR+ had a cytogenetic and hematologic relapse of CML, but entered a molecular remission on imatinib. Autotransplantation followed by costimulated autologous T cells is feasible for patients with chronic phase CML, who lack allogeneic donors and can be associated with molecular remissions.

Amifostine and autologous hematopoietic stem cell support of escalating-dose melphalan: A phase I study

This study was conducted to define a new maximum tolerated dose and the dose-limiting toxicity (DLT) of melphalan and autologous hematopoietic stem cell transplantation (AHSCT) when used with the cytoprotective agent amifostine. Fifty-eight patients with various types of malignancy who were ineligible for higher-priority AHSCT protocols were entered on a phase I study of escalating doses of melphalan beginning at 220 mg/m(2) and advancing by 20 mg/m(2) increments in planned cohorts of 4 to 8 patients until severe regimen-related toxicity (RRT) was encountered. In all patients, amifostine 740 mg/m(2) was given on 2 occasions before the first melphalan dose (ie, 24 hours before and again 15 minutes before). AHSCT was given 24 hours after the first melphalan dose. Melphalan was given in doses up to and including 300 mg/m(2). Hematologic depression was profound, although it was rapidly and equally reversible at all melphalan doses. Although mucosal RRT was substantial, it was not the DLT, and some patients given the highest melphalan doses (ie, 300 mg/m(2)) did not develop mucosal RRT. The DLT was not clearly defined. Cardiac toxicity in the form of atrial fibrillation occurred in 3 of 36 patients treated with melphalan doses >/=280 mg/m(2) and was deemed fatal in 1 patient given melphalan 300 mg/m(2). (Another patient with a known cardiomyopathy was given melphalan 220 mg/m(2) and died as a result of heart failure but did not have atrial fibrillation.) Another patient given melphalan 300 mg/m(2) died of hepatic necrosis. The maximum tolerated dose of melphalan in this setting was thus considered to be 280 mg/m(2), and 27 patients were given this dose without severe RRT. Moreover, 38 patients were evaluable for delayed toxicity related to RRT; none was noted. Tumor responses have been noted at all melphalan doses and in all diagnostic groups, and 21 patients are alive at median day +1121 (range, day +136 to day +1923), including 16 without evidence of disease progression at median day +1075 (range, day +509 to day +1638). Amifostine and AHSCT permit the safe use of melphalan 280 mg/m(2), an apparent increase over the dose of melphalan that can be safely administered with AHSCT but without amifostine. Further studies are needed not only to confirm these findings, but also to define the antitumor efficacy of this regimen. Finally, it may be possible to evaluate additional methods of further dose escalation of melphalan in this setting.

Transplantation as salvage therapy for high-risk patients with myeloma in relapse

Patients with myeloma relapsing after tandem transplant have a poor survival and treatment options are limited. The role of additional salvage transplant procedures for these patients is unknown. To evaluate the benefit and identify prognostic factors, the outcome of 76 consecutive patients with recurrent myeloma after tandem transplant receiving salvage transplants (ST) was analyzed. Prior to ST, 23 patients (30%) had shown chemosensitive response to preceding salvage chemotherapy: two complete remissions (CR); eight near CRs (nCR: only immunofixation positive); 13 partial remissions (PR >or=75% reduction in M protein). Fifty received an autologous transplant, 22 a sibling-matched allogeneic transplant, and four a matched-unrelated allogeneic transplant. Overall response after ST was 59%: eight CRs (11%); 14 nCRs (18%); 23 PRs (30%). Overall survival (OS) at 2 years was 19%; 2 year event-free survival rate (EFS) 7%. On univariate analysis for survival, only pre-transplant chemosensitive relapse (P < 0.05), serum albumin >3 g/dl (P = 0.001), normal LDH (P = 0.04), and long interval between the second transplant and relapse/progression were significant beneficial factors. In a Cox proportional hazard model, chemosensitive relapse, and albumin >3 g/dl were significant for better OS: hazard ratio (HR) 1.4, 1.7, respectively, while normal LDH, and absence of CA13 were significant for better EFS: HR 1.8, 1.7, respectively. Patients with albumin >3 g/dl who had chemosensitive disease before ST (n = 16) had a median survival of 16 months, compared to 7 months (n = 34) and 2 months (n = 26) for patients with only one (n = 34) or no favorable prognostic factors (n = 28), respectively (P < 0.001). Their survival at 2 years post-ST was 43%, 17% and 11%, respectively. Our study suggests further transplantation should only be considered in the setting of a clinical trial in patients with favorable prognostic factors.

