Endogenous peptides of a soluble major histocompatibility complex class I molecule, H-2Lds: sequence motif, quantitative binding, and molecular modeling of the complex.

To gain insight into the rules that govern the binding of endogenous and viral peptides to a given major histocompatibility complex (MHC) class I molecule, we characterized the amino acid sequences of a set of self peptides bound by a soluble analogue of murine H-2Ld, H-2Lds. We tested corresponding synthetic peptides quantitatively for binding in several different assays, and built three-dimensional computer models of eight peptide/H-2Lds complexes, based on the crystallographic structure of the human HLA-B27/peptide complex. Comparison of primary and tertiary structures of bound self and antigenic peptides revealed that residues 2 and 9 were not only restricted in sequence and tolerant of conservative substitutions, but were spatially constrained in the three-dimensional models. The degree of sequence variability of specific residues in MHC-restricted peptides reflected the lack of structural constraint on those amino acids. Thus, amino acid residues that define a peptide motif represent side chains required or preferred for a close fit with the MHC class I heavy chain.

Phase II trial of oral vorinostat (suberoylanilide hydroxamic acid) in relapsed diffuse large-B-cell lymphoma.

BACKGROUND: Vorinostat has demonstrated activity in refractory cutaneous T-cell lymphoma. In a phase I trial, an encouraging activity in diffuse large-B-cell lymphoma (DLBCL) was noted. PATIENTS AND METHODS: We carried out a phase II trial (NCT00097929) of oral vorinostat 300 mg b.i.d. (14 days/3 weeks or 3 days/week) in patients with measurable, relapsed DLBCL who had received two or more systemic therapies. Response rate and duration (DOR), time to progression (TTP) and safety were assessed. RESULTS: Eighteen patients were enrolled (median age: 66 years; median prior therapies: 2). Seven received 300 mg b.i.d. 14 days/3 weeks, but four had grade 3 or 4 toxicity (dose-limiting toxicity, DLT). The schedule was amended to 300 mg b.i.d. 3 days/week), and none had DLT. One achieved a complete response (TtR = 85 days; DOR =or >468 days) and one had stable disease (301 days). Sixteen discontinued for progressive disease; median TTP was 44 days. Median number of cycles was 2 (1 to >19). Common drug-related adverse experiences (AEs; mostly grade 1/2) were diarrhea, fatigue, nausea, anemia and vomiting. Three patients had dose reduction; none discontinued for drug-related AEs. Drug-related AE >or=grade 3 included thrombocytopenia (16.7%) and asthenia (11.1%). CONCLUSION: Vorinostat was well tolerated at 300 mg b.i.d. 3 days/week or 200 mg b.i.d. 14 days/3 weeks but had limited activity against relapsed DLBCL.

Potential mechanisms of human natural killer cell expansion in vivo during low-dose IL-2 therapy.

The continuous, in vivo infusion of low-dose IL-2 selectively expands the absolute number of human natural killer (NK) cells after 4-6 weeks of therapy. The mechanism responsible for this expansion is unknown and was examined in this study. NK cells cultured at low concentrations of IL-2, comparable to those found during in vivo therapy, proliferate for 6 days and then exit the cell cycle. However, NK cells in vivo did not traverse the S/G(2)/M phase of the cell cycle during low-dose IL-2 therapy. Low concentrations of IL-2 delay programmed cell death of NK cells but have the same effect on resting T cells that do not expand in vivo. When CD34(+) bone marrow hematopoietic progenitor cells are cultured for 21 days with low concentrations of IL-2, they differentiate into CD56(+)CD3(-) NK cells, not T cells. Thus, the selective expansion of human NK cells during continuous in vivo infusion of low-dose IL-2 likely results from enhanced NK-cell differentiation from bone marrow progenitors, combined with an IL-2-dependent delay in NK-cell death, rather than proliferation of mature NK cells in the periphery.

Clinical pharmacology of oral all-trans retinoic acid in patients with acute promyelocytic leukemia.

