Spindle cell tumours of the ureter: Operation or observation?

We describe a rare case of inflammatory spindle cell tumour of the ureter in a patient who presented with renal colic and macroscopic haematuria. Pyeloscopy revealed a partially obstructing mass at the proximal right ureter which confirmed a myofibroblastic tumour on biopsy. Radical nephrectomy was performed which confirmed a spindle cell tumour of the ureter confined to the resection margins. Follow-up imaging in 12 months did not illustrate recurrence or metastasis. The decision to perform a nephrectomy was due to the limited experience with this tumour. Reports illustrate that this tumour is unlikely to metastasize, and thus be managed conservatively.

Impact of modern media on analgesic requirements during extracorporeal shockwave lithotripsy.

BACKGROUND: In Australia, shockwave lithotripsy (SWL) to treat urinary tract stones is routinely performed with general anaesthesia (GA). We have established a SWL service avoiding GA based outside operating theatres and wish to assess the effectiveness of utilizing modern media on patient satisfaction and analgesic requirements during treatment. METHODS: A randomized three-arm trial was performed. Patients were allocated to either watching videos or listening to music on a tablet device, or to getting no media distraction. A total of 95 patients were recruited in a 1:1:1 fashion. Analgesic requirements were recorded during the procedure and patients were asked to fill out a questionnaire with a visual analogue scale to assess their overall pain and satisfaction with the procedure. RESULTS: Overall pain scores were decreased - the sound media group reported a mean pain score of 3.52 (P = 0.005), the visual group was 3.62 (P = 0.007), compared to 5.45 in the control group. Analgesic requirements were significantly decreased when compared to the control group (P = 0.05). Overall satisfaction with the procedure was improved in the treatment groups, with the sound group having the best result (P = 0.04). CONCLUSION: Modern media can be used as a distraction during SWL in a safe and effective way when treating renal tract stones without GA. Analgesic requirements are decreased significantly, therefore decreasing any potential side-effects and complications. Other departments in Australia should consider using this technique.

Safety and survival outcomes for bloodless transplantation in patients with myeloma.

High-dose therapy (HDT) and autologous stem cell transplantation (ASCT) are established components in the treatment of multiple myeloma; however, undergoing transplantation usually requires hematopoietic support, which poses a challenge among patients who are unwilling to receive blood products. Most transplant centers decline HDT/ASCT to these patients because of safety concerns. Here, the authors' institutional data on safety, engraftment parameters, and survival outcomes after bloodless ASCT (BL-ASCT) are examined among patients with myeloma. This retrospective case-control study included patients who underwent BL-ASCT and Transfusion-supported ASCT (TS-ASCT) at Emory University Hospital between August 2006 and August 2016. In total, 24 patients who underwent BL-ASCT and 70 who underwent TS-ASCT were included. The median time for neutrophil engraftment, platelet engraftment and the median length of hospital stay all were equivalent for both groups. There were no transplant-related cardiovascular complications or mortality in either the BL-ASCT group or the TS-ASCT group. The median progression-free survival was 36 months and 44 months in the BL-ASCT and TS-ASCT groups, respectively (P = .277), and the median OS was not reached in either group at a median follow-up of 59 months after ASCT (P = .627). There was no transplant-related mortality at the 100-day or 1-year mark in either group. BL-ASCT is safe and feasible; transplant-related mortality, cardiovascular and hematologic complications are similar to those associated with TS-ASCT. Furthermore, BL-ASCT can yield similar engraftment and survival parameters comparable to those observed with TS-ASCT.

Upper gastrointestinal acute graft-versus-host disease adds minimal prognostic value in isolation or with other graft-versus-host disease symptoms as currently diagnosed and treated.

