Sub-epitopic dissection of HCV E1315-328HRMAWDMMMNWSPT sequence by similarity analysis.

Our labs are focused on identifying amino acid sequences having the ability to react specifically with the functional binding site of a complementary antibody. Our epitopic definition is based on the analysis of the similarity level of antigenic amino acid sequences to the host proteome. Here, the similarity profile to the human proteome of an HCV E1 immunodominant epitope, i.e. the HCV E1(315-328)HRMAWDMMMNWSPT sequence, led to i) characterizing the immunoreactive HCV E1 315-328 region as a sequence endowed with a low level of similarity to human proteins; ii) defining 2 contiguous immunodominant linear determinants respectively located at the NH(2) and COOH terminus of the conserved viral antigenic sequence. This study supports the hypothesis that low sequence similarity to the host's proteome modulates the pool of epitopic amino acid sequences in a viral antigen, and appears of potential value in defining immunogenic viral peptide sequences to be used in immunotherapeutic approaches for HCV treatment.

Active specific immunotherapy in patients with melanoma. A clinical trial with mouse antiidiotypic monoclonal antibodies elicited with syngeneic anti-high-molecular-weight-melanoma-associated antigen monoclonal antibodies.

In two clinical trials the mouse antiidiotypic monoclonal antibody (MAb) MF11-30, which bears the internal image of human high-molecular-weight-melanoma-associated antigen (HMW-MAA) was administered by subcutaneous route without adjuvants to patients with stage IV malignant melanoma on day 0, 7, and 28. Additional injections were administered if anti-antiidiotypic antibodies were not found or their titer decreased. In the first phase I trial with 16 patients the initial dose was 0.5 mg per injection and escalated to 4 mg per injection. Neither toxicity nor allergic reactions were observed despite the development of anti-mouse Ig antibodies. Minor responses were observed in three patients. In a second clinical trial MAb MF11-30 was administered to 21 patients at a dose of 2 mg per injection, since this dose had been shown in the initial study to be effective in inducing anti-antiidiotypic antibodies. Two patients were inevaluable; in the remaining 19 patients, the average duration of treatment was 34 wk. In this trial as well, neither toxicity nor allergic reactions were observed. 17 of the 19 immunized patients increased the levels of anti-mouse Ig antibodies and 16 developed antibodies that inhibit the binding of antiidiotypic MAb MF11-30 to the immunizing anti-HMW-MAA MAb 225.28. One patient increased the level of anti-HMW-MAA antibodies. One patient achieved a complete remission with disappearance of multiple abdominal lymph nodes for a duration of 95 wk. Minor responses were observed in three patients. These results suggest that mouse antiidiotypic MAb that bear the internal image of HMW-MAA may be useful reagents to implement active specific immunotherapy in patients with melanoma.

Diet in the epidemiology of cancer of the colon and rectum.

We examined the diets as reported in interviews of 256 white male patients with cancer of the colon and of 330 white male patients with cancer of the rectum. Controls were 783 patients with nonneoplastic, nondigestive system diseases distributed by age similarly to the colon cancer patients and 628 patients with nonneoplastic, nondigestive diseases distributed by age like those with cancer of the rectum. We found no increase in risk for cancer of the colon or rectum regardless of the amounts of beef or other meats ingested. However, we found an increase in risk of colon cancer with decreases in the frequency with which vegetables were eaten. A study of 214 females with cancer of the colon and 182 females with cancer of the rectum yielded similar results. The decrease in risk we found associated with frequent ingestion of vegetables, and especially cabbage, Brussels sprouts, and broccoli, is consistent with the decreased numbers of tumors observed in animals challenged with carcinogens and fed compounds found in these same vegetables.

Plasminogen activator content of human colon tumors and normal mucosae: separation of enzymes and partial purification.