All-trans retinoic acid (RA) induces leukemic cell differentiation and complete remission in a high proportion of patients with acute promyelocytic leukemia (APL). However, remissions induced by all-trans RA tend to be brief, and relapses are associated with resistance to further treatment in vivo, although the leukemic cells appear to retain sensitivity to the cytodifferentiating effects of all-trans RA in vitro. The clinical pharmacology of all-trans RA was examined in 13 patients with APL. The drug was administered at a constant dose of 45 mg/m2/day, given as a single dose on the first day of therapy and in two divided doses thereafter. Plasma and urinary concentrations of the parent drug and metabolites were quantitated by reverse-phase high-performance liquid chromatography and, where required, by a combination of normal-phase liquid chromatography/negative chemical ionization mass spectrometry. In patients with APL, basal levels of endogenous retinol and natural retinoids were within the normal range. Peak plasma levels of all-trans RA (347 +/- 266 ng/ml, mean +/- SD) were reached 1-2 h after drug ingestion and decayed in a monoexponential fashion with a half-life of 0.8 +/- 0.1 h. The only drug metabolite detected in plasma or urine was 4-oxo-all-trans RA (present in urine as the glucuronide conjugate). This metabolite accounted for less than 10% of the circulating drug in plasma, and its cumulative urinary excretion accounted for less than 1% of the administered dose. The drug was not found in cerebrospinal fluid. Continued oral administration of all-trans RA was associated with a significant decrease in both the plasma peak levels and the area under the concentration-time curve (P = 0.01 and 0.004, respectively) when measured after 2-6 weeks of treatment. We previously reported that a decrease in plasma area under the concentration-time curve was highly correlated with clinical relapse. Observations in a subset of patients in this study suggested that, in fact, the major decrease occurred early, within the first 7 days of treatment. These changes were associated with a 10-fold increase in urinary excretion of 4-oxo-all-trans RA glucuronide, suggesting that the accelerated clearance from plasma was associated with increased drug catabolism. The rapid disappearance may explain early relapse from remissions induced by all-trans RA; clinical "resistance" to all-trans RA may either wholly or in part result from an inability to sustain effective plasma concentrations of all-trans RA during continuous treatment.(ABSTRACT TRUNCATED AT 400 WORDS)

Molecular rearrangement of the ALL-1 gene in acute myeloid leukemia without cytogenetic evidence of 11q23 chromosomal translocations.

Translocations which involve chromosome band 11q23 are frequently found in infants and adults with acute myeloid leukemia (AML) or acute lymphoblastic leukemia. We previously cloned a gene called ALL-1 which spans the 11q23 breakpoint and is rearranged in most cases of leukemia with 11q23 abnormalities. In the present report, we have investigated the occurrence of ALL-1 rearrangement in cases of AML without cytogenetic evidence of 11q23 abnormalities. We detected molecular rearrangements of the ALL-1 gene in 3 of 4 patients with de novo AML and trisomy 11 as a sole chromosomal abnormality. Furthermore, we found DNA rearrangements of ALL-1 in 2 of 19 patients with de novo AML and normal cytogenetics. We conclude that molecular rearrangement of ALL-1 often can be detected in de novo AML, despite the absence of cytogenetic abnormalities involving 11q23.

United States multicenter study of arsenic trioxide in relapsed acute promyelocytic leukemia.

