Shorter long-term post-transplant life expectancy may be due to prior chemotherapy for the underlying disease: analysis of 3012 patients with acute myeloid leukemia enrolled on 9 consecutive ECOG-ACRIN trials.

Several studies reported that patients with acute myeloid leukemia (AML) who remain in long-term remission after allogeneic or autologous transplant have a shorter life expectancy, compared to the general population. However, little is known about the life expectancy of adult long-term survivors of AML who were treated with chemotherapy alone without a transplant and there have been no comparisons with survival among the general population. The current study indicates that the life expectancy of AML patients who achieved and maintained CR for at least 3 years is shorter than expected for age in the US population. This was observed also in patients who did not undergo a transplant including those who have not relapsed during the entire long follow-up period. Thus, late relapse does not explain why patients without transplants have a shortened life expectancy. Taken together, these data strongly suggest that prior chemotherapy for the underlying AML is at least a major contributing factor for the known shortened life expectancy post-transplant.

Long-term outcomes of adults with acute lymphoblastic leukemia after autologous or unrelated donor bone marrow transplantation: a comparative analysis by the National Marrow Donor Program and Center for International Blood and Marrow Transplant Research.

For adults with high-risk or recurrent ALL who lack a suitable sibling donor, the decision between autologous (Auto) and unrelated donor (URD) hematopoietic stem cell transplantation (HSCT) is difficult due to variable risks of relapse and treatment-related mortality (TRM). We analysed data from two transplant registries to determine outcomes between Auto and URD HSCT for 260 adult ALL patients in first (CR1) or second (CR2) CR. All patients received a myeloablative conditioning regimen. The median follow-up was 77 (range 12-170) months. TRM at 1 year post transplant was significantly higher with URD HSCT; however, there were minimal differences in TRM according to disease status. Relapse was higher with Auto HSCT and was increased in patients transplanted in CR2. Five-year leukemia-free (37 vs 39%) and overall survival (OS) rates (38 vs 39%) were similar for Auto HSCT vs URD HSCT in CR1. There were trends favoring URD HSCT in CR2. The long-term follow-up in this analysis demonstrated that either Auto or URD HSCT could result in long-term leukaemia-free survival and OS for adult ALL patients. The optimal time (CR1 vs CR2) and technique to perform HSCT remains an important clinical question for adult ALL patients.

Unique antigen of cultured Hodgkin's cells. A putative sialyltransferase.

Hodgkin's disease-derived giant cell lines (HD-cells) express high levels of ectosialyltransferase activity presumed to be a galactose-specific lectin recognizing the desialylated 3-fucosyl-N-acetyllactosamine structure (X-hapten). Both the anti-X-hapten monoclonal antibody VIM-D5 and a polyclonal antiserum to another galactose-lectin, the hepatic asialoglycoprotein receptor (HBP), recognize a 55,000-mol wt HD-cell protein (Paietta, E., R. J. Stockert, A. G. Morell, V. Diehl, and P. H. Weirnik. 1986. Proc. Natl. Acad. Sci. USA. 83:3451-3455.) That the expression of the 55,000-mol wt protein is restricted to HD-cells among X-hapten positive cells lines is confirmed in this study. The 55,000-mol wt protein is shown to be present on the cell surface and intracellularly, where an additional immunocrossreactive 150,000-mol wt protein is recognized. Extraction of the 55,000 mol wt protein from HD-cell lysates by affinity chromatography results in the loss of sialyltransferase activity. While evidence for a single protein possessing both the antigenic and the enzymatic activity is not direct, these results suggest that the ectosialyltransferase unique to HD-cells is a 55,000-mol wt membrane glycoprotein possessing the X-hapten oligosaccharide.

High-dose recombinant interleukin-2 alone: a regimen with limited activity in the treatment of advanced renal cell carcinoma.