Plasminogen activator content was determined quantitatively in extracts of 23 pairs of surgically removed colon tumors and adjacent normal mucosa specimens. The activator content averaged 4.4 times higher in the tumor samples than in the corresponding normal tissue. Polyps removed with the adenocarcinomas gave values intermediate between those for tumors and those for the normal mucosae. The enzyme content of the group of tumors that showed invasive propagation or metastatic spread was significantly higher (P < 0.05) than was the enzyme content of the group not manifesting these conditions. Activator activity of the tumor extracts was completely inhibited by rabbit antibody formed against human urokinse. The activity of the normal mucosae was variably inhibited, suggesting the presence of several kinds of activator in normal tissues. The activator from the normal tissues could be separated into a completely refractory fraction and a completely inhibitable fraction by means of an affinity column made of Sepharose-linked, rabbit antiurokinase antibody. The activator, eluted from this column with 1 M acetic acid in 0.5 M NaCl (pH 2.2), was highly purified and had an isoelectric point of 8.6, as does authentic urokinase. The details of the isoelectric profile of the two, however, differed. The data are discussed in relation to earlier studies on the fibrinolytic system in colon cancer.

Kinetics of the immune response and regression of metastatic lesions following development of humoral anti-high molecular weight-melanoma associated antigen immunity in three patients with advanced malignant melanoma immunized with mouse antiidiotypic monoclonal antibody MK2-23.

Active specific immunotherapy has been implemented in patients with advanced malignant melanoma, utilizing the mouse antiidiotypic (anti-id) monoclonal antibody (mAb) MK2-23 which bears the internal image of high molecular weight-melanoma associated antigen (HMW-MAA). In a previous study, development of anti-HMW-MAA immunity in patients with advanced malignant melanoma immunized with anti-id mAb MK2-23 was found to be associated with a statistically significant survival prolongation. Since no information is available about the relationship between development of immunity and clinical response in patients immunized with anti-id mAb, the present study has characterized the kinetics of the immune response in three patients with advanced malignant melanoma who experienced regression of metastatic lesions following immunization with the anti-id mAb MK2-23. The three patients developed anti-mouse IgG antibodies, anti-anti-id antibodies and anti-HMW-MAA antibodies. The anti-HMW-MAA antibodies are mainly IgG, suggesting that the immune response elicited by anti-id mAb MK2-23 is T-cell dependent. The development of anti-HMW-MAA immunity preceded the reduction in the size of metastatic lesions. This temporal relationship suggests but does not prove that the anti-HMW-MAA immunity elicited by anti-id mAb MK2-23 has a beneficial effect on the clinical course of the disease in patients with malignant melanoma. This finding in conjunction with minor side effects associated with repeated administrations of mouse anti-id mAb MK2-23 suggest that active specific immunotherapy with anti-id mAb which bear the internal image of melanoma-associated antigen represents a viable therapeutic approach to malignant melanoma.

Effects of 1,2-symmetrical dimethylhydrazine on jejunocolic transposition in Sprague-Dawley rats.

In this experiment, a segment of the left colon including the upper part of the rectum was transposed to the upper jejunum, and a segment of upper jejunum was transposed to the left colon of the same animal. In another group, the same colon and jejunum segments were transsected and reanastomosed in place. A third group served as a normal control. After a recovery period, weekly s.c. 1,2-symmetrical dimethylhydrazine injections were begun. Each animal received a total of 20 injections at a dose of 20 mg/kg. Five weeks after the last 1,2-symmetrical dimethylhydrazine injection, 15 of 19 (79%) of the animals had one or more tumor(s) in the transposed colon segment, while none had tumor in the transposed jejunal segment. Transsected and reanastomosed animals showed the same distribution of tumors as did the normal control animals. All three groups had tumors at other sites in the colon and rectum. In addition, about 20% had tumors of the duodenojejunal area. These data indicate that the colonic mucosa is the primary target for the carcinogenic effect of 1,2-symmetrical dimethylhydrazine, independent of other variables such as the fecal stream.

Plasminogen activator secretion of human tumors in short-term organ culture, including a comparison of primary and metastatic colon tumors.

