Joseph Brandwein

Identification of pre-leukaemic haematopoietic stem cells in acute leukaemia

In acute myeloid leukaemia (AML), the cell of origin, nature and biological consequences of initiating lesions, and order of subsequent mutations remain poorly understood, as AML is typically diagnosed without observation of a pre-leukaemic phase. Here, highly purified haematopoietic stem cells (HSCs), progenitor and mature cell fractions from the blood of AML patients were found to contain recurrent DNMT3A mutations (DNMT3Amut) at high allele frequency, but without coincident NPM1 mutations (NPM1c) present in AML blasts. DNMT3Amut-bearing HSCs showed a multilineage repopulation advantage over non-mutated HSCs in xenografts, establishing their identity as pre-leukaemic HSCs. Pre-leukaemic HSCs were found in remission samples, indicating that they survive chemotherapy. Therefore DNMT3Amut arises early in AML evolution, probably in HSCs, leading to a clonally expanded pool of pre-leukaemic HSCs from which AML evolves. Our findings provide a paradigm for the detection and treatment of pre-leukaemic clones before the acquisition of additional genetic lesions engenders greater therapeutic resistance.

A phase 3 study of gemtuzumab ozogamicin during induction and postconsolidation therapy in younger patients with acute myeloid leukemia

This randomized phase 3 clinical trial evaluated the potential benefit of the addition of gemtuzumab ozogamicin (GO) to standard induction and postconsolidation therapy in patients with acute myeloid leukemia. Patients were randomly assigned to receive daunorubicin (45 mg/m(2) per day on days 1, 2, and 3), cytarabine (100 mg/m(2) per day by continuous infusion on days 1-7), and GO (6 mg/m(2) on day 4; DA+GO) vs standard induction therapy with daunorubicin (60 mg/m(2) per day on days 1, 2, and 3) and cytarabine alone (DA). Patients who achieved complete remission (CR) received 3 courses of high-dose cytarabine. Those remaining in CR after consolidation were randomly assigned to receive either no additional therapy or 3 doses of GO (5 mg/m(2) every 28 days). From August 2004 until August 2009, 637 patients were registered for induction. The CR rate was 69% for DA+GO and 70% for DA (P = .59). Among those who achieved a CR, the 5-year relapse-free survival rate was 43% in the DA+GO group and 42% in the DA group (P = .40). The 5-year overall survival rate was 46% in the DA+GO group and 50% in the DA group (P = .85). One hundred seventy-four patients in CR after consolidation underwent the postconsolidation randomization. Disease-free survival was not improved with postconsolidation GO (HR, 1.48; P = .97). In this study, the addition of GO to induction or postconsolidation therapy failed to show improvement in CR rate, disease-free survival, or overall survival.

Phase III Randomized Multicenter Study of a Humanized Anti-CD33 Monoclonal Antibody, Lintuzumab, in Combination With Chemotherapy, Versus Chemotherapy Alone in Patients With Refractory or First-Relapsed Acute Myeloid Leukemia

PURPOSE Lintuzumab (HuM195) is an unconjugated humanized murine monoclonal antibody directed against the cell surface myelomonocytic differentiation antigen CD33. In this study, the efficacy of lintuzumab in combination with induction chemotherapy was compared with chemotherapy alone in adults with first relapsed or primary refractory acute myeloid leukemia (AML). PATIENTS AND METHODS Patients with relapsed or primary resistant AML (duration of first response, zero to 12 months) were randomly assigned to receive either mitoxantrone 8 mg/m(2), etoposide 80 mg/m(2), and cytarabine 1 g/m(2) daily for 6 days (MEC) in combination with lintuzumab 12 mg/m(2), or MEC alone. Overall response, defined as the rate of complete remission (CR) and CR with incomplete platelet recovery (CRp), was the primary end point of the study, with additional analyses of survival time and toxicity. RESULTS A total of 191 patients were randomly assigned from November 1999 to April 2001. The percent CR plus CRp with MEC plus lintuzumab was 36% v 28% in patients treated with MEC alone (P = .28). The overall median survival was 156 days and was not different in the two arms of the study. Apart from mild antibody infusion-related toxicities (fever, chills, and hypotension), no differences in chemotherapy-related adverse effects, including hepatic and cardiac dysfunction, were observed with the addition of lintuzumab to induction chemotherapy. CONCLUSION The addition of lintuzumab to salvage induction chemotherapy was safe, but did not result in a statistically significant improvement in response rate or survival in patients with refractory/relapsed AML.

