Search

Background: T cells engineered to express chimeric antigen receptors (CARs) have established efficacy in the treatment of B-cell malignancies, but their relevance in solid tumors remains undefined. Here we report results of the first human trials of CAR-T cells in the treatment of solid tumors performed in the 1990s., Methods: Patients with metastatic colorectal cancer (CRC) were treated in two phase 1 trials with first-generation retroviral transduced CAR-T cells targeting tumor-associated glycoprotein (TAG)-72 and including a CD3-zeta intracellular signaling domain (CART72 cells). In trial C-9701 and C-9702, CART72 cells were administered in escalating doses up to 10 10 total cells; in trial C-9701 CART72 cells were administered by intravenous infusion. In trial C-9702, CART72 cells were administered via direct hepatic artery infusion in patients with colorectal liver metastases. In both trials, a brief course of interferon-alpha (IFN-α) was given with each CART72 infusion to upregulate expression of TAG-72., Results: Fourteen patients were enrolled in C-9701 and nine in C-9702. CART72 manufacturing success rate was 100% with an average transduction efficiency of 38%. Ten patients were treated in CC-9701 and 6 in CC-9702. Symptoms consistent with low-grade, cytokine release syndrome were observed in both trials without clear evidence of on target/off tumor toxicity. Detectable, but mostly short-term (≤14 weeks), persistence of CART72 cells was observed in blood; one patient had CART72 cells detectable at 48 weeks. Trafficking to tumor tissues was confirmed in a tumor biopsy from one of three patients. A subset of patients had 111 Indium-labeled CART72 cells injected, and trafficking could be detected to liver, but T cells appeared largely excluded from large metastatic deposits. Tumor biomarkers carcinoembryonic antigen (CEA) and TAG-72 were measured in serum; there was a precipitous decline of TAG-72, but not CEA, in some patients due to induction of an interfering antibody to the TAG-72 binding domain of humanized CC49, reflecting an anti-CAR immune response. No radiologic tumor responses were observed., Conclusion: These findings demonstrate the relative safety of CART72 cells. The limited persistence supports the incorporation of co-stimulatory domains in the CAR design and the use of fully human CAR constructs to mitigate immunogenicity.

We report the results of a phase I study of the tolerance and biologic activity of intramuscularly (IM)-administered recombinant interferon-gamma (rIFN-gamma). Forty-four patients with metastatic cancer were given rIFN-gamma at doses ranging from 0.01 to 2.5 mg/m2/d for 42 days. The most common side effects were fever, flulike symptoms, night sweats, and granulocytopenia. The maximum tolerated dose was 0.5 mg/m2/d. Administration of rIFN-gamma resulted in modulation of immune system functions, including induction of major histocompatibility complex-associated antigens on blood leukocytes, an increase in blood surface immunoglobulin-bearing B cell and natural killer (NK) cell number, and NK cell cytotoxicity. Serum lysozyme, determined as an estimate of tissue macrophage activity, also increased. Serum assays for anti-interferon antibodies were negative in all patients. Five of eight evaluable patients with lymphoproliferative disorders showed objective evidence of tumor regression consisting of partial responses (two patients), and minor responses (three patients). These data suggest that further phase II studies of IM-administered rIFN-gamma are indicated.

Combinations of interferon-alpha and interferon-gamma demonstrate synergistic antiviral and anti-proliferative activity in vitro. Therefore, we initiated a clinical study of combination interferon therapy in humans. Eighteen patients with metastatic solid tumors received daily intramuscular (IM) injections of recombinant interferon-alpha-A (IFN alfa-2a, Roferon-A; Hoffman-LaRoche, Nutley, NJ) and recombinant IFN-gamma (rIFN-gamma) for 6 weeks. The dose levels were 0.5, 1.0, 2.0, and 5.0 X 10(6) U/m2/d of each interferon. A minimum of two patients were entered sequentially at each dose level. Fever, chills, fatigue, and a greater than or equal to 50% drop in granulocyte counts were observed at all doses. Severity of symptoms corresponded to increasing dose levels. In contrast to the tachyphylaxis to these symptoms that usually develops in patients treated with the individual interferons, many patients on this study experienced persistent fever and worsening fatigue over 6 weeks. The maximum tolerated dose was 1 X 10(6) U/m2/d of each interferon. One patient with renal-cell carcinoma achieved a partial remission (duration, 3 months). Enzyme-linked immunoassay analysis in all four patients for whom complete data were available revealed that peak blood levels of IFN alfa-2a on day 22 were about tenfold higher than on day 1. Because of the possibility of cumulative toxicity, the recommended starting dose for further studies is 0.5 X 10(6) U/m2/d of each interferon, with escalation to 1.0 X 10(6) U/m2/d after 1 month if tolerance is acceptable. Phase II investigations to explore the antitumor efficacy of this regimen are planned.

A new, genetically transmitted retrovirus has been isolated from the Old World monkey Colobus polykomos. This virus, designated CPC-1, is readily transmitted to both feline and human cells in culture. Nucleic acid hybridization studies reveal that there are 50-70 copies of the CPC-1 genome in colobus cellular DNA. Related virogene sequences can be detected in the DNA of all other Old World monkeys, as well as in the DNA of at least one ape species, the chimpanzee, indicating that this virus has been genetically transmitted in primates for 30-40 million years. CPC-1 is partially related to the type C virus previously isolated from stumptail monkeys (MAC-1). These two viruses have nucleic acid sequence homology, antigenic crossreactivity in their major viral structural protein, and a very similar host range in vitro. CPC-1 and MAC-1 therefore belong to the same class of genetically transmitted primate type C viruses and, as such, represent the first example in primates of analogous endogenous retroviruses isolated from two distantly related species.