The secretion of plasminogen activator by explants of 92 human malignant tumors was studied in short-term organ culture. Where possible, adjacent normal tissue of the presumed origin of the tumors was also studied. The study included adenocarcinomas of the lung, colon, prostate, breast, and stomach and different types of sarcomas. In addition to the measurement of secretion rates, all tissues were quantitatively extracted to determine the amount of cell-bound enzyme. Both culture fluids and extracts were analyzed with respect to the type of plasminogen activator they contained by immunoinhibition with goat immunoglobulin G formed against purified human urinary urokinase sodium dodecyl sulfate:gel electrophoresis followed by zymography. The study yielded the following conclusions: (a) the measurement of plasminogen activator secretion rates gives a much sharper differentiation between malignant and normal tissues than does the amount of extractable enzyme; (b) the enzymes secreted in short-term organ culture are, in the great majority of the cases studied, of the urokinase type, even when a large fraction of the activator contained in the tissue is of the vascular type; (c) the secretion rates of metastatic tumors of the colon are much lower than those of the primary ones; (d) immunoperoxidase staining of tissue sections reveals that urokinase is localized predominantly in the tumor cells. The low secretion rates of metastatic tumors, probably a reflection of this property in the original cell that gave rise to the metastatic focus, could be of advantage to circulating cancer cells. Such cells would not dissolve the microthrombus thought to be essential for the arrest of cancer cells in the capillaries of target organs.

Expression of an unusual isozyme of lactate dehydrogenase in the serum of cancer patients and comparison with carcinoembryonic antigen.

Two studies reported here demonstrate a statistically significant association between metastatic cancer and the appearance of the k isozyme of lactate dehydrogenase in serum of affected patients. The first study included 190 coded samples from three types of cancer patients and matched controls; the second included 155 preoperative and 200 postoperative colorectal cancer patients. In the second, plasma carcinoembryonic antigen was compared with serum k isozyme of lactate dehydrogenase as an indicator of the presence of metastatic cancer. This comparison showed that both markers were independently useful for assessing patient status and predicted that a combination of the two should be a better discriminator for the presence of metastases than either marker alone.

Genetics of colon carcinogenesis in mice treated with 1,2-dimethylhydrazine.

Genetic analysis of colon tumor induction by symmetrical 1,2-dimethylhydrazine (DMH) was undertaken in F1, F2, and reciprocal backcross hybrids derived from a cross between two inbred mouse strains, the 100% susceptible ICR/Ha and completely resistant C57BL/Ha. Mice, 12 to 14 weeks old, received 22 successive weekly s.c. injections of 0.35% aqueous solution of DMH buffered to pH 6.5. A dose of 15 mg/kg/mouse/week produced invasive colon adenocarcinomas in all ICR/Ha males and females (60 of 60) within 22 weeks. None of the 90 C57BL/Ha mice developed DMH tumors during 44 weeks of observation. Susceptibility to the carcinogen was dominant, as indicated by 100% colon tumor incidence in reciprocal ICR/Ha X C57BL/HaF1 hybrids (68 of 68) and in the susceptible backcross ICR/Ha X F1 (42 of 42). Tumor yield in F2 hybrids (94 of 120) was 78%, which is in close agreement with the 3:1 ratio expected if a single dominant DMH susceptibility gene is inherited via the F1 from the ICR/Ha grandparent. Likewise, tumor yield in resistant backcross mice of genotype C57BL/Ha X F1 (46 of 117) is not out of line with the anticipated 1:1 ratio in the latter type of test hybrids. Tests with five isozyme markers and two coat color genes have tentatively ruled out linkage of DMH susceptibility on seven autosomes. The 47% tumor incidence among 57 male resistant backcross hybrids, regardless of whether their single X chromosome was inherited from the ICR/Ha or C57BL/Ha strain, provides evidence against sex linkage.

Clinical pharmacological studies of concurrent infusion of 5-fluorouracil and thymidine in treatment of colorectal carcinomas.