Sixteen patients with metastatic renal cell carcinoma were treated with high-dose bolus recombinant interleukin-2 (rIL-2) alone at a dose and schedule identical to those that produced a 35% response rate among 72 patients in a trial reported by the Surgery Branch, National Cancer Institute (NCI), Bethesda, Md, in which rIL-2 plus lymphokine-activated killer (LAK) cells was used for the treatment of renal cell carcinoma. Patients received two 5-day cycles of 100,000 Cetus U/kg (600,000 IU/kg) of rIL-2 infused intravenously over 15 minutes every 8 hours; each treatment cycle was separated by 1 week. No objective responses were seen. The toxicity of rIL-2 given alone at these high doses was similar to that noted with high-dose rIL-2-LAK cell therapy. The lack of responses seen in this trial also differed from the 21% response rate observed by the NCI Surgery Branch, using rIL-2 alone at an identical schedule and dose in 56 patients with renal cell carcinoma. Only minor differences in such recognized prognostic variables as performance status, tumor burden, and rIL-2 dose intensity were noted between this study and other trials reported by the NCI Surgery Branch and by the IL-2-LAK Working Group. Our analysis indicates that, because of the smaller number of patients in our trial, not enough subjects were included with the ideal characteristics to attain the 21% response rate seen in the NCI study. However, the precise nature of these characteristics remains unclear.

Opportunistic infection and immunologic function in patients with human immunodeficiency virus-associated non-Hodgkin's lymphoma treated with chemotherapy.

BACKGROUND: The incidence of systemic non-Hodgkin's lymphoma (NHL) is higher in the population infected with human immunodeficiency virus (HIV) than in the uninfected population. Standard treatment for this cancer involves the administration of systemic chemotherapy. PURPOSE: Our objective was to determine the relative risk (RR) of opportunistic infection and the relative change in immunologic function in a cohort of patients who had HIV-associated NHL and who were treated with combination chemotherapy and to compare them with those in a matched cohort of control subjects who had advanced HIV infection but no signs of NHL. METHODS: We performed a case-control study in which the clinical course of each patient with HIV-associated NHL (n = 43; case subjects) treated with infusional cyclophosphamide, doxorubicin, and etoposide was compared with that of two patients with HIV infection but without lymphoma who were matched for CD4 lymphocyte count and prior opportunistic infection (n = 86; control subjects). The patients' medical records were reviewed for all information related to acquired immunodeficiency syndrome (AIDS)-defining opportunistic infections, survival, cause of death, and lymphocyte subset analyses. Univariate and multivariate analyses were performed to determine whether any of a number of confounding factors (e.g., age, sex, CD4 count, prior opportunistic infection, and prior antiretroviral therapy) could have influenced the risk of developing a first infectious event (defined as opportunistic infection or nonlymphoma death). All P values resulted from two-sided statistical tests. RESULTS: In the univariate analysis, a significantly greater risk for a first event was associated with being a case subject (RR = 1.8; 95% confidence intervals [CI] = 1.1-3.0; P < .05), having a low CD4 count (< 100/microL) (RR = 3.1; 95% CI = 1.8-5.4; P < .0001), being female (RR = 1.7; 95% CI = 1.1-3.3; P < .05), having prior Pneumocystis carinii pneumonia (RR = 3.5; 95% CI = 1.9-6.3; P < .0001), having any prior opportunistic infection (RR = 3.6; 95% CI = 2.1-6.4; P < .0001), and having prior antiretroviral therapy (RR = 1.9; 95% CI = 1.1-3.3; P < .05). In the multivariate analysis, however, being a case subject (RR = 2.1; 95% CI = 1.2-3.6; P < .01), having a low CD4 count (RR = 2.1; 95% CI = 1.2-3.9; P < .05), and being female (RR = 3.0; 95% CI = 1.8-5.6; P < .001) were the only characteristics associated with an increased risk of a first event. When the mean CD4 lymphocyte count at approximately 1 year was compared with that at baseline, there was a significantly greater decrease in the CD4 count among case subjects than among control subjects (mean decrease +/- standard deviation [SD] = 99/microL +/- 138/microL versus 29/microL +/- 100/microL; P = .03). CONCLUSIONS: Treatment of patients who have HIV-associated NHL with a non-steroid-containing chemotherapy regimen was associated with a significant and sustained reduction in the CD4 lymphocyte count and a twofold increase in the risk of developing opportunistic infection. IMPLICATIONS: Oncologists and other physicians who treat patients with HIV-associated NHL should be familiar with the prophylaxis, recognition, and management of opportunistic infection. In addition, there is a need to identify effective strategies for the amelioration of chemotherapy-induced immunosuppression in this population.

