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Ketterling, Rhett P

0000-0001-6479-7897

Mayo Clinic

Division of Laboratory Genetics and Genomics, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.

Citations 73

Calreticulin variant stratified driver mutational status and prognosis in essential thrombocythemia

American Journal of Hematology | February 19, 2016 | Volume: 91 | Issue: 5 | Pages: 503-506

10.1002/ajh.24338 | PMID 26890983

About 85% of patients with essential thrombocythemia (ET) harbor one of three driver mutations: JAK2, calreticulin (CALR), and MPL; the remaining ( ∼15%) are wild type for all three mutations and are referred to as being “triple negative.” Furthermore, CALR mutations in ET are structurally classified as type 1/type 1‐like or type 2/type 2‐like variants. The objective of the current study was to examine the impact of CALR mutation variant stratified driver mutational status on overall (OS), myelofibrosis‐free (MFFS), thrombosis‐free, and leukemia‐free survival (LFS) in ET; 495 patients (median age 58 years; 61% females) with ET were fully annotated for the their driver mutational status: 321 (65%) harbored JAK2, 109 (22%) CALR, and 12 (2%) MPL mutations and 11% were triple‐negative. Among the 109 CALR‐mutated cases, 52% were classified as type 1/type 1‐like and 48% as type 2/type 2‐like. In univariate analysis, triple‐negative patients displayed the best and MPL mutated the worst OS (P = 0.007); however, the difference in OS was no longer apparent on multivariable analysis that included age and sex as covariates (P = 0.5). LFS was also similar among the different mutational groups (P = 0.6) whereas MFFS was significantly shorter in MPL‐mutated patients on both univariate and multivariable analyses (age‐adjusted P = 0.02; HR 7.9, 95% CI 2.0–31.5). Also in multivariable analysis that included thrombosis history, age, and cardiovascular risk factors, the presence of JAK2 or MPL mutations was independently associated with higher risk of thrombosis (P = 0.02; HR 1.9, 95% CI 1.1–3.4). In conclusion, driver mutational status in ET does not appear to influence overall or LFS, even after CALR variant stratification. However, the presence of MPL mutations might be associated with a higher risk of fibrotic transformation and the presence of JAK2/MPL mutations with higher risk of thrombosis. Am. J. Hematol. 91:503–506, 2016. © 2016 Wiley Periodicals, Inc.
Predictors of survival in refractory anemia with ring sideroblasts and thrombocytosis (RARS‐T) and the role of next‐generation sequencing

American Journal of Hematology | February 14, 2016 | Volume: 91 | Issue: 5 | Pages: 492-498

10.1002/ajh.24332 | PMID 26874914

Refractory anemia with ring sideroblasts and thrombocytosis (RARS‐T) shares overlapping features of myelodysplastic syndromes (MDS) and myeloproliferative neoplasms (MPN). RARS‐T is characterized by SF3B1 and JAK2 mutations and prognosis is considered to be better than MDS but not as good as MPN. The objective of the study was to identify predictors of survival in RARS‐T. We analyzed clinical and laboratory variables in 82 patients and applied a 27‐gene NGS assay to 48 marrow samples obtained at diagnosis. 94% of patients had ≥1 mutations; common mutations being: SF3B1 85%, JAK2 V617F 33%, ASXL1 29%, DNMT3A 13%, SETBP1 13% and TET2 10%. In a multivariable survival analysis ( n = 82), anemia ( P = 0.02) [HB< 10 gm/dl: HR 2.3, 95% CI 1.2–4.6] and abnormal karyotype ( P =.01) [HR 6.1, 95% CI 2.7‐13.8] were independently prognostic for inferior survival. In patients with NGS information ( n = 48), univariate analysis showed association between poor survival and presence of SETBP1 ( P = 0.04) or ASXL1 ( P = 0.08) mutations whereas the absence of these mutations ( ASXL1 wt/ SETBP1 wt) was favorable ( P = 0.04); the number of concurrent mutations did not provide additional prognostication ( P = 0.3). We developed a HR‐weighted prognostic model, with 2 points for an abnormal karyotype, 1 point for either ASXL1 and/or SETBP1 mutations, and 1 point for a HB level < 10 gm/dl, which effectively stratified patients into three risk categories; low (0 points), intermediate (1 point) and high (≥2 points), with median survivals of 80, 42 and 11 months respectively ( P = 0.01). In summary, we confirm the unique mutational landscape in RARS‐T and provide a novel mutation‐enhanced prognostic model. Am. J. Hematol. 91:492–498, 2016. © 2016 Wiley Periodicals, Inc.
Benefit of high-dose daunorubicin in AML induction extends across cytogenetic and molecular groups

Blood | January 11, 2016 | Volume: 127 | Issue: 12 | Pages: 1551-1558

10.1182/blood-2015-07-657403 | PMID 26755712

Key Points High-dose daunorubicin benefits AML patients with favorable and intermediate cytogenetics and with FLT3-ITD, NPM1, and DNMT3A mutations. High-dose daunorubicin is required for the favorable impact of the NPM1 mutation in AML.
A phase II randomized trial comparing standard and low dose rituximab combined with alemtuzumab as initial treatment of progressive chronic lymphocytic leukemia in older patients: a trial of the ECOG‐ACRIN cancer research group (E1908)

