Roberto Cairoli

Alemtuzumab As Consolidation After a Response to Fludarabine Is Effective in Purging Residual Disease in Patients With Chronic Lymphocytic Leukemia

PURPOSE Treatment with alemtuzumab has resulted in negative responses for minimal residual disease (MRD) in patients with chronic lymphocytic leukemia (CLL). In a prior analysis we demonstrated that it is possible to achieved MRD negativity, as assessed by polyclonality of immunoglobulin heavy chain after consolidation with alemtuzumab. This phase II study evaluated 34 patients with CLL who received alemtuzumab consolidation in an effort to improve the quality of their response to fludarabine-based induction. Subsequent peripheral blood stem-cell (PBSC) collection and transplantation, tolerability, and pharmacokinetics also were assessed. PATIENTS AND METHODS Thirty-four patients younger than 65 years who had a clinical response to fludarabine-based induction therapy received alemtuzumab 10 mg subcutaneously three times per week for 6 weeks. PBSCs were collected after mobilization with cytarabine and granulocyte colony-stimulating factor. Blood samples for pharmacokinetics study were taken between days 1 and 31. RESULTS The complete response rate improved from 35% after fludarabine induction to 79.4% after alemtuzumab consolidation, including 19 patients (56%) who achieved MRD negativity. The most common adverse events were injection-site reactions and fever. Cytomegalovirus reactivation occurred in 18 patients, all of whom were successfully treated with oral ganciclovir. PBSC collection was successful in 24 (92%) of 26 patients, and 18 patients underwent autologous PBSC transplantation. Alemtuzumab plasma concentrations increased gradually during the first 2 weeks and accumulated more rapidly thereafter. CONCLUSION Subcutaneously administered alemtuzumab was effective, safe, and well tolerated as consolidation therapy in patients with CLL who responded to fludarabine induction therapy. Subsequent PBSCT was feasible thereafter.

Trisomy 4 Leading to Duplication of a Mutated KIT Allele in Acute Myeloid Leukemia with Mast Cell Involvement

A G-->T transversion at nucleotide 2467 of the c-KIT gene leading to Asp816-->Tyr (D816Y) substitution in the phosphotransferase domain has been previously identified in a patient with rapidly progressing AML-M2 and mast cell involvement; the patients blasts had a 47,XY, +4,t(8;21)(q22;q22) karyotype. Herein we confirm the simultaneous presence of both major chromosomal changes by multicolor fluorescence in situ hybridization (FISH) on interphase CD34+ mononuclear cells. By setting up culture leukemic blasts, spontaneous differentiation of adherent cells with mast-cell like features was proved by histochemical and immunoenzymatic analyses. Fluorescence in situ hybridization evidence of trisomy 4 confirmed the origin of differentiated cells from the leukemic blasts. Semiquantitative polymerase chain reaction (PCR) and phosphoimage densitometry of wild-type and mutated KIT alleles on bone marrow blasts made it possible to demonstrate that chromosome 4 trisomy led to a double dosage of the mutated KIT allele. This finding, and that of trisomy 7 and MET mutation in hereditary renal carcinoma represent the only cases of human tumors in which an increased number of chromosomes carrying an oncogene activated by point mutation have been detected.

Immunochemotherapy with in vivo purging and autotransplant induces long clinical and molecular remission in advanced relapsed and refractory follicular lymphoma

BACKGROUND To evaluate the clinical outcome of patients with relapsed or refractory follicular lymphoma treated with immunochemotherapy, in vivo purging and high-dose therapy with autotransplant. PATIENTS AND METHODS Sixty-four patients were enrolled in the trial. Primary end point was progression-free survival (PFS). Secondary end points were the in vivo purging effect on stem-cell harvest and the impact of molecular response on the outcome. RESULTS At enrollment, 59% of patients were PCR+ for bcl-2 rearrangement in bone marrow (PCR-informative). After the immunochemotherapy, before mobilization, 97% obtained complete response or partial response and 87% of patients informative for bcl-2 were molecularly negative. Sixty-one patients proceeded to in vivo purging and peripheral blood stem cell (PBSC) mobilization with rituximab and high-dose AraC. The median number of CD34+ cells collected was 16.6 x 10(6)/kg. Of 33 PCR-informative patients, the harvests resulted in PCR- in all. Fifty-eight patients received high-dose therapy and autotransplant of in vivo purged PBSC. After a median follow-up of 3.5 years, 41 patients are in complete remission. Five-year PFS is 59%. CONCLUSION This study demonstrates that patients with advanced relapsed or refractory follicular lymphoma treated with immunochemotherapy, in vivo purging and autotransplant may obtain long-lasting PFS. In bcl-2-positive patients, in vivo purging allows the harvest of lymphoma-free PBSC. Absence of the bcl-2 rearrangement after autotransplant is associated with persistent clinical remission.

Prognostic value of circulating CD34+ cells in myelodysplastic syndromes.

We studied circulating (C)CD34(+) cells by flow cytometry in 96 patients with myelodysplastic syndromes (MDS) at diagnosis, and in a subset of 35 cases during follow-up. CCD34(+) counts were stratified within both International Prognostic Scoring System (IPSS) and World Health Organization (WHO) categories. Counts >10/microl were associated with poorer leukemia-free survival, a prognostic value for evolution independent from that of WHO, and a higher progression probability within intermediate-risk IPSS and WHO classes. When serial measurements were performed, counts >10/microl more frequently correlated to evolution. Separating newly diagnosed patients on the basis of 10/microl cut-off of circulating CD34(+) cells retains prognostic utility, especially in intermediate-risk MDS.

