David F. Claxton

Transplant-lite: induction of graft-versus-malignancy using fludarabine-based nonablative chemotherapy and allogeneic blood progenitor-cell transplantation as treatment for lymphoid malignancies.

PURPOSE To investigate the use of a nonmyeloablative fludarabine-based preparative regimen to produce sufficient immunosuppression to allow engraftment of allogeneic stem cells and induction of graft-versus-leukemia/lymphoma (GVL) as the primary treatment modality for patients with chronic lymphocytic leukemia (CLL) and lymphoma. PATIENTS AND METHODS Fifteen patients were studied. Six patients were in advanced refractory relapse, and induction therapy had failed in two patients. Patients with CLL or low-grade lymphoma received fludarabine 90 to 150 mg/m2 and cyclophosphamide 900 to 2,000 mg/m2. Patients with intermediate-grade lymphoma or in Richters transformation received cisplatin 25 mg/m2 daily for 4 days; fludarabine 30 mg/m2; and cytarabine 500 mg/m2 daily for 2 days. Chemotherapy was followed by allogeneic stem-cell infusion from HLA-identical siblings. Patients with residual malignant cells or mixed chimerism could receive a donor lymphocyte infusion of 0.5 to 2 x 10(8) mononuclear cells/kg 2 to 3 months posttransplantation if graft-versus-host disease (GVHD) was not present. RESULTS Eleven patients had engraftment of donor cells, and the remaining four patients promptly recovered autologous hematopoiesis. Eight of 11 patients achieved a complete response (CR). Five of six patients (83.3%) with chemosensitive disease continue to be alive compared with two of nine patients (22.2%) who had refractory or untested disease at the time of study entry (P = .04). CONCLUSION These findings indicate the feasibility of allogeneic hematopoietic transplantation with a nonablative preparative regimen to produce engraftment and GVL against lymphoid malignancies. The ability to induce remissions with donor lymphocyte infusion in patients with CLL, Richters, and low-grade and intermediate-grade lymphoma is direct evidence of GVL activity against these diseases. This approach appears to be most promising in patients with chemotherapy-responsive disease and low tumor burden.

Hyper-CVAD and high-dose methotrexate/cytarabine followed by stem-cell transplantation: an active regimen for aggressive mantle-cell lymphoma.

PURPOSE Diffuse and nodular forms of mantle-cell lymphoma (MCL) are consistently associated with poor prognosis. In an effort to improve the outcome, we adopted a treatment plan that consisted of four courses of fractionated cyclophosphamide (CY) 1,800 mg/m2 administered with doxorubicin (DOX), vincristine (VCR), and dexamethasone (Hyper-CVAD) that alternated with high-dose methotrexate (MTX) and cytarabine (Ara-C). After four courses, patients were consolidated with high-dose CY, total-body irradiation, and autologous or allogeneic blood or marrow stem-cell transplantation. PATIENTS AND METHODS Forty-five patients were enrolled; 25 patients were previously untreated, 43 patients had Ann Arbor stage IV disease, and 42 patients had marrow involvement. Forty-one patients had diffuse histology, two patients had nodular, and two patients had blastic variants. RESULTS Hyper-CVAD/MTX-Ara-C induced a response rate of 93.5% (complete response [CR], 38%; partial response [PR], 55.5%) after four cycles of pretransplantation induction chemotherapy. All patients who went on to undergo transplantation achieved CRs. For the 25 previously untreated patients, the overall survival (OS) and event-free survival (EFS) rates at 3 years were 92% (95% confidence interval [CI], 80 to 100) and 72% (95% CI, 45 to 98) compared with 25% (95% CI, 12 to 62; P = .005) and 17% (95% CI, 10 to 43; P = .007), respectively, for the previously treated patients. When compared with a historic control group who received a CY, DOX, VCR, and prednisone (CHOP)-like regimen, untreated patients in the study had a 3-year EFS rate of 72% versus 28% (P = .0001) and a better OS rate (92% v 56%; P = .05). Treatment-related death occurred in five patients: all were previously treated and two received allogeneic transplants. CONCLUSION The Hyper-CVAD/MTX-Ara-C program followed by stem-cell transplantation is a promising new therapy for previously untreated patients with MCL.

