Sa A. Wang

Inotuzumab ozogamicin, an anti-CD22–calecheamicin conjugate, for refractory and relapsed acute lymphocytic leukaemia: a phase 2 study

BACKGROUND The outlook for patients with refractory and relapsed acute lymphocytic leukaemia (ALL) is poor. CD22 is highly expressed in patients with ALL. Inotuzumab ozogamicin is a CD22 monoclonal antibody conjugated to the toxin calecheamicin. We did a phase 2 study to assess the efficacy of this antibody. METHODS We recruited patients at the MD Anderson Cancer Center, Houston, TX, USA, between June, 2010, and March, 2011. Adults and children with refractory and relapsed ALL were eligible. Ten adults were treated before enrolment of children started. Patients were given 1·8 mg/m(2) inotuzumab ozogamicin intravenously over 1 h every 3-4 weeks (the first three adults and three children received 1·3 mg/m(2) in the first course). The primary endpoint was overall response (complete response or marrow complete response with no recovery of platelet count or incomplete recovery of neutrophil and platelet counts). Analysis was done by intention to treat. This study is registered, number NCT01134575. FINDINGS 49 patients were enrolled and treated. Median age was 36 years (range 6-80). CD22 was expressed in more than 50% of blasts in all patients. The median number of courses was two (range one to five) and the median time between courses was 3 weeks (range 3-6). Nine (18%) patients had complete response, 19 (39%) had marrow complete response, 19 (39%) had resistant disease, and two (4%) died within 4 weeks of starting treatment. The overall response rate was 57% (95% CI 42-71). The most frequent adverse events during course one of treatment were fever (grade 1-2 in 20 patients, grade 3-4 in nine), hypotension (grade 1-2 in 12 patients, grade 3 in one), and liver-related toxic effects (bilirubin: grade 1-2 in 12 patients, grade 3 in two; raised aminotransferase concentration: grade 1-2 in 27 patients, grade 3 in one). INTERPRETATION Inotuzumab ozogamicin shows promise as a treatment for refractory and relapsed ALL. FUNDING Pfizer.

Detection of MRD may predict the outcome of patients with Philadelphia chromosome–positive ALL treated with tyrosine kinase inhibitors plus chemotherapy

From 2001 to 2011, 122 patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia were treated with chemotherapy + imatinib (n = 54) or + dasatinib (n = 68). One hundred fifteen (94%) achieved complete remission (CR) including 101 patients who achieved it with only 1 induction course and had at least 1 minimal residual disease (MRD) assessment; 25 patients underwent an allogeneic stem cell transplant in first CR and were excluded, leaving 76 patients as the subject of this report. MRD monitoring by multiparameter flow cytometry (MFC) and real-time quantitative polymerase chain reaction (PCR) was performed at the end of induction and at ~3-month intervals thereafter. Median age was 54 years (range, 21-84 years). There was no difference in survival by achievement of at least a major molecular response (MMR; BCR-ABL/ABL < 0.1%) at CR (P = .22). Patients achieving MMR at 3, 6, 9, and 12 months had a better survival (P = .02, .04, .05, and .01, respectively). Negative MFC at CR did not predict for improved survival (P = .2). At 3 and 12 months, negative MRD by MFC was associated with improved survival (P = .04 and .001). MRD monitoring by PCR and MFC identifies patients who benefit from treatment intensification in first CR.

Donor-specific anti-HLA Abs and graft failure in matched unrelated donor hematopoietic stem cell transplantation.