PURPOSE: To determine the safety and efficacy of arsenic trioxide (ATO) in patients with relapsed acute promyelocytic leukemia (APL). PATIENTS AND METHODS: Forty patients experiencing first (n = 21) or > or = second (n = 19) relapse were treated with daily infusions of ATO to a maximum of 60 doses or until all leukemic cells in bone marrow were eliminated. Patients who achieved a complete remission (CR) were offered one consolidation course of ATO that began 3 to 4 weeks later. Patients who remained in CR were eligible to receive further cycles of ATO therapy on a maintenance study. RESULTS: Thirty-four patients (85%) achieved a CR. Thirty-one patients (91%) with CRs had posttreatment cytogenetic tests negative for t(15;17). Eighty-six percent of the patients who were assessable by reverse transcriptase polymerase chain reaction converted from positive to negative for the promyelocytic leukemia/retinoic acid receptor-alpha transcript by the completion of their consolidation therapy. Thirty-two patients received consolidation therapy, and 18 received additional ATO as maintenance. Eleven patients underwent allogeneic (n = 8) or autologous (n = 3) transplant after ATO treatment. The 18-month overall and relapse-free survival (RFS) estimates were 66% and 56%, respectively. Twenty patients (50%) had leukocytosis (> 10,000 WBC/microL) during induction therapy. Ten patients developed signs or symptoms suggestive of the APL syndrome and were effectively treated with dexamethasone. Electrocardiographic QT prolongation was common (63%). One patient had an absolute QT interval of > 500 msec and had an asymptomatic 7-beat run of torsades de pointe. Two patients died during induction, neither from drug-related causes. CONCLUSION: This study establishes ATO as a highly effective therapy for patients with relapsed APL.

Treatment of acute promyelocytic leukemia with all-trans retinoic acid: an update of the New York experience.

In an ongoing study, we treated 79 patients with a molecular diagnosis of acute promyelocytic leukemia (APL) using all-trans retinoic acid (RA) for remission induction. Newly diagnosed patients received cytotoxic chemotherapy for consolidation, and previously treated patients received extended all-trans RA therapy, or a radionuclide-conjugated monoclonal antibody as post-remission treatment. Unlike studies in Europe, full-dose chemotherapy was not given during induction for patients who developed leukocytosis. Overall, 43 of 49 newly diagnosed patients (88%) and 25 of 30 previously treated patients (83%) achieved complete remission. We did not encounter de novo resistance to all-trans RA in any patient who was positive for PML/RAR-alpha rearrangements by reverse transcription polymerase chain reaction analysis. Ten patients died during induction from intracranial or pulmonary hemorrhage (six patients) or the 'retinoic acid syndrome' (four patients). The use of leukapheresis or low-dose chemotherapy (hydroxyurea or cytosine arabinoside) for drug-induced leukocytosis did not decrease early mortality. Compared to historical controls, early mortality was not affected by treatment with all-trans RA; however, both relapse-free and overall survival were significantly increased. Maintenance therapy with all-trans RA was associated with short remission duration, and relapses while taking the drug were universally associated with resistance to further retinoid treatment. We conclude that the use of all-trans RA for remission induction, with or without full-dose chemotherapy, has significantly increased the survival of patients with APL. While early mortality has not yet been reduced, the avoidance of full-dose chemotherapy during induction has significantly reduced early morbidity. The major outstanding clinical issue is the development of strategies that maximize safety in high-risk patients for whom intracranial hemorrhage remains the major cause of death.

Treatment of acute promyelocytic leukemia with all-trans retinoic acid: an update of the New York experience.

In an ongoing study, we treated 79 patients with a molecular diagnosis of acute promyelocytic leukemia (APL) using all-trans retinoic acid (RA) for remission induction. Newly diagnosed patients received cytotoxic chemotherapy for consolidation, and previously treated patients received extended all-trans RA therapy, or a radionuclide-conjugated monoclonal antibody as post-remission treatment. Unlike studies in Europe, full-dose chemotherapy was not given during induction for patients who developed leukocytosis. Overall, 43 of 49 newly diagnosed patients (88%) and 25 of 30 previously treated patients (83%) achieved complete remission. We did not encounter de novo resistance to all-trans RA in any patient who was positive for PML/RAR-alpha rearrangements by reverse transcription polymerase chain reaction analysis. Ten patients died during induction from intracranial or pulmonary hemorrhage (six patients) or the 'retinoic acid syndrome' (four patients). The use of leukapheresis or low-dose chemotherapy (hydroxyurea or cytosine arabinoside) for drug-induced leukocytosis did not decrease early mortality. Compared to historical controls, early mortality was not affected by treatment with all-trans RA; however, both relapse-free and overall survival were significantly increased. Maintenance therapy with all-trans RA was associated with short remission duration, and relapses while taking the drug were universally associated with resistance to further retinoid treatment. We conclude that the use of all-trans RA for remission induction, with or without full-dose chemotherapy, has significantly increased the survival of patients with APL. While early mortality has not yet been reduced, the avoidance of full-dose chemotherapy during induction has significantly reduced early morbidity. The major outstanding clinical issue is the development of strategies that maximize safety in high-risk patients for whom intracranial hemorrhage remains the major cause of death.