A clinical trial to determine the antitumor activity of recombinant interferon-gamma (rIFN-gamma) was conducted in 36 patients with advanced colorectal cancer. Severe constitutional symptoms were seen in the first five patients who received rIFN-gamma as a 2- to 4-hour intravenous infusion, and this method of administration was therefore abandoned. One transient partial tumor regression was observed in the 31 patients who received treatment by the intramuscular route of administration. Although a clinically tolerable regimen suitable for outpatient administration was developed, rIFN-gamma given in this dose and schedule had minimal antitumor effect for the treatment of advanced colorectal cancer. NK activity was depressed within 48 hours of rIFN-gamma administration but became significantly higher than normal controls or pretreatment levels during therapy despite disease progression, indicating discordance between augmentation of this immune parameter and tumor status. Serum CA 19-9 levels were unusually high and increased significantly more than CA 125 or CEA during rIFN-gamma treatment. This observation suggests that rIFN-gamma could augment localization of anti-CA 19-9 used to diagnostically image or therapeutically target a labeled chemotherapy agent to tumor in those patients expressing this antigen.

A major difficulty limiting the use of immunomodulators in clinical medicine has been the complexity of the immunoregulatory network in which modulation of one component usually perturbs the entire system, thus diminishing the specificity of the approach. Lymphokine-activated killer cells infused with interleukin-2 have proved effective in inducing remissions in several advanced cancers, particularly metastatic renal cell carcinomas. The interferons have shown direct antiproliferative effects as well as specific effects on immune function. Alpha-interferon has shown impressive antitumor effects in hairy cell leukemia and significant antiviral effects in papillomavirus infection of the genital tract. Interleukin-2 has multifaceted effects on various limbs of the inflammatory and immune responses and may be the critical common denominator in the adjuvant effects of several other compounds. Monoclonal antibodies have assumed an increasing role in diagnostic and therapeutic approaches to neoplastic and immune-mediated diseases. Finally, several immunomodulators are currently being tested in the treatment of the immune defect of the acquired immunodeficiency syndrome.

Urine from nude mice contains epidermal growth factor (EGF) and a minor acid-stable component with an apparent molecular weight of 20,000, which competes with EGF for binding to EGF membrane receptors and which promotes colony formation by normal rat kidney cells in soft agar. The levels of this Mr 20,000 urine-derived growth factor are increased approximately 4- to 10-fold in nude mice bearing tumors following s.c. injection of cultured human tumor cells. Following removal of the primary tumor, the concentration of this factor is reduced to basal levels, and thus, elevated levels of this growth factor appear to be dependent on tumor burden. The Mr 20,000 urinary component is separable into four EGF competing activities by high-performance liquid chromatography; the major species is immunologically related to mouse submaxillary gland EGF and therefore appears to be of host origin. However, in addition to elevated levels of host growth factor, urine from tumor-bearing mice also contains transforming growth factor activity in amounts comparable to that released by the tumor cells in culture. The tumor-derived urinary transforming growth factor activity is immunologically unrelated to EGF but is immunoreactive with an antiserum to transforming growth factor-alpha. We propose that the nude mouse may be a useful model to examine the role of both host- and tumor-derived growth factors in tumorigenesis and the usefulness of these factors as biological markers of response to therapy and tumor progression.

This study was undertaken to determine an immunologically active regimen for the administration of recombinant gamma-interferon (rIFN-gamma). The patient population included patients with completely resected melanoma, stage I (Clark's level IV or V) or stage II. All patients exhibited no evidence of disease (NED) at the time of the study. Patients received rIFN-gamma by intramuscular (IM) injection daily for 15 days at 0.0001 mg/m2, 0.001 mg/m2, 0.01 mg/m2, 0.1 mg/m2 (ten patients/group), or 0.25 mg/m2 (five patients). Interferon (IFN) was well tolerated, with non-dose-limiting constitutional symptoms occurring in the majority of patients at 0.1 mg/m2 and 0.25 mg/m2. All five patients receiving 0.25 mg/m2 developed elevated transaminase levels, which led to a discontinuation of therapy in one patient. Immunological activity was assessed by serial measurements of natural killer (NK) cell activity, hydrogen peroxide production by monocytes, and changes in expression of Fc receptors and human leukocyte class II antigen (HLA-DR) on monocytes. These changes were determined at baseline (X2), six to seven time points during rIFN-gamma therapy, and two times after the last dose of rIFN-gamma. No changes were observed at the two lowest doses. At the 0.01 mg/m2 dose, all parameters were elevated but not as consistently nor to the same levels as seen following administration of 0.1 mg/m2. At 0.25 mg/m2, H2O2 production was enhanced, but unlike at 0.1 mg/m2, it declined during the last few days of IFN therapy. Subcutaneous (SC) administration was compared with IM administration using the 0.1 mg/m2 dose. SC administration resulted in enhanced H2O2 production and Fc receptor expression by monocytes. More consistent elevations in peroxide generation and higher levels of Fc receptor expression were seen following SC administration. No significant difference was found between the two routes of administration. A comparison of two schedules, daily and three times weekly, suggested that monocyte activation may return to normal 72 hours after IFN administration. Of the doses tested, 0.1 mg/m2 administered daily appeared to be the most effective biological response modifier (BRM) regimen, and because of ease of administration, we favor the SC route.

Patients with a variety of malignancies were treated in phase I clinical trials of recombinant leukocyte A interferon (IFL-rA) schedules consisting of either twice-daily doses for 28 days (48 patients) or three times weekly for 28 days (86 patients). Extensive monitoring of several immune functions was done on these patients, with rigorously standardized assays and determination of inherent variability of function for each individual. The assays performed were natural killer (NK) cell cytotoxicity, monocyte cytostatic activity, lymphoproliferative responses to concanavalin A (con A) and mixed leukocyte culture, and an analysis of changes in leukocyte populations as determined using a panel of monoclonal antibodies and flow cytometry. No appreciable increase in NK activity was observed on any of the treatment regimens, and an unexpected observation was the depression of activity in a substantial proportion (30%) of patients. In contrast, monocyte function, as measured in an assay of growth inhibition of tumor target cells, was found to be elevated in 70% of the patients. Lymphoproliferative responses were depressed in most patients in response to both con A and the mixed leukocyte culture. Cell surface marker studies revealed an increase in the percentage of OKT10 positive cells in the majority of patients studied and a transient increase in cells reacting with the antibody MO2. The data have been analyzed in terms of their relationship to dose and schedule of administration, and the depression of NK activity was shown to be greatest at the highest doses and more frequent schedule of administration.