High-dose etoposide and melphalan, and autologous bone marrow transplantation for patients with advanced Hodgkin's disease: importance of disease status at transplant.

PURPOSE To evaluate an intensive therapy regimen of high-dose etoposide and melphalan and autologous bone marrow transplantation (ABMT) in advanced Hodgkins disease; and to determine possible prognostic factors that predict for long-term disease-free survival (DFS). PATIENTS AND METHODS Seventy-three patients with advanced Hodgkins disease who had failed to achieve remission with front-line chemotherapy (n = 16) or who had relapsed (n = 57) were treated with high-dose etoposide 60 mg/kg and melphalan 160 mg/m2 and ABMT. Previous therapy included mechlorethamine, vincristine, procarbazine, and prednisone (MOPP) alternating with doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD), or hybrid MOPP/ABV. All patients received pretransplant cytoreduction with conventional-dose salvage chemotherapy and 40 also received pretransplant extended-field radiation to areas of bulky nodal disease (> 5 cm). RESULTS Response to high-dose etoposide and melphalan was determined at 3 months post-ABMT. The complete response (CR) rate was 75% (95% confidence interval [CI], 64% to 84%), including 35 of 50 patients with measurable disease before ABMT (70%; 95% CI, 60% to 86%). There were three early deaths (septicemia) and four late deaths (three interstitial pneumonitis, one intracerebral hemorrhage). Actuarial DFS is 38.6% at 4 years. Multivariate regression analysis showed that disease status at the time of ABMT (no evidence of disease [NED], nonbulky residual disease [NBRD], or bulky disease) was the most important factor determining DFS: 68% of those transplanted with NED versus 26% for patients with NBRD and 0% for bulky disease (P = .0002, log-rank test). Relapse in a previous radiation field was the only other significant prognostic factor. CONCLUSION Etoposide and melphalan is an effective and well-tolerated intensive therapy regimen in advanced Hodgkins disease. Patients in complete remission after conventional-dose salvage therapy transplanted with this regimen enjoy superior long-term DFS.

Midostaurin plus Chemotherapy for Acute Myeloid Leukemia with a FLT3 Mutation

Background Patients with acute myeloid leukemia (AML) and a FLT3 mutation have poor outcomes. We conducted a phase 3 trial to determine whether the addition of midostaurin — an oral multitargeted kinase inhibitor that is active in patients with a FLT3 mutation — to standard chemotherapy would prolong overall survival in this population. Methods We screened 3277 patients, 18 to 59 years of age, who had newly diagnosed AML for FLT3 mutations. Patients were randomly assigned to receive standard chemotherapy (induction therapy with daunorubicin and cytarabine and consolidation therapy with high‐dose cytarabine) plus either midostaurin or placebo; those who were in remission after consolidation therapy entered a maintenance phase in which they received either midostaurin or placebo. Randomization was stratified according to subtype of FLT3 mutation: point mutation in the tyrosine kinase domain (TKD) or internal tandem duplication (ITD) mutation with either a high ratio (>0.7) or a low ratio (0.05 to 0.7) of mutant to wild‐type alleles (ITD [high] and ITD [low], respectively). Allogeneic transplantation was allowed. The primary end point was overall survival. Results A total of 717 patients underwent randomization; 360 were assigned to the midostaurin group, and 357 to the placebo group. The FLT3 subtype was ITD (high) in 214 patients, ITD (low) in 341 patients, and TKD in 162 patients. The treatment groups were well balanced with respect to age, race, FLT3 subtype, cytogenetic risk, and blood counts but not with respect to sex (51.7% in the midostaurin group vs. 59.4% in the placebo group were women, P=0.04). Overall survival was significantly longer in the midostaurin group than in the placebo group (hazard ratio for death, 0.78; one‐sided P=0.009), as was event‐free survival (hazard ratio for event or death, 0.78; one‐sided P=0.002). In both the primary analysis and an analysis in which data for patients who underwent transplantation were censored, the benefit of midostaurin was consistent across all FLT3 subtypes. The rate of severe adverse events was similar in the two groups. Conclusions The addition of the multitargeted kinase inhibitor midostaurin to standard chemotherapy significantly prolonged overall and event‐free survival among patients with AML and a FLT3 mutation. (Funded by the National Cancer Institute and Novartis; ClinicalTrials.gov number, NCT00651261.)