The effects of thymidine (dThd) coadministration on the pharmacokinetics and metabolism of 5-fluorouracil (FUra) were investigated in 29 colorectal cancer patients. Five patients received 5-day i.v. infusion of FUra at 15 mg/kg/day and 24 patients received infusion of FUra (7.5 mg/kg/day, 5 days) and dThd (216 mg/kg/day, 6 days) preceded by a bolus dose of dThd (405 mg/kg). Plasma and urine concentrations of FUra, 5-fluorodeoxyuridine (FdUrd), thymine, and dThd were quantitated by a high-pressure liquid chromatographic assay. Concurrent dThd administration reduced the plasma clearance of FUra at steady state from 389.1 +/- 153.5 (S.D.) to 56.0 +/- 36.4 liters/kg/day. The mean steady-state plasma concentration of FUra in patients receiving FUra alone was 0.38 microM and was significantly lower than the 1.30 microM in patients receiving FUra-dThd. Plasma concentrations of FUra were linearly dependent on those of thymine. Furthermore, the metabolic and renal clearances of FUra decreased inversely with thymine concentrations indicating that the elimination of FUra was reduced by thymine. In contrast to the absence of FdUrd as a circulating metabolite in patients treated with FUra alone, microM concentrations of FdUrd were detected in plasma of most of the patients treated with FUra-dThd. This together with the linear correlation of FdUrd and dThd concentrations indicates that the interconversion of FUra to FdUrd was enhanced by dThd. The incidence of dose-limiting leukopenia in the FUra-dThd combination therapy was 40%. There is an inverse correlation between the plasma clearance of FUra at steady state and hematological toxicity. The plasma clearance of FUra in the toxic population was 32.0 +/- 16.8 liters/kg/day and was significantly lower than the clearance of 72.0 +/- 37.3 liters/kg/day in the nontoxic population (p less than 0.001). The corresponding critical toxic steady-state FUra plasma concentration was 1.5 microM. The biochemical effects of dThd on the incorporation of FUra and FdUrd into RNA and into acid-soluble 5-fluorodeoxyuridine monophosphate (FdUMP) in human colon tumor cells were studied in vitro. At 100 microM, dThd increased the incorporation of FUra into RNA up to 4-fold but diminished the acid-soluble FdUMP pool. Similarly, the incorporation of FdUrd into acid-soluble FdUMP was inhibited by dThd. The response rate of colorectal carcinoma to FUra was not improved by coadministration of dThd; only one of the 11 patients who had no prior FUra therapy achieved partial remission. The lack of clinical response in these patients may be partly due to the inhibition of anabolism of FUra and FdUrd to FdUMP by dThd.

Isolation and characterization of a novel nucleoside, 7-beta-D-ribofuranosylhypoxanthine, from the urine of a chronic myelogenous leukemia patient.

A novel nucleoside, in the amount of 400 micrograms, was isolated from a 24-h collection of urine of a chronic myelogenous leukemia patient. On the basis of ultraviolet, nuclear magnetic resonance, and mass spectrometry and chromatography, its structure was established to be 7-beta-D-ribofuranosylhypoxanthine. The ultraviolet and mass spectral data and the thin layer chromatographic mobilities of the natural material were identical to those of a synthetic sample. High performance liquid chromatographic retention times and the coinjection high performance liquid chromatography of the natural material with the synthetic samples of the alpha and beta-anomers of 7-ribofuranosylhypoxanthines further confirmed the identity of the isolated material as 7-beta-D-ribofuranosylhypoxanthine.

Phase I-II trial of high-dose calcium leucovorin and 5-fluorouracil in advanced colorectal cancer.

Twenty-six patients with metastatic colorectal adenocarcinoma were entered into a Phase I-II study of 5-fluorouracil (5-FUra)-high-dose leucovorin (CF). The starting dose of 5-FUra was 300 mg/sq m with escalation to 750 mg/sq m/week in 6 doses given by rapid i.v. injection midway during a 2-hr infusion of CF, 500 mg/sq m. Partial responses were seen in 9 of 23 patients (6 of 12 who had had previous 5-FUra). Complete normalization of liver enzymes was seen in two of these patients. Side effects were seen sporadically with 5-FUra doses up to 600 mg/sq m. At a 600-mg/sq m 5-FUra dose, 8 of 18 patients had diarrhea, and 2 of 18 had white blood cell counts less than 3000/microliter. At a 750-mg/sq m dose of 5-FUra, 6 of 11 patients had severe diarrhea and 6 of 11 had white blood cell counts less than 3000/microliter. Other toxicities were mild conjunctivitis and lacrimation, thinning of the nails, and alopecia. In bioavailability studies of CF p.o., no plasma CF could be detected. After CF i.v., mean plasma peak was 111.3 +/- 40.3 (S.D.) microM. 5-FUra-CF appears to be effective in patients clinically resistant to 5-FUra. This study is being extended to randomized trial of 5-FUra-CF versus 5-FUra alone.