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.

Separating graft-versus-tumor from graft-versus-host reactions

The full therapeutic potential of allogeneic stem cell transplantation, through its immunologically mediated graft-versus-tumor effect, in patients with hematologic malignancies is greatly compromised by the occurrence of graft-versus-host disease. Unfortunately, the use of non-selective immunosuppressive agents to reduce the incidence and severity of graft-versus-host disease is associated with severe immune compromise of the host and most likely a greater relapse risk of the underlying malignancy. Many attempts have been made to clinically separate these two effects. A critical overview of the published experience is the focus of this report. As the effector cells responsible for the two reactions are largely unknown, the limited success of the various approaches used is not surprising. A more thorough understanding of the antigenic stimuli involved in the initiation of the two reactions and of the molecular pathways through which the cytotoxic effects of T-cells are mediated is essential for abrogating graft-versus-host disease while preserving the graft-versus-tumor effect.

Activated protein C resistance in the absence of factor V Leiden mutation is a common finding in multiple myeloma and is associated with an increased risk of thrombotic complications

Thromboembolism is not uncommon in multiple myeloma (MM) patients on treatment, but its pathogenesis remains poorly understood. We report the results of a prospective randomized trial of 62 newly diagnosed MM patients tested at baseline for hypercoagulability and treated with intensive chemotherapy with or without thalidomide in a randomized fashion. During the induction phase, 12 patients (19%) developed evidence of deep venous thrombosis (DVT), which was significantly more common in the thalidomide arm (36%) than in the control group (3%) (P = 0.001). Fourteen patients (23%) were found to have a baseline-reduced response to activated protein C (APC) in the absence of factor V Leiden mutation. Using a Kaplan-Meier analysis, a significantly higher proportion of patients with APC resistance developed DVT (5/14 versus 7/38; P = 0.04) irrespective of thalidomide administration. The risk of DVT was highest (50%) in patients with APC resistance on thalidomide. None of the patients with normal APC response and not receiving thalidomide developed DVT. In conclusion, in this series, acquired APC resistance was present in almost one-quarter of newly diagnosed myeloma patients and significantly increased the risk of DVT.

Autotransplantation for advanced lymphoma and Hodgkin's disease followed by post-transplant rituxan/GM-CSF or radiotherapy and consolidation chemotherapy