Anti-HLA donor-specific Abs (DSAs) have been reported to be associated with graft failure in mismatched hematopoietic stem cell transplantation; however, their role in the development of graft failure in matched unrelated donor (MUD) transplantation remains unclear. We hypothesize that DSAs against a mismatched HLA-DPB1 locus is associated with graft failure in this setting. The presence of anti-HLA Abs before transplantation was determined prospectively in 592 MUD transplantation recipients using mixed-screen beads in a solid-phase fluorescent assay. DSA identification was performed using single-Ag beads containing the corresponding donors HLA-mismatched Ags. Anti-HLA Abs were detected in 116 patients (19.6%), including 20 patients (3.4%) with anti-DPB1 Abs. Overall, graft failure occurred in 19 of 592 patients (3.2%), including 16 of 584 (2.7%) patients without anti-HLA Abs compared with 3 of 8 (37.5%) patients with DSA (P = .0014). In multivariate analysis, DSAs were the only factor highly associated with graft failure (P = .0001; odds ratio = 21.3). Anti-HLA allosensitization was higher overall in women than in men (30.8% vs 12.1%; P < .0001) and higher in women with 1 (P = .008) and 2 or more pregnancies (P = .0003) than in men. We conclude that the presence of anti-DPB1 DSAs is associated with graft failure in MUD hematopoietic stem cell transplantation.

Lobular intraepithelial neoplasia [lobular carcinoma in situ] with comedo-type necrosis: A clinicopathologic study of 18 cases.

The recent finding that lobular, and not ductal intraepithelial neoplasia (DIN) displays loss of E-cadherin expression has greatly facilitated the categorization of a large proportion of morphologically ambiguous intraepithelial neoplasias into ductal or lobular types. One reason for such morphologic ambiguity is the presence of comedo-type necrosis within an intraepithelial lesion that otherwise shows archetypal cytologic and architectural features of lobular intraepithelial neoplasia (LIN). The clinicopathologic features of 18 such cases are described in this report. These 18 cases of classic LIN were accumulated from the recent databases of 6 institutions. All cases, by definition, showed no expression of E-cadherin. The 18 patients, all women, were 41 to 85 years of age (mean 61.3). The lesions were initially identified in an excisional biopsy or mastectomy in 12 cases and in an incisional/core biopsy in the remaining 6 cases. An associated invasive carcinoma was present in 12 (67%) of 18 cases (7 classic lobular, 1 pleomorphic lobular, 1 ductal, 1 mixed lobular and ductal, 1 tubular, and 1 case with ductal and lobular carcinomas as separate foci). The average age of the 6 patients with pure LIN (ie, LIN without an invasive component (62.5 y) was not significantly different from the 12 patients in which there was an invasive component (60.7 y) (P=0.78). The lesions had associated calcifications, typically within the necrotic foci, in 10 (55%) of 18 cases. Immunoreactivity for estrogen receptor, progesterone receptor (in >10% of lesional cells), and high-molecular weight keratin was present in 17/18 (94%), 15/18 (83%) and 17/18 (94%) of cases, respectively. Overexpression of HER2/neu, as assessed immunohistochemically, was absent in all 15 cases available for such evaluation. Foci of DIN, separate from the lobular lesions, were present in 6 (33%) of 18 cases. LIN with necrosis seems to occur at an older age than classic LIN, is commonly associated with invasive carcinoma and is significantly more frequently associated with lobular than ductal invasive carcinoma. When present without an invasive component, it may be mistaken for DIN 2 (grade 2 ductal carcinoma in situ). Although the necrosis suggests a ductal phenotype for these intraepithelial proliferations, architectural and cytologic features, high-molecular weight keratin[+], estrogen receptor[+], progesterone receptor[+], and human epidermal growth factor receptor 2 /neu[−] immunoprofile, frequent association with invasive lobular carcinoma, and lack of immunoreactivity for E-cadherin, strongly suggests that these lesions are within the morphologic spectrum of lobular neoplasia. Long-term follow-up studies are required to define the true natural history of these lesions. However, because classic LIN with necrosis is apparently rare in its pure form, reexcision is recommended when this lesion is detected in isolation in a core biopsy.

Cytogenetic Abnormalities in a Series of 1029 Patients With Primary Myelodysplastic Syndromes A Report From the US With a Focus on Some Undefined Single Chromosomal Abnormalities

Conventional karyotype has an established role in myelodysplastic syndrome (MDS) and is included in the International Prognostic Scoring System (IPSS) for patient risk stratification and treatment selection. Although some chromosomal abnormalities have been well characterized, the significance of several miscellaneous, infrequent, single chromosomal abnormalities remains to be defined. In addition, the emerging therapeutic agents may change the natural course of disease in patients with MDS and the cytogenetic impact on risk stratification.