Phase I study of high-dose methotrexate with thymidine and low-dose leucovorin.

A total of 15 patients with advanced neoplastic disease, 13 with different solid tumors, one with lymphoma, and one with acute lymphocytic leukemia, underwent treatment consisting of continuous infusion of methotrexate (2 g/sq m/day) with concomitant thymidine (8 g/sq m/day) and leucovorin (1 mg/sq m/day). The dose of methotrexate was increased progressively by lengthening the methotrexate infusion from 2 to 7 days. After cessation of methotrexate infusion, thymidine and leucovorin were continued until the plasma level of methotrexate decreased to 2 X 10(-8) M. Toxicity was mucositis (23 of 27 evaluable courses), leukopenia (15 of 26 evaluable courses), thrombocytopenia (10 of 26 evaluable courses), renal and hepatic toxicity and diarrhea. Plateau levels of plasma methotrexate or methotrexate plasma half-life did not correlate with toxicity.

Phase II trial of Serratia marcescens extract in recurrent malignant astrocytoma.

Nineteen assessable patients with recurrent malignant astrocytomas who had failed standard therapy (surgery, radiation, and/or chemotherapy) were treated on a phase I-II trial with a biologic extract of Serratia marcescens (ImuVert; Cell Technology, Boulder, CO) a new biologic response modifier (BRM). Two complete responses (CRs) were seen, of 63 and 77+ weeks duration. One minor response (MR) occurred, of 6 weeks duration. There were four additional stable (S) patients, with durations of 58+, 39, 12, and 7 weeks. Median time to progression and median survival in the CR plus MR patients were 63 and 129+ weeks, respectively. Overall, median time to progression and median survival were 12 and 19 weeks, respectively. Three patients are alive greater than or equal to 2.5 years from study entry. Common toxicities included transient (less than 72 hours) tenderness, induration, and erythema at the injection sites. Systemic toxicities were less frequent and included fever, chills, nausea/vomiting, headache, arthralgia, and hypotension. The response rate (CR plus MR) to this new BRM is modest (16%). However, the observation of CRs in patients with advanced recurrent malignant astrocytomas, with acceptable overall toxicity, warrants further study of this agent.

Plasma and tumor tissue pharmacology of high-dose intravenous leucovorin calcium in combination with fluorouracil in patients with advanced colorectal carcinoma.

Plasma pharmacokinetics of high-dose (500 mg/m2) leucovorin calcium (dl-5-formyltetrahydrofolic acid [dl-CF]) and fluorouracil (FUra) have been evaluated in patients with advanced colorectal cancer treated with the combination of FUra and dl-CF by two different intravenous (IV) schedules: (A) In patients with no prior chemotherapy, dl-CF was administered by a two-hour IV infusion and FUra by rapid IV injection one hour after the start of the dl-CF infusion and (B) in previously treated patients, dl-CF and FUra were administered by five-day continuous IV infusion (CI). Following the two-hour infusion of dl-CF, mean peak plasma concentration and elimination half-life of I-5-formyltetrahydrofolic acid (I-CF) were 24 +/- 6 mumol/L and 0.8 +/- 0.1 hour, respectively. CI of dl-CF over five days yielded a mean steady-state plasma level of I-CF of only 1.2 +/- 0.5 mumol/L. Peak and steady-state plasma concentrations of the metabolite 5-methyl tetrahydrofolic acid were comparable in the two schedules (17 +/- 8 mumol/L for the two-hour infusion and 12 +/- 5 mumol/L for the CI). Areas under the concentration v time curve (AUC) of total reduced folates were significantly greater under conditions of CI: 89.0 v 16.7 mmol/L/min for the two-hour infusion. In tumor tissue, 5,10-methylenetetrahydrofolate increased eight-fold two to four hours following the two-hour infusion and two-fold during the CI of dl-CF and FUra. Inhibition of thymidylate synthase (dTMP-S) by the two-hour and CI infusion schedules were 66% v 39%, respectively. The observed differences in the intracellular dTMP-S folate cofactor pools and the degree of inhibition of dTMP-S achieved in patients treated by two different schedules may be due to differences in the biochemical properties and/or to differences in the modulation of FUra metabolism by folate of tumor tissues obtained from newly diagnosed and previously treated patients.