Tumor necrosis factor is a cytokine derived from activated macrophages. This agent is cytostatic and cytolytic against transformed human cell lines in vitro and has in vivo activity against a variety of murine tumors. We report a clinical study of the pharmacokinetics, toxicity, and biological activity of i.v. and i.m. administered recombinant human tumor necrosis factor (rTNF). Twenty patients with metastatic cancer were given rTNF in doses ranging from 1 to 200 micrograms/m2 by alternating i.m. and i.v. bolus injections with a minimal intervening period of 72 h. Each patient received a maximum of eight treatments given twice weekly over a 4-week period. With i.v. bolus administration, serum concentrations of rTNF were detected by enzyme-linked immunosorbent assay at doses of 25 micrograms/m2 or greater. The clearance of rTNF in the serum was described by a monoexponential equation with a half-life calculated to be 14-18 min. After i.m. administration, serum concentrations of rTNF were consistently detected by enzyme-linked immunosorbent assay at doses of 150 micrograms/m2 or greater. Peak concentrations were observed within 2 h and rTNF was occasionally detected, at the lower limit of sensitivity of the assay, at 24 h postinjection. rTNF was well tolerated clinically in this dose range, and there was evidence of antitumor effect.

Twelve patients with the acquired immune deficiency syndrome (AIDS) and Kaposi's sarcoma were treated with recombinant human gamma-interferon (rIFN-gamma). A rapid, substantial increase in the fraction of HLA-DQ-positive monocytes was noted after treatment with rIFN-gamma. The rIFN-gamma-induced increase in monocyte HLA-DQ was seen throughout the course of treatment, with the percentage of HLA-DQ-positive monocytes dropping slightly following each week's treatment with rIFN-gamma and then rapidly increasing following the next course of treatment. Although the percentage of HLA-DR-positive monocytes was unchanged (HLA-DR was expressed on greater than 80% of monocytes prior to treatment), the density of HLA-DR on monocytes also increased following rIFN-gamma treatment. Following rIFN-gamma treatment, no changes were seen in CD3, CD4, CD8 T cell numbers, in T cell subset ratio (CD4/CD8), in Leu 7 or CD16 (Leu 11) cell number, in spontaneous Ig secretion, in PHA-induced in vitro proliferation, or in NK activity. These results indicate that exposure to rIFN-gamma in vivo led to the increased expression of class II antigens on monocytes in patients with AIDS.

Seventeen well-characterized human lung cancer cell lines were examined for the presence of specific membrane receptors for epidermal growth factor (EGF) and nerve growth factor (NGF) as well as for the production of diffusible factors capable of stimulating soft agar growth. These cell lines represented all four major histological types of human lung cancer including small cell carcinoma of the lung (SCCL) and the three types of non-SCCL (epidermoid, large cell, and adenocarcinoma). The SCCL lines included three lines referred to as "converters" because they had lost SCCL morphological and biochemical properties during prolonged passage in vitro. Specific receptors for EGF and NGF were detected by measuring the binding of 125I-radiolabeled growth factor to the cell surface. These assays revealed that EGF receptors are found on five of six non-SCCL cell lines and are not found on any of the SCCL lines. In contract, NGF binding was detected at low levels on three of eight SCCL lines and on all three SCCL converters but was not observed for non-SCCL lines. Thus, SCCL and SCCL converter cell lines are distinguished from non-SCCL by the pattern of membrane receptors for EGF and NGF. Such differences may ultimately prove useful as biological markers for the different histological types of lung cancer. Moreover, the majority of SCCL cells and all of the non-SCCL cells tested were found to produce diffusible growth factors which can stimulate soft agar growth of nontransformed normal rat kidney fibroblasts. Although some correlation between soft agar growth factor production and the absence of EGF receptors may exist for SCCL cells, the production of transforming growth factors appears to be a general property of human lung cancer cells in vitro and is independent of EGF receptor expression.

Fifteen patients with advanced malignancy were treated with recombinant interferon gamma (rIFN-gamma) (specific activity approximately 2 X 10(7) units/mg, purity greater than 99%) given by 1-hour iv infusion three times a week for 6 weeks, at fixed dose levels of 0.1, 0.5, 1.0, or 2.0 mg/m2/day. The common side effects were constitutional symptoms, including fever, chills, myalgias, and headache, but these were less severe than those observed following daily 6-hour iv infusions. Significant changes in blood cell counts and routine serum chemistries were not observed, but there was a dose-dependent increase in serum triglyceride levels. The maximum safely tolerated dose achieved was 1.0 mg/m2/day. Peak serum interferon levels occurred at the midpoint of the infusion and were dose-dependent. rIFN-gamma was rapidly cleared from serum and no detectable activity was found 2 hours after the infusion. Two patients, both with B-cell malignancies, showed objective evidence of tumor regression during the treatment. Treatment was associated with an increase in serum levels of beta 2-microglobulin and the H2O2 secretory capacity of peripheral blood monocytes. We conclude that rIFN-gamma administered by short iv infusion can induce biological activities and causes less toxicity than when given by prolonged iv infusion.

We report a clinical study of the pharmacokinetics, toxicity, and biological activity of i.v.- and i.m.-administered recombinant gamma-interferon (rIFN-gamma) consisting of 143 amino acids. Ten patients with metastatic cancer were given rIFN-gamma at doses of 0.01 to 2.5 mg/sq m by alternating i.m. and i.v. bolus injections with a minimum intervening period of 72 h. After i.v. administration, rIFN-gamma was cleared monoexponentially with a short half-life of 25 to 35 min as determined by bioassay and enzyme immunoassay. After i.m. injection, a longer half-life of 227 to 462 min was measured by enzyme immunoassay. Serum titers were detected by bioassay only at high doses, suggesting partial loss of antiviral activity at the i.m. site. However, other biological effects were retained as evidenced by fever, chills, and fatigue after both routes of administration and granulocytopenia after i.m., but not i.v., doses. Two of ten patients showed objective evidence of tumor regression. These data suggest that further studies with i.m. as well as prolonged i.v. infusions of rIFN-gamma are indicated.

