Acalabrutinib versus rituximab plus idelalisib or bendamustine in relapsed/refractory chronic lymphocytic leukemia: ASCEND results at 4 years of follow-up

7538

Background: Acalabrutinib (acala) is a next-generation, highly selective, covalent Bruton tyrosine kinase (BTK) inhibitor approved for patients (pts) with chronic lymphocytic leukemia (CLL). In the primary analysis of ASCEND (median follow-up 16.1 mo), acala showed superior efficacy with an acceptable tolerability profile vs idelalisib (Id) plus rituximab (R) (IdR) or bendamustine (B) plus R (BR) in pts with relapsed/refractory (R/R) CLL (Ghia et al. J Clin Oncol. 2020;38:2849-2861). We report the results of the ASCEND study at ~4 years of follow-up. Methods: In this multicenter, randomized, open-label, phase 3 study (NCT02970318), pts with R/R CLL received oral (PO) acala 100 mg BID until progression or unacceptable toxicity or investigator’s (INV) choice of IdR (Id: 150 mg PO BID until progression or unacceptable toxicity; R: 375 mg/m2 x1 then 500 mg/m2 IV [8 total infusions]) or BR (B: 70 mg/m2 IV; R: 375 mg/m2 x1 then 500 mg/m2 IV [6 cycles]). Progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and safety were assessed. Results: A total of 310 pts (acala, n=155; IdR, n=119; BR, n=36) were randomized (median age 67 y; del(17p) 15%, unmutated IGHV 74%, Rai stage 3/4 42%). At median follow-up of 46.5 mo (acala) and 45.3 mo (IdR/BR), acala significantly prolonged INV-assessed PFS vs IdR/BR (median not reached [NR] vs 16.8 mo; P<0.0001); 42-mo PFS rates were 62% for acala vs 19% for IdR/BR. In pts with del(17p), median PFS was NR (acala) vs 13.8 mo (IdR/BR; P<0.0001). In pts with unmutated IGHV, median PFS was NR (acala) vs 16.2 mo (IdR/BR; P<0.0001). Median OS was NR in both arms; 42-mo OS rates were 78% (acala) vs 65% (IdR/BR). ORR was 83% (acala) vs 84% (IdR/BR) (ORR + partial response with lymphocytosis: 92% [acala] vs 88% [IdR/BR]). AEs led to drug discontinuation in 23% of acala, 67% of IdR, and 17% of BR pts. Events of clinical interest (acala vs IdR/BR) included all-grade atrial fibrillation/flutter (8% vs 3%), all-grade hypertension (8% vs 5%), all-grade major hemorrhage (3% vs 3%), and grade ≥3 infections (29% vs 29%). Conclusions: At ~4 years of follow-up, acala maintained efficacy compared with standard-of-care regimens and a consistent tolerability profile in R/R CLL. Clinical trial information: NCT02970318. [Table: see text]

ASCEND: Phase III, Randomized Trial of Acalabrutinib Versus Idelalisib Plus Rituximab or Bendamustine Plus Rituximab in Relapsed or Refractory Chronic Lymphocytic Leukemia

PURPOSE

Acalabrutinib, a highly selective, potent, Bruton tyrosine kinase inhibitor, was evaluated in this global, multicenter, randomized, open-label, phase III study in patients with relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL).

METHODS

Eligible patients, aged ≥ 18 years with R/R CLL, were randomly assigned 1:1 centrally and stratified by del(17p) status, Eastern Cooperative Oncology Group performance status score, and number of prior lines of therapy. Patients received acalabrutinib monotherapy or investigator's choice (idelalisib plus rituximab [I-R] or bendamustine plus rituximab [B-R]). The primary end point was progression-free survival (PFS) assessed by an independent review committee (IRC) in the intent-to-treat population. Key secondary end points included IRC-assessed overall response rate, overall survival, and safety.

RESULTS

From February 21, 2017, to January 17, 2018, a total of 398 patients were assessed for eligibility; 310 patients were randomly assigned to acalabrutinib monotherapy (n = 155) or investigator's choice (n = 155; I-R, n = 119; B-R, n = 36). Patients had received a median of two prior therapies (range, 1-10). After a median follow-up of 16.1 months (range, 0.03-22.4 months), median PFS was significantly longer with acalabrutinib monotherapy (PFS not reached) compared with investigator's choice (16.5 months [95% CI, 14.0 to 17.1 months]; hazard ratio, 0.31 [95% CI, 0.20 to 0.49]; P < .0001). Estimated 12-month PFS was 88% (95% CI, 81% to 92%) for acalabrutinib and 68% (95% CI, 59% to 75%) for investigator's choice. Serious adverse events occurred in 29% of patients (n = 44 of 154) treated with acalabrutinib monotherapy, 56% (n = 66 of 118) with I-R, and 26% (n = 9 of 35) with B-R. Deaths occurred in 10% (n = 15 of 154), 11% (n = 13 of 118), and 14% (n = 5 of 35) of patients receiving acalabrutinib monotherapy, I-R, and B-R, respectively.

