Diminished humoral and cellular responses to SARS-CoV-2 vaccines in patients with chronic lymphocytic leukemia

Previous studies have demonstrated low rates of seroconversion to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA (mRNA) vaccines in patients with chronic lymphocytic leukemia (CLL). In this national collaboration of 11 cancer centers in the United States, we aimed to further characterize and understand vaccine-induced immune responses, including T-cell responses, and the impact of CLL therapeutics (#NCT04852822). Eligible patients were enrolled in 2 cohorts (1) at the time of initial vaccination and (2) at the time of booster vaccination. The serologic response rates (anti-S) from 210 patients in the initial vaccination cohort and 117 in the booster vaccination cohort were 56% (95% confidence interval [CI], 50-63) and 68% (95% CI, 60-77), respectively. Compared with patients not on therapy, those receiving B-cell-directed therapy were less likely to seroconvert (odds ratio [OR], 0.27; 95% CI, 0.15-0.49). Persistence of response was observed at 6 months; anti-S titers increased with the administration of booster vaccinations. In the initial vaccination cohort, positive correlations were observed between the quantitative serologic response and CD4 T-cell response for the Wuhan variant and, to a lesser degree, for the Omicron variant (Spearman P = 0.45 Wuhan; P = 0.25 Omicron). In the booster vaccination cohort, positive correlations were observed between serologic responses and CD4 T-cell responses for both variants (P = 0.58 Wuhan; P = 0.57 Omicron) and to a lesser degree for CD8 T-cell responses (P = 0.33 Wuhan; P = 0.22 Omicron). Although no deaths from coronavirus disease 2019 (COVID-19) have been reported after booster vaccinations, patients should use caution as newer variants emerge and escape vaccine-induced immunity. This trial was registered at www.clinicaltrials.gov as #NCT04852822.

Recognizing Unmet Need in the Era of Targeted Therapy for CLL/SLL: "What's Past Is Prologue" (Shakespeare)

The management of chronic lymphocytic leukemia (CLL) has undergone unprecedented changes over the last decade. Modern targeted therapies are incorporated into clinical practice. Unfortunately, patients have begun to develop resistance or intolerance to multiple classes. Symptomatic patients previously treated with a BTK inhibitor (BTKi) and venetoclax represent a new and rapidly growing unmet need in CLL. Here, we define unmet needs in a modern treatment context. We also critically review the literature for PI3K inhibitors and chemoimmunotherapy and lack of data to support their utility following BTKis and venetoclax. Finally, we suggest opportunities to ensure the continued innovation for patients with CLL.

Inotuzumab ozogamicin in combination with low-intensity chemotherapy (mini-HCVD) with or without blinatumomab versus standard intensive chemotherapy (HCVAD) as frontline therapy for older patients with Philadelphia chromosome-negative acute lymphoblastic leukemia: A propensity score analysis

BACKGROUND

The outcome of older patients with newly diagnosed, Philadelphia chromosome (Ph)-negative acute lymphoblastic leukemia (ALL) is poor. The combination of targeted therapy with low-intensity chemotherapy is safe and effective. The objective of the current analysis was to compare the outcome of patients who received a combination of inotuzumab ozogamicin plus low-intensity chemotherapy (mini-hyperfractionated cyclophosphamide, vincristine, and dexamethasone [mini-HCVD]) with or without blinatumomab versus the outcome of those who received the standard, intensive, hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (HCVAD) regimen.

METHODS

The authors analyzed 135 older patients with newly diagnosed, Ph-negative ALL who were treated prospectively with standard HCVAD (n = 77) or with the combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab (n = 58). A propensity score analysis was conducted using 1:1 matching using the nearest neighbor matching method.

