Autologous stem cell transplantation for non-Hodgkin's lymphoma: comparison of radiation-based and chemotherapy-only preparative regimens

Outcome of autologous hematopoietic stem cell transplant in older patients with B cell lymphoma when selected for fitness and chemosensitive disease

BACKGROUND

Autologous hematopoietic stem cell transplantation (AHSCT) in the older population is associated with an increased risk of morbidity and mortality. Determination of the hematopoietic cell transplant comorbidity index (HCT-CI) has contributed to improve patient selection while allowing prediction of their non-relapse mortality (NRM). The goal of this study was to identify factors influencing both safety and efficacy of AHSCT in an older non-Hodgkin lymphoma (NHL) population to better select those who will benefit from this intervention in the Canadian context of a single-payer government healthcare program.

METHODS

This single center, retrospective study, examined clinical outcomes in 90 consecutive older patients (≥60 years old) with B-cell NHL treated with AHSCT between 2008 and 2014.

FINDINGS

Median age was 63 (60-69) at time of transplantation. The HCT-CI risk score was low, intermediate and high in 34%, 40% and 26% of patients, respectively. NRM was 1% at 100 days and one-year post transplant and not influenced by age. At a median follow-up of 52 months, median progression-free survival (PFS) was 56 months while median overall survival (OS) was still not reached. Stable and progressive disease status at time of transplantation were associated with a lower PFS (HR 2.94) and OS (HR 3.91). BEAC conditioning and a graft cell dose  5 × 10⁶ CD34+/kg led to faster recovery, decreased toxicity and resource consumption.

INTERPRETATION

In the older population, AHSCT is safe and optimal when restricted to fit chemosensitive patients.

Bendamustine-based conditioning prior to autologous stem cell transplantation (ASCT): Results of a French multicenter study of 474 patients from LYmphoma Study Association (LYSA) centers

Carmustine shortage has led to an increase use of alternative conditioning regimens prior to autologous stem cell transplantation for the treatment of lymphoma, including Bendamustine-based (BeEAM). The aim of this study was to evaluate the safety of the BeEAM regimen in a large cohort of patients. A total of 474 patients with a median age of 56 years were analyzed. The majority of patients had diffuse large B-cell lymphoma (43.5%). Bendamustine was administered at a median dose of 197 mg/m² /day (50-250) on days-7 and -6. The observed grade 1-4 toxicities included mucositis (83.5%), gastroenteritis (53%), skin toxicity (34%), colitis (29%), liver toxicity (19%), pneumonitis (5%), and cardiac rhythm disorders (4%). Nonrelapse mortality (NRM) was reported in 3.3% of patients. Acute renal failure (ARF) was reported in 132 cases (27.9%) (G ≥2; 12.3%). Organ toxicities and death were more frequent in patients with post conditioning renal failure. In a multivariate analysis, pretransplant chronic renal failure, bendamustine dose >160 mg/m² and age were independent prognostic factors for ARF. Pretransplant chronic renal failure, hyperhydration volume, duration of hyperhydration, and etoposide dose were predictive factors of NRM. A simple, four-point scoring system can stratify patients by levels of risk for ARF and may allow for a reduction in the bendamustine dose to avoid toxicity. Drugs shortage may have dangerous consequences. Prospective, comparative studies are needed to confirm the toxicity/efficacy extents from this conditioning regimen compared to other types of high dose therapy.

Total Body Irradiation Is Safe and Similarly Effective as Chemotherapy-Only Conditioning in Autologous Stem Cell Transplantation for Mantle Cell Lymphoma

Autologous stem cell transplant (ASCT) consolidation has become a standard approach for patients with mantle cell lymphoma (MCL), yet there is little consensus on the role of total body irradiation (TBI) as part of high-dose transplantation conditioning. We analyzed 75 consecutive patients with MCL who underwent ASCT at our institution between 2001 and 2011 with either TBI-based (n = 43) or carmustine, etoposide, cytarabine, melphalan (BEAM; n = 32) high-dose conditioning. Most patients (97%) had chemosensitive disease and underwent transplantation in first remission (89%). On univariate analysis, TBI conditioning was associated with a trend toward improved PFS (hazard ratio [HR], .53; 95% confidence interval [CI], .28-1.00; P = .052) and similar OS (HR, .59; 95% CI, .26-1.35; P = .21), with a median follow-up of 6.3 years in the TBI group and 6.6 years in the BEAM group. The 5-year PFS was 66% in the TBI group versus 52% in the BEAM group; OS was 82% versus 68%, respectively. However, on multivariate analysis, TBI-based conditioning was not significantly associated with PFS (HR, .57; 95% CI .24-1.34; P = .20), after controlling for age, disease status at ASCT, and receipt of post-transplantation rituximab maintenance. Likewise, early toxicity, nonrelapse mortality, and secondary malignancies were similar in the 2 groups. Our data suggest that both TBI and BEAM-based conditioning regimens remain viable conditioning options for patients with MCL undergoing ASCT.