CONCLUSION

Acalabrutinib significantly improved PFS compared with I-R or B-R and has an acceptable safety profile in patients with R/R CLL.

Acalabrutinib (Acala) versus idelalisib plus rituximab (IdR) or bendamustine plus rituximab (BR) in relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL): ASCEND final results

8015

Background: Acala is a next-generation, highly selective, covalent Bruton tyrosine kinase inhibitor approved for patients (pts) with CLL including those with R/R CLL. The efficacy and safety of acala alone vs IdR or BR were shown in R/R CLL pts in a preplanned interim analysis of ASCEND; final results are reported herein. Methods: In this randomized, multicenter, phase 3, open-label study (NCT02970318), R/R CLL pts were randomized 1:1 to receive oral (PO) acala 100 mg BID or investigator’s (INV) choice of IdR (Id: 150 mg PO BID until progression or toxicity; R: 375 x1 then 500 mg/m2 intravenously [IV] for 8 total infusions) or BR (B: 70 mg/m2 IV and R: 375 x1 then 500 mg/m2 IV for 6 total cycles) until progression or toxicity. Progression-free survival (PFS), overall survival (OS), overall response rate (ORR), and safety were assessed. Results: 310 pts (acala, n=155; IdR, n=119; BR, n=36) were enrolled (median age: 67 y; del(17p) 16%, del(11q) 27%, Rai stage 3/4 42%). At a median follow-up of 22.0 m, acala significantly prolonged INV-assessed PFS vs IdR/BR (median: not reached vs 16.8 m; hazard ratio: 0.27, P<0.0001); 18-m PFS rates were 82% for acala and 48% for IdR/BR. 18-m OS rate was 88% for both treatment regimens. ORR was 80% with acala vs 84% with IdR/BR (ORR + partial response with lymphocytosis: 92% vs 88%, respectively). Common adverse events (AEs) are listed in the Table. AEs led to drug discontinuation in 16% of acala, 56% of IdR, and 17% of BR pts. AEs of interest included atrial fibrillation (acala 6%, IdR/BR 3%), major hemorrhage (all grade; acala 3%, IdR/BR 3%), grade ≥3 infections (acala 20%, IdR/BR 25%), and second primary malignancies excluding non-melanoma skin cancer (acala 5%, IdR/BR 2%). Conclusions: Final ASCEND results with additional follow-up confirm earlier findings and support the favorable efficacy and safety of acala compared with standard-of-care regimens in R/R CLL pts. Clinical trial information: NCT02970318 . [Table: see text]

Idelalisib addition has neutral to beneficial effects on quality of life in bendamustine/rituximab-treated patients: results of a phase 3, randomized, controlled trial

Background

In a phase 3 randomized, double-blind, placebo-controlled trial, treatment with idelalisib, a phosphoinositol-3 kinase δ inhibitor, + bendamustine/rituximab improved progression-free survival (PFS) and overall survival (OS) in adult patients with relapsed/refractory chronic lymphocytic leukemia (R/R CLL). Here we report the results of health-related quality of life (HRQL) analyses from this study.

Methods

From June 15, 2012 to August 21, 2014, 416 patients with R/R CLL were enrolled; 207 patients were randomized to the idelalisib arm and 209 to the placebo arm. In the 416 patients randomized to receive bendamustine/rituximab and either oral idelalisib 150 mg twice-daily or placebo, HRQL was assessed at baseline and throughout the blinded part of the study using the Functional Assessment of Cancer Therapy–Leukemia (FACT-Leu) and EuroQoL Five-Dimension (EQ-5D) visual analogue scale (VAS) questionnaires. The assessments were performed at scheduled patient visits; every 4 weeks for the first 6 months from the initiation of treatment, then every 8 weeks for the next 6 months, and every 12 weeks thereafter until end of study. Least-squares mean changes from baseline were estimated using a mixed-effects model by including treatment, time, and treatment-by-time interaction, and stratification factors as fixed effects. Time to first symptom improvement was assessed by Kaplan-Meier analysis.