Disease relapse occurs in 50% or more of patients who are autografted for relapsed or refractory lymphoma (NHL) or Hodgkin's disease (HD). The administration of non-cross-resistant therapies during the post-transplant phase could possibly control residual disease and delay or prevent its progression. To test this approach, 55 patients with relapsed/refractory or high-risk NHL or relapsed/refractory HD were enrolled in the following protocol: stem cell mobilization: cyclophosphamide (4.5 g/m(2)) + etoposide (2.0 g/m(2)) followed by GM-CSF or G-CSF; high-dose therapy: gemcitabine (1.0 g/m(2)) on day -5, BCNU (300 mg/m(2)) + gemcitabine (1.0 g/m(2)) on day -2, melphalan (140 mg/m(2)) on day -1, blood stem cell infusion on day 0; post-transplant immunotherapy (B cell NHL): rituxan (375 mg/m(2)) weekly for 4 weeks + GM-CSF (250 microg thrice weekly) (weeks 4-8); post-transplant involved-field radiotherapy (HD): 30-40 Gy to pre-transplant areas of disease (weeks 4-8); post-transplant consolidation chemotherapy (all patients): dexamethasone (40 mg daily)/cyclophosphamide (300 mg/m(2)/day)/etoposide (30 mg/m(2)/day)/cisplatin (15 mg/m(2)/day) by continuous intravenous infusion for 4 days + gemcitabine (1.0 g/m(2), day 3) (months 3 + 9) alternating with dexamethasone/paclitaxel (135 mg/m(2))/cisplatin (75 mg/m(2)) (months 6 + 12). Of the 33 patients with B cell lymphoma, 14 had primary refractory disease (42%), 12 had relapsed disease (36%) and seven had high-risk disease in first CR (21%). For the entire group, the 2-year Kaplan-Meier event-free survival (EFS) and overall survival (OS) were 30% and 35%, respectively, while six of 33 patients (18%) died before day 100 from transplant-related complications. The rituxan/GM-CSF phase was well-tolerated by the 26 patients who were treated and led to radiographic responses in seven patients; an eighth patient with a blastic variant of mantle-cell lymphoma had clearance of marrow involvement after rituxan/GM-CSF. Of the 22 patients with relapsed/refractory HD (21 patients) or high-risk T cell lymphoblastic lymphoma (one patient), the 2-year Kaplan-Meier EFS and OS were 70% and 85%, respectively, while two of 22 patients (9%) died before day 100 from transplant-related complications. Eight patients received involved field radiation and seven had radiographic responses within the treatment fields. A total of 72 courses of post-transplant consolidation chemotherapy were administered to 26 of the 55 total patients. Transient grade 3-4 myelosuppression was common and one patient died from neutropenic sepsis, but no patients required an infusion of backup stem cells. After adjustment for known prognostic factors, the EFS for the cohort of HD patients was significantly better than the EFS for an historical cohort of HD patients autografted after BEAC (BCNU/etoposide/cytarabine/cyclophosphamide) without consolidation chemotherapy (P = 0.015). In conclusion, post-transplant consolidation therapy is feasible and well-tolerated for patients autografted for aggressive NHL and HD and may be associated with improved progression-free survival particularly for patients with HD.

Increased risk of deep-vein thrombosis in patients with multiple myeloma receiving thalidomide and chemotherapy

The occurrence of deep-vein thrombosis (DVT) in patients with newly diagnosed multiple myeloma, who were randomly assigned to receive identical induction chemotherapy with or without thalidomide, are reported in this study. The 2 study arms were comparable with respect to key myeloma prognostic factors and known risk factors for DVT. One hundred patients received induction chemotherapy including 4 cycles of continuous infusion of combinations of dexamethasone, vincristine, doxorubicin, cyclophosphamide, etoposide, and cisplatin, and each patient completed at least one induction cycle. DVT developed in 14 of 50 patients (28%) randomly assigned to receive thalidomide but in only 2 of 50 patients (4%) not given the agent (P =.002). All episodes of DVT occurred during the first 3 cycles of induction. Administration of thalidomide was resumed safely in 75% of patients receiving anticoagulation therapy. Thus, thalidomide given in combination with multiagent chemotherapy and dexamethasone is associated with a significantly increased risk of DVT, which appears to be safely treated with anticoagulation and does not necessarily warrant discontinuation of thalidomide.

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 micromol/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 x 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 x 109/l and to platelets > 50 x 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 > or = 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 x 10(6) versus 8 x 10(6) cells/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 x 10(9)/l and to platelets > 20 x 10(9)/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 < or = 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.

Extended survival in advanced and refractory multiple myeloma after single-agent thalidomide: identification of prognostic factors in a phase 2 study of 169 patients

This report of a phase 2 trial of thalidomide (THAL) (200 mg/d; 200 mg increment every 2 weeks to 800 mg) for 169 patients with advanced myeloma (MM) (abnormal cytogenetics (CG), 67%; prior autotransplant, 76%) extends earlier results in 84 patients. A 25% myeloma protein reduction was obtained in 37% of patients (50% reduction in 30% of patients; near-complete or complete remission in 14%) and was more frequent with low plasma cell labeling index (PCLI) (below 0.5%) and normal CG. Two-year event-free and overall survival rates were 20% +/- 6% and 48% +/- 6%, respectively, and these were superior with normal CG, PCLI of less than 0.5%, and beta(2)-microglobulin of 3 mg/L. Response rates were higher and survival was longer especially in high-risk patients given more than 42 g THAL in 3 months (median cumulative dose) (landmark analysis); this supports a THAL dose-response effect in advanced MM.