Bronchiectasis following treatment for high-risk neuroblastoma: A case series

High-risk (HR) neuroblastoma remains a very challenging disease to treat and long-term cure is only possible with intensive, multimodal treatment including chemotherapy, high-dose therapy, radiotherapy, surgery, and immunotherapy. As a result, treatment-related morbidity and late effects are common in survivors. This report outlines a case series of six patients who developed a chronic productive cough following treatment for HR neuroblastoma. High-resolution computed tomography scanning confirmed the diagnosis of bronchiectasis. Two of the patients who have undergone immunological testing demonstrate hypogammaglobulinaemia and impaired vaccine response. Persistent cough in patients treated for neuroblastoma warrants investigation and consideration of immunological referral.

Efficacy of Pharmacokinetics-Directed Busulfan, Cyclophosphamide, and Etoposide Conditioning and Autologous Stem Cell Transplantation for Lymphoma: Comparison of a Multicenter Phase II Study and CIBMTR Outcomes

Busulfan, cyclophosphamide, and etoposide (BuCyE) is a commonly used conditioning regimen for autologous stem cell transplantation (ASCT). This multicenter, phase II study examined the safety and efficacy of BuCyE with individually adjusted busulfan based on preconditioning pharmacokinetics. The study initially enrolled Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) patients ages 18 to 80 years but was amended due to high early treatment-related mortality (TRM) in patients > 65 years. BuCyE outcomes were compared with contemporaneous recipients of carmustine, etoposide, cytarabine, and melphalan (BEAM) from the Center for International Blood and Marrow Transplant Research. Two hundred seven subjects with HL (n = 66) or NHL (n = 141) were enrolled from 32 centers in North America, and 203 underwent ASCT. Day 100 TRM for all subjects (n = 203), patients > 65 years (n = 17), and patients ≤ 65 years (n = 186) were 4.5%, 23.5%, and 2.7%, respectively. The estimated rates of 2-year progression-free survival (PFS) were 33% for HL and 58%, 77%, and 43% for diffuse large B cell lymphoma (DLBCL; n = 63), mantle cell lymphoma (MCL; n = 29), and follicular lymphoma (FL; n = 23), respectively. The estimated rates of 2-year overall survival (OS) were 76% for HL and 65%, 89%, and 89% for DLBCL, MCL, and FL, respectively. In the matched analysis rates of 2-year TRM were 3.3% for BuCyE and 3.9% for BEAM, and there were no differences in outcomes for NHL. Patients with HL had lower rates of 2-year PFS with BuCyE, 33% (95% CI, 21% to 46%), than with BEAM, 59% (95% CI, 52% to 66%), with no differences in TRM or OS. BuCyE provided adequate disease control and safety in B cell NHL patients ≤ 65 years but produced worse PFS in HL patients when compared with BEAM.

Impact of conditioning regimen on outcomes for patients with lymphoma undergoing high-dose therapy with autologous hematopoietic cell transplantation

There are limited data to guide the choice of high-dose therapy (HDT) regimen before autologous hematopoietic cell transplantation (AHCT) for patients with Hodgkin (HL) and non-Hodgkin lymphoma (NHL). We studied 4917 patients (NHL, n = 3905; HL, n = 1012) who underwent AHCT from 1995 to 2008 using the most common HDT platforms: carmustine (BCNU), etoposide, cytarabine, and melphalan (BEAM) (n = 1730); cyclophosphamide, BCNU, and etoposide (CBV) (n = 1853); busulfan and cyclophosphamide (BuCy) (n = 789); and total body irradiation (TBI)-containing treatment (n = 545). CBV was divided into CBV(high) and CBV(low) based on BCNU dose. We analyzed the impact of regimen on development of idiopathic pulmonary syndrome (IPS), transplantation-related mortality (TRM), and progression-free and overall survival. The 1-year incidence of IPS was 3% to 6% and was highest in recipients of CBV(high) (hazard ratio [HR], 1.9) and TBI (HR, 2.0) compared with BEAM. One-year TRM was 4% to 8%, respectively, and was similar between regimens. Among patients with NHL, there was a significant interaction between histology, HDT regimen, and outcome. Compared with BEAM, CBV(low) (HR, .63) was associated with lower mortality in follicular lymphoma (P < .001), and CBV(high) (HR, 1.44) was associated with higher mortality in diffuse large B cell lymphoma (P = .001). For patients with HL, CBV(high) (HR, 1.54), CBV(low) (HR, 1.53), BuCy (HR, 1.77), and TBI (HR, 3.39) were associated with higher mortality compared with BEAM (P < .001). The impact of specific AHCT regimen on post-transplantation survival is different depending on histology; therefore, further studies are required to define the best regimen for specific diseases.