RESULTS

Propensity score matching identified 38 patients in each cohort. The antibody plus low-intensity chemotherapy combination induced higher response rates (98% vs 88%), with lower rates of early death (0% vs 8%) and lower rates of death in complete remission (5% vs 17%). With propensity score matching, the 3-year event-free survival rates for patients who received HCVAD and those who received the combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab were 34% and 64%, respectively (P = .003), and the 3-year overall survival rates were 34% and 63%, respectively (P = .004). By multivariate analysis, age (P = .019; hazard ratio, 1.045) and the combination of inotuzumab plus mini-HCVD with or without blinatumomab (P = .020; hazard ratio, 0.550) were identified as independent prognostic factors for survival.

CONCLUSIONS

The combination of inotuzumab ozogamicin plus mini-HCVD with or without blinatumomab is safe and effective in older patients with newly diagnosed, Ph-negative ALL and confers a better outcome compared with standard HCVAD chemotherapy.

Duvelisib, an oral dual PI3K-δ,γ inhibitor, shows clinical and pharmacodynamic activity in chronic lymphocytic leukemia and small lymphocytic lymphoma in a phase 1 study

Duvelisib (IPI-145), an oral, dual inhibitor of phosphoinositide-3-kinase (PI3K)-δ and -γ, was evaluated in a Phase 1 study in advanced hematologic malignancies, which included expansion cohorts in relapsed/refractory (RR) chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) and treatment-naïve (TN) CLL. Per protocol, TN patients were at least 65 years old or had a del(17p)/TP53 mutation. Duvelisib was administered twice daily (BID) in 28-day cycles at doses of 8-75 mg in RR patients (n = 55) and 25 mg in TN patients (n = 18.) Diarrhea was the most common nonhematologic AE (TN 78%, RR 47%); transaminase elevations the most frequent lab-abnormality AE (TN 33.3%, RR 30.9%); and neutropenia the most common ≥grade 3 AE (RR 44%, TN 33%). The overall response rates were 56.4% for RR patients (1.8% CR, 54.5% PR) and 83.3% for TN patients (all PRs); median response duration was 21.0 months in RR patients but was not reached for TN patients. Based upon phase 1 efficacy, pharmacodynamics, and safety, duvelisib 25 mg BID was selected for further investigation in a phase 3 study in RR CLL/SLL.

Knee manipulation for reduced flexion after Total Knee Arthroplasty. Is timing critical?

BACKGROUND

Reduced flexion following knee arthroplasty (TKA) may compromise patient's function and outcome. The timing of manipulation under anaesthesia (MUA) has been controversial. We present our experience in a high volume practice and analyse the impact of timing.

METHODS

All TKA patients requiring MUA from February 1996 to June 2015 under the care of a single surgeon were analysed. MUA was offered to patients who had ≤ 75° of flexion post-op, providing that they had 30° more flexion preoperatively. To address the impact of timing from primary surgery to MUA on flexion gain we looked at 3 groups: Group I ≤ 90 days, Group II 91-180 days and Group III > 180 days.

RESULTS

Sixty two out of 7,423 (0.84%) underwent MUA. The MUA patients were significantly younger than the overall TKA cohort 61.2 vs 70.5 years (p = < 0.01). The median duration between arthroplasty and MUA was 3.9 months (IQR 3.4, Range 1.6-72.5 months). Overall flexion gained at 6-12 Weeks and 1 year post MUA showed significant improvements of 20.9° (p = <0.01) and 25° respectively (p = < 0.01). The flexion gain in group I (≤ 90 days) was significantly better than group III ( > 180 days) both at 6 weeks and 1 year following MUA but not better than group II (90-180 days).

CONCLUSIONS

MUA is an effective treatment for reduced flexion following TKA and should be the first line of management after failed physiotherapy. It can still have benefit beyond 6 months but the gains become less effective with time.