Thalidomide in the management of multiple myeloma

Thalidomide has recently been shown to have significant activity in refractory multiple myeloma (MM). A follow-up of the original phase II trial, expanded to 169 patients, shows 2-year survival of 60%; patients receiving > or =42 g over 3 months had a higher response rate and superior survival than those receiving lower doses. The addition of thalidomide to dexamethasone and chemotherapy for the management of post-transplant relapses results in higher response rates. The early results of the Total Therapy II trial for newly diagnosed MM patients show an unprecedented complete remission (CR) and near-CR rate of 69% after two melphalan-based transplants (whether or not receiving thalidomide). In addition, available clinical trial information involving at least 20 patients confirms that thalidomide is active in one third of patients in single-agent trials for refractory disease, with response rates increasing to 50% to 60% in combination with dexamethasone and to as high as 80% in combination with dexamethasone and chemotherapy. When applied as primary therapy in smoldering myeloma, one third of patients experienced 50% paraprotein reduction (PPR); in combination with dexamethasone pulsing, 70% to 80% of symptomatic patients responded. Thus, thalidomide is a major new tool in the treatment armamentarium of MM. The virtual lack of myelosuppression makes it an ideal agent for combination with cytotoxic chemotherapy. Newer, more potent, and less toxic derivatives of thalidomide are being evaluated.

High response rate in refractory and poor-risk multiple myeloma after allotransplantation using a nonmyeloablative conditioning regimen and donor lymphocyte infusions

Standard allogeneic stem cell transplant (allo-SCT) regimens have been associated with a high transplant-related mortality (TRM) in multiple myeloma (MM). Nonmyeloablative therapy can establish stable engraftment after allo-SCT and maintain the antitumor effect with less toxicity, which is important in heavily pretreated and elderly patients. We report on 16 poor-risk MM patients receiving allo-SCT from an HLA-matched (n = 14) or mismatched (n = 2) sibling following conditioning with melphalan 100 mg/m(2) (MEL-100). Ten patients had refractory relapse, 4 responsive relapse, and 2 patients were in near complete remission (nCR) with poor-prognosis disease. Patients had received 1 (n = 9) or 2 (n = 7) prior autotransplants. Donor lymphocyte infusions (DLIs) were given to 14 patients with no clinical evidence of graft versus host disease (GVHD) either to attain full donor chimerism (n = 4) or to eradicate residual disease (n = 10). Fifteen patients showed myeloid engraftment, and 12 patients were full donor chimeras at day +21. No TRM was observed during the first 100 days. Acute GVHD developed in 10 patients; 1 had fatal grade IV GVHD. Seven progressed to chronic GVHD, limited in 3 and extensive in 4 patients. At a median follow-up of 1 year, 5 patients achieved and sustained CR, 3 nCR, and 4 partial remission. Of 4 patients progressing after transplantation, 3 achieved a remission following further chemotherapy and DLI. Remarkable graft versus myeloma responses were seen in chemotherapy-refractory patients. Two patients died of progressive disease, and 3 died of GVHD complications without active disease. GVHD remains a major problem with this procedure.

Expression of a free gamma heavy chain in serum following autologous stem cell transplantation for IgG kappa multiple myeloma

A 41-year-old male with IgG kappa multiple myeloma is described. He developed a free gamma heavy chain without an accompanying light chain following high-dose chemotherapy and autologous peripheral blood stem cell transplantation. The free gamma heavy chain was detected in serum and urine specimens 2 months after transplant, and eventually evolved into an IgG kappa monoclonal protein with electrophoretic properties similar to the original myeloma protein. Although the origin of the free gamma heavy chain remains uncertain, it was most likely related to the underlying plasma cell malignancy and, therefore, was an early sign of disease relapse.