Phase III randomized study of rituximab/carmustine, etoposide, cytarabine, and melphalan (BEAM) compared with iodine-131 tositumomab/BEAM with autologous hematopoietic cell transplantation for relapsed diffuse large B-cell lymphoma: results from the BMT CTN 0401 trial

PURPOSE

This clinical trial evaluated standard-dose radioimmunotherapy with a chemotherapy-based transplantation regimen followed by autologous hematopoietic cell transplantation versus rituximab with the same regimen in patients with relapsed diffuse large B-cell lymphoma (DLBCL).

PATIENTS AND METHODS

Patients with chemotherapy-sensitive persistent or relapsed DLBCL were randomly assigned to receive iodine-131 tositumomab (dosimetric dose of 5 mCi on day -19 and therapeutic dose of 0.75 Gy on day -12), carmustine 300 mg/m(2) (day -6), etoposide 100 mg/m(2) twice daily (days -5 to -2), cytarabine 100 mg/m(2) twice daily (days -5 to -2), and melphalan 140 mg/m(2) (day -1; B-BEAM) or rituximab 375 mg/m(2) on days -19 and -12 and the same chemotherapy regimen (R-BEAM).

RESULTS

Two hundred twenty-four patients were enrolled, with 113 patients randomly assigned to R-BEAM and 111 patients assigned to B-BEAM. Two-year progression-free survival (PFS) rates, the primary end point, were 48.6% (95% CI, 38.6% to 57.8%) for R-BEAM and 47.9% (95% CI, 38.2% to 57%; P = .94) for B-BEAM, and the 2-year overall survival (OS) rates were 65.6% (95% CI, 55.3% to 74.1%) for R-BEAM and 61% (95% CI, 50.9% to 69.9%; P = .38) for B-BEAM. The 100-day treatment-related mortality rates were 4.1% (95% CI, 0.2% to 8.0%) for R-BEAM and 4.9% (95% CI, 0.8% to 9.0%; P = .97) for B-BEAM. The maximum mucositis score was higher in the B-BEAM arm (0.72) compared with the R-BEAM arm (0.31; P < .001).

CONCLUSION

The B-BEAM and R-BEAM regimens produced similar 2-year PFS and OS rates for patients with chemotherapy-sensitive relapsed DLBCL. No differences in toxicities other than mucositis were noted.

Phase II trial of 131-Iodine tositumomab with high-dose chemotherapy and autologous stem cell transplantation for relapsed diffuse large B cell lymphoma

The purpose of this study was to evaluate the standard outpatient dose of 131-Iodine tositumomab (75 cGy) combined with high-dose carmustine, etoposide, cytarabine, and melphalan (BEAM) followed by autologous stem cell rescue for the treatment of chemotherapy-sensitive relapsed or refractory, or high-risk first complete remission (CR) patients with diffuse large B cell non-Hodgkin's lymphoma (DLBCL). Forty patients with chemotherapy-sensitive persistent or relapsed or high/intermediate or high international prognostic index DLCBL were treated in a phase II trial combining 75 cGy 131-Iodine tositumomab with high-dose BEAM followed by autologous stem cell transplantation. The CR rate after transplantation was 78%, and the overall response rate was 80%. Short-term and long-term toxicities were similar to historical control patients treated with BEAM alone. With a median follow-up of 6 years (range, 3-10 years), the 5-year overall survival (OS) was 72% (95% confidence interval [CI], 55%-83%), and the 5-year progression-free survival (PFS) rate was 70% (95% CI, 53%-82%). The PFS and OS were encouraging in this group of chemotherapy-sensitive persistent, relapsed, or high-risk patients with DLBCL. A follow-up phase III trial with 131-Iodine tositumomab/BEAM vs rituximab/BEAM was planned based on this information.

The role of transplantation in diffuse large B-cell lymphoma: the impact of rituximab plus chemotherapy in first-line and relapsed settings

Rituximab has improved the prognosis of patients with diffuse large B-cell lymphoma, but a high proportion of patients with advanced disease will relapse or will fail to achieve a remission with front-line treatment. Salvage chemotherapy, followed by high-dose chemotherapy or radiation therapy and autologous stem cell transplantation, remains the best treatment option for such patients, especially those who retain chemosensitivity. Allogeneic transplantation is under investigation in this setting, often as a treatment for relapse after autologous transplantation. Treatment-related mortality due to graft-versus-host disease, preparative regimen toxicity, and poor immune recovery often limits its benefits. This article reviews the role of hematopoietic stem cell transplantation in the treatment of diffuse large B-cell lymphoma, the incorporation of rituximab, and avenues of clinical investigation in this rapidly evolving field.

