antimicrobial-peptide-ib-367 and Stomatitis

Iseganan HCl is an antimicrobial peptide under development for the prevention of oral mucositis, a severe consequence of some chemotherapy and radiation therapy regimens. Several attributes of iseganan make it an optimal candidate for study in this clinical situation where both local and systemic host defenses may be impaired. These include broad spectrum and rapid bactericidal activity, a lack of observed resistance and cross-resistance and stability in biological fluids. Clinical trials of patients receiving stomatotoxic chemotherapy followed by a haematopoietic stem cell transplant show iseganan reduces the occurrence of oral mucositis and ameliorates sequelae such as mouth pain, throat pain and difficulty swallowing. Iseganan is well-tolerated, which is partly attributable to a lack of systemic absorption following topical oral administration. Other promising areas of investigation include topical oral application for the prevention of ventilator-associated pneumonia and nebulisation for treatment of chronic lung infection in patients with cystic fibrosis. Future studies will expand on the role of iseganan as a novel antimicrobial.

Topics: Animals; Anti-Infective Agents; Antimicrobial Cationic Peptides; Bacterial Infections; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Humans; Neoplasms; Peptides; Proteins; Stomatitis; Treatment Outcome

Iseganan (IB-367) is a protegrin under development by IntraBiotics, as part of a larger protegrin program, for the potential treatment of oral mucositis, a frequent side effect of anticancer therapies. The company is developing three formulations of the drug: A rinse for the potential treatment of mucositis, an aerosolized liquid for the potential treatment of respiratory infection and a gel formulation for the potential treatment of pneumonia [376325]. Iseganan kills a broad-spectrum of bacteria and fungi, including those resistant to conventional antimicrobial drugs, by attaching to and destroying the integrity of the lipid cell membrane [241594]. Until August 1999, Pharmacia & Upjohn was a codeveloper of iseganan. IntraBiotics re-acquired the global rights to iseganan in December 1999, and both companies agreed to terminate the collaboration [335766]. In May 2000, analysts at SG Cowen predicted the drug's potential market at US $100 to US $200 million [376325].

Topics: Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Drug Industry; Drugs, Investigational; Gram-Negative Bacterial Infections; Gram-Positive Bacterial Infections; Humans; Mouth Mucosa; Peptides; Proteins; Randomized Controlled Trials as Topic; Stomatitis; Structure-Activity Relationship; Treatment Outcome

Cytotoxic chemotherapy induces changes in the oral microflora that may cause oral and systemic infections in myelosuppressed cancer patients. These complications prompted us to assess the antimicrobial activity of a topical Iseganan HCl mouthwash vs. placebo on the aerobic and facultatively anaerobic oral flora in these patients.. Two hundred and twenty-five chemotherapy patients were recruited into a randomized, double-blind, placebo-controlled trial, conducted at multiple centers. The study compared the antimicrobial efficacy of Iseganan HCl vs. placebo (95% of the Iseganan and 97% of the control group received myeloablative chemotherapy). Iseganan HCl 9 mg/3 ml was administered as a swish and swallow solution, six times daily for 21-28 days. Microbial cultures were made before and after the daily Iseganan mouth rinse on the first and final days of chemotherapy.. The reduction in total microbial load after the first day of treatment was statistically significant (1.59 vs. 0.18 log10 CFU for the Iseganan HCl and placebo groups, respectively, P < 0.0001). Iseganan HCl rinse had a cumulative effect demonstrated by the significant difference between the two groups on the last day of the study (i.e. completion of Iseganan daily treatment) (P < 0.05). The reduction was mainly due to decreased densities of viridans streptococci, non-hemolytic streptococci, and yeasts. The minimal inhibitory concentration (MIC) of Iseganan HCl remained the same throughout the course of treatment.. Topical Iseganan HCl significantly reduces the total oral aerobic bacterial, streptococcal, and yeast load. Its potential as an oral antimicrobial agent in preventing these types of infections is clear.

Topics: Anti-Infective Agents; Antimicrobial Cationic Peptides; Antineoplastic Agents; Bacteria, Aerobic; Bacteria, Anaerobic; Bacterial Load; Double-Blind Method; Female; Follow-Up Studies; Gram-Negative Bacteria; Humans; Male; Middle Aged; Mouth Mucosa; Mouthwashes; Myeloablative Agonists; Placebos; Safety; Staphylococcus; Stomatitis; Streptococcus; Treatment Outcome; Viridans Streptococci; Yeasts