A phase i study of the pan bcl-2FamilyInhibitor obatoclax mesylate in patients with advanced hematologic malignancies

Purpose: The outcome of patients with refractory leukemia and myelodysplasia is poor, and new therapies are needed. The antiapoptotic proteins of the Bcl-2 family are overexpressed in these malignancies and are potential therapeutic targets. Therefore, we conducted a phase I clinical trial of the small-molecule pan-Bcl-2 inhibitor, obatoclax mesylate, in patients with refractory leukemia and myelodysplasia to assess its safety and define its optimal dose. Experimental Design: Forty-four patients with refractory leukemia or myelodysplasia were treated with obatoclax mesylate by continuous intravenous infusion at increasing doses and frequencies. Results: A total of 306 infusions of obatoclax mesylate were administered with a median of 5 infusions per patient. The study drug was well tolerated up to the highest dose planned without dose-limiting toxicity. Grade 1/2 central nervous system symptoms were the most common adverse events attributable to the study drug. One patient with acute myeloid leukemia with mixed lineage leukemia t(9;11) rearrangement achieved a complete remission, which lasted 8 months. Three of 14 patients with myelodysplasia showed hematologic improvement with RBC or platelet transfusion independence. Conclusions: Obatoclax mesylate is well tolerated and these results support its further investigation in patients with leukemia and myelodysplasia.

A randomized phase 3 study of tipifarnib compared with best supportive care, including hydroxyurea, in the treatment of newly diagnosed acute myeloid leukemia in patients 70 years or older

This phase 3, multicenter, open-label study evaluated the efficacy and safety of tipifarnib compared with best supportive care (BSC), including hydroxyurea, as first-line therapy in elderly patients (>or=70 years) with newly diagnosed, de novo, or secondary acute myeloid leukemia. A total of 457 patients were enrolled with 24% 80 years of age or older. Tipifarnib 600 mg orally twice a day was administered for the first 21 consecutive days, in 28-day cycles. The primary endpoint was overall survival. The median survival was 107 days for the tipifarnib arm and 109 days for the BSC arm. The hazard ratio (tipifarnib vs BSC) for overall survival was 1.02 (P value by stratified log-rank test, .843). The complete response rate for tipifarnib in this study (8%) was lower than that observed previously, but with a similar median duration of 8 months. The most frequent grade 3 or 4 adverse events were cytopenias in both arms, slightly more infections (39% vs 33%), and febrile neutropenia (16% vs 10%) seen in the tipifarnib arm. The results of this randomized study showed that tipifarnib treatment did not result in an increased survival compared with BSC, including hydroxyurea. This trial was registered at www.clinicaltrials.gov as #NCT00093990.

A randomized controlled trial comparing standard- and low-dose strategies for transfusion of platelets (SToP) to patients with thrombocytopenia