LACE-conditioned autologous stem cell transplantation for relapsed or refractory diffuse large B-cell lymphoma: treatment outcome and risk factor analysis from a single centre

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a recognized treatment option for patients with relapsed diffuse large B-cell lymphoma. We have analysed 51 patients who underwent ASCT after LACE (lomustine (CCNU), cytarabine (Ara-C), cyclophosphamide, etoposide) conditioning for relapsed (n = 34, 67%) or primary refractory (n = 17, 33%) diffuse large B-cell lymphoma. With a median follow-up of 60 months (range 2-216) the probabilities of overall survival (OS) and progression-free survival (PFS) at 5 years were 47 and 42%, respectively. The cumulative treatment-related mortality was 10% (n = 5). Probabilities for OS and PFS at 5 years were 56 and 50% for patients with chemosensitive and 29 and 27% for patients with chemorefractory disease. In multivariate analysis abnormal pre-ASCT levels of C-reactive protein (>5 mg/L) were identified as a risk factor for worse OS, whereas abnormal pre-ASCT levels of C-reactive protein and chemoresistance predicted inferior PFS. LACE followed by ASCT is an effective treatment for approximately half of patients with chemosensitive relapsed diffuse large B-cell lymphoma, and a proportion of chemorefractory patients also benefit.

The role of cytotoxic therapy with hematopoietic stem cell transplantation in the treatment of follicular lymphoma: an evidence-based review

Clinical research examining the role of hematopoietic stem cell transplantation (SCT) in the therapy of follicular non-Hodgkin lymphoma in adults is presented and critically evaluated in this systematic evidence-based review. Specific criteria were used for searching the published literature and for grading the quality and strength of the evidence and the strength of the treatment recommendations. Treatment recommendations reached unanimously by a panel of follicular lymphoma experts are: (1) autologous SCT is recommended as salvage therapy based on pre-rituximab data, with a significant improvement in overall survival (OS) and progression-free (PFS) survival; (2) autologous SCT is not recommended as first-line treatment for most patients because of no significant improvement in OS; (3) autologous SCT is recommended for transformed follicular lymphoma patients; (4) reduced intensity conditioning before allogeneic SCT appears to be an acceptable alternative to myeloablative regimens; (5) an HLA-matched unrelated donor appears to be as effective an HLA-matched related donor for reduced intensity conditioning allogeneic SCT. There are insufficient data to make a recommendation on the use of autologous SCT after rituximab-based salvage therapy. Eleven areas of needed research in the treatment of follicular lymphoma with SCT were identified and are presented in the review.

Autologous stem cell transplantation using a modified TAM conditioning regimen for clinically aggressive non-Hodgkin's lymphoma

PURPOSE

High-dose chemotherapy (HDT) and autologous stem cell transplantation (ASCT) have been used for the treatment of clinically aggressive non-Hodgkin's lymphoma (NHL). However, the superiority of specific conditioning regimens has not yet been established. The present study evaluated the efficacy and toxicity of a conditioning regimen involving fractionated total body irradiation (TBI), and the use of Ara-C and melphalan (TAM) for clinically aggressive NHL.

MATERIALS AND METHODS

Between March 2002 and December 2004, 31 patients with aggressive NHL received fractionated TBI with a dose of 12 Gy over 3 days, and were administered 9 g/m(2) Ara-C and 100 mg/m(2) melphalan followed by autologous peripheral blood stem Cell Transplantation at the Catholic Hematopoietic Stem cell transplantation Center Korea. Patients that responded to first line chemotherapy and achieved complete remission (CR), or were in a first sensitive relapse were defined as having less advanced disease, while the other patients were defined as having more advanced disease.

RESULTS

Objective responses were obtained in 24 of 31 patients (77.4%), comprising complete remission in 19 patients (61.3%) and partial remission in 5 (16.1%) patients. The median follow-up time was 28 months (range 1 approximately 62 months). At 3 years, the overall survival and event-free survival (EFS) rates were 62.3% and 47.3%, respectively. Patients with less advanced disease and more advanced disease showed 3-year EFS rates of 73.3% and 22.5 %, respectively (p=0.006). Early (within the first 100 days) treatment-related mortality occurred in 3 (9.7%) patients. Of the 31 total patients, 15 (48.4%) developed grade 3 mucositis, 22 (70.9%) developed neutropenic fever, and two (6.5%) developed interstitial pneumonia syndrome>grade 3.