Partial reversal of doxorubicin resistance by forskolin and 1,9-dideoxyforskolin in murine sarcoma S180 variants.

Acquired resistance to chemotherapeutic agents is an important clinical problem. One preclinical model, termed multidrug resistance (MDR), is characterized by a complex phenotype of cross-resistance to biochemically unrelated antineoplastic agents, the presence of a high-molecular-weight membrane glycoprotein, and impaired accumulation of drug. To determine whether MDR is mediated in part by altered cyclic 3',5'-adenosine monophosphate (cAMP) levels, the effect of incubation with the adenylate cyclase agonist, forskolin, was investigated in the murine sarcoma S180 cell line and two MDR variants (A5-.8, A5-2.5). Basal cAMP levels in sensitive and MDR lines were not significantly different (range, 0.15 +/- 0.05 to 0.31 +/- 0.09 pmol/mg protein); however, 1-h incubation with forskolin, 10 microM, elevated intracellular cAMP 2-fold in the parent line and 43- and 35-fold in the variants. The adenylate cyclase agonists, prostaglandin E2 and cholera toxin, and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine had no significant effect on cAMP levels. To determine the effect of forskolin on doxorubicin-induced cell lethality, S180 and MDR lines were incubated with doxorubicin plus forskolin for 1 h and cloned in soft agar. Coincubation with forskolin partially reversed doxorubicin resistance in the MDR lines in a dose-dependent fashion. To determine whether this effect was mediated solely by elevation of intracellular cAMP, the inactive 1,9-dideoxy analogue of forskolin (DF) was used. Incubation with DF resulted in no elevation of cAMP levels in the sensitive or resistant cell lines; however, DF also partially reversed doxorubicin resistance in the MDR variants. Furthermore, coincubation of the A5-2.5 cell line with doxorubicin and 8-bromo cAMP, 1 mM, did not result in reversal of resistance to doxorubicin. To determine whether the reversal of resistance by the diterpenes was associated with alteration of doxorubicin transport, uptake and efflux of [14C]doxorubicin were measured. Coincubation with both forskolin and DF, 10 microM, enhanced [14C]doxorubicin uptake in the resistant cells, while drug efflux was significantly affected only in the cell line exhibiting intermediate resistance. Since both forskolin and its inactive analogue are effective in partially reversing resistance to doxorubicin and augmenting anthracycline uptake, a mechanism other than elevation of cAMP is most likely responsible.

Phase I trial of 5-fluorouracil and recombinant alpha 2a-interferon in patients with advanced colorectal carcinoma.

We have previously shown that the combination of 5-fluorouracil (5-FUra) and recombinant alpha-2a-interferon (rIFN-alpha-2a) produced objective responses in 23 of 32 (63%) previously untreated patients with advanced colorectal carcinoma. Because in vitro data suggest that rIFN-alpha-2a modulates the cytotoxic effects of 5FUra in a concentration-dependent manner, a phase I clinical trial was initiated to determine the maximum tolerated dose of rIFN-alpha 2a when administered in combination with 5FUra. A total of 27 patients with advanced colorectal carcinoma were enrolled. The median age was 64 years, and the median performance status was 1. A total of 18 patients had no prior chemotherapy and 19 no prior 5FUra. 5FUra was administered at 750 mg/m2/day by continuous i.v. infusion for 5 days, followed by weekly bolus therapy. rIFN-alpha 2a was administered at 6, 9, 12, 15, or 18 x 10(6) units s.c. beginning on day 1. The dose-limiting toxicity of this regimen was fatigue, resulting in a decrease in performance status, and this was the only toxicity that correlated with increasing dose of rIFN-alpha 2a. Eastern Cooperative Oncology Group grade 3-4 toxicities included leukopenia (6), thrombocytopenia (2), anemia (4), stomatitis (4), diarrhea (4), neurological (2), infection (2), and allergy (2). Three quarters of the patients required interruption of therapy or dose reductions of either 5FUra or rIFN-alpha 2a for toxicity. Among the patients with measurable disease who were previously untreated with 5FUra, 5 of 9 at the lowest dose levels achieved an objective response, including one pathological complete responder, whereas 0 of 9 at the three highest dose levels responded. Among patients previously treated with 5FUra, only 1 achieved an objective response. We conclude that the maximum tolerated dose of rIFN-alpha 2a, when administered with 5FUra as above, is 15-18 x 10(6) units; however, the efficacy of this regimen does not appear to be related to the dose intensity of rIFN-alpha 2a, and future regimens should employ a lower dose, intermittent schedule of rIFN-alpha 2a, which may be better tolerated.