Results

In mixed-effects model analysis, idelalisib + bendamustine/rituximab treatment led to clinically meaningful improvements from baseline in leukemia-associated symptoms. Moreover, per Kaplan-Meier analysis, the proportion of patients with symptom improvement was higher and time to improvement was shorter among patients in the idelalisib-containing arm compared with those who did not receive idelalisib. The physical and social/family FACT-Leu subscale scores, along with the self-rated health assessed by EQ-VAS, showed improvement with idelalisib over placebo, but the difference did not reach statistical significance. The functional and emotional FACT-Leu subscale scores remained similar to placebo.

Conclusions

Addition of idelalisib to bendamustine/rituximab, apart from improving PFS and OS, had a neutral to beneficial impact on HRQL in patients with R/R CLL, particularly by reducing leukemia-specific disease symptoms.

Trial registration

Clinicaltrials.gov NCT01569295. Registered April 3, 2012.

Autologous Hematopoietic Stem Cell Transplantation for Adults With Acute Myeloid Leukemia

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) remains the most efficacious therapy in patients with acute leukemia. For older patients and those lacking a related HLA-compatible donor, autologous transplantation (auto-HSCT) is a valid alternative therapeutic option.

METHODS

From 1997 until 2014 in the Department of Hematooncology and Bone Marrow Transplantation, Medical University of Lublin, Poland, 29 auto-HSCT were performed in patients with acute myeloid leukemia (AML; 15 men and 14 women; median age, 52.2 years). The following FAB types of AML were diagnosed: M0, 3; M1, 4; M2, 6; M4, 10; and M5, 6. Patients with AML were classified into 3 cytogenetic prognostic groups: high risk, 9; intermediate risk, 16; and low risk, 4. Twenty-five were in first complete remission and 4 in second complete remission. The peripheral HSCs mobilized after chemotherapy (mainly second course of consolidation) and granulocyte colony-stimulating factor were the source of the stem cells in all cases. The median number of infused CD34+ cells was 3.58 × 10(6)/kg. The conditioning regimen was busulfan and cyclophosphamide in all patients with AML. The intravenous form of busulfan was applied in the last 15 patients.

RESULTS

The median time for absolute neutrophil count recovery >0.5 × 10(9)/L and for platelet count >20.0 × 10(9)/L was 12 and 16.5 days, respectively. Treatment-related mortality rate in the whole group was 3.4% (1 patient with sepsis in the aplastic period). The median follow-up time of survivors was 21.9 months (range, 11.7-142.4). The 3-year projected disease-free survival and overall survival rates were 60% and 68%, respectively.

CONCLUSIONS

Our data confirm that auto-HSCT is a valuable therapeutic option for patients with AML, especially older patients and those lacking related HLA-compatible donors.

Cladribine, But Not Fludarabine, Added to Daunorubicin and Cytarabine During Induction Prolongs Survival of Patients With Acute Myeloid Leukemia: A Multicenter, Randomized Phase III Study

Purpose

The goal of this study was to evaluate whether the addition of a purine analog, cladribine or fludarabine, to the standard induction regimen affects the outcome of adult patients with acute myeloid leukemia (AML).

Patients and Methods

A cohort of 652 untreated AML patients with median age 47 years (range, 17 to 60 years) were randomly assigned to receive one of three induction regimens: DA (daunorubicin plus cytarabine), DAC (DA plus cladribine), or DAF (DA plus fludarabine). Postremission treatment was the same for all arms.

Results

Complete remission rate in the DAC arm was higher compared with the DA arm (67.5% v 56%; P = .01) as a consequence of reduced incidence of resistant disease (21% v 34%; P = .004). There was no significant difference in early outcome between the DAF and DA arms. The probability of overall survival was improved for the DAC arm (45% ± 4% at 3 years) compared with the DA arm (33% ± 4%; P = .02), and leukemia-free survival was comparable. Long-term outcome did not differ significantly for the comparison of the DAF and DA arms. A survival advantage of the DAC arm over the DA arm was observed among patients age 50 years or older (P = .005), those with initial leukocyte count above 50 × 109/L (P = .03), and those with unfavorable karyotype (P = .03). DAF revealed a significant advantage over DA in patients with adverse karyotype (P = .02).

Conclusion

The addition of cladribine to the standard induction regimen is associated with increased rate of complete remission and improved survival of adult patients with AML.