Atypical chronic myeloid leukemia is clinically distinct from unclassifiable myelodysplastic/myeloproliferative neoplasms

Atypical chronic myeloid leukemia (aCML) is a rare subtype of myelodysplastic/myeloproliferative neoplasm (MDS/MPN) largely defined morphologically. It is, unclear, however, whether aCML-associated features are distinctive enough to allow its separation from unclassifiable MDS/MPN (MDS/MPN-U). To study these 2 rare entities, 134 patient archives were collected from 7 large medical centers, of which 65 (49%) cases were further classified as aCML and the remaining 69 (51%) as MDS/MPN-U. Distinctively, aCML was associated with many adverse features and an inferior overall survival (12.4 vs 21.8 months, P = .004) and AML-free survival (11.2 vs 18.9 months, P = .003). The aCML defining features of leukocytosis and circulating myeloid precursors, but not dysgranulopoiesis, were independent negative predictors. Other factors, such as lactate dehydrogenase, circulating myeloblasts, platelets, and cytogenetics could further stratify MDS/MPN-U but not aCML patient risks. aCML appeared to have more mutated RAS (7/20 [35%] vs 4/29 [14%]) and less JAK2p.V617F (3/42 [7%] vs 10/52 [19%]), but was not statistically significant. Somatic CSF3R T618I (0/54) and CALR (0/30) mutations were not detected either in aCML or MDS/MPN-U. In conclusion, within MDS/MPN, the World Health Organization 2008 criteria for aCML identify a subgroup of patients with features clearly distinct from MDS/MPN-U. The MDS/MPN-U category is heterogeneous, and patient risk can be further stratified by a number of clinicopathological parameters.

Acute erythroid leukemia: a reassessment using criteria refined in the 2008 WHO classification

Acute erythroid leukemia (AEL) is a rare type of acute myeloid leukemia (AML) for which diagnostic criteria have been refined in the 2008 World Health Organization (WHO) classification of AML. The relationship of AEL to myelodysplastic syndromes (MDSs) and to AML with myelodysplasia-related changes (AML-MRC) is not clearly defined. We conducted a retrospective, multi-institutional study of patients with AEL and compared them with patients with MDS or AML-MRC with erythroid hyperplasia (> or = 50% erythroid cells). Among a total of 124 patients with AEL, 32% had a history of MDS or chronic cytopenia, 32% had therapy-related disease, and 35% had de novo disease. Sixty-four percent of patients had unfavorable AML risk-group karyotypes. FLT3 and RAS mutations were infrequent, occurring in 6% and 2%, respectively. The median overall survival (OS) of all AEL patients was 8 months, comparable with that of patients with MDS or AML-MRC with erythroid hyperplasia. The OS was related to cytogenetic risk group, but not blast count or morphologic dysplasia. Our findings suggest that AEL is in the continuum of MDS and AML with erythroid hyperplasia, where karyotype rather than an arbitrary blast cutoff represents the most important prognostic factor.

Low histologic grade follicular lymphoma with high proliferation index: Morphologic and clinical features

Histologic grading has been used as a guide for clinical management in follicular lymphoma (FL). Proliferation index (PI) of FL generally correlates with tumor grade; however, in cases of discordance, it is not clear whether histologic grade or PI correlates with clinical aggressiveness. To objectively evaluate these cases, we determined PI by Ki-67 immunostaining in 142 cases of FL (48 grade 1, 71 grade 2, and 23 grade 3). A total of 24 cases FL with low histologic grade but high PI (LG-HPI) were identified, a frequency of 18%. On histologic examination, LG-HPI FL often exhibited blastoid features. Patients with LG-HPI FL had inferior disease-specific survival but a higher 5-year disease-free rate than low-grade FL with concordantly low PI (LG-LPI). However, transformation to diffuse large B-cell lymphoma was uncommon in LG-HPI cases (1 of 19; 5%) as compared with LG-LPI cases (27 of 74; 36%). In conclusion, LG-HPI FL appears to be a subgroup of FL with clinical behavior more akin to grade 3 FL. We propose that these LG-HPI FL cases should be classified separately from cases of low histologic grade FL with concordantly low PI.