Identification of hematopoietic progenitor cell donor characteristics predicting successful mobilization: results of an Italian multicenter study

Peripheral blood (PB) hematopoietic progenitor cells (HPC) collected by apheresis are the first‐choice source for allogeneic stem cell transplantation. The target HPC dose is usually considered to be 4 × 106 CD34+ cells/kg of the recipient, but higher doses are required in reduced‐intensity conditioning and haploidentical transplants. Thus, prolonged stimulation and repeated collections or failure to reach HPC target may occur, increasing risks for donors and recipients. We carried out a retrospective multicenter study on healthy donors, to identify donor variables which may correlate with HPC mobilization.

Old and new prognostic factors in acute myeloid leukemia with deranged core-binding factor beta

Acute myeloid leukemia (AML) with deranged core‐binding factor beta (CBFβ) is usually associated with a favorable prognosis with 50–70% of patients cured using contemporary treatments. We analyzed the prognostic significance of clinical features on 58 patients with CBFβ‐AML aged ≤60 years. Increasing age was the only predictor for survival (P <0.001), with an optimal cut‐point at 43 years. White blood cells (WBCs) at diagnosis emerged as an independent risk factor for relapse incidence (P = 0.017), with 1.1% increase of hazard for each 1.0 × 109/L WBC increment. KIT mutations lacked prognostic value for survival and showed only a trend for relapse incidence (P = 0.069). Am. J. Hematol. 88:594–600, 2013.

Flow cytometry vs cytomorphology for the detection of hematologic malignancy in body cavity fluids.

Flow cytometry and cytomorphology results on 92 body cavity fluids [61 effusions and 31 bronchoalveolar lavage fluids (BALF)] from hematologic malignancy were compared with retrospective clinical outcome. We observed double true positive/negative results in 67 cases (73%), and double false negative results in 2 cases (2%). Immunophenotyping accounted for true positive/negative results in 22 out of 23 mismatched cases (25%), and retained significantly higher accuracy than that of cytomorphology especially in effusions and differentiated lymphoma. In BALF analysis, immunophenotyping and cytomorphology sensitivity was 75% and 0%, respectively. Flow cytometry retains the highest accuracy in detecting neoplastic cells in body cavity fluids.

Limited feasibility of double transplant in multiple myeloma: results of a multicenter study on 153 patients aged <65 years.

Although high‐dose therapy is considered the standard therapy for younger patients with multiple myeloma (MM), the advantages of performing a second transplant remain debated. The current study was conducted to evaluate the efficacy and the feasibility of a front‐line double transplant program in young MM patients.

Response loss and development of neutralizing antibodies during long-term treatment with romiplostim in patients with immune thrombocytopenia: a case series

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by low platelet counts resulting from both immune‐mediated platelet destruction and inappropriate bone marrow platelet production. Therefore, in patients with ITP failing immunosuppressants/splenectomy, an alternative approach is to enhance platelet production stimulating thrombopoiesis. Studies on the development of recombinant thrombopoietins (rhTPO) were halted as a minority of patients developed an autoantibody that neutralized pegylated rhTPO and also cross‐reacted with and neutralized endogenous TPO resulting in thrombocytopenia. Clinical use of romiplostim, a second‐generation TPO‐RAs, has shown that during long‐term treatment, it may elicit the development of neutralizing antibodies to this agent resulting in acute thrombocytopenia. In our case series of 47 primary adult patients with ITP treated with romiplostim, 28 of 47 are evaluable for response loss. Among these, we observed eight patients who either progressively (3 of 8) or abruptly (5 of 8) lost response which accounts for a prevalence of 28.5%. Neutralizing antibody testing could be performed in 4 of 8 patients and 3 of 4 tested positive. These antibodies did not cross‐react with endogenous TPO and retesting of 2 patients at 9 and 7 months yielded a negative result. At follow‐up, 5 of 8 patients – including the 3 patients with neutralizing antibodies – went into long‐term complete response when switched to a different therapy while 3 of 8 patients never regained a response on subsequent lines of therapy. Response loss does not seem to be so rare an event during romiplostim administration (28.5% in our series) and in a minority of patients, it can be associated with development of drug neutralizing antibodies. Although recognized by the manufacturer as a possible adverse event ensuing during romiplostim administration, development of neutralizing antibody in everyday clinical practice has so far not been specifically addressed in reports on romiplostim use outside controlled studies. Unfortunately, testing for these antibodies requires adhesion to strict procedures which is not easily accomplished in everyday clinical practice. This complexity represents a significant drawback in extending antibody testing to all patients who lose response to romiplostim.

Total serum tryptase: a predictive marker for KIT mutation in acute myeloid leukemia.

Human tryptase is a serine protease expressed in mast-cells. We previously observed that AML blast cells, cultured in vitro from a KIT D816Y patient, give rise to adherent cells with mast-cell like phenotype and tryptase was released in the serum-free medium. To correlate total serum tryptase (ts-try) levels with cytogenetic features and KIT mutational status, we analyzed serum samples from AML patients at diagnosis. In 70 out of 155 patients (45%) we detected elevated ts-try (>15 ng/mL), significantly linked to t(8;21) (P < .001) and inv(16) (P = .007). In patients that achieved complete remission the ts-try decreased to normal values. In 75 patients screened for KIT mutation, we found a clear relationship between elevated ts-try and mutated patients with t(8;21) (P < .001). In conclusion, we propose that checking for ts-try at diagnosis of AML may be a simple tool to select patients to be addressed to KIT mutation screening.