Allogeneic peripheral-blood progenitor-cell transplantation for poor-risk patients with metastatic breast cancer.

PURPOSE To evaluate the feasibility of allogeneic peripheral-blood progenitor-cell (PBPC) transplantation and to assess graft-versus-tumor effects in patients with metastatic breast cancer. PATIENTS AND METHODS Ten patients with metastatic breast cancer that involved the liver or bone marrow were treated with high-dose chemotherapy and allogeneic PBPC transplantation. The median age was 42 years (range, 29 to 55). The median number of metastatic sites was three (range, one to five). The conditioning regimen was cyclophosphamide (6,000 mg/m2), carmustine (BCNU; 450 mg/m2), and thiotepa (720 mg/m2) (CBT regimen). Patients received graft-versus-host disease (GVHD) prophylaxis using cyclosporine- or tacrolimus-based regimens. RESULTS All patients had engraftment and hematologic recovery. Three patients developed grade > or = 2 acute GVHD and four patients had chronic GVHD. After transplantation, one patient was in complete remission (CR), five achieved a partial remission (PR), and four had stable disease (SD). In two patients, metastatic liver lesions regressed in association with skin GVHD after withdrawal of immunosuppressive therapies. The median follow-up time was 408 days (range, 53 to 605). The median progression-free survival duration was 238 days (range, 53 to 510). CONCLUSION We conclude that allogeneic PBPC transplantation is a feasible procedure for patients with poor-risk metastatic breast cancer. The regression of tumor associated with GVHD provides suggestive clinical evidence that graft-versus-tumor effects may occur against breast cancer. Compared with autologous transplantation, allogeneic PBPC transplantation is associated with the additional risks of GVHD and related infections. Allogeneic transplantation should only be performed in the context of clinical trials and its ultimate role requires demonstration of improved progression-free survival.

Phase I study of obatoclax mesylate (GX15-070), a small molecule pan-Bcl-2 family antagonist, in patients with advanced chronic lymphocytic leukemia

Obatoclax mesylate is a small molecule pan-Bcl-2 antagonist with in vitro activity against chronic lymphocytic leukemia (CLL) cells. Obatoclax was administered to patients with advanced CLL at doses ranging from 3.5 to 14 mg/m(2) as a 1-hour infusion and from 20 to 40 mg/m(2) as a 3-hour infusion every 3 weeks. Twenty-six patients received a total of 74 cycles. Dose-limiting reactions were neurologic (somnolence, euphoria, ataxia) and associated with the infusion. The maximum tolerated dose (MTD) was 28 mg/m(2) over 3 hours every 3 weeks. One (4%) of 26 patients achieved a partial response. Patients with anemia (3/11) or thrombocytopenia (4/14) experienced improvements in hemoglobin and platelet counts. Circulating lymphocyte counts were reduced in 18 of 26 patients with a median reduction of 24%. Overall, the maximum plasma concentration (C(max)) and area under the curve (AUC) values of obatoclax were dose proportional. Activation of Bax and Bak was demonstrated in peripheral blood mononuclear cells, and induction of apoptosis was related to overall obatoclax exposure, as monitored by the plasma concentration of oligonucleosomal DNA/histone complexes. Obatoclax mesylate has biologic activity and modest single-agent activity in heavily pretreated patients with advanced CLL. Further evaluation in less heavily pretreated patients and in combination with other therapeutic agents is warranted. This trial has been registered with http://clinicaltrials.gov under identifier NCT00600964.