Upper gastrointestinal acute graft-versus-host disease is reported in approximately 30% of hematopoietic stem cell transplant recipients developing acute graft-versus-host disease. Currently classified as Grade II in consensus criteria, upper gastrointestinal acute graft-versus-host disease is often treated with systemic immunosuppression. We reviewed the Center for International Blood and Marrow Transplant Research database to assess the prognostic implications of upper gastrointestinal acute graft-versus-host disease in isolation or with other acute graft-versus-host disease manifestations. 8567 adult recipients of myeloablative allogeneic hematopoietic stem cell transplant receiving T-cell replete grafts for acute leukemia, chronic myeloid leukemia or myelodysplastic syndrome between 2000 and 2012 were analyzed. 51% of transplants were from unrelated donors. Reported upper gastrointestinal acute graft-versus-host disease incidence was 12.1%; 2.7% of recipients had isolated upper gastrointestinal acute graft-versus-host disease, of whom 95% received systemic steroids. Patients with isolated upper gastrointestinal involvement had similar survival, disease-free survival, transplant-related mortality, and relapse as patients with Grades 0, I, or II acute graft-versus-host disease. Unrelated donor recipients with isolated upper gastrointestinal acute graft-versus-host disease had less subsequent chronic graft-versus-host disease than those with Grades I or II disease (P=0.016 and P=0.0004, respectively). Upper gastrointestinal involvement added no significant prognostic information when present in addition to other manifestations of Grades I or II acute graft-versus-host disease. If upper gastrointestinal symptoms were reclassified as Grade 0 or I, 425 of 2083 patients (20.4%) with Grade II disease would be downgraded, potentially impacting the interpretation of clinical trial outcomes. Defining upper gastrointestinal acute graft-versus-host disease as a Grade II entity, as it is currently diagnosed and treated, is not strongly supported by this analysis. The general approach to diagnosis, treatment and grading of upper gastrointestinal symptoms and their impact on subsequent acute graft-versus-host disease therapy warrants reevaluation.

HMG-CoA synthase 1 is a synthetic lethal partner of BRAFV600E in human cancers.

Contributions of metabolic changes to cancer development and maintenance have received increasing attention in recent years. Although many human cancers share similar metabolic alterations, it remains unclear whether oncogene-specific metabolic alterations are required for tumor development. Using an RNAi-based screen targeting the majority of the known metabolic proteins, we recently found that oncogenic BRAFV600E up-regulates HMG-CoA lyase (HMGCL), which converts HMG-CoA to acetyl-CoA and a ketone body, acetoacetate, that selectively enhances BRAFV600E-dependent MEK1 activation in human cancer. Here, we identified HMG-CoA synthase 1 (HMGCS1), the upstream ketogenic enzyme of HMGCL, as an additional "synthetic lethal" partner of BRAFV600E Although HMGCS1 expression did not correlate with BRAFV600E mutation in human melanoma cells, HMGCS1 was selectively important for proliferation of BRAFV600E-positive melanoma and colon cancer cells but not control cells harboring active N/KRAS mutants, and stable knockdown of HMGCS1 only attenuated colony formation and tumor growth potential of BRAFV600E melanoma cells. Moreover, cytosolic HMGCS1 that co-localized with HMGCL and BRAFV600E was more important than the mitochondrial HMGCS2 isoform in BRAFV600E-expressing cancer cells in terms of acetoacetate production. Interestingly, HMGCL knockdown did not affect HMGCS1 expression levels, whereas HMGCS1 knockdown caused a compensating increase in HMGCL protein level because of attenuated protein degradation. However, this increase did not reverse the reduced ketogenesis in HMGCS1 knockdown cells. Mechanistically, HMGCS1 inhibition decreased intracellular acetoacetate levels, leading to reduced BRAFV600E-MEK1 binding and consequent MEK1 activation. We conclude that the ketogenic HMGCS1-HMGCL-acetoacetate axis may represent a promising therapeutic target for managing BRAFV600E-positive human cancers.

Immune responses and long-term disease recurrence status after telomerase-based dendritic cell immunotherapy in patients with acute myeloid leukemia.