A prospective randomized trial of 5-fluorouracil versus 5-fluorouracil and high-dose leucovorin versus 5-fluorouracil and methotrexate in previously untreated patients with advanced colorectal carcinoma.

Seventy-four previously untreated patients with metastatic colorectal adenocarcinoma were prospectively randomized into one of three treatment regimens: (1) 5-fluorouracil (5-FU) 450 mg/m2 as an intravenous (IV) bolus daily for five days or toxicity, then 200 mg/m2 IV bolus every other day for six doses; (2) methotrexate (MTX) 50 mg/m2 in normal saline by IV infusion over four hours followed by an IV bolus of 5-FU 600 mg/m2. This was administered weekly for 4 weeks and then every 2 weeks. (3) Leucovorin 500 mg/m2 in a two-hour IV infusion of normal saline with 5-FU 600 mg/m2 as an IV bolus one hour after the Leucovorin began every week for 6 weeks. The combined complete and partial response rates in the three regimens were 11%, 5%, and 48%, respectively (P = .0009). The median duration of response in the 5-FU and Leucovorin regimen was 10 months. There was no statistically significant difference between the treatment regimens with respect to survival time (P = .6). Toxicity in the 5-FU and Leucovorin regimen was predominantly diarrhea (13 of 30 patients, 40%). In this regimen, eight of 13 patients (52%) who developed diarrhea not only required a dose reduction of 5-FU, but also hospitalization for IV hydration. The predominant toxicity in the 5-FU alone regimen and the 5-FU and MTX regimen was leukopenia. One drug-related death occurred in each regimen.

Squamous cell carcinoma antigen as a marker for squamous cell carcinoma of the anal canal.

Twenty-one patients with documented squamous cell carcinoma (SCC) of the anal canal underwent prospective serial collection of 101 serum samples for radioimmunoassay of SCC antigen to evaluate regression or progression of disease. Eighteen presented with primary SCC of the anal canal, two with metastatic disease, and one with a recurrence in the perineum. Median follow-up was 18 months. Thirteen of 22 serum samples were true-positives, and nine of 22 were false-negatives. Four of 79 serum samples were false-positives and 75 of 79 were true-negatives. The sensitivity of this test is 59% and the specificity is 95%, with the accuracy of a positive test being 76%.

A loading dose/continuous infusion schedule of fludarabine phosphate in chronic lymphocytic leukemia.

Using a loading dose/continuous infusion schedule, fludarabine phosphate was administered to 51 patients with previously treated chronic lymphocytic leukemia (CLL). All patients had evidence of active disease, and the majority had advanced Rai stages. Of the 42 patients assessable for response, 22 (52%) achieved a partial response, five (12%) had stable disease, and 15 (36%) progressed. Thirteen of the 22 responders improved their Rai stages with fludarabine therapy, including six patients who achieved stage 0. Response rates for pretreatment stages III and IV were 60% and 53%, respectively. Patients with final Rai stages 0 to II had better survival than those with stages III and IV. Patients who had undergone splenectomy before starting therapy were more likely to respond. Myelosuppression was the primary toxicity and did not appear to be cumulative. Severe leukopenia and thrombocytopenia, although infrequent, were associated with several deaths in the early cycles of treatment. Nonhematologic toxicity was mild with no serious neurotoxicity noted. Infections were common with 22 minor, 18 major, and 10 fatal episodes. Fludarabine phosphate by this alternative dosing schedule is effective in refractory advanced CLL and is well tolerated by the majority of patients.