Phase II Study of Clofarabine Monotherapy in Previously Untreated Older Adults With Acute Myeloid Leukemia and Unfavorable Prognostic Factors

PURPOSE This phase II study assessed clofarabine monotherapy in older adults (>or= 60 years of age) with untreated acute myeloid leukemia (AML) and at least one unfavorable baseline prognostic factor. PATIENTS AND METHODS Clofarabine was administered intravenously for 5 days at 30 mg/m(2)/d during induction and 20 mg/m(2)/d during reinduction/consolidation (six cycles maximum). The primary end point was overall remission rate (ORR; ie, complete remission [CR] plus CR with incomplete platelet recovery [CRp]). RESULTS In 112 evaluable patients who were treated (median age, 71 years; range, 60 to 88 years), the ORR was 46% (38% CR, 8% CRp). ORR by unfavorable prognostic factor was 39% for patients >or= 70 years of age; 32% for Eastern Cooperative Oncology Group (ECOG) performance status 2; 51% for antecedent hematologic disorder; 54% for intermediate karyotype; 42% for unfavorable karyotype; and 48%, 51%, and 38% for one, two, and three risk factors, respectively. The median disease-free survival was 37 weeks (95% CI, 26 to 56 weeks). Median duration of remission was 56 weeks (95% CI, 33 to not estimable). The estimated median overall survival was 41 weeks (95% CI, 28 to 53 weeks) for all patients, 59 weeks for patients with CR/CRp, and 72 weeks for patients with CR. The 30-day all-cause mortality was 9.8%. The most common non-laboratory drug-related toxicities (>or= 20% patients) were nausea, febrile neutropenia, vomiting, diarrhea, rash, and fatigue. CONCLUSION Clofarabine is an active agent with acceptable toxicity in patients age 60 years or older with untreated AML who have at least one unfavorable prognostic factor. ORR did not seem affected by the presence of multiple unfavorable prognostic factors.

Targeted Indocyanine-Green-Loaded Calcium Phosphosilicate Nanoparticles for In Vivo Photodynamic Therapy of Leukemia

Leukemia is one of the most common and aggressive adult cancers, as well as the most prevalent childhood cancer. Leukemia is a cancer of the hematological system and can be divided into a diversity of unique malignancies based on the onset of the disease as well as the specific cell lineages involved. Cancer stem cells, including recently identified leukemia stem cells (LSCs), are hypothesized to be responsible for cancer development, relapse, and resistance to treatment, and new therapeutics targeting these cellular populations are urgently needed. Nontoxic and nonaggregating calcium phosphosilicate nanoparticles (CPSNPs) encapsulating the near-infrared fluoroprobe indocyanine green (ICG) were recently developed for diagnostic imaging and drug delivery as well as for photodynamic therapy (PDT) of solid tumors. Prior studies revealed that specific targeting of CPSNPs allowed for enhanced accumulation within breast cancer tumors, via CD71 targeting, or pancreatic cancer tumors, via gastrin receptor targeting. In the present study, ICG-loaded CPSNPs were evaluated as photosensitizers for PDT of leukemia. Using a novel bioconjugation approach to specifically target CD117 or CD96, surface features enhanced on leukemia stem cells, in vitro ICG-CPSNP PDT of a murine leukemia cell line and human leukemia samples were dramatically improved. Furthermore, the in vivo efficacy of PDT was dramatically enhanced in a murine leukemia model by utilizing CD117-targeted ICG-CPSNPs, resulting in 29% disease-free survival. Altogether, this study demonstrates that leukemia-targeted ICG-loaded CPSNPs offer the promise to effectively treat relapsing and multidrug-resistant leukemia and to improve the life of leukemia patients.