Oral mucositis (OM) causes significant morbidity during the course of radiotherapy (RT) treatment of head-and-neck cancer. It is hypothesized that infection plays a role in the development of OM. We tested the efficacy of iseganan HCl (iseganan), a synthetic peptide with broad-spectrum antimicrobial activity, for preventing RT-associated OM.. A multinational, randomized, double-blind, controlled trial was performed on patients receiving primary RT, primary chemoradiotherapy or postoperative RT. Patients were randomized to receive iseganan oral solution plus standard-of-care oral hygiene (SOC), placebo plus SOC, or SOC alone throughout the RT administration period. The severity of OM was assessed by NCI-CTC scoring and clinical symptoms by patient questionnaire.. A total of 545 patients were randomized to the study. Nine percent of the patients in both the iseganan and placebo groups did not develop ulcerative OM (Grades 2, 3, 4) (p = 0.998) whereas only 2% of the patients receiving SOC alone remained free of oral ulceration (p = 0.049). The maximum severity of mouth pain and difficulty swallowing did not differ in patients treated with iseganan or placebo. However, patients in both intervention groups reported less mouth pain and difficulty swallowing than did patients receiving SOC alone. Nausea was the only adverse event that occurred with >/=5% increased frequency in the iseganan group than in either the placebo or SOC groups (51% vs. 42% vs. 46%). Adverse events leading to study drug discontinuation and death did not differ significantly between groups.. Iseganan oral solution was safe but did not reduce the risk for developing ulcerative OM relative to placebo. Intensified oral hygiene or the administration of the vehicle used to deliver study drug in this trial appears to have reduced the risk and severity of OM. Our results suggest that antimicrobial intervention may not meaningfully affect the pathogenesis of radiation-induced OM.

Topics: Adult; Antimicrobial Cationic Peptides; Candidiasis, Oral; Double-Blind Method; Female; Head and Neck Neoplasms; Humans; Male; Middle Aged; Mouth Mucosa; Nausea; Oral Hygiene; Peptides; Proteins; Radiation Injuries; Stomatitis

The invasion and colonization of oral cavity mucosal tissues by microflora may contribute to the pathophysiology of ulcerative oral mucositis (UOM). Iseganan is an analog of protegrin-1, a naturally occurring peptide with broad-spectrum microbicidal activity. A randomized, double-blind, placebo-controlled study was conducted to evaluate the efficacy and safety of iseganan in preventing UOM after stomatotoxic therapy. Patients received an oral rinse, consisting of iseganan 9mg or placebo, to be swished/swallowed six times daily, starting with stomatotoxic therapy and continuing up to 21 days. Patients were assessed for stomatitis and UOM, and administered a questionnaire evaluating mouth pain and difficulty swallowing thrice weekly. The primary study efficacy endpoint was the proportion of patients who did not have peak stomatitis NCI-CTC grade >or=2. Between November 2001 and June 2002, 502 patients were randomized to receive iseganan (251) or placebo (251). Equivalent numbers of patients in both cohorts received bone marrow or peripheral blood allogeneic or autologous stem cell transplantation (SCT). Forty-three percent and 37% of iseganan and placebo patients, respectively, did not have peak stomatitis grade =2 (P = 0.182). There was no significant difference between the cohorts in stomatitis severity, incidence of UOM, peak mouth pain, peak difficulty swallowing, amount of opiate analgesics used, or adverse event type or incidence. A major impact of Iseganan on reducing stomatitis, UOM, or its clinical sequelae in patients receiving stomatotoxic therapy was not detected on this study.

Topics: Antimicrobial Cationic Peptides; Antineoplastic Agents; Bone Marrow Transplantation; Cohort Studies; Double-Blind Method; Female; Humans; Male; Middle Aged; Mouth Mucosa; Neoplasms; Peptides; Placebos; Proteins; Stem Cell Transplantation; Stomatitis; Surveys and Questionnaires; Transplantation, Homologous; Treatment Outcome

No single oral mucositis (OM) assessment scale is universally accepted; the most commonly used scales are deficient because they combine subjective and objective measures and do not capture the patient's perspective. Because pain is the hallmark symptom of OM, the authors sought to determine whether a simple measure of patient-reported pain was correlated with objective, physician-assessed measures of OM. The findings of the current study may provide a clinical context for understanding the relation between objective indicators and patients' perceptions of OM.. Three hundred twenty-three patients receiving stomatotoxic chemotherapy and randomized to receive either iseganan or placebo for treatment of OM underwent periodic objective and subjective evaluations of OM. Objective measures included clinician scoring of stomatitis and dysphagia using the National Cancer Institute Common Toxicity Criteria scales. A subjective measure was obtained by having patients complete a questionnaire (with questions based on an 11-point numeric scale) regarding oral pain.. More than 90% of scheduled oral assessments were obtained. Mouth pain scores were closely related to stomatitis and dysphagia; peak mouth pain coincided with peak stomatitis and dysphagia. Analgesic use increased by 0.7 days for each unit rise on the pain scale. Patients receiving iseganan had a significantly lower level of peak mouth pain than did patients receiving placebo (P=0.041).. A separate measurement of patient-reported pain was useful for capturing the patient's perspective on OM and was correlated with the physician's objective assessment. These findings support the use of a simple, patient-reported rating of mouth pain as a clinically relevant and responsive endpoint in clinical trials. This rating system also may provide a straightforward method of following OM in clinical practice.