Duvelisib treatment is associated with altered expression of apoptotic regulators that helps in sensitization of chronic lymphocytic leukemia cells to venetoclax (ABT-199)

Duvelisib, an oral dual inhibitor of PI3K-δ and PI3K-γ, is in phase III trials for the treatment of chronic lymphocytic leukemia (CLL) and indolent non-Hodgkin's lymphoma. In CLL, duvelisib monotherapy is associated with high iwCLL (International Workshop on Chronic Lymphocytic Leukemia) and nodal response rates, but complete remissions are rare. To characterize the molecular effect of duvelisib, we obtained samples from CLL patients on the duvelisib phase I trial. Gene expression studies (RNAseq, Nanostring, Affymetrix array and real-time RT-PCR) demonstrated increased expression of BCL2 along with several BH3-only pro-apoptotic genes. In concert with induction of transcript levels, reverse phase protein arrays and immunoblots confirmed increase at the protein level. The BCL2 inhibitor venetoclax induced greater apoptosis in ex vivo-cultured CLL cells obtained from patients on duvelisib compared with pre-treatment CLL cells from the same patients. In vitro combination of duvelisib and venetoclax resulted in enhanced apoptosis even in CLL cells cultured under conditions that simulate the tumor microenvironment. These data provide a mechanistic rationale for testing the combination of duvelisib and venetoclax in the clinic. Such combination regimen (NCT02640833) is being evaluated for patients with B-cell malignancies including CLL.

Five-year clinical and radiological outcomes in 257 consecutive cementless Oxford medial unicompartmental knee arthroplasties

Aims

Our aim was to examine the clinical and radiographic outcomes in 257 consecutive Oxford unicompartmental knee arthroplasties (OUKAs) (238 patients), five years post-operatively.

Patients and Methods

A retrospective evaluation was undertaken of patients treated between April 2008 and October 2010 in a regional centre by two non-designing surgeons with no previous experience of UKAs. The Oxford Knee Scores (OKSs) were recorded and fluoroscopically aligned radiographs were assessed post-operatively at one and five years.

Results

The median age of the 238 patients was 65.0 years (interquartile range (IQR) 59.0 to 73.0), the median body mas index was 30.0 (IQR 27.5 to 33.0) and 51.7% were male. There were no intra-operative complications. There was a significant improvement in the median OKS at six weeks (34, IQR 31.0 to 37.0), one year (38, IQR 29.0 to 43.0) and five years (37, IQR 27.0 to 42.0) when compared with the pre-operative scores (16, IQR 13.0 to 19.0) (all p = < 0.01). No patient had progressive radiolucent lines or loosening. A total of 16 patients had died by five years. The cumulative survival at five years was 98.8% and the mean survival time was 5.8 years (95% confidence interval 5.6 to 5.9). A total of seven OUKAs (2.7%) were revised; three within five years and four thereafter, between 5.1 and 5.7 years post-operatively. Five (1.9%) had re-operations within five years.

Conclusion

The proportion of patients requiring revision at five years is lower than that generally reported for UKA. These findings add support for the use of the cementless OUKA outside the design centre. Longer follow-up is required. Cite this article: Bone Joint J 2017;99-B:623–31.

Correction: Interface structure, precursor rheology and dielectric properties of BaTiO3/PVDF–hfp nanocomposite films prepared from colloidal perovskite nanoparticles

Correction for ‘Interface structure, precursor rheology and dielectric properties of BaTiO₃/PVDF–hfp nanocomposite films prepared from colloidal perovskite nanoparticles’ by Y. N. Hao et al., RSC Adv., 2017, 7, 32886–32892.

Novel agents in chronic lymphocytic leukemia

The advent of novel small-molecule inhibitors has transformed the treatment approaches for patients with chronic lymphocytic leukemia (CLL). These therapies are becoming increasingly used in patients with relapsed disease, patients with 17p deletion, and, as of recently, also in the frontline setting for previously untreated patients with CLL. Moreover, many of these are oral therapies that are significantly less myelosuppressive than chemoimmunotherapy. However, these agents have their own set of unique toxicities with which providers must gain familiarity. There is also ongoing development of second-generation agents which have the promise of less toxicity than the US Food and Drug Administration (FDA)-approved compounds. In addition, immunotherapy and the role of the microenvironment are becoming increasingly important and have therapeutic implications in the treatment of patients with CLL. Ultimately, investigators need to evaluate how to position these and other new exciting therapies and decide on the ultimate role for chemoimmunotherapy in modern times.