Highly purified human lymphoblastoid interferon derived from virus-stimulated Namalwa cells was administered daily by 6-h i.v. infusion or i.m. injection to 40 patients with a variety of disseminated malignancies refractory to standard therapy. Each patient received escalating doses of 0.1-50 X 10(6) U for up to 5 weeks. Extensive monitoring for changes in various immune functions revealed no sustained elevation in natural killer cell activity, elevated monocyte-mediated antitumor cytostatic activity in approximately 30% of the patients, and depressed lymphoproliferative responses to mitogens and mixed leukocyte culture.

Transforming growth factor (TGF) activities could be detected in the urine of normal, pregnant, and tumor-bearing humans. These acid- and heat-stable polypeptides competed for binding to epidermal growth factor (EGF) membrane receptors and promoted the anchorage-independent growth of nontransformed rodent cells. They differed from human EGF in their apparent molecular weights and soft-agar growth-stimulating activity. The urine from pregnant females contained TGF activities with apparent molecular weight(s) (relative) (Mr) of 10,000 ad 17,000--20,000. In the case of a lung cancer patient, an additional major activity of approximately 30,000--35,000 Mr was found. All urine specimens examined also contained a "common" 8,000-Mr soft-agar growth-stimulating activity, which competed for binding to EGF membrane receptors and which was chromatographically separable from EGF (urogastrone). Thus urine may provide a convenient and readily available source for the biochemical characterization of these TGF-like activities, some of which may be clinically useful biologic markers for certain types of cancer.

Biochemical and clinical signs of tumor lysis syndrome developed in a 57-year-old man with recurrent T cell lymphoma during therapy with recombinant leukocyte A interferon. When therapy was interrupted due to thrombocytopenia and later resumed, biochemical changes compatible with tumor lysis recurred. This is the first case of tumor lysis syndrome observed during therapy with a biologic response modifier, a new class of agents entering cancer clinical trials. The atypical features of the clinical presentation and possible implications of these observations are discussed.

Human urine contains an acid and heat stable peptide with an apparent molecular weight of 8,000-10,000 that, in the presence of urogastrone (EGF), induces the anchorage-independent growth of nontransformed cells in semisolid media. This nonmitogenic growth-modulating activity does not compete with EGF for binding to EGF membrane receptor sites and can be resolved from EGF by high-performance liquid chromatography. The urine-derived growth factor has been purified more than 10,000-fold and shares many biochemical properties with and is functionally related to the B class of TGFs isolated from transformed cells and non-neoplastic tissues. The low molecular weight anchorage-independent growth-stimulating activity universally present in human urine is a result of the synergistic interaction of this urine-derived TGF-beta and urogastrone.

Recombinant interferon gamma (rIFN-gamma) activates macrophage antimicrobial and antitumor functions and related metabolic processes, including secretion of reactive oxygen intermediates in mice and in cultured mouse and human macrophages. To look for similar actions in man, we monitored the H2O2 secretory capacity of monocytes from cancer patients receiving intravenous rIFN-gamma at 0.1, 0.5, or 1.0 mg/m2 of body area over 6 hr daily or over 1 hr on alternate days. Monocytes taken just before the first infusion served as controls and were comparable to normal donor monocytes in secretion of H2O2. Monocytes from 11 of the 13 subjects (85%) studied through 20 treatment cycles responded to rIFN-gamma with elevation in H2O2 secretion in greater than or equal to 67% of the tests conducted greater than 1 hr after the start of treatment. Five of the five subjects tested had monocytes with diminished H2O2 secretory capacity when tested immediately after a 1-hr infusion of rIRN-gamma, at which time the amount of adherent mononuclear cell protein recovered from the blood averaged only 24% of the control. At all other times tested (from 6 hr to 5 days after infusion) combined results for all subjects showed enhancement of H2O2 releasing capacity. Statistically significant mean increases ranged from 1.4- to 2.8-fold above the control and included the sets in which monocytes collected 24 hr following a single infusion were assayed the same day or the next. By the criterion of enhanced H2O2 secretory capacity, the ability of rIFN-gamma to activate mononuclear phagocytes is manifest upon its administration to patients with advanced malignancy.

Animals suffering from malignancy or chronic infection develop characteristic metabolic abnormalities, including a well-defined hypertriglyceridemic state. These abnormalities have been attributed to release of one or more mediators from activated macrophages. We report that cancer patients receiving RIFN-gamma, a potent macrophage activator, at doses of greater than or equal to 0.25 mg/m2/d i.m. show marked increases in triglyceride but not in cholesterol levels (pretreatment triglyceride level of 180 +/- 190 mg/dl [mean +/- SD] vs. a day-14 level of 370 +/- 242 mg/dl, n = 23, p less than 0.001 by the paired t test). This hypertriglyceridemia was characterized by an increase in very low-density lipoproteins and a decrease in plasma post-heparin lipase activity, consistent with defective triglyceride clearance (mean pretreatment lipase level of 2.1 mumol/ml/h vs. a day-14 level of 1.2 mumol/ml/h, n = 6, p = 0.02 by the paired t test). rIFN-gamma did not directly inhibit lipoprotein lipase enzymatic activity in vitro. Other possible mechanisms of action, such as suppression of lipase by an rIFN-gamma-induced mediator released from activated macrophages, or a direct effect of interferon on lipase biosynthesis, require further investigation. Our observations provide evidence that factors produced by the immune system can regulate lipid metabolism in man.

One hundred thirty-four patients with a variety of malignancies were treated in two phase I clinical trials of recombinant leukocyte A interferon (IFL-rA) produced by recombinant DNA methodology. IFL-rA was given by intra-muscular injection either twice daily or three times weekly for 28 days. Extensive monitoring of natural killer (NK) cell cytotoxicity was done on these patients with rigorously standardized assays and determination of the inherent variability of NK function for each individual. Interferon, as used in these two treatment regimens, failed to produce an appreciable increase in NK activity; in the majority of patients, there was no significant change in NK activity from the pretreatment baseline levels. An unexpected finding was the depression of NK activity in 30% of the patients. The data have been analyzed in terms of their possible relationship to dose and schedules of IFL-rA administration and to antitumor response.