Topics: Adolescent; Adult; Aged; Antimetabolites, Antineoplastic; Antimicrobial Cationic Peptides; Child; Deglutition Disorders; Female; Humans; Lymphoma; Male; Methotrexate; Middle Aged; Mouth Mucosa; Pain; Pain Measurement; Peptides; Proteins; Severity of Illness Index; Stomatitis; Treatment Outcome

Microfloral invasion and colonization of oral cavity mucosal tissues contribute to the pathophysiology of ulcerative oral mucositis (UOM). Iseganan is an analog of Protegrin-1, a naturally occurring peptide with broad-spectrum microbicidal activity. A randomized, double-blind, placebo-controlled study was conducted to evaluate iseganan in preventing UOM after stomatotoxic therapy. Patients received an oral rinse of iseganan 9 mg or placebo, swished/swallowed 6 times daily, starting with stomatotoxic therapy and continuing for 21-28 days. One hundred sixty three and 160 patients, respectively, were randomized to receive iseganan or placebo. One hundred and two patients (32%) were affected by a drug dispensing error, caused by a flawed computerized allocation system. Among all 323 patients, analyzed according to randomization assignment, 43% and 33% of iseganan and placebo patients, respectively, did not develop UOM (P = 0.067). On an 11-point scale, iseganan patients experienced less mouth pain (3.0 and 3.8 (P = 0.041), throat pain (3.8 and 4.6 (P = 0.048)), and difficulty swallowing (3.9 and 4.7 (P = 0.074)), compared to placebo patients. On the 5-point NCI CTC scale, iseganan patients experienced lower stomatitis scores (1.6 and 2.0 (P = 0.0131). Iseganan was well tolerated; no systemic absorption was detected. Iseganan is safe and may be effective in reducing UOM and its clinical sequelae.

Topics: Adolescent; Adult; Aged; Anti-Infective Agents; Antimicrobial Cationic Peptides; Antineoplastic Agents; Child; Double-Blind Method; Humans; International Agencies; Middle Aged; Mouth Mucosa; Neoplasms; Peptides; Placebos; Proteins; Stomatitis

Protegrin antimicrobial peptides possess activity against gram-positive and gram-negative bacteria and yeasts. An extensive structure-activity relationship (SAR) study was conducted on several hundred protegrin analogues to gain understanding of the relationship between the primary and secondary structure of the protegrins and their antimicrobial activities, and to identify a protegrin analogue for clinical development. Native sequence protegrins are cationic, amphiphilic peptides that are characterized by the presence of a beta-sheet structure that is maintained by two disulfide bridges. The presence of the beta-sheet is key to the stability of the protegrin structure; linearized analogues or analogues that have amino acid substitutions that eliminate hydrogen bonding across the beta-sheet have reduced activity, especially in the presence of physiological concentrations of NaCl. Also, maintaining amphiphilicity of the beta-sheet is key; analogues with substitutions of polar amino acids in the hydrophobic face have reduced activity. Analogues with reduced positive charge tend to be less active, an observation that is more marked for gram-negative than gram-positive bacteria, and may implicate binding to lipopolysaccharide as a key mechanistic step in the killing of gram-negative bacteria. A very large number of amino acid substitutions are tolerated by the protegrin structure, implying that overall structural features such as amphiphilicity, charge, and shape are more important to activity than the presence of specific amino acids. This lack of importance of specific stereochemistry is supported by the fact that completely D-amino acid substituted protegrins are fully potent. Based on the SAR studies, and on the microbiological data from an animal model, one protegrin analogue, IB-367, was selected for clinical development as a topical agent to prevent the oral mucositis associated with cancer therapy.

Topics: Amino Acid Sequence; Animals; Anti-Bacterial Agents; Antimicrobial Cationic Peptides; Cathelicidins; Cricetinae; Disease Models, Animal; Microbial Sensitivity Tests; Molecular Sequence Data; Mouth Mucosa; Peptides; Peptides, Cyclic; Proteins; Stomatitis; Structure-Activity Relationship

The purpose of this animal study was to determine whether IB-367, an antimicrobial peptide, is able to ameliorate oral mucositis by reducing microflora densities on the mucosal surfaces of the mouth.. Oral mucositis was induced in hamsters by intraperitoneal injection of 5-fluorouracil followed by superficial abrasion of the buccal mucosa. A test formulation was applied topically to the buccal mucosa 5 or 6 times per day starting 6 to 8 hours before abrasion.. Mucositis scores were significantly lower (P < .05) in hamsters given formulations containing 0.5 or 2.0 mg/mL of IB-367 than in placebo-treated controls. Treatment with IB-367 produced a more than 100-fold reduction in oral microflora densities. In a second experiment, treatment of hamsters with a formulation containing IB-367 at 0.12, 0.5 or 2.0 mg/mL resulted in a dose-dependent reduction in mucositis severity.. The results indicate that reduction of local microflora densities through use of IB-367 may improve clinical outcomes in patients at risk for the development of oral mucositis.

Topics: Animals; Anti-Infective Agents, Local; Antimicrobial Cationic Peptides; Bacillus; Colony Count, Microbial; Cricetinae; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Escherichia coli; Fluorouracil; Male; Mesocricetus; Mouth Mucosa; Pasteurella; Peptide Fragments; Peptides; Proteins; Proteus mirabilis; Statistics, Nonparametric; Stomatitis; Streptococcus