Differences between in vivo and in vitro activation of cancer patient lymphocytes by recombinant interleukin 2: possible role for lymphokine-activated killer cell infusion in the in vivo-induced activation.

In this study 15 consecutive melanoma patients were treated with two courses of bolus recombinant interleukin 2 (rIL2) and rIL2 plus in vitro-generated lymphokine-activated killers (LAK), respectively. The immunological monitoring performed after 4 days of rIL2 or rIL2 plus LAK, indicate that the in vivo peripheral blood lymphocyte (PBL), activation (spontaneous proliferation, tumor cytotoxicity, number of DR+ PBL, obtained after the second cycle of rIL2 plus LAK is significantly higher than after the first cycle of rIL2 alone. During the 5-day interval between the two courses, PBL activation returns to baseline levels and no evidence for increased sensitivity of PBL to rIL2 is present. To further confirm this, two additional patients were studied, in whom rIL2 was administered by continuous i.v. infusion. In these two patients the in vitro versus in vivo PBL activation could be directly and simultaneously compared by using in vitro the same concentration of rIL2 reached and maintained in the patients' sera. The PBL activation induced in vivo by a cycle of rIL2 alone was significantly less (about 10 times) than that obtained in vitro with a comparable rIL2 concentration. Thus, the infusion of in vitro highly activated PBL could explain the increased in vivo lymphocyte activation of the second cycle of rIL2 plus LAK over the first cycle of rIL2 alone.

Recombinant human interferon-beta in the treatment of condylomata acuminata.

The number of clinic consultations for condylomata acuminata (genital warts) has increased substantially during the last 30 years. Most infections produce benign lesions but a few types may be associated with cervical and penile cancers. Interferons (IFN) have shown antiviral properties to these infections and IFN-beta in particular has demonstrated a specific cytopathic effect in humans. A total of 124 patients with condylomata acuminata, the majority of whom had failed previous therapy, were treated intralesionally with either recombinant human interferon-beta la (r-hIFN-beta-1a) or placebo. Up to 6 lesions were treated in each patient, and injections were made 3 times per week for a total of 9 injections. The patients were then followed up for 3 months. Efficacy assessments at all time points (day 19, week 6 and month 3) showed a clear advantage for the r-hIFN-beta-1a interferon-beta treatment. Patients receiving r-hIFN-beta-1a showed a greater proportion of treatment success in terms of the complete or partial reduction (at least 50%) of the total area of the treated lesions. The treatment was also well tolerated. Headache, flu-like symptoms and asthenia were more common in patients receiving r-hIFN-beta-1a, but these adverse events were generally mild in severity and rarely led to patient withdrawal. It was concluded that r-hIFN-beta-1a has good efficacy in condylomata acuminata, and therefore presents a useful therapeutic alternative in this hard-to-treat condition.

Atopic manifestations in the acquired immune deficiency syndrome: response to recombinant interferon gamma.

Six patients with the acquired immune deficiency syndrome (AIDS) had exacerbations or recurrences of previously quiescent atopic disease when they developed immunodeficiency. Four developed a different atopic illness from that suffered previously. Atopic symptoms developed within three months after the patients developed AIDS or during prodromal illness. Two of the patients were treated with recombinant interferon gamma: both showed a striking improvement in symptoms and cellular immunity. These results indicate that cellular immunity, through interferon gamma, may have a role in regulating atopic disease.

Incidence of antibodies to interferon-beta in patients treated with recombinant human interferon-beta 1a from mammalian cells.

Patients receiving recombinant human interferon-beta 1a (IFN-beta 1a) produced in Chinese hamster ovary (CHO) cells were tested for the formation of neutralizing antibodies (NABs) to IFN-beta. Samples were tested in an enzyme-linked immunosorbent assay (ELISA), and if positive were then tested for neutralization of antiviral activity in an IFN-beta bioassay. A total of 793 patients with viral diseases, premalignant and malignant diseases, and multiple sclerosis received IFN-beta 1a in clinical studies. Long-term studies included 56 patients with cancer treated for 6 or 12 months and 334 patients with multiple sclerosis (MS) at the end of one year of treatment. All of the NAB-positive patients were found in the latter. Positivity in a single specimen was found in 14.4% of the MS patients. The incidence of sustained neutralizing antibody titres (i.e. positive in two tests at least 6 months apart) was 6.9% in this group. Comparison with results from other studies suggests that CHO-derived IFN-beta 1a induces less neutralizing antibody than IFN-beta 1b produced in E. coli.