G3139, a Bcl-2 antisense oligodeoxynucleotide, induces clinical responses in VAD refractory myeloma.

Expression of Bcl-2 in multiple myeloma is associated with resistance to chemotherapeutic drugs. Conversely, suppression of Bcl-2 enhanced the chemosensitivity of myeloma cells in vitro. G3139 is an antisense oligodeoxynucleotide targeted to the first six codons of the Bcl-2 mRNA open reading frame. In this study, G3139 was delivered as a continuous intravenous infusion for 7 days at a fixed dose of 7 mg/kg/day in combination with VAD (vincristine, adriamycin, and dexamethasone) chemotherapy. In total, 10 heavily pretreated patients with refractory myeloma participated in this trial, including eight patients with VAD refractory disease. The combination of G3139 and VAD was feasible and well tolerated. Seven patients (70%) responded including four patients (40%) with a partial response and three patients (30%) with a minor response. Median progression-free survival was 6 months (range, 2-7+ months) and median overall survival has not been reached. G3139 downregulated Bcl-2 protein levels in peripheral blood circulating myeloma cells, B cells, T cells, and monocytes. These results indicate that G3139 may overcome classical resistance and restore sensitivity of myeloma tumor cells to VAD chemotherapy.

High-dose cytarabine, idarubicin, and granulocyte colony-stimulating factor remission induction therapy for previously untreated de novo and secondary adult acute myeloid leukemia.

This report describes the preliminary results of the remission induction phase of a protocol for previously untreated de novo and secondary acute myeloid leukemia (AML) designed to deliver very intensive therapy over a brief period of time using hematopoietic growth factor support. Remission induction therapy consisted of cytarabine 3 g/m2 (1.5 g/m2 for age > 50 years) intravenously over 1 hour every 12 hours for 12 doses and idarubicin 12 mg/m2 over 30 minutes on days 2, 3, and 4 of cytarabine, followed by 10 micrograms/kg granulocyte colony-stimulating factor subcutaneously daily until the absolute neutrophil count increased to > or = 5.0 x 10(9)/L on 2 consecutive days. Twenty-seven patients received all the planned doses of chemotherapy. The complete remission (CR) rate to a single course of therapy was 65% in 20 patients with de novo AML (median age, 60.5 years; age range, 26 to 78 years); for those aged less than 60 and > or = 60 years, the CR rates were 90% and 40%, respectively. In contrast, only two of 10 patients with secondary AML (median age, 68 years; age range, 35 to 77 years) achieved a CR. The median time from initiation of chemotherapy to recovery of 0.5 x 10(9)/L neutrophils in de novo AML patients achieving CR was 20 days (range, 18 to 23 days). Median times to last platelet transfusion and to 100 x 10(9)/L platelet count were 23 days (range, 18 to 41 days) and 28 days (range, 24 to 97 days), respectively. The major nonhematologic toxicity was transient hyperbilirubinemia, which was observed in 64% of patients. Reversible cerebellar toxicity was seen in three patients. Thus, idarubicin at full dose (12 mg/m2 x 3 days) may be safely administered with high-dose cytarabine, even in elderly patients. The use of granulocyte colony-stimulating factor is associated with rapid neutrophil recovery without obvious toxicity. The CR rate for de novo AML patients treated with a single course of high-dose cytarabine, idarubicin, and granulocyte colony-stimulating factor is at least comparable to CR rates achieved with standard-dose cytarabine and anthracycline regimens. The response of secondary AML patients remains inferior.

Double-blind, randomized, parallel-group study on the efficacy and safety of oral granisetron and oral ondansetron in the prophylaxis of nausea and vomiting in patients receiving hyperfractionated total body irradiation.

