Adan Rios

Clinical toxicity of interferons in cancer patients: A review

All major types of human interferons (IFNs) have been purified and clinically administered as antitumor agents. We summarize here experience to date with toxicity of IFNs in cancer patients. The acute syndrome consists of fever, chills, myalgias, arthralgias, and headache, with some variation according to type of IFN, route of administration, schedule, and dose. Fatigue, perhaps reflecting CNS toxicity, is the most prevalent nonacute symptom. At high doses, IFNs are neurotoxic; the abnormalities seen by EEG resemble those in diffuse encephalitis. Hematologic toxicity consists mainly of leukopenia, but anemia and thrombocytopenia occur in some patients. Nausea, vomiting, and diarrhea are the main gastrointestinal symptoms. Elevation of serum transaminases seems to reflect liver toxicity. Renal function is well preserved, except for rare instances of acute renal failure. Cardiac toxicity remains questionable, although heart failure and arrhythmias have been associated with the administration of IFNs. Most, if not all, of these effects are reversible or can be ameliorated. With IFN alpha, the type most widely used in clinical studies, doses of 1 million to 9 million units (MU) are generally well tolerated, but doses greater than or equal to 18 MU yield moderate to severe toxicity. Doses greater than or equal to 36 MU can induce severe toxicity and significantly alter the performance status of the patient.

Randomized comparative trial of pegylated liposomal doxorubicin versus bleomycin and vincristine in the treatment of AIDS-related Kaposi's sarcoma. International Pegylated Liposomal Doxorubicin Study Group.

PURPOSE Cytotoxic chemotherapy is frequently required for the more severe manifestations of human immunodeficiency virus (HIV)-related Kaposis sarcoma. Combinations of bleomycin and vincristine (BV) or BV with the addition of doxorubicin (ABV) are the most commonly used regimens against which new treatments may be compared. We report a multicenter phase III study that compared pegylated liposomal doxorubicin (PLD) to the BV combination. PATIENTS AND METHODS We conducted a randomized study that compared PLD 20 mg/m2 with a combination of bleomycin 15 IU/m2 and vincristine 2 mg in 241 patients with HIV-related Kaposis sarcoma. Both regimens were administered by intravenous infusion every 3 weeks for six cycles. RESULTS A total of 121 patients received PLD and 120 patients the BV combination. The response to PLD was superior to BV: 58.7% versus 23.3% (P < .001). Patients who were randomized to receive BV, however, were more likely to terminate treatment early because of an adverse event (26.7% v 10.7%), and fewer completed the full six cycles of treatment (30.8% v 55.4%). Treatment with BV was associated with a significantly higher incidence of peripheral neuropathy (P < .001), whereas PLD treatment was more commonly associated with neutropenia and delays in receiving treatment (P < or = .001). CONCLUSION Pegylated liposomal doxorubicin is an effective treatment for HIV-related Kaposis sarcoma with a higher response rate than the BV combination. It is well tolerated but more myelosuppressive.

Antitumor activity of recombinant-derived interferon alpha in metastatic renal cell carcinoma.

Fifty-six patients with metastatic renal cell carcinoma (RCC) were treated with recombinant DNA-derived interferon alpha (rIFN alpha A). The first 30 patients were randomized between doses of 2 X 10(6) U/m2 and 20 X 10(6) U/m2 intramuscularly daily. No complete (CR) or partial (PR) remissions were achieved in 15 patients receiving the low dose. In contrast, 27% of those receiving the high dose achieved CR or PR. Subsequently, 26 additional patients were given the high dose and achieved a 31% response rate. Remissions lasted from 1 to more than 12 months (median, 3 months). Responses occurred predominantly in lung parenchyma or mediastinal node metastases. Toxicity of the high dose required dose reduction in 50% of the patients. Neutralizing antibodies to rIFN alpha A developed in seven of 12 responsive (58%) and nine of 29 (31%) nonresponsive patients (P = greater than .5). The median duration of remission among the antibody-positive and antibody-negative patients were 2 and 10 months, respectively (P = .009). The clinical significance of the antibodies to rIFN alpha A remains unclear, but the coincidence between the detection of antibodies and the early relapse of the disease in some responsive patients suggests that these antibodies may abrogate the biologic activity of rIFN alpha A. This effect, however, was not associated with adverse clinical sequelae.