A membrane-bound lectin responsive to monocytic maturation in the promyelocytic leukemia cell line HL-60.

A novel mammalian lectin activity responsive to monocytic differentiation is described in the human promyelocytic leukemia cell line HL-60. Glycoprotein binding indicates that the lectin recognizes both N-acetylneuraminic acid and galactose-terminating biantennary oligosaccharide structures. Lectin activity is independent of calcium and appears to reside in a Mr 17,000 intracellular membrane protein. Induction of wild-type HL-60 cells into their macrophage-like counterparts by 1,25-dihydroxyvitamin D3 markedly enhances lectin activity. Induction of granulocytic differentiation by retinoic acid does not affect expression of the lectin. HL-60 sublines which are resistant to granulocytic differentiation by retinoic acid, dimethylsulfoxide, or 6-thioguanine are largely deficient in orosomucoid-binding activity. Induction of monocyte/macrophage differentiation of these sublines upregulates lectin activity to the level seen in induced wild-type cells.

Clinical phase I-II and pharmacokinetic study of high-dose thymidine given by continuous intravenous infusion.

High-dose thymidine (dThd) was given to 12 patients with advanced hematological and solid tumors. The dose schedule used was 75 g/sq m/day, given i.v. continuously for 5 days or more. Myelosuppression, especially leukopenia, was the dose-limiting toxicity. Nonhematological toxicities affected the gastrointestinal tract (nausea, vomiting, anorexia, diarrhea, and indigestion) and the central nervous system (somnolence, headache, visual illusions, and memory impairment). Patients who had received cumulative doses of dThd developed alopecia. Thymine crystals were noted in the urine after refrigeration. Tumor regression (less than partial remission) occurred in one patient with melanoma. Three of four patients with acute leukemia had a fall in peripheral white blood cell counts and blasts but no marrow improvement. Four patients with adenocarcinoma (three colon, one unknown primary) had stable disease. Pharmacokinetic studies revealed that, at a dThd dose of 75 g/sq m/day, millimolar concentrations of dThd and thymine can be achieved in the plasma. The half-life of dThd was approximately 100 min. One-third of the plasma concentrations was measurable in the cerebrospinal fluid. dThd was mainly excreted by the kidneys.

Pharmacokinetic studies during phase I trials of high-dose thymidine infusions.

Thymidine infusions (75 g/sq m/24 hr) were administered to 12 cancer patients as part of a Phase I study. Thymidine and thymine measurements, by high-pressure liquid chromatography, were made on plasma and urine from eight of these patients. Only the pharmacokinetic aspects of these studies are reported in this paper. Millimolar thymidine and thymine concentrations were achieved in all patients and maintained for 120 hr during each of three courses of infusion. The half-life of thymidine was approximately 100 min following cessation of infusion. The half-life of thymine was much longer but could not be accurately determined because it did not decline as a first-order rate function. The cerebrospinal fluid:plasma ratios at steady state for thymidine and thymine were 0.29 and 1.03, respectively. Total body clearance of thymidine ranged from 95 to 266 ml/min/sq m, and 41 to 67% was by kidney clearance of intact thymidine. Calculations and comparison to other studies at lower infusion rates (micromolar plasma thymidine) indicate that thymidine is metabolized significantly by organs in addition to the liver and that, at millimolar plasma thymidine, total body metabolic processes of thymidine are saturated as is the secretory portion of kidney clearance.