Randomised double-blind trial of recombinant interferon-beta for condyloma acuminatum.

OBJECTIVE: To evaluate the safety and efficacy of two intralesional doses of recombinant human interferon-beta (r-hIFN-beta: Rebif, Ares Serono), given 3 times a week for 3 weeks, in the treatment of condyloma acuminatum. DESIGN: A randomised, double-blind, within-patient, placebo-controlled study. SUBJECTS: 25 patients (24 males, 1 female) with a history of condyloma acuminatum. Twenty had failed previous treatment for condyloma acuminatum. In each patient, 3 distinct lesions were selected for treatment. Each selected lesion was randomly assigned to receive intralesionally one of the following: r-hIFN-beta 33,000 IU/day, r-hIFN-beta 1 x 10(6) IU/day, or matching placebo. SETTING: Institut Alfred Fournier, Paris, France. OUTCOME MEASURES: Response was evaluated colposcopically at the end of treatment (day 22) and 5 weeks later (month 2). Complete response (CR) was defined as disappearance of the treated lesion. Partial response (PR) was defined as at least a 50% reduction in size, but not disappearance of the treated lesion. RESULTS: The higher dose of 1 x 10(6) IU achieved significantly more complete and partial remissions than placebo, both by the end of treatment, and 5 weeks later. CONCLUSIONS: r-hIFN-beta appears to be safe and effective when administered intralesionally to patients with condyloma acuminatum. Most of the treated patients had failed previous treatments and were therefore a resistant population.

In vivo activation of lymphocytes in melanoma patients receiving escalating doses of recombinant interleukin 2.

A phase-I study of the recombinant, non-mutagenized interleukin 2 (rIL2, BioleukinTM) was performed in 12 melanoma patients (Pts). From 100 to 800 micrograms/m2 of rIL2 were administered by i.v. bolus injection, TID for 4-8 days. Side-effects included fever, malaise, low serum K+ and Ca++ values, electrocardiographic abnormalities, leukopenia and thrombocytopenia. No major organ toxicity and no significant fluid retention were observed at the administered doses. Treatment induced a rapid depletion of peripheral blood lymphocytes (PBL) with a rebound (2-6 times the pre-treatment values), 24-48 hr after rIL2 discontinuation. PBL obtained between the 5th treatment day and the 2nd post-treatment day showed: (a) enhanced proliferation (II/12 Pts) with stimulation indexes of 6-52; (b) increased cytotoxicity against autologous tumor cells (2/2 Pts), allogeneic melanomas (5/7 Pts), the Daudi (5/6 Pts) and K562 cell lines (7/12 Pts); and (c) increased expression of IL2 receptors (8/12 Pts) and of DR antigens (6/12 Pts). Lymphocytes collected 1-2 days after treatment and activated in vitro with rIL2 showed a more rapid development of tumor cytotoxicity, with an earlier loss of activity. Spontaneous proliferation, autologous or allogeneic tumor cytotoxicity and expression of IL2 receptors obtained after in vivo treatment with rIL2 were significantly weaker than those induced during in vitro stimulation. No major objective responses were detected in these patients.

Malignant plasma cells are sensitive to LAK cell lysis: pre-clinical and clinical studies of interleukin 2 in the treatment of multiple myeloma.

To assess the role of the cytokine interleukin 2 (IL2) in the treatment of patients with multiple myeloma, we examined the sensitivity of plasma cell lines and malignant plasma cells from multiple myeloma (MM) patients to cell and cytokine-mediated killing induced by IL2. Unstimulated peripheral blood mononuclear cells (PBM) from normal donors produced little killing (mean lysis 1.0 +/- 1.0%, effector:target (ET) ratio 50:1), but cytotoxicity was modestly increased when PBM were incubated with IL2 prior to assay (8.0 +/- 2.9%). Unstimulated PBM from patients with MM also failed to kill autologous malignant plasma cells (mean 0.6 +/- 0.6%), but after exposure to IL2 they induced substantial lysis of autologous malignant cells (mean 55.3 +/- 22.1%). In addition, tumour necrosis factor (TNF) and interferon-gamma (IFN-gamma), two cytokines released from mononuclear cells in response to IL2, also reduced the survival and thymidine uptake of malignant plasma cells in culture. To determine whether these potentially beneficial immunomodulatory effects could be reproduced by in vivo administration of IL2, we have administered seven courses of IL2 to four patients with MM after autologous bone marrow transplant (ABMT). No serious adverse effects were noted. Increases in natural killer (NK) and lymphokine-activated killer (LAK) activity of PBM occurred during IL2 infusion, although cells capable of killing autologous MM cells did not circulate. However, IL2 infusions also induced substantial increases in the production of the cytokines TNF and IFN-gamma from peripheral blood lymphocytes. These results suggest that the in vivo administration of IL2 in MM deserves further evaluation, particularly for its potential to control minimal residual disease.