CONCLUSION

The modified TAM conditioning regimen and ASCT appear to be a feasible treatment regimen for clinically aggressive NHL, particularly for patients with less advanced disease.

Role of hematopoietic stem cell transplantation for advanced-stage diffuse large cell B-cell lymphoma-B

The prognosis of patients with relapsed or refractory diffuse large cell B-cell lymphoma-B (DLCL-B) is poor with conventional salvage chemotherapy; therefore, high-dose therapy (HDT) combined with autologous stem cell transplant (ASCT) has become the treatment of choice for these patients. The outcomes of transplant are better in patients with chemosensitive relapse: those with a longer duration of first remission (>12 month) and those with an age-adjusted low-risk International Prognostic Index (IPI) at relapse. Several high-dose regimens with or without total body irradiation (TBI) have been used with similar outcomes. Relapse remains the most common cause of treatment failure, and thus the use of radioimmunotherapy (RIT) in the high-dose regimens and incorporation of rituximab in the transplant setting have been explored. Several studies have shown that RIT both at conventional dose and at high dose can be given in combination with high-dose chemotherapy regimens without additional toxicity or delay in hematopoietic recovery after ASCT. Additional studies using RIT in combination with high-dose chemotherapy and ASCT are ongoing, and preliminary results suggest that these approaches may be superior to conventional high-dose regimens. Since rituximab is an effective therapy for B-cell non-Hodgkin's lymphoma and given its limited toxicity, rituximab has been incorporated into HDT and ASCT for DLCL-B as in vivo purging, as part of high-dose regimens, and as maintenance therapy to prevent relapse. Preliminary results suggested that rituximab during ASCT and as maintenance therapy post-transplant reduces the risk of relapse and improves survival; however, these results need to be confirmed in phase III randomized trials. The role of ASCT during first remission as consolidative therapy in patients with DLCL-B remains controversial and should not be performed outside of the clinical trial setting. Allogeneic stem cell transplant (allo-SCT) for patients with relapsed DLCL-B is associated with significant toxicity and should be reserved for patients who relapse after ASCT or those with persistent marrow involvement. Innovative approaches are needed for primary refractory and chemoresistant relapsed DLCL-B since these patients have very poor outcomes after ASCT.

Dose response and factors related to interstitial pneumonitis after bone marrow transplant

PURPOSE

Total body irradiation (TBI) and chemotherapy are common components of conditioning regimens for bone marrow transplantation. Interstitial pneumonitis (IP) is a known regimen-related complication. Using published data of IP in a multivariate logistic regression, this study sought to identify the parameters in the bone marrow transplantation conditioning regimen that were significantly associated with IP and to establish a radiation dose-response function.

METHODS AND MATERIALS

A retrospective review was conducted of articles that reported IP incidence along with lung dose, fractionation, dose rate, and chemotherapy regimen. In the final analysis, 20 articles (n = 1090 patients), consisting of 26 distinct TBI/chemotherapy regimens, were included in the analysis. Multivariate logistic regression was performed to determine dosimetric and chemotherapeutic factors that influenced the incidence of IP.

RESULTS

A logistic model was generated from patients receiving daily fractions of radiation. In this model, lung dose, cyclophosphamide dose, and the addition of busulfan were significantly associated with IP. An incidence of 3%-4% with chemotherapy-only conditioning regimens is estimated from the models. The alpha/beta value of the linear-quadratic model was estimated to be 2.8 Gy. The dose eliciting a 50% incidence, D50, for IP after 120 mg/kg of cyclophosphamide was 8.8 Gy; in the absence of chemotherapy, the estimated D50 is 10.6 Gy. No dose rate effect was observed. The use of busulfan as a substitute for radiation is equivalent to treating with 14.8 Gy in 4 fractions with 50% transmission blocks shielding the lung. The logistic regression failed to find a model that adequately fit the multiple-fraction-per-day data.

CONCLUSIONS

Dose responses for both lung radiation dose and cyclophosphamide dose were identified. A conditioning regimen of 12 Gy TBI in 6 daily fractions induces an IP incidence of about 11% in the absence of lung shielding. Shielding the lung to receive 50% of this dose lowers the estimated incidence to about 2.3%. Because the lungs can be adequately shielded, we recommend against using busulfan as a substitute for fractionated TBI with cyclophosphamide.