Interferon gamma (IFN-gamma) is a lymphokine with potent in vitro effects on cell growth and immune function. We have investigated the effects of rIFN-gamma (sp act approximately 2 X 10(7) U/mg, purity greater than 99%) in 16 evaluable patients with advanced malignancy in a phase 1 trial. Patients were treated with six-hour intravenous (IV) infusions daily, five days a week for 2 weeks. After a 2-week rest period, the IV treatment cycle was repeated. Responders were maintained on repeated IV treatment cycles or daily intramuscular (IM) injections. Patients were entered at fixed dose levels of 0.1, 0.5, or 1.0 mg/m2/d. The maximum safely tolerated dose was 0.5 mg/m2. The most common side effects were constitutional symptoms, including fever, chills, fatigue, and myalgias. Reversible and transient increases in hepatic transaminase and decrease in granulocyte counts were seen. Treatment was associated with a dose-dependent increase in serum levels of beta 2 microglobulin. Partial responses (PRs) were observed in one patient with Hodgkin's disease and one patient with chronic lymphocytic leukemia. Fairly constant levels of serum IFN were found at four and six hours during infusion, followed by a rapid decline within one to two hours. We conclude that rIFN-gamma can be safely administered by a six-hour IV infusion and that it can induce in vivo some of the biologic effects reported in in vitro studies.

A clinical trial was conducted to determine the tolerance and toxicity of recombinant tumor necrosis factor (rTNF) and recombinant interferon gamma (rIFN-gamma) when administered concurrently by continuous intravenous infusion to 11 patients with the AIDS-related complex (ARC). In addition, HIV culture, p24 antigen levels, and CD4 positive lymphocytes were monitored to obtain preliminary evidence of antiviral and immunologic effects. Two 5-day treatment cycles were separated by a 9-day washout period. Two patients were entered at each dosage level and each patient received the two 5-day treatment cycles at two sequential dose levels ranging from 1 to 25 micrograms/m2. Two patients did not complete their second treatment cycle--one due to the development of a rash, the second due to central venous catheter discomfort. The occurrence of phlebitis with peripheral vein administration of these agents necessitated administration via central venous catheter. With the exception of a single patient who developed severe headache at the 25 micrograms/m2 dose, severe clinical toxicities were not observed. Fever, chills, headache, and myalgias were the most significant clinical toxicities observed and all were dose dependent. The percentage fall in total granulocytes was dose dependent and ranged from 17% at the 1 microgram/mm2 dose to 48% at both the 15 and 25 micrograms/mm2 dose levels. The mean nadir granulocyte count was 1694/mm3. No significant renal or hepatic toxicity was observed. Of 22 treatment cycles the CD4 cell number was increased in 11, unchanged in 7, and decreased in 4. The mean CD4 cell number did not change significantly (176 +/- 143/mm3 pretherapy versus 279 +/- 305/mm3 posttherapy).(ABSTRACT TRUNCATED AT 250 WORDS)

Reverse-phase high-performance liquid chromatography (HPLC) performed on urine from cancer patients and normal controls revealed the presence of seven chromatographically distinct peaks of transforming growth factor (TGF) activity, as measured by colony formation of normal rat kidney cells in soft agar. Comparison of urines from normal donors and cancer patients showed no differences in EGF (epidermal growth factor)-dependent beta-TGF-like activity but did reveal distinct patterns of EGF-related, EGF-independent alpha-TGF-like activity. All urine samples contained at least two chromatographically distinguishable forms of EGF-dependent TGF activity, eluting from HPLC as broad peaks with 30 and 43% acetonitrile. The remaining five TGFs eluted as sharp peaks with 32, 34, 35, 37, and 38% acetonitrile, demonstrated EGF-competing activity, and thus were functionally related to EGF. Two of the five EGF-related TGFs were consistently elevated only in the urine of cancer patients and eluted with 32% (TGFA) and 37% (TGFD) acetonitrile Two of the other EGF-related TGFs, eluting with 34% (TGFB) and 35% (TGFC) acetonitrile, were commonly found in both normals and cancer patients. The fifth EGF-related TGF, TGFE, eluting with 38% acetonitrile, was found only in normal donor specimens. TGFA corresponded to the unique Mr 30,000 TGF activity previously identified only in the urine of cancer patients. These observations demonstrate that cancer patients produce high levels of EGF-related TGF activities which can be readily distinguished, using reverse-phase HPLC, from EGF-related TGFs produced by normal individuals. Using a solid-phase competitive radioreceptor binding assay for EGF, we demonstrated that quantitation of EGF-competing activity is as sensitive and effective as the soft-agar colony formation assay for distinguishing HPLC profiles of urinary TGF from cancer patients versus that from normal individuals.

A phase I clinical trial was initiated to treat patients with stage IV B-derived chronic lymphocytic leukemia (CLL) with the IgG2a murine monoclonal antibody T101. This antibody binds to a 65,000-mol wt (T65) antigen found on normal T lymphocytes, malignant T lymphocytes, and B-derived CLL cells. All of the patients had a histologically confirmed diagnosis of advanced B-derived CLL and were refractory to standard therapy, and more than 50% of their leukemia cells reacted with the T101 antibody in vitro. The patients received T101 antibody two times per week, over two to 50 hours by intravenous administration in 100 mL of normal saline containing 5% human albumin. Twelve patients were treated with a fixed dosage of 1, 10, 50, or 100 mg, and one patient was treated with 140 mg of antibody. It was demonstrated that patients given two-hour infusions of 50 mg developed pulmonary toxicity, with shortness of breath and chest tightness. This toxicity was eliminated when infusions of 50 or 100 mg of T101 were prolonged to 50 hours. All dose levels caused a rapid but transient decrease in circulating leukemia cell counts. In vivo binding to circulating and bone marrow leukemia cells was demonstrated at all dose levels with increased binding at higher dosages. Antimurine antibody responses were not demonstrated in any patients at any time during treatment. Circulating free murine antibody was demonstrated in the serum of only the two patients treated with 100 mg of antibody as a 50-hour infusion and the patient treated with 140 mg of antibody over 30 hours. Antigenic modulation was demonstrated in patients treated at all dose levels but was particularly apparent in patients treated with prolonged infusions of 50 and 100 mg of antibody. We were also able to demonstrate antigenic modulation in lymph node cells, which strongly suggests in vivo labeling of these cells. Overall, T101 antibody alone appears to have a very limited therapeutic value for patients with CLL. The observations of in vivo labeling of tumor cells, antigenic modulation, antibody pharmacokinetics, toxicity, and antimurine antibody formation may be used in the future for more effective therapy when drugs or toxins are conjugated to the antibody.