The efficacy and safety of granisetron and ondansetron for the prophylaxis of nausea and vomiting resulting from hyperfractionated total body irradiation (TBI) were assessed. Thirty-four patients randomly received double-blind, oral granisetron (2 mg, 1 h before first daily fraction of radiation) or ondansetron (8 mg, 1.5 h prior to each fraction of TBI). Ninety patients who received the same TBI regimen prior to bone marrow transplantation (BMT), but no 5-HT3-receptor antagonist, were identified and comprised the historical control group. By design, this study was only powered to show a difference between each of the active treatment groups and the historical control group. Significantly more patients given granisetron (33.3%) or ondansetron (26.7%) had zero emetic episodes over 4 days, the primary efficacy end point, than those in the historical control group (0%) (P < 0.01; intent-to-treat). Secondary efficacy end points were also evaluated. During the first 24 h, significantly more patients taking granisetron (61.1%) or ondansetron (46.7%) had zero emetic episodes than patients in the historical control group (6.7%) (P < 0.01). Complete emetic control (no emesis or rescue antiemetic) over 4 days was more frequent in patients taking granisetron (27.8%) or ondansetron (26.7%) compared with the historical control group (0%) (P < 0.01). Significantly fewer patients taking granisetron (18/18), but not those taking ondansetron (12/15), experienced more than five emetic episodes during the 4 days of the study compared with the historical control group (40/90; P < 0.01). Oral granisetron and ondansetron are safe and effective for the prevention of nausea and vomiting resulting from TBI.

Autotransplantation for advanced lymphoma and Hodgkin's disease followed by post-transplant rituxan/GM-CSF or radiotherapy and consolidation chemotherapy.

Disease relapse occurs in 50% or more of patients who are autografted for relapsed or refractory lymphoma (NHL) or Hodgkin's disease (HD). The administration of non-cross-resistant therapies during the post-transplant phase could possibly control residual disease and delay or prevent its progression. To test this approach, 55 patients with relapsed/refractory or high-risk NHL or relapsed/refractory HD were enrolled in the following protocol: stem cell mobilization: cyclophosphamide (4.5 g/m(2)) + etoposide (2.0 g/m(2)) followed by GM-CSF or G-CSF; high-dose therapy: gemcitabine (1.0 g/m(2)) on day -5, BCNU (300 mg/m(2)) + gemcitabine (1.0 g/m(2)) on day -2, melphalan (140 mg/m(2)) on day -1, blood stem cell infusion on day 0; post-transplant immunotherapy (B cell NHL): rituxan (375 mg/m(2)) weekly for 4 weeks + GM-CSF (250 microg thrice weekly) (weeks 4-8); post-transplant involved-field radiotherapy (HD): 30-40 Gy to pre-transplant areas of disease (weeks 4-8); post-transplant consolidation chemotherapy (all patients): dexamethasone (40 mg daily)/cyclophosphamide (300 mg/m(2)/day)/etoposide (30 mg/m(2)/day)/cisplatin (15 mg/m(2)/day) by continuous intravenous infusion for 4 days + gemcitabine (1.0 g/m(2), day 3) (months 3 + 9) alternating with dexamethasone/paclitaxel (135 mg/m(2))/cisplatin (75 mg/m(2)) (months 6 + 12). Of the 33 patients with B cell lymphoma, 14 had primary refractory disease (42%), 12 had relapsed disease (36%) and seven had high-risk disease in first CR (21%). For the entire group, the 2-year Kaplan-Meier event-free survival (EFS) and overall survival (OS) were 30% and 35%, respectively, while six of 33 patients (18%) died before day 100 from transplant-related complications. The rituxan/GM-CSF phase was well-tolerated by the 26 patients who were treated and led to radiographic responses in seven patients; an eighth patient with a blastic variant of mantle-cell lymphoma had clearance of marrow involvement after rituxan/GM-CSF. Of the 22 patients with relapsed/refractory HD (21 patients) or high-risk T cell lymphoblastic lymphoma (one patient), the 2-year Kaplan-Meier EFS and OS were 70% and 85%, respectively, while two of 22 patients (9%) died before day 100 from transplant-related complications. Eight patients received involved field radiation and seven had radiographic responses within the treatment fields. A total of 72 courses of post-transplant consolidation chemotherapy were administered to 26 of the 55 total patients. Transient grade 3-4 myelosuppression was common and one patient died from neutropenic sepsis, but no patients required an infusion of backup stem cells. After adjustment for known prognostic factors, the EFS for the cohort of HD patients was significantly better than the EFS for an historical cohort of HD patients autografted after BEAC (BCNU/etoposide/cytarabine/cyclophosphamide) without consolidation chemotherapy (P = 0.015). In conclusion, post-transplant consolidation therapy is feasible and well-tolerated for patients autografted for aggressive NHL and HD and may be associated with improved progression-free survival particularly for patients with HD.