Distinct T-cell clonal expansion in the vicinity of tumor cells in plasmacytoma

BACKGROUND

Although various clinical observations suggested that myeloma cell growth might be modulated by the immune system, evidence supporting the in situ immunogenicity of myeloma cells remains scarce. The authors reasoned that if there is any specific T-cell/tumor cell interaction in myeloma, it is most likely reflected in the T-cell population in the vicinity of the tumor cells.

METHODS

The authors used a molecular method to compare the T-cell populations in the vicinity of tumor cells with those in the peripheral blood in patients with plasmacytomas and multiple myeloma.

RESULTS

Six patients were studied. When compared with the peripheral blood from the corresponding patients, T cells in the vicinity of tumor cells in five of the six patients showed significant contraction of the T-cell receptor (TCR) Vbeta repertoire. In addition to this, the T cells isolated from the sites of the tumor cells from four of these five patients also demonstrated significant increase in the number of TCR Vbeta gene families with restricted number of CDR3 size peaks and loss of the normal CDR3 size gaussian distribution pattern. These findings were observed in patients who experienced recurrence after allogeneic stem cell transplantation and also in those who had autologous stem cell transplant. They also were found in previously untreated myeloma patients. In all six patients, distinct TCR Vbeta recurring transcripts indicative of a T-cell clonal expansion were found in the vicinity of the tumor cells and either absent or detected at only a low frequency in the peripheral blood.

CONCLUSIONS

Our results provide evidence for an in situ local T-cell clonal expansion in the vicinity of tumor cells and support the presence of specific T-cell/tumor cell interaction in myeloma.

Preceding chemotherapy, tumour load and age influence engraftment in multiple myeloma patients mobilized with granulocyte colony-stimulating factor alone

Haematopoietic growth factors, especially granulocyte colony-stimulating factor (G-CSF), are frequently utilized alone for peripheral blood stem cell (PBSC) procurement to avoid the morbidity associated with high-dose chemotherapy (HDT). Moreover, the cytotoxic agents used may not be the most optimal therapy for the malignancy. It also makes scheduling of apheresis easier. Factors having an impact on PBSC procurement and engraftment after HDT were analysed in 117 multiple myeloma patients mobilized with G-CSF (10-16 microg/kg, median 12 microg/kg) alone using Cox regression analysis. A median of 6.2 x 10(6) CD34 cells/kg (range 0.6-34.1) were procured during leukapheresis and a median of 2.5 x 10(6) CD34 cells was infused after the first HDT (range 0.3-23.9). The only factor significantly affecting optimal PBSC procurement was duration of preceding conventional chemotherapy (P = 0.002). Granulocyte recovery was prompt in almost all patients, 75% of whom attained a granulocyte count of 0.5 x 10(9)/l by day 13 (median 11, range 7-19). However, platelet recovery to both 20 x 10(9)/l (median 12 d, range 8-50+) and 50 x 10(9)/l (median 20 d, range 7-205+) varied widely. On univariate analysis, factors influencing platelet recovery were the number of CD34 cells/kg infused, age, beta(2)-microglobulin levels, response to preceding therapy, bone marrow plasmacytosis and duration of prior therapy. Factors attaining significance on multivariate analysis included number of CD34 cells/kg infused (P = 0.007), beta(2)-microglobulin levels (P = 0.0001), most probably representing disease load, and age (P = 0.002). Patients with high tumour burden, i.e. beta(2)-microglobulin levels > 2.5 mg/l, probably benefit from chemotherapy for mobilization both in terms of cytoreduction and adequate stem cell mobilization resulting in accelerated engraftment.