A new class of endogenous primate type C virus has been isolated from a continuous tissue culture line of Macaca arctoides cells by co-cultivation with a human cell line. The virus, designated MAC-1, can be transmitted to human and feline cells in tissue culture, and is unrelated, by immunological and nucleic acid hybridization criteria, to previously characterized retroviral isolates of primates. In particular, MAC-1 shows no detectable homology to the baboon type C viruses, even though viral genes related to the latter group are readily detected in M. arctoides cellular DNA. Viral gene sequences related to the MAC-1 genome are present in multiple copies (50-150 per haploid genome) in Old World primates, and are expressed in the cellular RNAs of uninfected and "virus-free" primate cells and tissues. Thus there are at least two distinct sets of genetically transmitted Old World primate type C viral genes, each of which is found in multiple copies in normal primate cellular DNA. With the description of this new retrovirus, there are now a minimum of five distinct genetically transmitted viruses of primates, three type C and type D, each represented in multiple copies in the normal cellular DNA.

Thirty-three patients with metastatic renal cell carcinoma were treated with recombinant human interferon gamma (rIFN gamma) in two sequential, nonrandomized phase II studies. Fifteen patients received rIFN gamma by daily i.m. injection in doses ranging from 0.25 to 1.0 mg/m2, and 18 patients received it by daily continuous i.v. infusion in doses ranging from 0.01 to 0.05 mg/m2. Partial remissions were achieved by one of 14 (7%) evaluable patients in the i.m. study and in one of 16 in the i.v. study (6%). The incidence of clinical toxicity was similar for both studies. Toxicity was severe in patients receiving rIFN gamma by the i.m. route at 1.0 mg/m2 and by the i.v. route at 0.05 mg/m2. Toxicity includes constitutional symptoms (fatigue, anorexia, weight loss), leukopenia, abnormalities in liver function tests, and hypertriglyceridemia. At the doses and schedules used, rIFN gamma had minimal therapeutic activity as a single agent in metastatic renal cell carcinoma.

Twenty-eight patients with disseminated malignant melanoma received daily im therapy with recombinant interferon-gamma. The dose was 0.25 mg/m2 on Days 1-7 followed by a daily dose of 0.5 mg/m2 if tolerated. Among 27 patients, we observed three objective partial regressions (8.3, 3.7, and 3.9+ months). The median leukocyte count nadir was 2.5 X 10(3)/mm3 (range, 1.4-5.1). Constitutional symptoms included moderate to severe fever greater than 37 degrees C (100%), fatigue (59%), chills (37%), and mild to moderate myalgias (64%). Recombinant interferon-gamma produces manageable side effects but limited efficacy as employed in this study.

A total of 11 patients were treated on an escalating, single dose trial of recombinant gamma interferon (rIFN-gamma), 6 patients by the i.m. and 5 patients by the i.v. route of administration. Dose ranges within each individual were from 0.05 mg/m2 of IFN (1 mg greater than or equal to 10 X 10(6) units of IFN) escalating to 10 mg/m2. All dosages were delivered twice weekly and the i.v. dose was infused over 5 min. The most common toxicities encountered included fever, chills, fatigue, anorexia, and granulocytopenia. The influenza-like symptoms were very similar to those encountered with IFN-alpha but were generally less severe. The granulocytopenia was dose-related and transient with recovery generally seen within 48-72 h following administration of rIFN-gamma. Absolute granulocyte counts only rarely dropped below 1000 mm3. Hepatotoxicity was not observed. IFN levels were determined by both a bioassay and an enzyme-linked immunosorbent assay. By the i.v. route, the peak level of IFN activity could usually be seen at completion of the infusion with a serum half-life of 30 min. By the i.m. route, the peak level of serum activity was generally detected between 4-8 h with a serum half-life of 4.5 h after the initial elimination phase. Peak IFN levels appeared to correlate with maximum toxicity. One patient with melanoma had a 25% reduction in a cutaneous lesion, but there were no other minimal, partial, or complete responses.

Human melanoma cells were examined in an indirect membrane immunofluorescence assay for surface nerve growth factor (NGF) and NGF receptors. This assay revealed that human melanoma cells have various levels of NGF and NGF receptors on the plasma membrane, whereas a variety of human sarcoma and carcinoma tumor cells and normal human fibroblasts are negative. Surface NGF could be detected on melanoma cells with a rabbit antiserum directed to NGF at titers as high as 1:64; prior adsorption of this antibody with mouse 2.5S NGF resulted in a loss of fluorescence. The melanoma cells were positive whether or not they were grown in the presence of fetal calf serum. NGF production by human melanomas is a previously unrecognized property of this differentiated cell type. Although other cells in culture have been shown to produce NGF, the association of NGF production with the presence of NGF receptors on the cell surface is rare among tumor cells, and may represent an opportunity for "autostimulation" of melanoma cells by this growth factor.

Two patients with advanced lymphoma involving the lungs that was resistant to chemotherapy had an initial excellent response to interferon therapy. After two months of stable disease, alpha interferon A therapy was discontinued, with relapse of a few months later. Both patients had extensive pulmonary involvement with relapse of the lymphoma, and both showed a dramatic response to retreatment with alpha interferon A. Unusual interferon-related pulmonary complications were observed in one patient, and their management is detailed.