Abnormalities of complement and its components in patients with acute leukemia, Hodgkin's disease, and sarcoma.

Whole complement and component titers were measured in patients with acute leukemia, Hodgkin's disease, and sarcoma. Serum samples were obtained from 42 consecutive patients and 11 healthy control subjects. Sera were frozen and maintained at -70 degrees until analyzed by hemolytic assay. Titers were normalized using a titer obtained from a single source of pooled human serum analyzed simultaneously with each patient sample to correct for day-to-day variation inherent in the assay technique. Significant elevations (p less than or equal to 0.05) of whole complement and C5, C8, and C9 were observed for each patient category, compared to controls. Forty-one of 42 patients had C9 titers greater than or equal to 2 S.D. above the mean titer for controls. Mean C3 and C7 titers were not elevated or depressed in any group. No clinical factors that correlated with abnormal complement or component titers were identified.

Hodgkin's cell lectin: an ectosialyltransferase and lymphocyte agglutinant related to the hepatic asialoglycoprotein receptor.

The galactophilic lectin expressed on the surface of cultured Hodgkin's cells, recently described by this laboratory, has binding characteristics similar to those of the hepatic asialoglycoprotein receptor (HBP), and has been recognized as a Mr 55,000 (p55) membrane glycoprotein by a polyclonal antiserum to rat HBP. This study confirms the close structural relationship between the two lectins showing immunological cross-reactivity of monoclonal and polyclonal antibodies recognizing distinct epitopes on rat or human HBP. In support of the suggested dual nature of p55 as lectin and ectosialyltransferase, enzyme activity is inhibited by the monoclonal anti-HBP antibody, anti-HA 116. Cultured Hodgkin's cells, as purified HBP, agglutinate T-lymphocytes expressing hyposialylated membrane glycosyl determinants. This cell-cell interaction mediated by p55 results in the incorporation of sialic acid into lymphocyte surface asialo-glycans. The function of the Hodgkin's lectin as lymphocyte agglutinant in vitro suggests its role as an immunomodulator contributing to the immunodeficiencies associated with Hodgkin's disease.

Phase I clinical and pharmacokinetic study of taxol.

Taxol, selected for clinical trial because of its animal antitumor activity and unique structure and mechanism of action, was administered in Cremophor by i.v. infusion over 6 h in a phase I study. Eastern Cooperative Oncology Group toxicity grading was used. Eighty-three taxol courses were administered to 34 patients. Grade 3-4 hypersensitivity reactions occurred in 4 of 13 courses at the first 2 dose levels, but premedication with dexamethasone, diphenhydramine, and cimetidine resulted in only 3 additional Grade 2 reactions in the next 70 courses. Neurotoxicity, which resolved or improved after stopping therapy, was Grade 1 with 2 of 10 courses of 230 mg/m2 and Grades 1-3 after 11 of 12 courses of 275 mg/m2. Leukopenia, first seen (Grade 1) after 1 of 8 75 mg/m2 courses, was Grades 3-4 after 10 of 34 courses of 175-230 mg/m2 and 10 of 12 courses of 275 mg/m2. The WBC nadir occurred at a median of 10 days and the median time required for normalization of the WBC was 18 days. Alopecia began 2-3 weeks posttaxol in 2 of 9 patients treated with 75-135 mg/m2 and in all 16 patients (Grade 3) treated with 175-275 mg/m2. Grades 1-2 nausea and vomiting occurred in about one-third of the patients treated at a dose of 105 mg/m2 or more. Taxol disappearance from plasma was biphasic; half-lives of the first and second phases after a 275 mg/m2 dose were 0.32 and 8.6 h, respectively. The apparent volume of distribution was 55 liters/m2, and the peak plasma concentration with a dose of 275 mg/m2, which occurred immediately postinfusion, was approximately 8 microM. Only 5% of parent drug was excreted in the urine within 24 h. Minor objective responses were noted in one patient with gastric cancer and another with ovarian carcinoma. In addition, one patient with massive ascites due to metastatic adenocarcinoma from an unknown primary had only minimal sonographic evidence of ascites for 6 months posttreatment. Neurotoxicity and leukopenia were dose limiting in this schedule. The recommended phase II trial dose is 250 mg/m2, with premedication.