First-line therapy for young patients with CLL

A 61-year-old man with a history of chronic lymphocytic leukemia (CLL) presents with complaints of worsening fatigue and night sweats. He was diagnosed with CLL 3 years ago on routine blood count testing. He has no major medical comorbidities. On examination, he has several 2- to 3-cm lymph nodes in the cervical and axillary area. Spleen is palpable 5 cm below the costal margin. Blood counts show lymphocytosis with thrombocytopenia and anemia. Prognostic markers include deletion 13q by fluorescence in situ hybridization analysis and mutated IGHV You are asked by the hematology fellow you are supervising about the best treatment of this patient.

Inotuzumab Ozogamicin versus Standard Therapy for Acute Lymphoblastic Leukemia

BACKGROUND

The prognosis for adults with relapsed acute lymphoblastic leukemia is poor. We sought to determine whether inotuzumab ozogamicin, an anti-CD22 antibody conjugated to calicheamicin, results in better outcomes in patients with relapsed or refractory acute lymphoblastic leukemia than does standard therapy.

METHODS

In this phase 3 trial, we randomly assigned adults with relapsed or refractory acute lymphoblastic leukemia to receive either inotuzumab ozogamicin (inotuzumab ozogamicin group) or standard intensive chemotherapy (standard-therapy group). The primary end points were complete remission (including complete remission with incomplete hematologic recovery) and overall survival.

RESULTS

Of the 326 patients who underwent randomization, the first 218 (109 in each group) were included in the primary intention-to-treat analysis of complete remission. The rate of complete remission was significantly higher in the inotuzumab ozogamicin group than in the standard-therapy group (80.7% [95% confidence interval {CI}, 72.1 to 87.7] vs. 29.4% [95% CI, 21.0 to 38.8], P<0.001). Among the patients who had complete remission, a higher percentage in the inotuzumab ozogamicin group had results below the threshold for minimal residual disease (0.01% marrow blasts) (78.4% vs. 28.1%, P<0.001); the duration of remission was longer in the inotuzumab ozogamicin group (median, 4.6 months [95% CI, 3.9 to 5.4] vs. 3.1 months [95% CI, 1.4 to 4.9]; hazard ratio, 0.55 [95% CI, 0.31 to 0.96]; P=0.03). In the survival analysis, which included all 326 patients, progression-free survival was significantly longer in the inotuzumab ozogamicin group (median, 5.0 months [95% CI, 3.7 to 5.6] vs. 1.8 months [95% CI, 1.5 to 2.2]; hazard ratio, 0.45 [97.5% CI, 0.34 to 0.61]; P<0.001); the median overall survival was 7.7 months (95% CI, 6.0 to 9.2) versus 6.7 months (95% CI, 4.9 to 8.3), and the hazard ratio was 0.77 (97.5% CI, 0.58 to 1.03) (P=0.04). In the safety population, the most frequent grade 3 or higher nonhematologic adverse events with inotuzumab ozogamicin were liver-related. Veno-occlusive liver disease of any grade occurred in 15 patients (11%) who received inotuzumab ozogamicin and in 1 patient (1%) who received standard therapy.

CONCLUSIONS

The rate of complete remission was higher with inotuzumab ozogamicin than with standard therapy, and a higher percentage of patients in the inotuzumab ozogamicin group had results below the threshold for minimal residual disease. Both progression-free and overall survival were longer with inotuzumab ozogamicin. Veno-occlusive liver disease was a major adverse event associated with inotuzumab ozogamicin. (Funded by Pfizer; INO-VATE ALL ClinicalTrials.gov number, NCT01564784.).