Treatment of multiple myeloma patients with autologous stem cell transplantation - a fresh analysis

Patients with multiple myeloma (MM) treated with conventional chemotherapy have an average survival of approximately three years. High dose chemotherapy followed by autologous stem cell transplantation (ASCT), first introduced in the mid-1980s, is now considered the standard therapy for almost all patients with multiple myeloma, because it prolongs overall survival and disease free survival. Between November 1997 and October 2006, 122 patients with MM (58 females, 64 males, median age 51.0 years [± 7.98] range: 30-66 years) were transplanted in the Department of Hematooncology and Bone Marrow Transplantation at the Medical University of Lublin: 47 patients were in complete remission or in unconfirmed complete remission, 66 patients were in partial remission, and nine had stable disease. Of these, there were 95 patients with IgG myeloma, 16 with IgA myeloma, one with IgG/IgA, one with IgM myeloma, five with non secretory type, two with solitary tumor and two with LCD myeloma. According to Durie-Salmon, 62 patients had stage III of the disease, 46 had stage II and four had stage I. Most patients (69/122) were transplanted after two or more cycles of chemotherapy, 48 patients were transplanted after one cycle of chemotherapy, one patient after surgery and rtg- -therapy and four patients had not been treated. In mobilisation procedure, the patients received a single infusion of cyclophosphamide (4-6 g/m(2)) or etoposide 1.6 g/m(2) followed by daily administration of G-CSF until the peripheral stem cells harvest. The number of median harvest sessions was 2.0 (± 0.89) (range: 1-5). An average of 7.09 (± 33.28) × 106 CD34(+) cells/kg were collected from each patient (range: 1.8-111.0 × 10⁶/kg). Conditioning regimen consisted of high dose melphalan 60-210 mg/m(2) without TBI. An average of 3.04 (± 11.59) × 10⁶ CD34+ cells/kg were transplanted to each patient. Fatal complications occured in four patients (treatment- -related mortality = 3.2%). In all patients there was regeneration of hematopoiesis. The median number of days for recovery to ANC > 0.5 × 10⁹/l was 13 (± 4.69) (range: 10-38) and platelets recovery to > 50 × 10⁹/l was 25 days (± 11.65) (range: 12-45). Median time of hospitalization was 22 days (± 7.14) (range: 14-50). Patients were evaluated on day 100 after transplantation: 74.9% achieved CR and nCR, 14.3% were in PR, 5.4% had SD and 5.4% had progressed. Median of OS was 45 months (± 30.67). OS at 3-years was 84% and at 7-years 59%. Median PFS was 25 months (± 26.13). PFS at 3-years was 68%, and at 7-years was 43%. At present (November 2009) 52 patients (42%) are still alive. High-dose chemotherapy followed by autologous stem cell transplantation is a valuable, well tolerated method of treatment for patients with MM that allows the achievement of long- -lasting survival.

Addition of cladribine to induction/consolidation regimen does not impair peripheral blood stem cell mobilization and bone marrow harvest for autotransplantation in acute myeloid leukemia patients

BACKGROUND

The previous study by the Polish Adult Leukemia Group has demonstrated that addition of cladribine to standard DNR+AraC induction potentiates the antileukemic activity. The goal of this study was to compare the efficacy of bone marrow or peripheral blood hematopoietic cell collection in patients who obtained remission after daunorubicine plus cytarabine induction with cladribine (DAC-7) or without addition of cladribine (DA-7) in preparation for autotransplantation.

PATIENTS AND METHODS

Sixty-six patients aged 41 years (range, 17-58 years) were included in this study: 33 cases in the DAC-7 and 33 in the DA-7 arm. Hematopoietic cells were collected from the bone marrow (ABMT, n = 29) or from the peripheral blood (ABCT, n = 37) using cytopheresis after administration of AraC (2 x 2 g/m2) on days 1, 3, 5 and subsequent G-CSF (10 microg/kg) from day 7 as mobilization therapy.

RESULTS

The numbers of harvested CD34+ cells were similar in the DAC-7 and DA-7 pretreated patients both after harvesting from peripheral blood (2.55 x 10(6)/kg vs 2.5 x 10(6)/kg) and from bone marrow (1.62 x 10(6)/kg vs 1.55 x 10(6)/kg), respectively. The proportion of patients with sufficient material for autologous bone marrow transplantation was higher in the DAC-7 compared with the DA-7 arm. All patients engrafted; hematopoietic recovery was similar in both subgroups.

CONCLUSION

Addition of cladribine to a standard DA induction does not impair the harvesting of hematopoietic cells and their engraftment after autotransplantation.