Expression of the macrophage growth factor, CSF-1 and its receptor c-fms by a Hodgkin's disease-derived cell line and its variants.

Expression of the macrophage colony-stimulating factor CSF-1 and its receptor, the product of the protooncogene c-fms, was detected in cell line L428, originally derived from a patient with nodular sclerosis Hodgkin's disease, and its two sublines L428KS and L428KSA. While all lines expressed membrane-associated and soluble CSF-1 proteins, L428KSA secreted 30-fold greater amounts of CSF-1 than the other cells. Three transcripts for CSF-1 (4.4, 3.7, 3.4 kilobases) were expressed in all lines and an additional 2.1-kilobase message in L428KSA. Restriction enzyme fragment analysis did not reveal any gross rearrangements of the CSF-1 gene. L428 and L428KS contained a 4.4-kilobase message for c-fms, whereas L428KSA expressed a smaller 3.8-kilobase c-fms transcript. The c-fms gene structure appeared to be unaltered in all lines by restriction enzyme fragment pattern analysis. Monoclonal anti-c-fms antibody precipitated from all cells a Mr 120,000/130,000 doublet and two lower molecular weight phosphoproteins; however, only L428KSA cells showed evidence for an autocrine growth regulation by CSF-1. DNA ploidy and proliferation kinetic studies suggested that L428KSA were derived from the actively proliferating mononuclear Hodgkin's cell population of the parental cell line. Since the simultaneous expression of CSF-1 and c-fms is a characteristic feature of mononuclear phagocytes, these results suggest that Hodgkin's cells are affiliated with the monocyte/macrophage lineage or, at least, derived from a hemopoietic cell type with the capability for aberrant expression of a monocyte-specific growth factor and its receptor.

Chromosomal alterations in acute leukemia patients studied with improved culture methods.

Cytogenetic studies, using improved short-term culture techniques, were performed on 64 patients with acute leukemia to determine the incidence and kinds of clonal karyotypic changes detectable with this newer methodology. An adequate number of analyzable mitoses was obtained from 59 patients. Clonal chromosomal alterations were found in 88% (52 of 59) of patients, as compared to approximately 50% in previous studies of acute leukemia in which conventional techniques were used. From our series, abnormal karyotypes were detected in 37 of 44 (84%) cases with primary acute nonlymphocytic leukemia, all 5 with secondary acute nonlymphocytic leukemia, and all 10 with acute lymphoblastic leukemia. Among the entire group of patients, several recurrent abnormalities were observed, e.g., -7 in eight cases, +8 in seven cases, t(15;17) in four cases, and t(8;21) or a variant of this translocation in four cases. In five patients, the only abnormality was a rather subtle structural rearrangement (e.g., tiny deletion). Five other patients had clonal changes which were found in less than 10% of the mitoses examined in each case. Our results indicate that most patients with acute leukemia, both acute nonlymphocytic leukemia and acute lymphoblastic leukemia, have clonal chromosome abnormalities associated with their disease.

Severe hypovitaminosis C occurring as the result of adoptive immunotherapy with high-dose interleukin 2 and lymphokine-activated killer cells.