BACKGROUND: Telomerase activity in leukemic blasts frequently is increased among patients with high-risk acute myeloid leukemia (AML). In the current study, the authors evaluated the feasibility, safety, immunogenicity, and therapeutic potential of human telomerase reverse transcriptase (hTERT)-expressing autologous dendritic cells (hTERT-DCs) in adult patients with AML. METHODS: hTERT-DCs were produced from patient-specific leukapheresis, electroporated with an mRNA-encoding hTERT and a lysosomal-targeting sequence, and cryopreserved. A total of 22 patients with a median age of 58 years (range, 30-75 years) with intermediate-risk or high-risk AML in first or second complete remission (CR) were enrolled. hTERT-DCs were generated for 24 patients (73%). A median of 17 intradermal vaccinations (range, 6-32 intradermal vaccinations) containing 1×107 cells were administered as 6 weekly injections followed by 6 biweekly injections. A total of 21 patients (16 in first CR, 3 in second CR, and 2 with early disease recurrence) received hTERT-DCs. RESULTS: hTERT-DCs were well tolerated with no severe toxicities reported, with the exception of 1 patient who developed idiopathic thrombocytopenic purpura. Of the 19 patients receiving hTERT-DCs in CR, 11 patients (58%) developed hTERT-specific T-cell responses that primarily were targeted toward hTERT peptides with predicted low human leukocyte antigen (HLA)-binding affinities. With a median follow-up of 52 months, 58% of patients in CR (11 of 19 patients) were free of disease recurrence at the time of their last follow-up visit; 57% of the patients who were aged ≥60 years (4 of 7 patients) also were found to be free of disease recurrence at a median follow-up of 54 months. CONCLUSIONS: The generation of hTERT-DCs is feasible and vaccination with hTERT-DCs appears to be safe and may be associated with favorable recurrence-free survival. Cancer 2017;123:3061-72. © 2017 American Cancer Society.

Improved survival after acute graft-versus-host disease diagnosis in the modern era.

A cute graft-versus-host disease remains a major threat to a successful outcome after allogeneic hematopoietic cell transplantation. While improvements in treatment and supportive care have occurred, it is unknown whether these advances have resulted in improved outcome specifically among those diagnosed with acute graft-versus-host disease. We examined outcome following diagnosis of grade II-IV acute graft-versus-host disease according to time period, and explored effects according to original graft-versus-host disease prophylaxis regimen and maximum overall grade of acute graft-versus-host disease. Between 1999 and 2012, 2,905 patients with acute myeloid leukemia (56%), acute lymphoblastic leukemia (30%) or myelodysplastic syndromes (14%) received a sibling (24%) or unrelated donor (76%) blood (66%) or marrow (34%) transplant and developed grade II-IV acute graft-versus-host disease (n=497 for 1999-2001, n=962 for 2002-2005, n=1,446 for 2006-2010). The median (range) follow-up was 144 (4-174), 97 (4-147) and 60 (8-99) months for 1999-2001, 2002-2005, and 2006-2010, respectively. Among the cohort with grade II-IV acute graft-versus-host disease, there was a decrease in the proportion of grade III-IV disease over time with 56%, 47%, and 37% for 1999-2001, 2002-2005, and 2006-2012, respectively (P<0.001). Considering the total study population, univariate analysis demonstrated significant improvements in overall survival and treatment-related mortality over time, and deaths from organ failure and infection declined. On multivariate analysis, significant improvements in overall survival (P=0.003) and treatment-related mortality (P=0.008) were only noted among those originally treated with tacrolimus-based graft-versus-host disease prophylaxis, and these effects were most apparent among those with overall grade II acute graft-versus-host disease. In conclusion, survival has improved over time for tacrolimus-treated transplant recipients with acute graft-versus-host disease.

Allogeneic transplantation for advanced acute myeloid leukemia: The value of complete remission.