American Journal of Hematology | December 11, 2015 | Volume: 91 | Issue: 3 | Pages: 308-312

10.1002/ajh.24265 | PMID 26662208

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL) patients requiring initial therapy are often older and frailer and unsuitable candidates for standard chemoimmunotherapy regimens. Shorter duration combination monoclonal antibody (mAb) therapy using alemtuzumab and rituximab has been shown to be effective and tolerable treatment for CLL. Standard dose anti‐CD20 mAb therapy causes loss of CD20 expression by surviving CLL cells, which can be minimized by decreasing the mAb dose. We report a randomized phase II clinical trial enrolling older (≥ 65 years) patients (median age 76 years, n = 31) with treatment naïve progressive CLL. Patients received 8‐12 weeks of standard subcutaneous alemtuzumab with either intravenous standard (375 mg/m2 weekly)(n = 16) or low dose (20 mg/m2 3x week)(n = 15) rituximab. This study was closed before full accrual because the manufacturer withdrew alemtuzumab for treatment of CLL. The overall response rate was 90% with an 45% complete response rate, median progression‐free survival of 17.9 months and no significant differences in outcome between the low and standard dose rituximab arms. The major toxicities were cytopenia and infection with one treatment fatality caused by progressive multifocal leukoencephalopathy but no other opportunistic infections. Combination mAb therapy was effective and tolerable treatment for older and frailer patients with progressive CLL, achieving a high rate of complete remissions. These data support the role of mAb in therapy for less fit CLL patients and the further study of low dose higher frequency anti‐CD20 mAb therapy as a potentially more effective use of anti‐CD20 mAb in the treatment of CLL. Am. J. Hematol. 91:308–312, 2016. © 2015 Wiley Periodicals, Inc.
ASXL1 and CBL mutations are independently predictive of inferior survival in advanced systemic mastocytosis

British Journal of Haematology | December 2, 2015 | Volume: 175 | Issue: 3 | Pages: 534-536

10.1111/bjh.13865 | PMID 26628266

Azacitidine with or without Entinostat for the treatment of therapy‐related myeloid neoplasm: further results of the E1905 North American Leukemia Intergroup study

British Journal of Haematology | November 18, 2015 | Volume: 172 | Issue: 3 | Pages: 384-391

10.1111/bjh.13832 | PMID 26577691

AbstractTherapy‐related myeloid neoplasms (tMN) are serious late effects of the treatment of cancer with poor response to conventional treatment. Azacitidine (AZA) has been used to treat patients with tMN but current data are retrospective. We present here 47 tMN patients prospectively enrolled as a specific cohort in the E1905 study. TheE1905 study was a randomized phase 2 study (NCT00313586) testing 10 d of AZA (50 mg/m2/d) +/− the histone deacetylase inhibitor entinostat (4 mg/m2/d PO day‐3 and day‐10). A total of 47 patients [29 therapy‐related myelosyspastic syndrome (t‐MDS) and 18 therapy‐related acute myeloid leukaemia (t‐AML)] were recruited to the study. 24 patients were treated with AZA monotherapy and 23 with AZA+entinostat. The median number of administered cycles was 4, significantly higher in patients treated with AZA (6 cycles vs. 3 cycles, P = 0·008). Haematological normalization rates were 46% in monotherapy and 17% in the combination arm. Median overall survivals were 13 and 6 months, respectively. The novel 50 * 10 schedule of azacitidine appears effective, with response rates, when given as single agent, comparable to those for patients with de novo MDS/AML treated on the same protocol. However, the combination of AZA and entinostat was associated with increased toxicity and could not be recommended for treatment of tMN.
Morphologically Occult Systemic Mastocytosis in Bone Marrow

American Journal of Clinical Pathology | August 14, 2015 | Volume: 144 | Issue: 3 | Pages: 493-502

10.1309/ajcpsgq71gjqqacl | PMID 26276780

Concurrent activating KIT mutations in systemic mastocytosis

British Journal of Haematology | June 16, 2015 | Volume: 173 | Issue: 1 | Pages: 153-156

10.1111/bjh.13560 | PMID 26080027

Conventional Karyotyping and Fluorescence In Situ Hybridization

American Journal of Clinical Pathology | May 13, 2015 | Volume: 143 | Issue: 6 | Pages: 873-878

10.1309/ajcpp6lvmqg4lnck | PMID 25972330

The oncogenic transcription factor IRF4 is regulated by a novel CD30/NF-κB positive feedback loop in peripheral T-cell lymphoma

Blood | April 2, 2015 | Volume: 125 | Issue: 20 | Pages: 3118-3127

10.1182/blood-2014-05-578575 | PMID 25833963

Key PointsThe NF-κB subunits p52 and RelB increase IRF4 promoter activity and expression in PTCL cells. A positive feedback loop involving CD30, NF-κB, and IRF4 drives PTCL cell proliferation and can be blocked by NF-κB inhibitors.