Urine from 22 patients with a variety of disseminated cancers and from an equivalent number of nonmalignant controls of similar age and sex was tested for the presence of transforming growth factor (TGF) activity as measured by the ability to promote the growth in soft agar of nontransformed indicator cells. Cancer patients included those with carcinomas of the lung, breast, colon, and ovary, as well as melanomas and sarcomas. The nonmalignant controls included both normals and individuals with a variety of inflammatory and infectious disorders. Aliquots of unfrozen urine were acid extracted, chromatographed on a Bio-Gel P-30 column, and then tested for TGF activity using normal rat kidney fibroblasts and epidermal growth factor (EGF)-competing activity with human carcinoma A431 cells. These assays revealed that a high-molecular-weight TGF activity (Mr 30,000 to 35,000) which coelutes with EGF-competing activity was present in 18 of 22 cancer patients but present in only five of 22 nonmalignant controls (p less than 0.01). In contrast, a low-molecular-weight TGF activity (Mr 6000 to 8000) which does not coelute with EGF-competing activity was found in all urines tested. These results indicate that an EGF-related, high-molecular-weight TGF activity is found in the urine of cancer patients and may be a useful tumor marker. Unlike other tumor markers described previously, high-molecular-weight TGF activity has a biological activity which is related to the expression of the transformed phenotype.

Twenty-three patients with chronic plaque-type psoriasis were treated with intramuscular administration of human recombinant interferon gamma. Patients were treated with doses of 0.01 to 0.25 mg/m2 daily (five out of seven days) for four weeks, or 0.25 mg/m2 three times weekly for one week with escalation to 0.5 mg/m2 for the subsequent seven weeks. Some patients treated with the 0.25-mg/m2 dose showed improvement coincident with their therapy. Although recombinant interferon gamma may have some therapeutic activity in certain patients' psoriasis, the magnitude of this effect is at best small. This result is in contrast to interferon alfa, which has been reported to cause an exacerbation of this disease. Staining of posttreatment biopsy specimens with a monoclonal antibody against HLA-DR antigen using an immunoperoxidase technique demonstrated HLA-DR expression by keratinocytes in some of the patients treated at the higher doses. No obvious correlation was seen between clinical improvement of the psoriasis and intensity or extent of HLA-DR antigen expression by keratinocytes in the skin biopsy specimens.

Evidence that interferon-gamma may be a physiologic macrophage-activating factor, and that macrophage activation may be defective in lepromatous leprosy, led us to test the effects of intradermal injection of low doses of recombinant interferon-gamma in six patients with this disease. Interferon-gamma, 1 or 10 micrograms, was administered daily by jet gun for three days into a single cutaneous lesion. A biopsy specimen was taken from the injection site on the sixth study day and compared with specimens obtained previously from a site where no injection had been made or where excipient alone had been injected in the same way as the interferon. Interferon-gamma elicited local effects similar to certain features of delayed-type hypersensitivity reactions or tuberculoid leprosy, including induration, T-cell and monocyte infiltration, keratinocyte proliferation, diminution of epidermal Langerhans cells, and dermal and epidermal cell HLA-DR (Ia) antigen expression. At some of the sites of interferon-gamma injection, there was also an apparent decrease in acid-fast bacilli. Before treatment, monocytes from patients with lepromatous leprosy released 48 percent as much hydrogen peroxide as did monocytes from controls in response to phorbol myristate acetate, and 36 percent as much as those from controls in response to Mycobacterium leprae. When recombinant interferon-gamma was injected, these responses became normal. No toxic effects were observed. These observations suggest that interferon-gamma can mediate certain manifestations of delayed-type hypersensitivity or cell-mediated immunity in vivo, and that recombinant interferon-gamma should be tested for possible therapeutic effects in certain nonviral infectious diseases.

A phase I trial of intramuscularly administered recombinant human tumor necrosis factor (rTNF) was conducted in 19 adult patients with advanced solid tumors. The agent was administered daily for up to five consecutive days every other week for two to four courses. Doses of rTNF ranged from 5 to 200 micrograms/m2/d. Dose-limiting toxicities were encountered at doses greater than 100 micrograms/m2/d. Toxicities included tenderness, erythema and induration at the site of injection, fatigue, fever, chills, headache, anorexia, nausea, vomiting, and diarrhea. Moderate to marked reductions in WBC and platelet counts were observed regularly at the highest dose levels, but none were clinically significant. Hepatic enzyme elevation was seen frequently, and two patients developed hyperbilirubinemia. Only one of seven patients treated with doses greater than 100 micrograms/m2/d completed the planned course of therapy. Even at the highest dose levels, serum concentrations of rTNF could only rarely be detected in the serum. No therapeutic responses were observed. The maximal tolerated dose (MTD) of rTNF in this trial was 150 micrograms/m2/d, administered for two courses.

Nineteen patients with advanced refractory metastatic breast cancer no longer responsive to chemotherapy were treated in the first phase II efficacy trial of recombinant leukocyte A interferon (IFL-rA), a highly purified single molecular species of alpha interferon prepared by recombinant DNA methods. Patients received a previously determined maximum tolerated dose for this agent (50 X 10(6) U/m2 body surface area) by intramuscular injection three times weekly for up to 3 months. The symptoms of toxicity observed in this trial resemble those previously reported for alpha interferons and include fever, chills, fatigue, anorexia, and leukopenia. All patients required dose reductions, most often for reasons of severe fatigue. Of the 17 patients evaluable for tumor response, one patient had stable disease and 16 had evidence of tumor progression. We conclude that IFL-rA is not an active agent in the treatment of advanced, refractory breast cancer when used at a maximum tolerated dose on this treatment schedule.