Pre-BCR signaling in precursor B-cell acute lymphoblastic leukemia regulates PI3K/AKT, FOXO1 and MYC, and can be targeted by SYK inhibition

Precursor-B-cell receptor (pre-BCR) signaling and spleen tyrosine kinase (SYK) recently were introduced as therapeutic targets for patients with B-cell acute lymphoblastic leukemia (B-ALL), but the importance of this pathway in B-ALL subsets and mechanism of downstream signaling have not fully been elucidated. Here, we provide new detailed insight into the mechanism of pre-BCR signaling in B-ALL. We compared the effects of pharmacological and genetic disruption of pre-BCR signaling in vitro and in mouse models for B-ALL, demonstrating exquisite dependency of pre-BCR(+) B-ALL, but not other B-ALL subsets, on this signaling pathway. We demonstrate that SYK, PI3K/AKT, FOXO1 and MYC are important downstream mediators of pre-BCR signaling in B-ALL. Furthermore, we define a characteristic immune phenotype and gene expression signature of pre-BCR(+) ALL to distinguish them from other B-ALL subsets. These data provide comprehensive new insight into pre-BCR signaling in B-ALL and corroborate pre-BCR signaling and SYK as promising new therapeutic targets in pre-BCR(+) B-ALL.

Allogeneic stem cell transplant in patients with chronic lymphocytic leukemia with 17p deletion: consult-transplant versus consult- no-transplant analysis

Allogeneic stem cell transplant (alloSCT) can overcome the adverse prognosis of chronic lymphocytic leukemia with 17p deletion (17p- CLL). However, its applicability remains unclear. Since 2007, our leukemia service has referred patients with 17p- CLL for alloSCT at presentation. In this study, the outcomes of these patients were reviewed retrospectively to determine whether they underwent alloSCT and why patients did not undergo alloSCT. Fifty-two patients with 17p- CLL who were referred to the transplant service from 2007 to 2010 were identified. Of these patients, 32 (62%) did not undergo alloSCT, mainly because of treatment- or disease-related complications (n = 15). The 2-year post-referral overall survival rates of the alloSCT and non-SCT groups were 64% and 25%, respectively (p = 0.001). These findings suggest that while alloSCT is an effective therapy in patients with 17p- CLL, pre-SCT complications may preclude a significant proportion of patients from undergoing the procedure.

Early surveillance of ceramic-on-metal total hip arthroplasty

Ceramic-on-metal (CoM) is a relatively new bearing combination for total hip arthroplasty (THA) with few reported outcomes. A total of 287 CoM THAs were carried out in 271 patients (mean age 55.6 years (20 to 77), 150 THAs in female patients, 137 in male) under the care of a single surgeon between October 2007 and October 2009. With the issues surrounding metal-on-metal bearings the decision was taken to review these patients between March and November 2011, at a mean follow-up of 34 months (23 to 45) and to record pain, outcome scores, radiological analysis and blood ion levels. The mean Oxford Hip Score was 19.2 (12 to 53), 254 patients with 268 hips (95%) had mild/very mild/no pain, the mean angle of inclination of the acetabular component was 44.8o (28o to 63o), 82 stems (29%) had evidence of radiolucent lines of > 1 mm in at least one Gruen zone and the median levels of cobalt and chromium ions in the blood were 0.83 μg/L (0.24 μg/L to 27.56 μg/L) and 0.78 μg/L (0.21 μg/L to 8.84 μg/L), respectively. The five-year survival rate is 96.9% (95% confidence interval 94.7% to 99%).

Due to the presence of radiolucent lines and the higher than expected levels of metal ions in the blood, we would not recommend the use of CoM THA without further long-term follow-up. We plan to monitor all these patients regularly.

Cite this article: Bone Joint J 2015;97-B:300–5.