BACKGROUND: Patients with acute myeloid leukemia (AML) without complete remission (CR) or in first relapse (Rel1) can have extended leukemia control and survival after allogeneic hematopoietic cell transplantation (HCT). For patients in Rel1 or primary induction failure (PIF), transplantation versus treatment to achieve a second CR (CR2) and subsequent HCT might yield similar outcomes, but available comparative data are scarce. METHODS: Survival was analyzed in 4682 HCT recipients according to disease status: PIF (N = 1440), Rel1 (failing ≥1 reinduction; N = 1256), and CR2 (N = 1986). RESULTS: Patient, disease, and transplantation characteristics were similar, except that patients in CR2 more often had performance scores of 90% to 100%, de novo AML, and longer CR1 duration. Adverse cytogenetics were more common in patients who experienced PIF. The 5-year survival rate adjusted for performance score, cytogenetic risk, and donor type for CR2 was 39% (95% confidence interval [CI], 37%-41%) compared with 18% (95% CI, 16%-20%) for HCT in Rel1 and 21% (95% CI, 19%-23%) in PIF (P < .0001). CONCLUSIONS: Although survival is superior for patients who undergo HCT in CR2, transplantation for selected patients in Rel1 or PIF may still be valuable. These data can guide decision making about additional salvage therapy versus prompt HCT for patients not in CR, but they also highlight that AML is intrinsically more treatable in patients who have favorable-risk cytogenetics, those with longer CR1 duration, and younger patients with better performance status. Cancer 2017;123:2025-2034. © 2017 American Cancer Society.

Prevention of Dietary-Fat-Fueled Ketogenesis Attenuates BRAF V600E Tumor Growth.

Lifestyle factors, including diet, play an important role in the survival of cancer patients. However, the molecular mechanisms underlying pathogenic links between diet and particular oncogenic mutations in human cancers remain unclear. We recently reported that the ketone body acetoacetate selectively enhances BRAF V600E mutant-dependent MEK1 activation in human cancers. Here we show that a high-fat ketogenic diet increased serum levels of acetoacetate, leading to enhanced tumor growth potential of BRAF V600E-expressing human melanoma cells in xenograft mice. Treatment with hypolipidemic agents to lower circulating acetoacetate levels or an inhibitory homolog of acetoacetate, dehydroacetic acid, to antagonize acetoacetate-BRAF V600E binding attenuated BRAF V600E tumor growth. These findings reveal a signaling basis underlying a pathogenic role of dietary fat in BRAF V600E-expressing melanoma, providing insights into the design of conceptualized "precision diets" that may prevent or delay tumor progression based on an individual's specific oncogenic mutation profile.

Tetrameric Acetyl-CoA Acetyltransferase 1 Is Important for Tumor Growth.

Mitochondrial acetyl-CoA acetyltransferase 1 (ACAT1) regulates pyruvate dehydrogenase complex (PDC) by acetylating pyruvate dehydrogenase (PDH) and PDH phosphatase. How ACAT1 is "hijacked" to contribute to the Warburg effect in human cancer remains unclear. We found that active, tetrameric ACAT1 is commonly upregulated in cells stimulated by EGF and in diverse human cancer cells, where ACAT1 tetramers, but not monomers, are phosphorylated and stabilized by enhanced Y407 phosphorylation. Moreover, we identified arecoline hydrobromide (AH) as a covalent ACAT1 inhibitor that binds to and disrupts only ACAT1 tetramers. The resultant AH-bound ACAT1 monomers cannot reform tetramers. Inhibition of tetrameric ACAT1 by abolishing Y407 phosphorylation or AH treatment results in decreased ACAT1 activity, leading to increased PDC flux and oxidative phosphorylation with attenuated cancer cell proliferation and tumor growth. These findings provide a mechanistic understanding of how oncogenic events signal through distinct acetyltransferases to regulate cancer metabolism and suggest ACAT1 as an anti-cancer target.

Long-term bosutinib for chronic phase chronic myeloid leukemia after failure of imatinib plus dasatinib and/or nilotinib.