A noninferiority study was performed comparing low-dose and standard-dose prophylactic platelet transfusions. A double-blind randomized controlled trial (RCT) was performed in 6 sites in 3 countries. Thrombocytopenic adults requiring prophylactic platelet transfusion were randomly allocated to standard-dose (300-600 x 10(9) platelets/product) or low-dose (150- < 300 x 10(9) platelets/product) platelets. The primary outcome (World Health Organization [WHO] bleeding > or = grade 2) was assessed daily through clinical examination, patient interview, and chart review. A WHO grade was assigned through adjudication. The Data Safety Monitoring Board stopped the study because the difference in the grade 4 bleeding reached the prespecified threshold of 5%. At this time, 129 patients had been randomized and 119 patients were included in the analysis (58 low dose; 61 standard dose). Three patients in the low-dose arm (5.2%) had grade 4 bleeds compared with none in the standard-dose arm. WHO bleeding grade 2 or higher was 49.2% (30/61) in the standard-dose arm and 51.7% (30/58) in the low-dose group (relative risk [RR], 1.052; 95% confidence interval [CI], 0.737-1.502). A higher rate of grade 4 bleeding in patients receiving low-dose prophylactic platelet transfusions resulted in this RCT being stopped. Whether this finding was due to chance or represents a real difference requires further investigation. These clinical studies are registered on (http://www.clinicaltrials.gov) as NCT00420914.

Single-agent lenalidomide in the treatment of previously untreated chronic lymphocytic leukemia

PURPOSE Lenalidomide is an oral immunomodulatory drug with multiple effects on the immune system and tumor cell microenvironment leading to inhibition of malignant cell growth. Based on encouraging reports of lenalidomide in relapsed and refractory chronic lymphocytic leukemia (CLL), we investigated the first-line use of single-agent lenalidomide in CLL. PATIENTS AND METHODS Using a starting dose of lenalidomide 10 mg/d for 21 days of a 28-day cycle and weekly 5-mg dose escalations to a target of 25 mg, we encountered severe toxicities (tumor lysis, fatal sepsis) in the first two patients enrolled. The study was halted and the protocol amended to a more conservative regimen: starting dose of lenalidomide 2.5 mg with monthly escalations to a target dose of 10 mg, and extended tumor lysis prophylaxis and monitoring. Gene expression profiles from patient samples before and after 7 days of lenalidomide were performed. RESULTS Twenty-five patients were enrolled on the amended protocol. No further tumor lysis events were reported. Tumor flare was common (88%) but mild. Grade 3 to 4 neutropenia occurred in 72% of patients, with only five episodes of febrile neutropenia. The overall response rate was 56% (no complete responses). Although rapid peripheral lymphocyte reductions were observed, rebound lymphocytoses during the week off-therapy were common. Lenalidomide-induced molecular changes enriched for cytoskeletal and immune-related genes were identified. CONCLUSION Lenalidomide is clinically active as first-line CLL therapy and is well-tolerated if a conservative approach with slow dose escalation is used. A lenalidomide-induced molecular signature provides insights into its immunomodulatory mechanisms of action in CLL.

Randomized, phase 2 trial of low-dose cytarabine with or without volasertib in AML patients not suitable for induction therapy

Treatment outcomes for older patients with acute myeloid leukemia (AML) have remained dismal. This randomized, phase 2 trial in AML patients not considered suitable for intensive induction therapy compared low-dose cytarabine (LDAC) with or without volasertib, a highly potent and selective inhibitor of polo-like kinases. Eighty-seven patients (median age 75 years) received LDAC 20 mg twice daily subcutaneously days 1-10 or LDAC + volasertib 350 mg IV days 1 + 15 every 4 weeks. Response rate (complete remission and complete remission with incomplete blood count recovery) was higher for LDAC + volasertib vs LDAC (31.0% vs 13.3%; odds ratio, 2.91; P = .052). Responses in the LDAC + volasertib arm were observed across all genetic groups, including 5 of 14 patients with adverse cytogenetics. Median event-free survival was significantly prolonged by LDAC + volasertib compared with LDAC (5.6 vs 2.3 months; hazard ratio, 0.57; 95% confidence interval, 0.35-0.92; P = .021); median overall survival was 8.0 vs 5.2 months, respectively (hazard ratio, 0.63; 95% confidence interval, 0.40-1.00; P = .047). LDAC + volasertib led to an increased frequency of adverse events that was most pronounced for neutropenic fever/infections and gastrointestinal events; there was no increase in the death rate at days 60 + 90. This study was registered at www.clinicaltrials.gov as #NCT00804856.