A multicenter, open, noncomparative, phase II study of the combination of cladribine (2-chlorodeoxyadenosine), cytarabine, granulocyte colony-stimulating factor and mitoxantrone as induction therapy in refractory acute myeloid leukemia: a report of the Polish Adult Leukemia Group

Purine nucleoside analogues, cladribine (2-chlorodeoxyadenosine, 2-CdA) and fludarabine (FAMP) are active agents in acute myeloid leukemias (AMLs). Synergistic interaction between FAMP or 2-CdA with cytarabine (cytosine arabinoside, Ara-C) has been demonstrated in preclinical and clinical studies. The current multicenter phase II study was initiated to evaluate the efficacy and toxicity of induction treatment consisting of 2-CdA (5 mg/m2), Ara-C (2 g/m2), mitoxantrone (MIT, 10 mg/m2) and granulocyte colony-stimulating factor (G-CSF) (CLAG-M) in refractory AML. In case of partial remission, a second CLAG-M was administered. Patients in complete remission (CR) received consolidation courses based on high-dose Ara-C and MIT with or without 2-CdA. Forty-three patients from five centers were registered: 25 primary resistant and 18 relapsed. CR was achieved in 21 (49%) patients, 20 (47%) were refractory and 2 (5%) died early. Hematologic toxicity was the most prominent toxicity of this regimen. The overall survival (OS; 1 year) for the 42 patients as a whole and the 20 patients in CR were 43% and 73%, respectively. Disease-free survival (1 year) was 68.6%. None of the analyzed prognostic factors influenced the CR and OS probability significantly. We conclude that CLAG-M regimen has significant antileukemia activity in refractory AML, which seems to be better than the activity of many other regimens. The toxicity of the treatment is acceptable.

Outcome and prognostic factors in advanced Hodgkin's disease treated with high-dose chemotherapy and autologous stem cell transplantation: a study of 341 patients

BACKGROUND

The reported probability of survival of patients with Hodgkin's disease (HD) following high-dose chemotherapy with autologous stem cell transplantation (HDC/ASCT) is 35-65% at 5 years. The Polish Lymphoma Research Group investigated retrospectively prognostic factors for overall survival (OS) and event-free survival (EFS), and the risk of secondary malignancies in a large series of patients who underwent HDC/ASCT.

PATIENTS AND METHODS

The data of 341 consecutive patients treated in 10 centers from 1990 to 2002 were collected and analyzed.

RESULTS

The actuarial 5-year OS and EFS were 64% [95% confidence interval (CI) 57% to 71%] and 45% (95% CI 39% to 51%), respectively. In the multivariate model, unfavorable prognostic factors for EFS were less than partial response at the time of ASCT [relative risk (RR), 2.92 (95% CI 1.68-5.08); P<0.001] and three or more previous chemotherapy lines (RR, 2.16; 95% CI 1.42-3.30; P<0.001). These two factors were also associated with unfavorable OS (RR, 3.32; 95% CI 1.90-5.79; P<0.001 and RR, 2.34, 95% CI 1.51-3.64; P<0.001). Five-year cumulative risk of secondary malignancy was 8.4% (95% CI 2% to 13%) and the only identified risk factor was splenectomy (P=0.02).

CONCLUSIONS

HDC/ASCT should be considered early in the course of disease for patients with a response after standard therapy.

Neutropenic enterocolitis: a serious complication during the treatment of acute leukemias

Neutropenic enterocolitis (NE) is a severe gastrointestinal complication in patients who undergo aggressive chemotherapy. It is a necrotizing inflammation of the cecum, colon, and the terminal part of the ileum. The serious clinical state of NE patients requires very frequent surgical consultations; however, in a few particular cases of NE, e.g., perforation of the bowels, a surgical intervention is necessary. Here, we report on six cases of NE in patients with acute leukemias. The patients were all women aged 21-55 years. Two of them had acute myeloid leukemia and four had lymphoblastic leukemia. NE occurred 7-10 days after the completion of chemotherapy, during the neutropenic phase. They represented a typical picture of NE: two of them died because of septic shock; five patients had subileus with irritation of the peritoneum; and one had hepatosplenic abscesses confirmed 6 months later by post-mortem examination. In each case, a surgical opinion was required. None of these patients were operated on. We present a report summarizing our experience and problems with six patients who had a clinical picture of NE and offer a short review of the current literature on the subject.