High-dose carmustine, etoposide, and cisplatin for autologous stem cell transplantation with or without involved-field radiation for relapsed/refractory lymphoma: An effective regimen with low morbidity and mortality

Over a 10-year period (January 1993 to October 2002), 101 relapsed or refractory non-Hodgkin lymphoma patients were treated at our center with high-dose chemotherapy and autologous transplantation. The median patient age was 54 years (range, 25-70 years). Thirty-two patients had indolent (low-grade), 42 had aggressive (intermediate-grade), and 27 had very aggressive (high-grade) non-Hodgkin lymphoma. Thirty-six patients had primary refractory disease, 20 had a chemoresistant relapse, 35 patients had a chemosensitive relapse, and 10 patients were "initial high risk" patients. The median number of prior chemotherapy regimens was 2 (range, 1-5). The preparative regimen (BEP) was bischloroethylnitrosourea (BCNU) 600 mg/m 2 , etoposide 2400 mg/m 2 , and Platinol (cisplatin) 200 mg/m 2 given intravenously over 5 days. Within 3 weeks before transplantation, 70 patients received involved-field radiotherapy (IFR) 20 Gy to sites of currently active (>2 cm) or prior bulky (>5 cm) disease. Most patients (n = 93) received mobilized peripheral blood stem cells (median CD34 + cell dose, 6.7 x 10 6 /kg). Median neutrophil (>500/microL) and platelet (>20 000/microL, untransfused) recoveries were 11 days (range, 7-19 days) and 14 days (range, 7-36 days), respectively. At a median follow-up of 41 months (range, 4 to 118 months) for survivors, Kaplan-Meier 5-year probabilities of overall survival (OS) and disease-free survival (DFS) were 58.6% and 51.1%, respectively. Four patients (4%) died within 30 days of stem cell infusion (1 pulmonary embolism, 2 septicemias with multiorgan failure, and 1 progressive lymphoma). Two patients (2%) developed interstitial pneumonitis most likely secondary to high-dose BCNU. Three cases (3%) of secondary acute myelogenous leukemia occurred. On multivariate analysis, age (<60 or > or =60 years), histologic grade (low versus intermediate or high), the use of IFR, and chemotherapy response at baseline did not affect OS or DFS. Of 70 patients given IFR, 27 relapsed: 10 (37%) within and 17 (63%) outside the radiation field. The use of IFR did not affect either OS or DFS, probably because IFR was offered to patients with bulky or chemoresistant disease. BEP with or without IFR is a highly effective and well-tolerated regimen in the relapsed/refractory lymphoma setting. It has low morbidity and transplant-related mortality and a low incidence (3%) of posttransplantation malignancy.

Phase I trial of iodine-131 tositumomab with high-dose chemotherapy and autologous stem-cell transplantation for relapsed non-Hodgkin's lymphoma

PURPOSE

To determine the maximum outpatient dose of iodine-131 tositumomab (up to 0.75 Gy) combined with high-dose carmustine, etoposide, cytarabine, and melphalan (BEAM) followed by autologous stem-cell transplantation (ASCT) for the treatment of chemotherapy-resistant relapsed or refractory B-cell non-Hodgkin's lymphoma (NHL).

PATIENTS AND METHODS

Twenty-three patients with chemotherapy-refractory or multiply-relapsed B-cell NHL were treated in a phase I trial combining iodine-131 tositumomab (ranging from 0.30 to 0.75 Gy total-body dose [TBD]) with high-dose BEAM followed by ASCT.

RESULTS

The complete response rate after transplantation was 57%, and the overall response rate was 65%. Short-term and long-term toxicities were similar to historical control patients treated with BEAM alone. With a median follow-up of 38 months (range, 27 to 60 months), the overall survival (OS) rate was 55%, and the event-free survival (EFS) rate was 39%.

CONCLUSION

There were no significant added toxicities apparent with the addition of iodine-131 tositumomab up to a dose of 0.75 Gy TBD to high-dose BEAM chemotherapy followed by ASCT. The EFS and OS were encouraging in this group of chemotherapy-resistant or refractory B-cell NHL patients. A follow-up phase II trial with iodine-131 tositumomab at the dose of 0.75 Gy TBD with BEAM is currently ongoing.

High-dose radioimmunotherapy versus conventional high-dose therapy and autologous hematopoietic stem cell transplantation for relapsed follicular non-Hodgkin lymphoma: a multivariable cohort analysis