Recombinant Human Erythropoietin in the Treatment of Anemia Associated with Human Immunodeficiency Virus (HIV) Infection and Zidovudine Therapy: Overview of Four Clinical Trials

OBJECTIVE To assess the effect of recombinant human erythropoietin (r-HuEPO) on anemia in patients with the acquired immunodeficiency syndrome (AIDS) who are receiving zidovudine therapy. DESIGN Combined analysis of four 12-week, randomized, double-blind, controlled clinical trials. SETTING Multiple centers in the United States. PATIENTS Two hundred and ninety-seven anemic (hematocrit < 30%) patients with AIDS who were receiving zidovudine therapy. Of the 297 patients, 255 were evaluable for efficacy, but all patients were included in analysis of safety. INTERVENTION Patients were randomly assigned to receive either r-HuEPO (100 to 200 U/kg body weight) or placebo, intravenously or subcutaneously, three times per week for up to 12 weeks. MEASUREMENTS Changes in mean hematocrit, transfusion requirement, and quality of life. RESULTS Sixty-nine percent of patients had endogenous serum erythropoietin levels less than or equal to 500 IU/L, and 31% had erythropoietin levels greater than 500 IU/L. In patients with low erythropoietin levels (< or equal to 500 IU/l), r-HuEPO therapy decreased the mean number of units of blood transfused per patient when compared with placebo (3.2 units and 5.3 units, respectively; P = 0.003) and increased the mean hematocrit from the baseline level (4.6 percentage points and 0.5 percentage points, respectively; P <0.001). Overall quality of life improved in patients on r-HuEPO therapy (P = 0.13). Patients with erythropoietin levels greater than 500 IU/L showed no benefit from r-HuEPO in any outcome variable. Placebo and r-HuEPO recipients did not differ in the incidence of adverse effects or opportunistic infections. CONCLUSION Therapy with r-HuEPO can increase the mean hematocrit and decrease the mean transfusion requirement in anemic patients with AIDS who are receiving zidovudine and have endogenous low erythropoietin levels (< or equal to 500 IU/L). Such therapy is of no apparent benefit in patients whose endogenous erythropoietin levels are higher than 500 IU/L.

Treatment of acquired immunodeficiency syndrome--related Kaposi's sarcoma with lymphoblastoid interferon.

Twelve homosexual patients with Kaposis sarcoma associated with the acquired immune deficiency syndrome (AIDS) were treated with a preparation of purified human lymphoblastoid interferon (Wellferon [Burroughs Wellcome, Research Triangle Park, NC]). They were given a dose of 20 X 10(6) U/m2 intramuscularly daily for approximately two months. Responders continued their treatment on a maintenance schedule of 20 X 10(6) U/m2 three times a week. Four patients experienced complete remissions, and four experienced partial remissions that resulted in a total response rate of 67%. The median duration of treatment was 14 weeks (7 to 28+ weeks), and the median response duration was 28+ weeks (19 to 29+ weeks). Of the four patients in complete remission, one relapsed at 25 weeks and one at 26 weeks; the other two remained in complete remission at 28 and 29+ weeks. The clinical toxicity consisted of chills, fever, fatigue, and asthenia. Hematologic toxicity was similar to that previously described for other preparations of alpha-interferon and consisted of moderate leukopenia and thrombocytopenia. Asthenia, a condition present in all 12 patients, was severe in 50%. A minimal tumor burden, the absence of circulating interferon before treatment, and a performance status of greater than or equal to 90% on the Karnofsky scale were related to an improved response rate. Measurement of immunologic parameters showed significant declines in the already impaired T cell levels, lymphocyte blastogenic response to concanavalin A, monocyte-mediated antibody-dependent cellular cytotoxicity, and monocyte-adherence. Activation of natural killer cells was not noted, and no life-threatening infections occurred during treatment. These data suggest that human lymphoblastoid interferon is an active agent in the treatment of Kaposis sarcoma, and its use warrants further study in a larger number of patients.

Bacteremia caused by Campylobacter-like organisms in two male homosexuals.

Bacteremia caused by newly described Campylobacter-like organisms occurred in two immunosuppressed homosexual patients with tuberculosis. Although these organisms grow well in aerobic bottles using a radiometric blood culture system, they are not readily seen in gram-stained smears and are easily missed if routine subculture methods are used. Microscopic examination of wet preparations and subculture to brucella agar base supplemented with 10% sheep blood and incubated in microaerophilic conditions are useful for identification and isolation. The recovery of Campylobacter-like organisms from the blood suggests that these organisms, formerly known only to be associated with proctocolitis or asymptomatic rectal infection in homosexual men, can also cause systemic infection in these patients.

Preclinical and clinical studies on immunogenicity and safety of the HIV-1 p17-based synthetic peptide AIDS vaccine--HGP-30-KLH.