High incidence of chromosome 13 deletion in multiple myeloma detected by multiprobe interphase FISH

Multiple myeloma (MM) is a hypoproliferative malignancy yielding informative karyotypes in no more than 30% of newly diagnosed cases. Although cytogenetic and molecular deletion of chromosome 13 is associated with poor prognosis, a MM tumor suppressor gene (TSG) has not been identified. To localize a minimal deleted region of chromosome 13, clonotypic plasma cells from 50 consecutive patients with MM were subjected to interphase fluorescence in situ hybridization (FISH) analysis using a panel of 11 probes spanning the entire long arm of chromosome 13. Whereas chromosome 13 abnormalities were absent in plasma cells from 25 normal donors, 86% of patients with MM demonstrated such aberrations. Heterogeneity, both in deletion frequency and extent, was confirmed by simultaneous FISH with 2 chromosome 13 probes. Deletion hot spots were noted at D13S272 (70%) and D13S31 (64%), 2 unlinked loci at 13q14. Homozygous deletions at these loci occurred in 12% (simultaneously in 8%) of the cases. Molecular deletions were found in all 14 patients with morphologic deletions, in 21 of 24 with uninformative karyotypes, and 8 of 12 patients with karyotype abnormalities lacking chromosome 13 deletion. Homozygous deletion of any marker was noted in 4% with low and in 36% with higher plasma cell labeling index greater than 0. 4% (P =.01). The absence of increasing deletion incidence and extent with therapy duration suggests that the observed lesions are not induced by treatment. The high incidence and extent of chromosome 13 deletions require the correlation of specific deletion(s) with poor prognosis. These analyses will provide valuable guidance toward cloning of an MM-TSG. (Blood. 2000;96:1505-1511)

Results of high-dose therapy for 1000 patients with multiple myeloma: durable complete remissions and superior survival in the absence of chromosome 13 abnormalities

High-dose therapy (HDT) has increased complete remission (CR) rates and survival in multiple myeloma (MM). We now report on continuous CR (CCR) and associated prognostic factors in 1000 consecutive patients receiving melphalan-based tandem HDT. Five-year CCR was 52% among 112 CR patients without chromosome 13 (triangle up13) abnormalities and with beta-2-microglobulin </= 2.5 mg/L, C-reactive protein </= 4 mg/L, and pre-HDT standard chemotherapy </= 12 months. Of all 390 CR patients without triangle up13 abnormalities, 35% enjoyed 5-year CCR but none of 54 with triangle up13 abnormalities. triangle up13 abnormalities, present in overall 16%, reduced 5-year event-free survival from 20% to 0% and overall survival from 44% to 16% (both P <.0001). CR and a second HDT cycle applied within 6 months both extended event-free and overall survival significantly, justifying further pursuit of HDT, especially toward curing non-triangle up13 MM. (Blood. 2000;95:4008-4010)

A pilot study evaluating interleukin-2-activated hematopoietic stem cell transplantation for hematologic malignancies

Cytotoxic effector cells are generated when autologous hematopoietic cells (HSC) are cultured with IL-2 for 24 h. Infusion of these cells followed by IL-2 administration may moderate a graft-versus tumor (GvT) effect in vivo. Sixteen patients--7 with non-Hodgkin's lymphoma (NHL), 2 with AML, 4 with multiple myeloma (MM), and 3 with Hodgkin's disease (HD)--received busulfan (4 mg/kg/day for 4 days) and cyclophosphamide (60 mg/kg/day for 2 days) or cyclophosphamide/TBI (1320 cGy). Autologous HSC were activated by culturing with IL-2 for 24 h before reinfusion. Subcutaneous administration of IL-2 began after engraftment at 1.8 x 10(6) IU/m2/day for 1-4 weeks. Neutrophil engraftment occurred on day 13.1 (median) (range 9-45 days), and platelet engraftment occurred on day 19.3 (median) (range 7-54 days) for 15 patients, with delayed engraftment observed in 3 patients. One patient experienced a fatal cardiac arrhythmia. Five patients developed transient skin rashes with histologic evaluation demonstrating findings consistent with GvHD. At 17 months (median) (range 7-23 months), 9 patients are alive, with 6 patients remaining disease free. This pilot trial demonstrates mild to moderate toxicities and a possible delay in platelet engraftment. Further trials will determine the optimal dose and duration of IL-2 therapy and possible impact of this therapy on survival. Laboratory investigations are evaluating the presence of autologous GvHD and a possible GvT effect.