We performed a multivariable comparison of 125 consecutive patients with follicular lymphoma (FL) treated at our centers with either high-dose radioimmunotherapy (HD-RIT) using 131I-anti-CD20 (n = 27) or conventional high-dose therapy (C-HDT) (n = 98) and autologous hematopoietic stem cell transplantation. The groups were similar, although more patients treated with HD-RIT had an elevated pretransplantation level of lactate dehydrogenase (41% versus 20%, P =.03) and elevated international prognostic score (41% versus 19%, P =.02). Patients treated with HD-RIT received individualized therapeutic doses of 131I-tositumomab (median, 19.7 GBq [531 mCi]) to deliver 17 to 31 Gy (median, 27 Gy) to critical organs. Patients treated with C-HDT received total body irradiation plus chemotherapy (70%) or chemotherapy alone (30%). Patients treated with HD-RIT experienced improved overall survival (OS) (unadjusted hazard ratio [HR] for death = 0.4 [95% confidence interval (95% CI), 0.2-0.9], P =.02; adjusted HR, 0.3, P =.004) and progression-free survival (PFS) (unadjusted HR =.6 [95% C.I., 0.3-1.0], P =.06; adjusted HR, 0.5, P =.03) versus patients treated with C-HDT. The estimated 5-year OS and PFS were 67% and 48%, respectively, for HD-RIT and 53% and 29%, respectively, for C-HDT. One hundred-day treatment-related mortality was 3.7% in the HD-RIT group and 11% in the C-HDT group. The probability of secondary myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) was estimated to be.076 at 8 years in the HD-RIT group and.086 at 7 years in the C-HDT group. HD-RIT may improve outcomes versus C-HDT in patients with relapsed FL.

Ex vivo B cell depletion using the Eligix B Cell SC system and autologous peripheral blood stem cell transplantation in patients with follicular non-Hodgkin's lymphoma

One limitation of ASCT is the potential reinfusion of tumor cells contaminating PBSC. The Eligix B cell SC system consists of high-density microparticles coated with anti-B cell antibodies. To determine if this system eliminates B cells and lymphoma cells from PBSC, immunocytochemistry and PCR of the bcl-2/IgH rearrangement were performed, and correlated with patient outcome after ASCT. Eligible patients (n=29) had relapsed or transformed follicular NHL with bone marrow involvement <20%, and all lymph nodes <5 cm. PBSCs were mobilized with cyclophosphamide/G-CSF (n=21), and patients were conditioned with cyclophosphamide, carmustine and etoposide. Using immunocytochemistry on PBSC, the median number of CD20+ cells pre-purge was 310/10(6) (range 0-16692) and post-purge was 0.75/10(6); the median log B cell depletion was 2.7 (range 1.4-3.9). B cell depletion correlated with PFS after ASCT (P=0.06). Of 17 available samples for PCR, only four had a detectable t(14;18) breakpoint. After purging, all four remained PCR+; two had a 1-3 log depletion of lymphoma cells. At median follow-up of 18 months, 10 patients, including five infused with PCR-negative PBSC, have had disease progression. The paucity of PCR-informative patients, possibly related to in vivo rituximab therapy, limited the utility of minimal residual disease as a surrogate marker of clinical outcome.

Autologous stem cell transplantation for Hodgkin's disease: busulfan, melphalan and thiotepa compared to a radiation-based regimen

We evaluated prognostic factors and treatment outcome of patients with relapsed/refractory Hodgkin's disease (HD) receiving autologous stem cell transplantation (ASCT). In total, 92 patients received total body irradiation, cyclophosphamide and etoposide (TBI/CY/E) (n=42) or busulfan, melphalan and thiotepa (Bu/Mel/T) (n=50) supported with ASCT. A total of 33 (66%) patients receiving the Bu/Mel/T regimen had a prior history of dose-limiting irradiation. Mucositis, hepatic and pulmonary toxicities were the main causes of morbidity and mortality, irrespective of the conditioning regimen. The transplant-related mortality was 15%. With a median follow-up of 6 years (range 2.5-11), the cumulative probabilities of survival, event-free survival (EFS) and relapse at 6 years were 55, 51 and 32%. The 6-year Kaplan-Meier (KM) probabilities of EFS for patients with less advanced disease (patients in first chemotherapy-responsive relapse or second remission (n=42)) and more advanced disease (all other patients (n=50)) were 60 and 44%. No differences in toxicities and efficacy between the conditioning regimens were found. ASCT is an effective treatment for patients with refractory/relapsed HD. Female patients and patients with less advanced disease at transplant had a better outcome. Patients with prior irradiation benefited from the Bu/Mel/T regimen.

Role of autologous stem cell transplantation in chronic lymphocytic leukemia

Autologous hematopoietic stem sell transplantation is increasingly considered for treatment of patients with high-risk chronic lymphocytic leukemia. Patients not eligible for allogeneic hematopoietic stem cell transplantation with poor prognosis disease, documented chemosensitivity, and a minimal tumor burden at the time of hematopoietic stem cell transplantation can be treated with autologous hematopoietic stem cell transplantation currently using peripheral blood stem cells. Different purging methods to obtain sources of stem cells free of tumor contamination are currently being evaluated. Major concerns are judicious selection of which patients may benefit from this approach, the subsequent risk of relapse of disease, and the long-term risk of development of secondary malignancies, including myelodysplastic syndrome and acute myelogenous leukemia. Recognizing and reducing the risk factors that contribute to relapse and complications of the procedure should improve outcome after autologous hematopoietic stem cell transplantation. With the increasing use, increasing effectiveness, and low treatment-related mortality associated with nonmyeloablative conditioning regimens, the question of whether a patient should be offered autologous or allogeneic hematopoietic stem sell transplantation can be a difficult one. Defining salvage settings for relapse and implementing a tandem autologous/allogeneic hematopoietic stem cell transplantation approach may provide a method to improve outcome for selected patients.