High-dose chemotherapy with autologous stem cell transplantation is an effective treatment of primary refractory Hodgkin's disease. Retrospective study of the Polish Lymphoma Research Group

We analysed the treatment outcome of primary refractory HD patients managed with high-dose chemotherapy and haematopoietic cell transplantation. Data of 65 adult patients who underwent HDC/ASCT in nine Polish centres for primary resistant Hodgkin's disease between June 1991 and July 2000 were collected retrospectively. Response rate to HDC/ASC: CR, 54%; PR, 20%; less than PR, 15%; early deaths, 11%. Actuarial 3-year OS and PFS were 55% and 36%, respectively. In multivariate analysis, lack of bulky lymph nodes and use of immunotherapy were favourable factors for both OS and PFS. IPF <3 at the time of transplantation was predictive for PFS. However, the prognostic impact of immunotherapy should be interpreted with caution since this group included more patients who achieved CR after HDC/ASCT. The results of HDC/ASCT are encouraging and confirm earlier findings. The role of immunotherapy should be further investigated in prospective trials.

Involvement of a cytochrome P450 monooxygenase in thaxtomin A biosynthesis by Streptomyces acidiscabies

The biosynthesis of the thaxtomin cyclic dipeptide phytotoxins proceeds nonribosomally via the thiotemplate mechanism. Acyladenylation, thioesterification, N-methylation, and cyclization of two amino acid substrates are catalyzed by the txtAB-encoded thaxtomin synthetase. Nucleotide sequence analysis of the region 3' of txtAB in Streptomyces acidiscabies 84.104 identified an open reading frame (ORF) encoding a homolog of the P450 monooxygenase gene family. It was proposed that thaxtomin A phenylalanyl hydroxylation was catalyzed by the monooxygenase homolog. The ORF was mutated in S. acidiscabies 84.104 by using an integrative gene disruption construct, and culture filtrate extracts of the mutant were assayed for the presence of dehydroxy derivatives of thaxtomin A. Reversed-phase high-performance liquid chromatography (HPLC) and HPLC-mass spectrometry indicated that the major component in culture filtrate extracts of the mutant was less polar and smaller than thaxtomin A. Comparisons of electrospray mass spectra as well as (1)H- and (13)C-nuclear magnetic resonance spectra of the purified compound with those previously reported for thaxtomins confirmed the structure of the compound as 12,15-N-dimethylcyclo-(L-4-nitrotryptophyl-L-phenylalanyl), the didehydroxy analog of thaxtomin A. The ORF, designated txtC, was cloned and the recombinant six-His-tagged fusion protein produced in Escherichia coli and purified from cell extracts. TxtC produced in E. coli exhibited spectral properties similar to those of cytochrome P450-type hemoproteins that have undergone conversion to the catalytically inactive P420 form. Based on these properties and the high similarity of TxtC to other well-characterized P450 enzymes, we conclude that txtC encodes a cytochrome P450-type monooxygenase required for postcyclization hydroxylation of the cyclic dipeptide.

Intravascular B-cell lymphoma in a 38-year-old woman: a case report

Intravascular lymphoma (IVL) is a rare aggressive disease characterised by the presence of lymphoma cells only in the lumina of small vessels, particularly capillaries. Only about 200 cases have been reported in the world (some of them retrospectively). IVL is predominantly of B-cell lineage origin but occasionally T-cell lineage occurs. Multiple organs may be involved and a variety of clinical presentations have been described. These include nephrotic syndrome, pyrexia and hypertension, breathlessness and haemolytic anaemia, leukopoenia, pancytopoenia and disseminated intravascular coagulation. We report a case of a 38-year-old woman with a highly aggressive clinical course of IVL. She was admitted to the Department of Neurosurgery because of spondylolisthesis of L5-S1 qualified to surgery. During hospitalisation haemolytic anaemia, thrombocytopoenia and splenomegaly were observed and she was admitted to the Department of Haematology for diagnosis. During her staying in the hospital, new symptoms, such as kidney and liver failure, occurred and the central nervous system was involved. The clinical course was very rapid and progressive. Corticosteroid therapy was started but the disease soon led to the fatal outcome. Diagnosis was established at post-mortem examination.

The txtAB genes of the plant pathogen Streptomyces acidiscabies encode a peptide synthetase required for phytotoxin thaxtomin A production and pathogenicity

Four Streptomyces species have been described as the causal agents of scab disease, which affects economically important root and tuber crops worldwide. These species produce a family of cyclic dipeptides, the thaxtomins, which alone mimic disease symptomatology. Structural considerations suggest that thaxtomins are synthesized non-ribosomally. Degenerate oligonucleotide primers were used to amplify conserved portions of the acyladenylation module of peptide synthetase genes from genomic DNA of representatives of the four species. Pairwise Southern hybridizations identified a peptide synthetase acyladenylation module conserved among three species. The complete nucleotide sequences of two peptide synthetase genes (txtAB) were determined from S. acidiscabies 84.104 cosmid library clones. The organization of the deduced TxtA and TxtB peptide synthetase catalytic domains is consistent with the formation of N-methylated cyclic dipeptides such as thaxtomins. Based on high-performance liquid chromatography (HPLC) analysis, thaxtomin A production was abolished in txtA gene disruption mutants. Although the growth and morphological characteristics of the mutants were identical to those of the parent strain, txtA mutants were avirulent on potato tubers. Moreover, introduction of the thaxtomin synthetase cosmid into a txtA mutant restored both pathogenicity and thaxtomin A production, demonstrating a critical role for thaxtomins in pathogenesis.