Initial experience with CMC-544 (inotuzumab ozogamicin) in pediatric patients with relapsed B-cell acute lymphoblastic leukemia

Survival is poor in pediatric patients with relapsed or refractory acute B-cell lymphoblastic leukemia (ALL) and therapeutic options are limited. CMC-544 (inotuzumab ozogamicin) has shown significant activity in adult patients with relapsed and refractory ALL. We evaluated CMC-544 in pediatric patients with multiply relapsed ALL. Five children 4-15 years old with relapsed, CD 22 positive B-cell ALL were enrolled on a phase II non-randomized trial of CMC-544. CMC-544 was initially administered at 1.3 mg/m(2) every 3 weeks. The dose then increased to 1.8 mg/m(2) every 3 weeks. Subsequently, a weekly schedule of CMC-544 given as 0.8 mg/m(2) on day 1 followed by 0.5 mg/m(2) on days 8 and 15 was administered. All five patients had refractory relapsed B-cell ALL. Lymphoblasts for all patients highly expressed CD22. Four patients had two or more relapses before starting the study drug. One patient achieved a complete remission in the bone marrow and normal peripheral counts, and two patients achieved bone marrow morphologic remission with absolute neutrophils >1,000/µl but platelets <100,000/µl. Two patients had no response to the drug. Toxicities consisted of fever, sepsis, and liver enzyme elevation. Single agent CMC-544 given at the single dose of 1.8 mg/m(2) every 3 weeks or given as a split, weekly dose was generally well tolerated considering the inherent risks in this population of patients and showed promising activity in pediatric patients with relapsed and refractory ALL.

The PI3-kinase delta inhibitor idelalisib (GS-1101) targets integrin-mediated adhesion of chronic lymphocytic leukemia (CLL) cell to endothelial and marrow stromal cells

CLL cell trafficking between blood and tissue compartments is an integral part of the disease process. Idelalisib, a phosphoinositide 3-kinase delta (PI3Kδ) inhibitor causes rapid lymph node shrinkage, along with an increase in lymphocytosis, prior to inducing objective responses in CLL patients. This characteristic activity presumably is due to CLL cell redistribution from tissues into the blood, but the underlying mechanisms are not fully understood. We therefore analyzed idelalisib effects on CLL cell adhesion to endothelial and bone marrow stromal cells (EC, BMSC). We found that idelalisib inhibited CLL cell adhesion to EC and BMSC under static and shear flow conditions. TNFα-induced VCAM-1 (CD106) expression in supporting layers increased CLL cell adhesion and accentuated the inhibitory effect of idelalisib. Co-culture with EC and BMSC also protected CLL from undergoing apoptosis, and this EC- and BMSC-mediated protection was antagonized by idelalisib. Furthermore, we demonstrate that CLL cell adhesion to EC and VLA-4 (CD49d) resulted in the phosphorylation of Akt, which was sensitive to inhibition by idelalisib. These findings demonstrate that idelalisib interferes with integrin-mediated CLL cell adhesion to EC and BMSC, providing a novel mechanism to explain idelalisib-induced redistribution of CLL cells from tissues into the blood.

Decitabine can be safely reduced after achievement of best objective response in patients with myelodysplastic syndrome

BACKGROUND

Decitabine is standard therapy in patients with myelodysplastic syndrome (MDS). Current recommendations suggest a dose of 20 mg/m(2) intravenously (IV) daily for 5 days every 4 weeks. However, this therapy is associated with frequent grade 3/4 hematologic toxicity, requiring dose delays and/or dose reductions (DD/DR).

RESULTS

We investigated the outcomes of 122 patients with MDS who had DD/DR of frontline decitabine therapy. Sixty-five patients (53%) had DR by at least 25% or DD (defined as a delay beyond 5 weeks between cycles). Thirty-five patients (29%) underwent DD/DR after achieving best objective response, 30 patients (25%) underwent DD/DR before best objective response, and 57 (54%) patients had no DD/DR. There was a trend for more durable responses in favor of patients requiring DD/DR after the achievement of best objective response (median not reached) (P = .161). Overall survival rates were significantly higher for patients who had DD/DR after best objective response compared with those who had DD/DR before best objective response or those with no DD/DR (30 vs. 22 vs. 11 months, respectively; P < .001). Progression-free survival (PFS) rates also trended higher for those with DD/DR after best objective response (median not reached) compared with those who required DD/DR before best objective response (median of 15 months) (P = .285).