Adoptive immunotherapy of human cancer was investigated in our institution as part of a National Cancer Institute extramural group study. This treatment, for patients with metastatic malignant melanoma, hypernephroma, and colon carcinoma, consisted of three phases: (a) 5 days of i.v. high-dose (10(5) units/kg every 8 h) interleukin 2, (b) 6 1/2 days of rest plus leukapheresis; and (c) 4 days of high-dose interleukin 2 plus three infusions of autologous lymphokine-activated killer cells. Toxicities included fever, chills, tachycardia, hypotension, vomiting, diarrhea, and fluid retention. Ascorbic acid is known to be important to cell-mediated immunity, and it has been reported to be depleted during physiologically stressful events. Therefore, we determined plasma ascorbic acid levels in patients (n = 11) before adoptive immunotherapy and before and after Phases 1, 2, and 3 of treatment. Patients entering the trial were not malnourished. Mean plasma ascorbic acid levels were normal (0.64 +/- 0.25 mg/dl) before therapy. Mean levels dropped by 80% after the first phase of treatment with high-dose interleukin 2 alone (0.13 +/- 0.08 mg/dl). Mean plasma ascorbic acid levels remained severely depleted (0.08 to 0.13 mg/dl) throughout the remainder of the treatment, becoming undetectable (less than 0.05 mg/dl) in eight of 11 patients during this time. Values obtained from 24-h urine collections on two of two patients indicated that ascorbate was not excreted in the urine. Plasma ascorbic acid normalized in three of three patients tested 1 mo after the completion of treatment. Unlike the results for ascorbic acid, blood pantothenate and plasma vitamin E remained within normal limits in all 11 patients throughout the phases of therapy. Responders (n = 3) differed from nonresponders (n = 8) in that plasma ascorbate levels in the former recovered to at least 0.1 mg/dl (frank clinical scurvy) during Phases 2 and 3, whereas levels in the latter fell below this level.

Clinical correlations of leukemic clonogenic cell chemosensitivity assessed by in vitro continuous exposure to drugs.

This study was performed to assess the value of prolonged, as opposed to short-pulse, in vitro exposure of leukemic cells to chemotherapeutic drugs in leukemic clonogenic assay for prediction of clinical response. In 21 patients with acute nonlymphocytic leukemia treated with intensive combination chemotherapy based on an anthracycline and 1-beta-D-arabinofuranosylcytosine infusion, chemotherapy sensitivity of leukemic clonogenic cells was assessed in comparison with that of normal myeloid clonogenic cells by the in vitro continuous exposure to drugs throughout the entire culture period. Analysis of these in vitro data in terms of prediction of achieving clinical complete remission was carried out in comparison with data on 22 cases in which in vitro sensitivity was assessed by the pulse 1-hr exposure. The in vitro sensitivity index, expressed as a log odds ratio, was positive (greater than 0) in 8 of 11 patients achieving complete remission and negative (less than 0) in 7 of 10 patients failing to achieve complete remission, with an overall correlation of 71%. This is at least as good as the pulse exposure method, which has a correlation of 68%. If sensitivity indexes of marginal magnitudes (--1.0 approximately +1.0) are excluded, the correlation increases to 92% (12 of 13 patients). The correlation appears to improve especially for 1-beta-D-arabinofuranosylcytosine by the continuous exposure method (71%) as compared with the pulse method (57%). This study establishes the feasibility of an in vitro chemotherapy sensitivity testing of leukemic clonogenic cells by continuous in vitro drug exposure and suggests that the continuous exposure method may be better than the pulse method for antimetabolites such as 1-beta-D-arabinofuranosylcytosine. The data also suggest that simulation of the in vivo drug schedule may be important in this in vitro test.

Phase I trial of N-(phosphonacetyl)-L-aspartate.

A Phase I clinical trial of N-(phosphonacetyl)-L-aspartate, an antimetabolite which inhibits a key enzyme in the de novo pathway of pyrimidine biosynthesis, was conducted. N-(Phosphonacetyl)-L-aspartate was given as an i.v. 15-min infusion once daily for five days; cycles of treatment were repeated every three weeks. Thirty-four patients received treatment. Dose-limiting toxicity was observed at 1500 to 2000 mg/sq m/day and was manifested by skin rash, diarrhea, and stomatitis. Rash and diarrhea usually began during the first week of treatment and persisted up to Day 17 of a cycle of therapy. No consistent hematopoietic, hepatic, or renal toxicity was observed. One partial response in a patient with colon carcinoma was seen and continues at more than eight months. Stable disease was observed in three patients with colon carcinoma, two patients with hypernephroma, one patient with pancreatic carcinoma, and one patient with melanoma. The predictability and reversibility of toxicity and the suggestion of antitumor activity in humans are observations which support the further evaluation of N-(phosphonacetyl)-L-aspartate in Phase II studies.