[Intravascular malignant lymphoma (angiotrophic large-cell lymphoma)]

Intravascular lymphoma (IVL) is characterized by proliferation of large malignant lymphoid cells within the lumen of small vessels. Sites usually affected include the central nervous system and skin although involvement of multiple organ symptoms have been described. IVL is very rare and aggressive type of lymphoma. Based on review of the literature we present clinicopathological, immunohistochemical and molecular features of the IVL. The etiological possibilities are discussed.

[Unusual cases of non-Hodgkin's lymphomas--case reports]

We describe 4 cases of non-Hodkin's lymphomas that were interesting because of their curiosal clinical courses and spontaneous complete remissions during the course of high malignancy lymphoma. We present three of them for the first time in Poland. Case 1: a 61-year old woman was admitted to the hospital because of the headache, lasting for 4 months before hospitalization and right hemiparesis. CT scans revealed the presence of tumor in the temporo-occipital region. The diagnosis of B-cell lymphoma was established at histopathological examination of the postoperative material. Co60--therapy of these region was applied after the operation with good response. Case 2: a 38-year woman was admitted to the hospital because of L5-S1 spondylolisthesis to operate it. During the hospitalization haemolytic anaemia of unknown origin, thrombocytopoenia, splenomegaly, fever and rising acute insufficiency of kidneys, heart, liver and CNS were occurred. The patient died, despite applying corticosteroidotherapy. The diagnosis of intravascular lymphoma was established at postmortem examination. Case 3: a 51-year old woman was admitted to the hospital with diagnosis: anaplastic non-Hodgkin lymphoma B-cell type high malignancy established after the double histopathological examination of lymph nodes and biopsy of the lung. At the admission to the Department of Haematology we stated absolute regression of these changes. The patient had been only observed in the Outpatient Department over 1 year. She died after 6 months since the beginning of the relapse despite intensive chemotherapy. Case 4: a 43-year old man was admitted to the hospital because of great hyperleukocytosis, hepatosplenomegaly and neurological symptoms. The diagnosis: chronic prolymphocytic leukaemia was established. The cerebrospinal fluid examination showed presence of mononuclears which infiltrated CNS. CT scans of the brain revealed leucaemic infiltrations of the hemispheres and cerebellum. The patient died despite intensive therapy due to rising progressive multiorgan failure.

Attempted reconstruction of the immune system using low doses of interleukin 2 in chronic lymphocytic leukemia patients treated with 2-chlorodeoxyadenosine: results of a pilot study

This study was designed to investigate the immunostimulatory effect of low dose Il-2 treatment in B-CLL patients previously treated with 2-chlorodeoxyadenosine (2CdA) in whom severe depletion of T lymphocyte subsets was observed. Four patients enrolled into the study had previously been treated with 3-6 courses of 2CdA. All patients suffered from recurrent infections and showed CD4+ and CD8+ immunosuppression. Recombinant Il-2 was given subcutaneously at a dose of 100 micrograms (1.8 x 10(6)IU) daily for 6 weeks. The drug was administered between 2CdA courses. These preliminary studies showed a marked increase in T cell subsets after Il-2 treatment. All patients displayed an increase of NK cells and there was increased expression of Il-2 receptors (CD 25 and CD 122) on lymphocytes. It is possible that the combination of cytotoxic therapy with 2CdA and low dose rIl-2 could stimulate the T-cell immune system and may be a promising regimen in patients with B-CLL with severe depletion in T-cell subsets.

Rb1 gene expression in B-cell lymphocytic leukaemia cases with deletion in the 13q14 region

Recent studies have been carried out to delineate further the role of the Rb1 gene in B-cell chronic lymphocytic leukaemia (B-CLL). The suggested role of the Rb1 gene in this disease was based on cytogenetic data. CLL patients (40 in toto) were examined using cytogenetic and molecular biological methods. R-banding analysis of metaphase chromosomes revealed aberrations in only seven cases containing either the Rb1 gene or a chromosome 13 monosomy. No evident differences were found by RT-PCR analysis of Rb1 gene expression. The amounts of the RT-PCR products obtained appeared to be approximately equal in all cases, and was independent of the clinical stage, immunophenotypes and LPS or TPA stimulation.