Tacrolimus and minidose methotrexate for prevention of acute graft-versus-host disease after HLA-mismatched marrow or blood stem cell transplantation

Thirty adults with leukemia or lymphoma transplanted with marrow or blood stem cells from 1-antigen mismatched related donors received tacrolimus and minidose methotrexate to prevent acute graft-versus-host disease (GVHD). The group had a median age of 42 years (range 18–56 years). Twenty-seven patients had advanced disease, and 13 were resistant to conventional therapy. Tacrolimus was administered at 0.03 mg/kg/day i.v. by continuous infusion from day −2, converted to oral at four times the i.v. dose following engraftment, and continued to day 180 post-transplant. Methotrexate 5 mg/m2 was given i.v. on days 1, 3, 6 and 11. Mild nephrotoxicity was common before day 100; 69% of patients had a doubling of creatinine, 56% had a peak creatinine greater than 2 mg/dl, and two patients were dialyzed. Other toxicities prior to day 100 thought to be related to tacrolimus included hypertension (45%), hyperkalemia (17%), hyperglycemia (14%), seizures (13%), headache (3%) and hemolytic uremic syndrome (3%). Grades 2–4 GVHD occurred in 59% (95% CI, 38–70%), and grades 3–4 GVHD in 17% (95% CI, 1–32%). Overall survival at 1 year was 29% (95% CI, 12–45%). We conclude that tacrolimus and minidose methotrexate is active post-transplant immunosuppression for patients with 1-antigen mismatched donors.

High-dose chemotherapy for relapsed and refractory diffuse large B-cell lymphoma: mediastinal localization predicts for a favorable outcome.

PURPOSE This study was performed to evaluate the outcome of high-dose chemotherapy and autologous transplantation in patients with diffuse B-cell large-cell lymphoma, and, specifically, to evaluate the impact of primary mediastinal localization on the outcome of high-dose chemotherapy. PATIENTS AND METHODS A retrospective review was performed of all patients with diffuse large B-cell lymphoma who underwent autologous marrow or peripheral-blood stem-cell transplantation at our institution between January 1 986 and December 1995. RESULTS Ninety patients were identified, of whom 31 (34%) had a primary mediastinal B-cell large-cell lymphoma (PML). Cumulative probabilities of disease-free survival, overall survival, and disease progression are 40% (95% confidence interval [CI], 29 to 51), 42% (95% CI, 31 to 53), and 52% (95% CI, 40 to 64), respectively. By univariate analysis, low lactate dehydrogenase (LDH) level and low Ann Arbor stage at transplant were associated with improved survival and disease-free survival. There was a trend for improved disease-free survival and survival for patients with PML. Multivariate stepwise Cox regression analysis showed that LDH level, Ann Arbor stage, and primary mediastinal localization were independent favorable prognostic factors for disease-free survival and survival. LDH level and Ann Arbor stage were also predictive for the risk of disease progression. CONCLUSION Our results indicate that patients with PML may display an increased susceptibility to high-dose chemotherapy compared with other types of B-cell large-cell lymphoma. These findings, if confirmed, may have implications for the initial management of patients with PML.

Sphingosine kinase 1 protein and mRNA are overexpressed in non-Hodgkin lymphomas and are attractive targets for novel pharmacological interventions.

Sphingosine kinase 1 (SphK1) is an oncoprotein capable of directly transforming cells and is associated with resistance to chemotherapy and radiotherapy. SphK1 is increased in various human cancers; whereas, blockade restores sensitivity to therapeutic killing in chemotherapy resistant cancer cell lines. We investigated SphK1 expression in clinical tissue samples from patients with non-Hodgkin lymphomas (NHL). Tissues from 69 patients with either NHL (n = 44) or reactive lymphoid hyperplasias (RH) (n = 25) were examined for expression of SphK1 protein by Western blot and immunohistochemistry (IHC), and SphK1 and SphK2 mRNA by quantitative real-time reverse transcriptase polymerase chain reaction. SphK1 protein (p = 0.008) and mRNA (p = 0.035) levels were higher in NHL than RH, with a clear trend toward increasing levels with increasing clinical grade (p = 0.005 for SphK1 protein, p = 0.035 for IHC score and p = 0.002 for SphK1 mRNA). IHC generally confirmed protein signal in neoplastic cells, but some lymphomas exhibited staining in non-neoplastic cells. SphK1 is overexpressed in NHL and increases with increasing clinical grade. These results, combined with prior mechanistic studies suggest that SphK1 is an attractive novel target for pharmacological interventions for NHL.