Effects of recombinant interleukin-2 administration on cytotoxic function following high-dose chemo-radiotherapy for hematological malignancy.

Activated killer cells, unrestricted by major histocompatibility (MHC) antigens circulate in the peripheral blood of patients who have undergone autologous and allogeneic bone marrow transplant (BMT) and may contribute to the reduced risk of leukemic relapse observed after these procedures. Interleukin-2 (IL-2) in vitro augments this cytotoxicity and used therapeutically might thereby promote the eradication of minimal residual disease. In order to assess whether these effects on cytotoxicity can be reproduced in vivo, we studied changes in number, phenotype, and MHC unrestricted cytotoxicity of peripheral blood mononuclear cells obtained from patients with hematologic malignancy receiving IL-2 infusions. Patients with acute myeloid leukemia and multiple myeloma were treated after cytotoxic chemotherapy or autologous BMT. IL-2 infusions produced an initial lymphopenia, followed by a progressive recovery in mononuclear cell numbers and a rebound lymphocytosis after the termination of treatment. This affected all lymphocyte subsets; in particular CD25 (IL-2 receptor) positive cell numbers rose sevenfold. Cells with the ability to kill a natural killer (NK)-resistant, lymphokine activated killer cell (LAK)-sensitive target appeared in the circulation during 16 of 19 infusions and mean LAK activity rose from 5.9% to 15.5% during infusion (E:T ratio, 50:1; P less than .001). During IL-2 infusion, cells present in the peripheral blood inhibited the growth of myeloid leukemia blasts in agar after overnight co-culture. Depletion experiments showed that LAK activity was mediated by cells of both CD3- CD16+ (NK derived) and CD3+ CD16- (T derived) subsets. LAK precursor activity in peripheral blood also significantly increased during IL-2 infusion. Increases in major histocompatibility complex (MHC) unrestricted cytotoxicity can be produced by IL-2 infusions in vivo and may result in improved relapse-free survival following chemotherapy or BMT.

A phase I clinical trial of recombinant interleukin 2 following high dose chemo-radiotherapy for haematological malignancy: applicability to the elimination of minimal residual disease.

Biological response modifiers such as interleukin 2 (IL2) may be most effective in the setting of minimal residual disease. In a phase I-II clinical trial, IL2 was administered to 10 patients in remission of acute myeloid leukaemia and three with multiple myeloma 1-4 weeks after treatment with ablative chemotherapy or chemotherapy and autologous bone marrow transplantation. The aim was to assess the capacity of these patients to tolerate IL2 after intensive therapy and to determine whether regenerating lymphocytes were capable of responding to IL2 with the generation of anti-leukaemic effector cells. Toxicity was severe in two patients treated with escalating doses of IL2 and 19 subsequent infusions administered to 11 patients on a fixed dose schedule for periods of 3-5 days were well tolerated. Major toxicity was confined to hypotension (two courses) which responded rapidly to treatment cessation. No patients required intensive care unit support. IL2 infusions produced no significant adverse effects on marrow regeneration; while there were transient falls in platelet counts there were no episodes of clinical bleeding and neutrophil counts increased from a mean of 1.1 pre-infusion to 2.5 x 10(9)l-1 during the infusion (P = 0.004). A significant biochemical abnormality was hypokalaemia which responded rapidly to correction. Cells with activity against leukaemic progenitor cells appeared in peripheral blood within 48 h of beginning treatment. We conclude that IL2 may be used in minimal residual haematological malignancy, and by producing anti-neoplastic effector cells has the potential, as yet unproven, to prolong disease-free survival of patients entering remission.