Detection of paroxysmal nocturnal hemoglobinuria clones in patients with myelodysplastic syndromes and related bone marrow diseases, with emphasis on diagnostic pitfalls and caveats

This study shows that paroxysmal hemoglobinuria clones can be found in many patients with low risk myelodysplastic syndromes. See related perspective article on page 3. Background The presence of paroxysmal nocturnal hemoglobinuria clones in the setting of aplastic anemia or myelodysplastic syndrome has been shown to have prognostic and therapeutic implications. However, the status of paroxysmal nocturnal hemoglobinuria clones in various categories of myelodysplastic syndrome and in other bone marrow disorders is not well-studied. Design and Methods By using multiparameter flow cytometry immunophenotypic analysis with antibodies specific for four glycosylphosphatidylinositol-anchored proteins (CD55, CD59, CD16, CD66b) and performing an aerolysin lysis confirmatory test in representative cases, we assessed the paroxysmal nocturnal hemoglobinuria-phenotype granulocytes in 110 patients with myelodysplastic syndrome, 15 with myelodysplastic/myeloproliferative disease, 5 with idiopathic myelofibrosis and 6 with acute myeloid leukemia. Results Paroxysmal nocturnal hemoglobinuria-phenotype granulocytes were detected in nine patients with low grade myelodysplastic syndrome who showed clinicopathological features of bone marrow failure, similar to aplastic anemia. All paroxysmal nocturnal hemoglobinuria-positive cases demonstrated loss of the four glycosylphosphatidylinositol-anchored proteins, with CD16−CD66b− clones being larger than those of CD55−CD59− (p<0.05). Altered glycosylphosphatidylinositol-anchored protein expression secondary to granulocytic hypogranulation, immaturity, and/or immunophenotypic abnormalities was present in a substantial number of cases and diagnostically challenging. Conclusions These results show that routine screening for paroxysmal nocturnal hemoglobinuria clones in patients with an intrinsic bone marrow disease who show no clinical evidence of hemolysis has an appreciable yield in patients with low grade myelodysplastic syndromes. The recognition of diagnostic caveats and pitfalls associated with the underlying intrinsic bone marrow disease is essential in interpreting paroxysmal nocturnal hemoglobinuria testing correctly. In our experience, the CD16/CD66b antibody combination is superior to CD55/CD59 in screening for subclinical paroxysmal nocturnal hemoglobinuria because it detects a large clone size and is less subject to analytical interference.

Toll-like receptor alterations in myelodysplastic syndrome

Recent studies have implicated the innate immunity system in the pathogenesis of myelodysplastic syndromes (MDS). Toll-like receptor (TLR) genes encode key innate immunity signal initiators. We recently identified multiple genes, known to be regulated by TLRs, to be overexpressed in MDS bone marrow (BM) CD34+ cells, and hypothesized that TLR signaling is abnormally activated in MDS. We analyzed a large cohort of MDS cases and identified TLR1, TLR2 and TLR6 to be significantly overexpressed in MDS BM CD34+ cells. Deep sequencing followed by Sanger resequencing of TLR1, TLR2, TLR4 and TLR6 genes uncovered a recurrent genetic variant, TLR2-F217S, in 11% of 149 patients. Functionally, TLR2-F217S results in enhanced activation of downstream signaling including NF-κB activity after TLR2 agonist treatment. In cultured primary BM CD34+ cells of normal donors, TLR2 agonists induced histone demethylase JMJD3 and interleukin-8 gene expression. Inhibition of TLR2 in BM CD34+ cells from patients with lower-risk MDS using short hairpin RNA resulted in increased erythroid colony formation. Finally, RNA expression levels of TLR2 and TLR6, as well as presence of TLR2-F217S, are associated with distinct prognosis and clinical characteristics. These findings indicate that TLR2-centered signaling is deregulated in MDS, and that its targeting may have potential therapeutic benefit in MDS.