Bosutinib is an Src/Abl tyrosine kinase inhibitor (TKI) indicated for adults with Ph+ chronic myeloid leukemia (CML) resistant/intolerant to prior TKIs. This long-term update of an ongoing phase 1/2 study evaluated the efficacy and safety of third-/fourth-line bosutinib in adults with chronic phase (CP) CML. Median durations of treatment and follow-up were 8.6 (range, 0.2-87.7) months and 32.7 (0.3-93.3) months, respectively. Cumulative confirmed complete hematologic response (cCHR) and major cytogenetic response (MCyR) rates were 74% (95% CI, 65-81%) and 40% (31-50%), respectively; Kaplan-Meier (K-M) probability of maintaining cCHR or MCyR at 4 years was 63% (95% CI, 50-73%) and 69% (52-81%). Cumulative incidence of on-treatment disease progression (PD)/death at 4 years was 24% (95% CI, 17-33%); K-M 4-year overall survival was 78% (68-85%). Baseline Ph+ cells ≤35 vs. ≥95% was prognostic of MCyR and CCyR by 3 and 6 months, increased baseline basophils was prognostic of PD/death, and no prior response to second-line TKI was prognostic of death. Common adverse events included diarrhea (83%), nausea (48%), vomiting (38%), and thrombocytopenia (39%). Bosutinib demonstrates durable efficacy and a toxicity profile similar to previous bosutinib studies in CP CML patients resistant/intolerant to multiple TKIs, representing an important treatment option for patients in this setting. This trial is registered at www.clinicaltrials.gov (NCT00261846). Am. J. Hematol. 91:1206-1214, 2016. © 2016 Wiley Periodicals, Inc.

Does Post-Transplant Maintenance Therapy With Tyrosine Kinase Inhibitors Improve Outcomes of Patients With High-Risk Philadelphia Chromosome-Positive Leukemia?

INTRODUCTION: The effect of post-transplant maintenance tyrosine kinase inhibitors (TKIs) on the outcomes of allogeneic hematopoietic stem cell transplantation in high-risk Philadelphia chromosome-positive (Ph(+)) leukemia remains unknown. PATIENTS AND METHODS: A retrospective analysis that included allograft recipients with accelerated phase and blast phase chronic myeloid leukemia or Ph(+) acute lymphoblastic leukemia who had received post-transplant maintenance TKI therapy from 2004 to 2014. RESULTS: A total of 26 patients, 9 with accelerated phase/blast phase CML and 17 with Ph(+) acute lymphoblastic leukemia, received maintenance post-transplant therapy with imatinib, dasatinib, nilotinib, or ponatinib. The TKI was selected according to the pretransplantation TKI response, anticipated toxicities, and ABL1 domain mutations, when present. Newer generation TKIs were initiated at a ≥ 50% dose reduction from the standard pretransplantation dosing to limit the toxicities and avoid therapy interruptions. TKIs were started a median of 100 days (range, 28-238 days) after transplantation and were administered for a median of 16 months (range, 8 days to 105 months). Eight patients discontinued therapy because of adverse events. With a median follow-up of 3.6 years (range, 4 months to 8.7 years), the 5-year relapse-free survival rate was 61%. All 3 patients who developed a relapse underwent successful salvage treatment and remained disease-free. The 5-year overall survival rate was 78%. CONCLUSION: Maintenance TKI therapy after transplantation is feasible and might reduce the incidence of relapses and improve outcomes after allogeneic hematopoietic stem cell transplantation for patients with high-risk Ph(+) leukemia.

Cross-Intolerance With Dasatinib Among Imatinib-Intolerant Patients With Chronic Phase Chronic Myeloid Leukemia.

BACKGROUND: BCR-ABL inhibitors have improved the prognosis of patients with chronic myeloid leukemia (CML). However, imatinib, the first approved BCR-ABL inhibitor, must be discontinued in many patients because of resistance or intolerance. PATIENTS AND METHODS: The present retrospective, pooled analysis of phase II and III data explored the extent of cross-intolerance between imatinib and dasatinib, a second-generation BCR-ABL inhibitor, in 271 CML imatinib-intolerant patients. RESULTS: Overall, 47 patients (17%) had cross-intolerance to dasatinib, determined by recurrence of grade 3 or 4 adverse events (AEs). Of the 228 patients who discontinued imatinib because of nonhematologic intolerance, 10 (4%) experienced the same severe nonhematologic AEs with dasatinib, with 4 of these patients (2%) discontinuing dasatinib because of cross-intolerance. Of the 43 patients who discontinued imatinib because of hematologic intolerance, 37 (86%) experienced a recurrence of grade 3 or 4 hematologic AEs with dasatinib, with 8 patients (19%) discontinuing dasatinib because of cross-intolerance. Of the 43 patients taking dasatinib at the optimized dose of 100 mg/d, 1 (2%) discontinued therapy because of recurrence of nonhematologic AEs and 3 (7%) because of recurrence of hematologic AEs. With a median treatment duration of 22 months, the estimated rates of progression-free survival and overall survival at 2 years were greater for patients with nonhematologic versus hematologic intolerance to imatinib who switched to dasatinib (progression-free survival, 94% vs. 68%, respectively; overall survival, 98% vs. 88%, respectively). CONCLUSION: Dasatinib could be an appropriate treatment option for imatinib-intolerant patients with CML, with cross-intolerance resulting in discontinuation in a few patients.