Autologous and allogeneic transplantation for aggressive NHL

BACKGROUND

Intermediate- and high-grade NHL are generally chemosensitive diseases with high initial response rates to combination chemotherapy. Dose intensification via autologous and allogeneic transplantation provides viable treatment options in specific clinical settings. Currently, autologous transplantation is the standard of care for relapsed but chemosensitive aggressive B-cell NHL. However, tools such as the International Prognostic Index allow risk-adapted analyses, and show that the magnitude of benefit from autologous transplantation differs in lymphoma subsets.

METHODS

Low-risk patients appear to do well regardless of salvage approaches, whereas high-risk patients have suboptimal outcomes with autologous transplantation. In high-risk patients, high-dose chemotherapy with autologous stem-cell transplantation has been examined as part of initial therapy, with long-term data promising but still evolving.

DISCUSSION

A significant concern with autologous transplantation in aggressive and high-grade NHL is the risk of graft contamination with tumor cells. Several investigators have demonstrated the presence of malignant cells in both BM and PBSC, although the clonagenic potential of such cells is unclear. Allogeneic stem-cell transplantation has several potential advantages over autologous transplantation for NHL,including procurement of an uncontaminated stem-cell graft, GvL effects, and the elimination of hematopoietic stem-cell damage and consequent secondary leukemia.

RESULTS

The ideal application of allogeneic transplantation in aggressive and high-grade lymphomas is still unclear; but the lower relapse rates demonstrated in several comparisons of the two approaches make this an exciting area to pursue. Finally, non-myeloablative stem-cell transplantation may broaden the use of allogeneic transplantation by lowering regimen-related mortality while capitalizing on GvL.

Stem cell mobilization

Successful blood and marrow transplant (BMT), both autologous and allogeneic, requires the infusion of a sufficient number of hematopoietic progenitor/stem cells (HPCs) capable of homing to the marrow cavity and regenerating a full array of hematopoietic cell lineages in a timely fashion. At present, the most commonly used surrogate marker for HPCs is the cell surface marker CD34, identified in the clinical laboratory by flow cytometry. Clinical studies have shown that infusion of at least 2 x 10(6) CD34(+) cells/kg recipient body weight results in reliable engraftment as measured by recovery of adequate neutrophil and platelet counts approximately 14 days after transplant. Recruitment of HPCs from the marrow into the blood is termed mobilization, or, more commonly, stem cell mobilization. In Section I, Dr. Tsvee Lapidot and colleagues review the wide range of factors influencing stem cell mobilization. Our current understanding focuses on chemokines, proteolytic enzymes, adhesion molecules, cytokines and stromal cell-stem cell interactions. On the basis of this understanding, new approaches to mobilization have been designed and are now starting to undergo clinical testing. In Section II, Dr. Michele Cottler-Fox describes factors predicting the ability to mobilize the older patient with myeloma. In addition, clinical approaches to improving collection by individualizing the timing of apheresis and adjusting the volume of blood processed to achieve a desired product are discussed. Key to this process is the daily enumeration of blood CD34(+) cells. Newer methods of enumerating and mobilizing autologous blood HPCs are discussed. In Section III, Dr. John DiPersio and colleagues provide data on clinical results of mobilizing allogeneic donors with G-CSF, GM-CSF and the combination of both as relates to the number and type of cells collected by apheresis. Newer methods of stem cell mobilization as well as the relationship of graft composition on immune reconstitution and GVHD are discussed.

Should involved-field radiation therapy be used as an adjunct to lymphoma autotransplantation?

Relapse at sites of prior disease involvement accounts for the majority of treatment failures following high-dose therapy and autologous transplantation for both Hodgkin's disease and non-Hodgkin's lymphoma. Several studies have demonstrated the utility of 'involved-field' radiation as a treatment modality in this setting to minimize disease bulk prior to transplants, to reduce relapse rates at sites of prior disease involvement and to improve local control for disease resistant to high-dose therapy. Other studies recommend caution due to potential toxicities including radiation-induced pneumonitis and secondary myelodysplasia. Further investigations are needed to better define the optimal extent, dose and timing of radiation in the setting of transplantation, as well as to identify those subsets of patients likely to be at a higher risk of radiation-induced morbidity.