CONCLUSION

DD/DR may be safely accomplished once the patient has achieved best objective response (preferably complete remission [CR]) without impacting outcome. Prospective evaluation of an approach conceived of a loading dose for induction of a best objective response followed by a maintenance schedule is to be considered.

Novel therapeutic strategies in adult acute lymphoblastic leukemia--a focus on emerging monoclonal antibodies

The outcomes in adult B-cell acute lymphoblastic leukemia (ALL) remain inferior to those achieved in pediatric populations. Targeted therapy with monoclonal antibodies may improve outcomes in adult B-cell ALL without significant additive toxicity. Rituximab is the best known monoclonal antibody and is routinely used in combination chemo-immunotherapy for treatment of adult B-cell ALL and Burkitts leukemia. A number of other monoclonal antibodies are currently under investigation for treatment of adult B-cell ALL including unconjugated antibodies (eg., ofatumumab, alemtuzumab and epratuzumab), antibodies conjugated to cytotoxic agents (eg., inotuzumab ozogamycin and SAR3419), antibodies conjugated to toxins such Pseudomonas or Diptheria toxins (eg., BL22 and moxetumomab pasudotox), and T-cell engaging bi-specific antibodies that redirect cytotoxic T lymphocytes to lyse target ALL cells (eg., blinatumomab). In this article we review the therapeutic implications, current status and results of monoclonal antibody-based therapy in adult B-cell ALL.

Rapid detection and quantitation of BRAF mutations in hairy cell leukemia using a sensitive pyrosequencing assay

BRAF protooncogene is an important mediator of cell proliferation and survival signals. BRAF p.V600E mutation was recently described as a molecular marker of hairy cell leukemia (HCL). We developed and validated a pyrosequencing-based approach that covers BRAF mutational hotspots in exons 11 (codon 468) and 15 (codons 595 to 600). The assay detects BRAF mutations at an analytical sensitivity of 5%. We screened 16 unenriched archived bone marrow aspirate samples from patients with a diagnosis of HCL (n = 12) and hairy cell leukemia-variant (HCL-v) (n = 4) using pyrosequencing. BRAF p.V600E mutation was present in all HCL cases and absent in all HCL-v. Our data support the recent finding that BRAF p.V600E mutation is universally present in HCL. Moreover, our pyrosequencing-based assay provides a convenient, rapid, sensitive, and quantitative tool for the detection of BRAF p.V600E mutations in HCL for clinical diagnostic testing.

Outcome of patients with chronic myeloid leukemia with multiple ABL1 kinase domain mutations receiving tyrosine kinase inhibitor therapy

We investigated the impact of carrying more than one BCR-ABL1 mutation in 207 patients with chronic myeloid leukemia (102 chronic, 61 accelerated, and 44 blast phase) post-imatinib failure. Seven (8%) of 92 patients carrying mutations had more than one mutation: 4 (4%) in chronic phase, 2 (2%) in accelerated phase, and one (1 %) in blast phase. The cytogenetic response rate to second generation TKIs for patients with no, one, or more than one mutation was 88%, 69%, 50% (P=0.03) in chronic phase, 54%, 42%, 50% in accelerated phase (P=0.67), and 35%, 25%, 0% (P=0.63) in blast phase, respectively. No differences were observed in event free survival or overall survival in accelerated or blast phase according to their mutational status. However, the 4-year event free survival rates among patients in chronic phase with no, one, or more than one BCR-ABL1 mutation were 56%, 49%, and 0%, respectively (P=0.02), with overall survival rates of 91%, 69%, and 75%, respectively (P=0.13). In conclusion, patients with more than one BCR-ABL1 mutation fare worse than those with no or one mutation.