Allogeneic Hematopoietic Cell Transplantation for Patients with Mixed Phenotype Acute Leukemia.

Acute biphenotypic leukemias or mixed phenotype acute leukemias (MPAL) are rare and considered high risk. The optimal treatment and the role of allogeneic hematopoietic stem cell transplantation (alloHCT) are unclear. Most prior case series include only modest numbers of patients who underwent transplantation. We analyzed the outcome of 95 carefully characterized alloHCT patients with MPAL reported to the Center for International Blood and Marrow Transplant Research between 1996 and 2012. The median age was 20 years (range, 1 to 68). Among the 95 patients, 78 were in first complete remission (CR1) and 17 were in second complete remission (CR2). Three-year overall survival (OS) of 67% (95% confidence interval [CI], 57 to 76), leukemia-free survival of 56% (95% CI, 46 to 66), relapse incidence of 29% (95% CI, 20 to 38), and nonrelapse mortality of 15% (95% CI, 9 to 23) were encouraging. OS was best in younger patients (<20 years), but no significant differences were observed between those 20 to 40 years of age and those who were 40 years or older. A matched-pair analysis showed similar outcomes comparing MPAL cases to 375 acute myelogenous leukemia or 359 acute lymphoblastic leukemia cases. MPAL patients had more acute and a trend for more chronic graft-versus-host disease. No difference was observed between patients who underwent transplantation in CR1 versus those who underwent transplantation in CR2. AlloHCT is a promising treatment option for pediatric and adult patients with MPAL with encouraging long-term survival.

Factors influencing long-term efficacy and tolerability of bosutinib in chronic phase chronic myeloid leukaemia resistant or intolerant to imatinib.

The dual SRC/ABL1 tyrosine kinase inhibitor bosutinib is indicated for adults with Ph+ chronic myeloid leukaemia (CML) resistant/intolerant to prior therapy. This analysis of an ongoing phase 1/2 study (NCT00261846) assessed effects of baseline patient characteristics on long-term efficacy and safety of bosutinib 500 mg/day in adults with imatinib (IM)-resistant (IM-R; n = 196)/IM-intolerant (IM-I; n = 90) chronic phase (CP) CML. Median treatment duration was 24·8 months (median follow-up, 43·6 months). Cumulative major cytogenetic response (MCyR) rate [95% confidence interval (CI)], was 59% (53-65%); Kaplan-Meier (KM) probability of maintaining MCyR at 4 years was 75% (66-81%). Cumulative incidence of on-treatment progression/death at 4 years was 19% (95% CI, 15-24%); KM 2-year overall survival was 91% (87-94%). Significant baseline predictors of both MCyR and complete cytogenetic response (newly attained/maintained from baseline) at 3 and 6 months included prior IM cytogenetic response, baseline MCyR, prior interferon therapy and <6 months duration from diagnosis to IM treatment initiation and no interferon treatment before IM. The most common adverse event (AE) was diarrhoea (86%). Baseline bosutinib-sensitive BCR-ABL1 mutation was the only significant predictor of grade 3/4 diarrhoea; no significant predictors were identified for liver-related AEs. Bosutinib demonstrates durable efficacy and manageable toxicity in IM-R/IM-I CP-CML patients.

6-Phosphogluconate dehydrogenase links oxidative PPP, lipogenesis and tumour growth by inhibiting LKB1-AMPK signalling.