Acute promyelocytic leukemia. New insights into diagnosis and therapy.

The clinical and laboratory features of APL are distinct. APL has been effectively treated with anthracyclines. Postremission therapy and the addition of other cytotoxic agents in induction may be beneficial. Early deaths remain a problem despite improved management of coagulopathy. The cytogenetic marker, t(15;17), reflects a molecular defect that splices two transcription factors, PML and RARA, to produce chimeric mRNA and proteins. RA, the natural ligand for RARA, is able to induce CR by stimulating differentiation and maturation of the malignant cells. The addition of RA to the therapeutic armamentarium of the hematologic oncologist will allow further refinement of the management of these patients. Diagnosis is unambiguous because the molecular defect can be readily detected. Our understanding of the biology downstream of the affected genes is incomplete. Other retinoids may be more effective than all-trans RA and may avoid the fall in plasma levels seen in patients chronically treated with RA. Combination of retinoids with other cytokines or cytotoxic agents may decrease the immediate mortality and improve long-term DFS in APL.

Sweet's syndrome during treatment with all-trans retinoic acid in a patient with acute promyelocytic leukemia.

A 46 year old male with acute promyelocytic leukemia treated with all-trans retinoic acid (ATRA), developed fever, bilateral erythematous nodules in his axillary area, lower abdomen and inguinal region. Histopathologic examination of the skin biopsy revealed dense neutrophil infiltration in the dermis without vasculitis. The diagnosis of Sweet's syndrome was made. High dose methylprednisolone was administered and the lesions started to improve within 24 hours.

Reversible tacrolimus-induced neurotoxicity isolated to the brain stem.

Diplopia, nystagmus, visual hallucinations, and internuclear ophthalmoplegia developed in a 30-year-old woman 84 days after she received a matched, unrelated bone marrow transplant for chronic myeloid leukemia. A regimen of tacrolimus had been administered since the transplantation was performed. MR imaging revealed bilaterally symmetric regions of signal abnormality with abnormal contrast enhancement in the brain stem. No supratentorial abnormality was present. Tacrolimus therapy was discontinued, and the symptoms resolved. MR imaging that was performed 10 days after tacrolimus was discontinued showed resolution of the abnormalities.

Retinoic acid and its rearranged receptor in the etiology and treatment of acute promyelocytic leukemia.

All-trans retinoic acid can induce complete remissions in patients with acute promyelocytic leukemia. The balanced chromosomal translocation t(15;17)(q22;q12-21) of this malignancy is now known to involve the nuclear retinoic acid receptor-alpha (RAR-alpha) on the long arm of chromosome 17 and a novel gene on the long arm of chromosome 15, designated PML (previously called myl). A unique fusion mRNA, PML/RAR-alpha, is produced. Paradoxically, this rearrangement of RAR-alpha results in clinical sensitivity to retinoic acid. Despite its efficacy, retinoic acid therapy has side effect, including a syndrome of hyperleukocytosis and respiratory distress in some patients. Remissions induced and maintained by continuous all-trans-retinoic treatment are not durable in most of these patients. Retinoic acid therapy for acute promyelocytic leukemia represents a unique example where a molecular defect may be involved both in the pathogenesis and treatment of a malignancy.