[Studies of immunoglobulin surface expression in lymphocytes of peripheral blood, bone marrow and lymph nodes in patients with B-cell chronic lymphocytic leukemia]

The expression of surface immunoglobulins (SIg) on peripheral blood, bone marrow, and lymph node lymphocytes was studied in a group of 10 patients with B cell chronic lymphocytic leukaemia. In 4 patients differences in the SIg phenotypes were found when cells from blood, bone marrow and lymph nodes were examined. Peripheral blood lymphocytes were characterized as a monoclonal B cell population whereas in the marrow or lymph node lymphocytes a tendency toward poly-clonality was found. We suggest that these differences reflect the origin of the initial leukaemic transformation: intra versus extra-medullar. In case of intramedullary origin of leukaemia the transformed clone infiltrates subsequently lymph nodes or other lymphoid structures. In leukaemia of extra-medullar origin the bone marrow is infiltrated later and therefore the tendency toward polyclonal SIg picture of the bone marrow lymphocytes contrasts with the monoclonality of the peripheral blood cells.

DNA amplification polymorphisms of the cultivated mushroom Agaricus bisporus

Single 10-bp primers were used to generate random amplified polymorphic DNA (RAPD) markers from commercial and wild strains of the cultivated mushroom Agaricus bisporus via the polymerase chain reaction. Of 20 primers tested, 19 amplified A. bisporus DNA, each producing 5 to 15 scorable markers ranging from 0.5 to 3.0 kbp. RAPD markers identified seven distinct genotypes among eight heterokaryotic strains; two of the commercial strains were shown to be related to each other through single-spore descent. Homokaryons recovered from protoplast regenerants of heterokaryotic strains carried a subset of the RAPD markers found in the heterokaryon, and both of the haploid nuclei from two heterokaryons were distinguishable. RAPD markers also served to verify the creation of a hybrid heterokaryon and to analyze meiotic progeny from this new strain: most of the basidiospores displayed RAPD fingerprints identical to that of the parental heterokaryon, although a few selected slow growers were homoallelic at a number of loci that were heteroallelic in the parent, suggesting that they represented rare homokaryotic basidiospores; crossover events between a RAPD marker locus and its respective centromere appeared to be infrequent. These results demonstrate that RAPD markers provide an efficient alternative for strain fingerprinting and a versatile tool for genetic studies and manipulations of A. bisporus.

[Results of the pilot treatment of 9 patients with chronic lymphocytic leukemia or CLL lymphoplasmacytoid lymphoma by the CHOP protocol]

In a group of 9 patients with chronic lymphocytic or lymphoplasmocytic leukaemia in clinical stage from 2 to 4 (classification of Rai et al.) 8 various CHOP programmes (cyclophosphamide, hydroxyldaunomycin, oncovin, prednisone) were used. In 6 cases (67%) partial remission was obtained, with normalization of peripheral blood and bone marrow patterns, with statistically significant decrease of the proportion of cells forming rosettes with murine erythrocytes, and with reduction or full normalization of the size of previously enlarged lymph nodes. In one case the control examination of a lymph node failed to demonstrate the previously present clone of cells with chromosomal aberration, although in histological examination the diagnosis of lymphoplasmocytic lymphoma was maintained. In the remaining 3 cases no partial remission was noted, and in one case progression was recognized. We think similarly as the French haematologists studying chronic lymphatic leukaemia, that the CHOP programme is effective in the treatment of chronic lymphatic or lymphoplasmocytic leukaemia.

[Phenotypic changes in peripheral blood lymphocytes of patients with chronic lymphoma and B-cell leukemia after treatment]

The purpose of the study was evaluation of the effect of treatment on the immunological phenotype of peripheral blood lymphocytes in patients with chronic lymphocytic leukaemia or in leukaemic forms of non-Hodgkin lymphomas, with low or medium grade malignancy. The study was carried out in 13 patient. In those responding to treatment a tendency was observed for normalization of the immunological phenotype of peripheral blood lymphocytes (increased proportion of cells forming rosettes with sheep erythrocytes, reduced proportion of cells forming rosettes with murine erythrocytes), and a tendency for polyclonal pattern of B-cells with immunoglobulins on their surface (although this feature was not a rule). In non-responders these tendencies were much less pronounced or absent. Similarly, in non-responders the tendency for polyclonal B-cell pattern may be only apparent, and may be connected with proliferation of a new lymphocyte population with another type of light chain.