Protein A immunoadsorption in the treatment of malignant disease.

Circulating immune complexes (CIC) are known to be present in cancer patients and are responsible for much of the cancer-associated immunosuppression. Removal or modulation of these "blocking factors" can reverse the immunosuppression. Protein A from Staphylococcus aureus has the unusual property of binding to CIC with high avidity. Use of protein A as an immunoadsorbent in extracorporeal immunotherapy affinity columns has resulted in antitumor and antiviral responses in animals. Our group developed a multicenter trial to assess toxicity and antitumor response with this biologic response modifier alone. Overall, 24% (21 of 87 patients) had objective tumor regressions including both partial responses (PR) and less than PR. No complete responses (CR) were observed. Responses were observed in acquired immune deficiency syndrome (AIDS)-related Kaposi's sarcoma (six of 17 PR; two of 17 less than PR; overall, 47%), breast adenocarcinoma (five of 22 PR; three of 22 less than PR; overall response, 36%), colon adenocarcinoma, (one PR, one less than PR; overall response, 11%), and non-oat cell lung carcinoma (two of seven less than PR). The procedure was well tolerated and could be performed on an outpatient basis. No adverse reaction was observed in 735 of 1,113 treatments (66%). The most common adverse effect was an "influenza-like" syndrome consisting of fever and chills. Pain was present in 12% of the patients. There were no study-related deaths. Serum IgG and CIC levels did not statistically change due to therapy in responding or nonresponding patients. Complement levels remained within the normal range. Liver and renal tests remained stable throughout the study. In summary, protein A immunoadsorption of plasma is well tolerated in the outpatient clinic, has demonstrated antitumor activity in resistant solid tumors, and functions as a biologic response modifier.

Phase I clinical and pharmacokinetic evaluation of high-dose mitoxantrone in combination with cytarabine in patients with acute leukemia.

PURPOSE: To determine the maximally tolerated dose of mitoxantrone in combination with cytarabine in patients with acute leukemia and advanced phases of chronic myelogenous leukemia (CML), and to assess the pharmacokinetics of high-dose mitoxantrone in this patient population. PATIENTS AND METHODS: In a phase I study, 68 patients with acute myelogenous leukemia (AML), acute lymphoblastic leukemia (ALL), and accelerated- and blastic-phase CML received induction therapy consisting of cytarabine 3 g/m2 by infusion over 3 hours daily for 5 days, with escalating doses of mitoxantrone 40 to 80 mg/m2 over 1 to 2 days by intravenous infusion over 15 minutes. Mitoxantrone pharmacokinetics were evaluated by high-performance liquid chromatography (HPLC) in 15 patients given a single dose of mitoxantrone ranging from 40 to 80 mg/m2 in combination with cytarabine. RESULTS: Severe, but reversible hyperbilirubinemia (> three times normal) was considered the dose-limiting toxicity, and was observed in 25% of all patients and in 35% of those who received 70 to 80 mg/m2 of mitoxantrone. Other extramedullary toxicity, including cardiac dysfunction, was mild. Myelosuppression was universal and the median time to complete remission (CR) was 28 days (range, 19 to 77). The CR rate for previously untreated and relapsed patients with AML was 85% (17 of 20) and 38% (seven of 18), respectively. Eighty-three percent (15 of 18) of patients with ALL achieved a CR, including all patients with previously untreated disease. Eight of 12 patients with advanced-phase CML achieved a CR. No significant changes in mean mitoxantrone plasma elimination rates (ie, terminal plasma half-life and total-body clearance rate) occurred as the mitoxantrone dose doubled, indicating linear pharmacokinetics. CONCLUSIONS: The recommended phase II dose of mitoxantrone is 80 mg/m2 administered over 15 minutes as a single intravenous infusion in combination with cytarabine 3 g/m2/d for 5 days. At this dose, high concentrations of mitoxantrone are achievable in vivo to levels that have been shown to be extremely cytotoxic in vitro.