Constitutive expression of cellular retinoic acid binding protein II and lack of correlation with sensitivity to all-trans retinoic acid in acute promyelocytic leukemia cells.

The up-regulation of cellular retinoic acid binding protein-II (CRABP-II) has been invoked as an important mechanism of clinically acquired resistance to all-trans retinoic acid (RA) therapy in acute promyelocytic leukemia (APL). To test this hypothesis, we used quantitative reverse transcription-PCR and fast performance liquid chromatography procedures to examine the levels of CRABP-II mRNA and RA binding activity in APL patient samples. We found that CRABP-II mRNA in APL cells from pretreatment patients (n = 36) was constitutively expressed at relatively high levels (median, 0.92; range, 0.16-4.13) relative to the level in CRABP-H protein-expressing NB4 cells (arbitrarily set at 1.0 unit). Consistent with this finding, the RA binding activity of CRABP in APL cells from three pretreatment cases (range, 27.2-53.2 fmol/mg protein) was similar to that of NB4 cells (22.6 +/- 5.4 fmol/mg protein). Furthermore, in the pretreatment samples, there was no association between CRABP-H mRNA expression level and APL cellular sensitivity to RA-induced differentiation in vitro. After 45 days of remission induction therapy on Eastern Cooperative Oncology Group protocol E2491, CRABP-II mRNA was modestly increased from day 0 values in patients treated with either RA (median increase, 0.41) or chemotherapy (median increase, 0.56), and there was no significant difference between the two treatment groups (P = 0.91). In patients studied after relapse from RA therapy (n = 7), there was a significant decline in APL cell sensitivity to RA-induced differentiation in vitro compared with patients after relapse from chemotherapy (n = 5; P = 0.015-0.055 at three RA concentrations tested), but in the RA relapse cases, there was no change from pretreatment levels of CRABP-II mRNA (median, 0.98) or, in three relapse cases studied, of RA protein binding activity (range, 22.1-70.7 fmol/mg protein). Taken together, our data strongly imply that variations in CRABP-II expression and RA binding activity are not causally related to the development of clinically acquired APL cellular RA resistance, but rather, they suggest that constitutive expression of CRABP-II could have a facilitative role in the response of APL cells to RA.

Phase I clinical and pharmacological study of 4'-(9-acridinylamino)-methanesulfon-m-anisidide using an intermittent biweekly schedule.

4'-(9-Acridinylamino)methanesulfon-m-anisidide (m-AMSA, NSC 249992), an acridine derivative, was given to 28 patients with solid tumors and one patient with Hodgkin's disease in a Phase I clinical trial. The dose schedule used was a single dose given every 14 days for three doses. The amount given ranged from 10 to 120 mg/sq m/dose. Dose-limiting toxicity was moderate to severe leukopenia which occurred at and above 70 mg/sq m. Thrombocytopenia was infrequent and did not require transfusion. Nonhematological side effects were mild and included nausea, vomiting, local irritation, and fever. Antineoplastic activity was noted in liposarcoma, adenocarcinoma of unknown primary origin, and squamous carcinoma of unknown primary origin (one patient each). Pharmacokinetics studies were done in 19 patients. Total m-AMSA and free m-AMSA concentrations showed a biphasic distribution with an initial rapid phase of t1/2 = 10 to 15 min for both, and a second slow phase of t1/2 = 8 to 9 hr for total m-AMSA and 3 hr for free m-AMSA. Phase II studies with m-AMSA, in hematological cancers are warranted, since its most consistent effect is on leukocytes. The recommended dosages for solid-tumor Phase II studies are 70 mg/sq m for good-risk patients and 50 mg/sq m for poor-risk patients, given as a single dose every other week, or 120 mg/sq m for poor-risk patients for the single-dose every-3-week schedule.