The oxidative pentose phosphate pathway (PPP) contributes to tumour growth, but the precise contribution of 6-phosphogluconate dehydrogenase (6PGD), the third enzyme in this pathway, to tumorigenesis remains unclear. We found that suppression of 6PGD decreased lipogenesis and RNA biosynthesis and elevated ROS levels in cancer cells, attenuating cell proliferation and tumour growth. 6PGD-mediated production of ribulose-5-phosphate (Ru-5-P) inhibits AMPK activation by disrupting the active LKB1 complex, thereby activating acetyl-CoA carboxylase 1 and lipogenesis. Ru-5-P and NADPH are thought to be precursors in RNA biosynthesis and lipogenesis, respectively; thus, our findings provide an additional link between the oxidative PPP and lipogenesis through Ru-5-P-dependent inhibition of LKB1-AMPK signalling. Moreover, we identified and developed 6PGD inhibitors, physcion and its derivative S3, that effectively inhibited 6PGD, cancer cell proliferation and tumour growth in nude mice xenografts without obvious toxicity, suggesting that 6PGD could be an anticancer target.

Metabolic Rewiring by Oncogenic BRAF V600E Links Ketogenesis Pathway to BRAF-MEK1 Signaling.

Many human cancers share similar metabolic alterations, including the Warburg effect. However, it remains unclear whether oncogene-specific metabolic alterations are required for tumor development. Here we demonstrate a "synthetic lethal" interaction between oncogenic BRAF V600E and a ketogenic enzyme 3-hydroxy-3-methylglutaryl-CoA lyase (HMGCL). HMGCL expression is upregulated in BRAF V600E-expressing human primary melanoma and hairy cell leukemia cells. Suppression of HMGCL specifically attenuates proliferation and tumor growth potential of human melanoma cells expressing BRAF V600E. Mechanistically, active BRAF upregulates HMGCL through an octamer transcription factor Oct-1, leading to increased intracellular levels of HMGCL product, acetoacetate, which selectively enhances binding of BRAF V600E but not BRAF wild-type to MEK1 in V600E-positive cancer cells to promote activation of MEK-ERK signaling. These findings reveal a mutation-specific mechanism by which oncogenic BRAF V600E "rewires" metabolic and cell signaling networks and signals through the Oct-1-HMGCL-acetoacetate axis to selectively promote BRAF V600E-dependent tumor development.

Long-term efficacy and safety of bosutinib in patients with advanced leukemia following resistance/intolerance to imatinib and other tyrosine kinase inhibitors.

Long-term efficacy and safety of bosutinib (≥4 years follow-up from last enrolled patient) were evaluated in an ongoing phase 1/2 study in the advanced leukemia cohort with prior treatment failure (accelerated-phase [AP, n = 79] chronic myeloid leukemia [CML], blast-phase [BP, n = 64] CML, acute lymphoblastic leukemia [ALL, n = 24]). Fourteen AP, 2 BP, and 1 ALL patient remained on bosutinib at 4 years (vs. 38, 8, 1 at 1 year); median (range) treatment durations: 10.2 (0.1-88.6), 2.8 (0.03-55.9), 0.97 (0.3-89.2) months. Among AP and BP patients, 57% and 28% newly attained or maintained baseline overall hematologic response (OHR); 40% and 37% attained/maintained major cytogenetic response (MCyR) by 4 years (most by 12 months). In responders at 1 versus 4 years, Kaplan-Meier (KM) probabilities of maintaining OHR were 78% versus 49% (AP) and 28% versus 19% (BP); KM probabilities of maintaining MCyR were 65% versus 49% (AP) and 21% versus 21% (BP). Most common AEs (AP, BP) were gastrointestinal (96%; 83%), primarily diarrhea (85%; 64%), which was typically low grade (maximum grade 1/2: 81%; 59%) and transient; no patient discontinued due to diarrhea. Serious AEs occurred in 44 (56%) AP and 37 (58%) BP patients, most commonly pneumonia (n = 9) for AP and pyrexia (n = 6) for BP; 11 and 13 died within 30 days of last dose (2 considered bosutinib-related [AP] per investigator). Responses were durable in ∼50% AP responders at 4 years (∼25% BP patients responded at year 1, suggesting possible bridge-to-transplant role in BP patients); toxicity was manageable.