Optimal Sequencing of Ibrutinib, Idelalisib, and Venetoclax in Chronic Lymphocytic Leukemia: Results from a Multi-Center Study of 683 Patients.

Background Ibrutinib, idelalisib, and venetoclax are approved for treating CLL patients in the United States. However, there is no guidance as to their optimal sequence. Patients and methods We conducted a multicenter, retrospective analysis of CLL patients treated with kinase inhibitors (KIs) or venetoclax. We examined demographics, discontinuation reasons, overall response rates (ORR), survival, and post-KI salvage strategies. Primary endpoint was progression-free survival (PFS). Results A total of 683 patients were identified. Baseline characteristics were similar in the ibrutinib and idelalisib groups. ORR to ibrutinib and idelalisib as first KI was 69% and 81%, respectively. With a median follow-up of 17 months (range 1-60), median PFS and OS for the entire cohort were 35 months and not reached. Patients treated with ibrutinib (versus idelalisib) as first KI had a significantly better PFS in all settings; front-line [hazard ratios (HR) 2.8, CI 1.3-6.3, P = 0.01], relapsed-refractory (HR 2.8, CI 1.9-4.1, P < 0.001), del17p (HR 2.0, CI 1.2-3.4, P = 0.008), and complex karyotype (HR 2.5, CI 1.2-5.2, P = 0.02). At the time of initial KI failure, use of an alternate KI or venetoclax had a superior PFS when compared with chemoimmunotherapy. Furthermore, patients who discontinued ibrutinib due to progression or toxicity had marginally improved outcomes if they received venetoclax (ORR 79%) versus idelalisib (ORR 46%) (PFS HR .6, CI.3-1.0, P = 0.06). Conclusions In the largest real-world experience of novel agents in CLL, ibrutinib appears superior to idelalisib as first KI. Furthermore, in the setting of KI failure, alternate KI or venetoclax therapy appear superior to chemoimmunotherapy combinations. The use of venetoclax upon ibrutinib failure might be superior to idelalisib. These data support the need for trials testing sequencing strategies to optimize treatment algorithms.BACKGROUND Ibrutinib, idelalisib, and venetoclax are approved for treating CLL patients in the US. However, there is no guidance as to their optimal sequence. PATIENTS AND METHODS We conducted a multicenter, retrospective analysis of CLL patients treated with kinase inhibitors (KIs) or venetoclax. We examined demographics, discontinuation reasons, overall response rates (ORR), survival, and post-KI salvage strategies. Primary endpoint was progression-free survival (PFS). RESULTS A total of 683 patients were identified. Baseline characteristics were similar in the ibrutinib and idelalisib groups. ORR to ibrutinib and idelalisib as first KI was 69% and 81% respectively. With a median follow up of 17 months (range 1-60), median PFS and OS for the entire cohort were 35 months and not reached. Patients treated with ibrutinib (vs. idelalisib) as first KI had a significantly better PFS in all settings; front-line (HR 2.8, CI1.3-6.3 p=.01), relapsed-refractory (HR 2.8, CI 1.9-4.1 p<.001), del17p (HR 2.0, CI 1.2-3.4 p=.008), and complex karyotype (HR 2.5, CI 1.2-5.2 p=.02). At the time of initial KI failure, use of an alternate KI or venetoclax had a superior PFS as compared to chemoimmunotherapy (CIT). Furthermore, patients who discontinued ibrutinib due to progression or toxicity had marginally improved outcomes if they received venetoclax (ORR 79%) versus idelalisib (ORR 46%) (PFS HR .6, CI.3-1.0, p=.06). CONCLUSIONS In the largest real-world experience of novel agents in CLL, ibrutinib appears superior to idelalisib as first KI. Further, in the setting of KI failure, alternate KI or venetoclax therapy appear superior to CIT combinations. The use of venetoclax upon ibrutinib failure might be superior to idelalisib. These data support the need for trials testing sequencing strategies to optimize treatment algorithms.