We report a phase I study of the biological effects, tolerance, and pharmacokinetics of 6- and 24-hour iv infusions of recombinant interferon-gamma (rIFN-gamma) in cancer patients. Twenty-one patients received the 6-hour iv infusion regimen at doses ranging from 0.016 to 0.65 mg/m2/day. Forty-one patients received the 24-hour iv infusion regimen at doses ranging from 0.01 to 0.05 mg/m2/day. Fever and flu-like symptoms were the most common side effects and were seen at all dose levels. The maximum tolerated dose was 0.16 mg/m2 for the 6-hour regimen and 0.01 mg/m2/day for the 24-hour regimen. A dose-dependent granulocytopenia was observed at doses greater than or equal to 0.05 mg/m2/day. A marked increase in beta2 microglobulin occurred by Day 5 of treatment in almost all patients, regardless of the dose level. Consistent serum levels of rIFN-gamma were achieved only at doses of 0.325 mg/m2/day of the 6-hour infusion. The mean serum concentrations at this dose ranged from 18 to 83 units/ml as measured by bioassay (0.64-2.4 ng/ml by enzyme-linked immunoassay). Antibody against rIFN-gamma did not develop in any patient. During the short period of evaluation of this study, one patient with renal cell carcinoma achieved a partial response, and three patients with renal cell (two) and lung carcinoma (one), respectively, achieved minor responses. This study will form the framework for phase II efficacy trials of iv rIFN-gamma.

We report the results of a trial of recombinant leukocyte A interferon in previously treated patients with non-Hodgkin's lymphoma who were no longer responsive to chemotherapy. Patients received recombinant leukocyte A interferon (50 X 10(6) U per square meter of body-surface area) by intramuscular injection three times weekly for three months or longer. Forty-five patients were enrolled in the study, and 37 were evaluated for a response. Thirteen of 24 (54 per cent) evaluable patients with low-histologic-grade non-Hodgkin's lymphoma had objective responses (nine partial responses and four histologically confirmed complete responses). Two of six (33 per cent) with intermediate-grade lymphoma responded (one partially and one completely), and one of seven (14 per cent) with high-grade lymphoma had a partial response. The median duration of responses was eight months. Four of the five complete responders have continued to receive maintenance interferon and have been in complete remission for 3, 7, 9, and 12 months, respectively; one had a recurrence at a site of previous disease seven months after interferon had been stopped. Side effects were noted in most patients. All 16 responders had been heavily pretreated with combination chemotherapy, including doxorubicin in 8 of the 16. These results suggest that recombinant leukocyte A interferon may be an effective new therapy for some patients with low- and intermediate-grade non-Hodgkin's lymphoma.

Thirty-three patients were treated in an escalating single-dose trial of partially purified nonrecombinant interferon-gamma (IFN-gamma). The first seven patients received intramuscular injections of IFN-gamma in doses up to 20 X 10(6) units/m2. When it became clear that these patients had no detectable antiviral activity in their serum, subsequent patients were treated by the intravenous route of administration, generally with 2-h infusions. A total of 26 patients received the agent intravenously in single escalating doses ranging from 0.2 to 60 X 10(6) units/m2, on a twice-weekly schedule for 4-6 weeks. The most common toxicities encountered included fever, chills, fatigue, anorexia, and occasional nausea and vomiting. No myelosuppression or hepatic toxicity was observed. A maximum tolerated dose for single-dose intravenous administration was defined as 50 X 10(6) units/m2 on the basis of unacceptable fatigue and prolonged systolic hypotension. Antiviral activity was detected in the serum following doses greater than 2 X 10(6) units/m2 when the IFN-gamma was administered intravenously. No evidence of antitumor activity was seen in this Phase I trial, although the treatment regimen employed did not lead to high or prolonged levels of serum IFN activity in the majority of patients. An accurate assessment of the antitumor activity of this particular IFN-gamma preparation will require Phase II trials employing multiple-treatment regimens.

Highly purified human lymphoblastoid interferon (HLBI) derived from virus-stimulated Namalwa cells was administered by 6-h IV infusion or IM injection to 40 patients with a variety of disseminated malignancies refractory to standard therapy. Each patient received doses escalating from 0.1 to 50 X 10(6) U for up to 5 weeks. Extensive monitoring for clinical effect, toxicity, and pharmacokinetics has revealed higher peak serum interferon levels and somewhat more pronounced systemic toxicity for the IV than for the IM route of administration. Objective evidence of tumor regression was observed in two patients receiving HLBI IV.

A Phase I study of recombinant interferon-gamma (rIFN-gamma) was conducted to determine the toxicity and pharmacokinetics of this lymphokine in acquired immunodeficiency syndrome (AIDS) patients with Kaposi's sarcoma (KS). Sixteen patients with AIDS/KS were entered into a fixed-dose trial at either 0.001, 0.01, 0.1, or 1.0 mg/m2 of rIFN-gamma. rIFN-gamma was initially administered either as a single 24-hr continuous iv infusion or as a single im injection, followed 4 days later by a 10-day course of daily therapy by the same route. Following a 1-week washout period, this sequence of administration was then repeated, with the drug given by the alternate route. Pharmacokinetic analysis of the 1.0-mg/m2 group revealed that peak serum levels of up to 153 U/ml occurred 2-4 hr after im injection and that steady-state levels of up to 40 U/ml were reached approximately 7-12 hr after beginning iv infusion. Dose-related toxicities in this trial included fever, headache, fatigue, nausea, and hepatitis, all of which were most severe at the two highest doses. Dose-dependent depression of the total white blood-cell (WBC) count, affecting both granulocytes and lymphocytes, was the most common laboratory abnormality. Natural killer (NK)-cell activity was slightly enhanced at a dose of 0.1 mg/m2 but suppressed at 1.0 mg/m2 of drug; monocyte-mediated cytotoxicity, in contrast, was significantly increased only at the highest dose. No dose-related changes were noted in KS lesions, HLA-DR expression by peripheral blood mononuclear cells, lymphocyte blastogenesis, or the ability to culture cytomegalovirus (CMV) from body fluids. We conclude that a maximally tolerated dose (MTD) for this drug is in the range of 0.1-1.0 mg/m2 and that at least modest evidence of systemic immunomodulation may be seen when rIFN-gamma is given at doses at or near this MTD.