Immunization with a synthetic HIV-1 p17 peptide analog (HGP-30; aa 85-115 of HIV p17), coupled to a carrier protein (KLH, keyhole limpet hemocyanin) given with alum as the adjuvant induces antibodies which cross-react with both HGP-30 and HIV p17 and clones of cytotoxic and helper T-cells which recognize HGP-30 and HIV p17. Proliferation of lymphocytes in response to HGP-30 has been observed in mice, in HIV-infected individuals and in healthy HIV-seronegative volunteers vaccinated with the p17-based synthetic peptide construct. Cytotoxic T-cell responses against EBV transformed, recombinant p17 pulsed targets were observed using antigen-expanded PBLs from HGP-30-KLH immunized individuals. These results are consistent with predictions that the HGP-30 domain of HIV p17 contains both T- and B-cell epitopes that are recognized by animals and humans. In preclinical toxicology studies in animals and in initial clinical trials in humans the synthetic peptide construct (HGP-30-KLH/alum) has been shown to be safe. This paper summarizes the preclinical immunogenicity and safety data for HGP-30-KLH and presents the initial results from the first Phase 1 clinical trial.

A pilot study of diethyldithiocarbamate in patients with acquired immune deficiency syndrome (AIDS) and the AIDS-related complex

We investigated the use of diethyldithiocarbamate (DTC, or Imuthiolr, Merieux Institute) as a therapeutic agent in patients with Acquired Immune Deficiency Syndrome (AIDS) and AIDS-Related Complex (ARC). Patients were prospectively stratified and randomized to receive DTC 200 mg/m2 intravenously weekly for 16 weeks or no therapy, followed by crossover to the opposite arm for an equal period. Forty-four patients were entered and forty were evaluable. There was a statistically significant decrease in symptoms in the DTC treated patients compared to the controls (p = .002). There was a significant improvement in lymphadenopathy in the treated patients compared to the controls (p = .005). One patient showed disappearance of splenomegaly, one clearing of antifungal agent-resistant perianal moniliasis, and one clearing of hairy leukoplakia. No significant differences in progression were noted. No changes were seen in any of the immunological parameters measured. There was no significant toxicity. Because of the changes in symptoms and in lymphadenopathy, we suggest that further study of DTC, both alone and in combination with other agents, may be indicated.

HER3/ErbB3, an emerging cancer therapeutic target

HER3 is a member of the HER (EGFR/ErbB) receptor family consisting of four closely related type 1 transmembrane receptors (EGFR, HER2, HER3, and HER4). HER receptors are part of a complex signaling network intertwined with the Ras/Raf/MAPK, PI3K/AKT, JAK/STAT, and PKC signaling pathways. Aberrant activation of the HER receptors and downstream signaling molecules tips the balance on cellular events, leading to various types of cancers. Monoclonal antibodies (mAbs) and small molecule inhibitors targeting EGFR and HER2 tyrosine kinase activities exhibit clinical benefits in the treatment of several types of cancers, but their clinical efficacy is limited by the occurrence of drug resistance. HER3 is the preferred dimerization partner of HER2 and it is well established that HER3 plays an important role in drug resistance to EGFR- and HER2-targeting therapies. Since HER3 has limited kinase activity, mAbs are being explored to target HER3 for cancer therapy. Currently, approximately a dozen of anti-HER3 mAbs are at different stages of clinical development. However, the lack of established biomarkers has made it more challenging to stratify cancer patients to whom HER3-targeting therapies can be more effective. In this review, we focus on the validation of HER3 as a cancer drug target, the recent development in biomarker discovery for anti-HER3 therapies, and the progress made in the clinical development of HER3-targeting mAbs.

HIV-Related Hematological Malignancies: A Concise Review

HIV (Human Immunodeficiency Virus) and its consequence, AIDS (acquired immunodeficiency syndrome) are responsible for a human tragedy of incalculable proportions. Patients afflicted by it are susceptible due to an early senescence of the immune system to opportunistic infections and malignancies. Since the introduction in 1996 of highly active anti-retroviral therapy (HAART), the landscape of malignancies associated to HIV/AIDS has changed in a significant manner as a direct result of significant improvement in the morbidity, mortality and life expectancy of HIV infected patients. While there has been a significant decrease in developed countries of malignancies such as Kaposis sarcoma and Primary CNS lymphomas associated to the pre-HAART HIV-related immunodeficiency, hematological malignancies, particularly non-Hodgkin lymphomas continue to be the most common cancer-related cause of death in HIV infected individuals. This concise review of the subject highlights aspects of the natural history of HIV disease as it relates to the cause of malignancies with emphasis in the management and treatment of HIV-related hematological malignancies.