Recombinant human relaxin in the treatment of scleroderma. A randomized, double-blind, placebo-controlled trial.

BACKGROUND: Relaxin is a pregnancy-related hormone that has tissue remodeling and antifibrotic effects. Systemic sclerosis (scleroderma) is characterized by fibrosis of the skin, vasculature, and internal organs. OBJECTIVE: To assess the efficacy, safety, and dose-response effect of recombinant human relaxin in patients with scleroderma. DESIGN: Multicenter, parallel-group, randomized, double-blind, placebo-controlled trial. SETTING: Academic referral centers. PATIENTS: 68 patients who had had stable, diffuse scleroderma (moderate to severe) for less than 5 years. INTERVENTION: Recombinant human relaxin, 25 or 100 microg/kg of body weight per day, or placebo administered by continuous subcutaneous infusion over 24 weeks. MEASUREMENTS: Modified Rodnan skin score was the primary efficacy measure. Secondary measurements were pulmonary function, the Health Assessment Questionnaire, and other measures of scleroderma that reflected fibrosis. RESULTS: Patients who received 25 microg/kg of recombinant human relaxin per day had significantly lower skin scores than those who received placebo (mean change, -3.6 at 4 weeks [P = 0.021], -7.5 at 12 weeks [P < 0.001], and -8.7 at 24 weeks [P = 0.040]). Similar trends were noted in other outcome measures, including forced vital capacity, measures of oral aperture and hand extension, functional status, and global assessment. Patients who received 100 microg/kg of relaxin per day did not differ from those who received placebo. Drug-related adverse events included menometrorrhagia, reversible anemia, and complications of the subcutaneous drug administration system (site irritation and local infection). CONCLUSIONS: Twenty-four weeks of recombinant human relaxin, 25 microg/kg per day, is associated with reduced skin thickening, improved mobility, and improved function in patients with moderate to severe diffuse scleroderma.

Betamethasone valerate foam 0.12%: a novel vehicle with enhanced delivery and efficacy.

BACKGROUND: A new topical formulation of betamethasone valerate (BMV) with enhanced dermal penetration has been developed. OBJECTIVE: These studies were designed to evaluate: (1) the relative bioavailability of BMV foam, and (2) the safety and efficacy of BMV foam in the treatment of scalp psoriasis as compared to a lotion formulation of BMV and placebo. METHODS: Safety and efficacy were evaluated in a randomized, multicenter, double-blind, active-and placebo-controlled trial in adult patients with moderate to severe scalp psoriasis. A separate study in 18 patients was conducted to evaluate the potential for suppression of the hypothalamic-pituitary-adrenal (HPA) axis. Relative bioavailability was measured using the human cadaver skin model. RESULTS: 72% of patients using BMV foam were clear or almost clear of disease at the end of 28-days of treatment as judged by the investigator's global assessment of response. Only 47% of BMV lotion patients and 21% of placebo showed a similar level of response. There was no evidence of increased toxicity or HPA-axis suppression for BMV foam, but assessment of relative bioavailability showed BMV penetration into the skin to be more than two-fold greater than from BMV lotion. CONCLUSIONS: A novel foam formulation with enhanced BMV bioavailability has been shown to be of increased efficacy in the treatment of scalp psoriasis without an associated increase in toxicity.

Human immune response to Pseudomonas aeruginosa mucoid exopolysaccharide (alginate) vaccine.

Chronic lung infection with mucoid Pseudomonas aeruginosa is the major pathologic feature of cystic fibrosis. Previous studies suggested that a failure to produce opsonic antibody to the mucoid exopolysaccharide (MEP; also called alginate) capsule is associated with the maintenance of chronic bacterial infection. Provision of MEP-specific opsonic antibodies has therapeutic potential. To evaluate the ability of MEP to elicit opsonic antibodies, humans were immunized with two lots of MEP vaccine that differed principally in molecular size. Lot 2 had a larger average MEP polymer size. Both vaccines were well tolerated, but lot 1 was poorly immunogenic, inducing long-lived opsonic antibodies in only 2 of 28 vaccinates given doses of 10 to 150 micrograms. In contrast, at the optimal dose of 100 micrograms, lot 2 elicited long-lived opsonic antibodies in 80 to 90% of the vaccinates. The antibodies elicited by both lots enhanced deposition of C3 onto mucoid P. aeruginosa cells and mediated opsonic killing of heterologous mucoid strains expressing distinct MEP antigens. These results indicate that the polymers of MEP with the largest molecular sizes safely elicit opsonic antibodies in a sufficiently large proportion of vaccinates to permit studies of active and passive immunization of cystic fibrosis patients against infection with mucoid P. aeruginosa.

The effects of cyclophosphamide on the toxicity and immunogenicity of ricin A chain immunotoxin in rats.

We conducted a study to determine if treatment with cyclophosphamide (CY) could suppress the formation of anti-murine and anti-ricin A chain antibodies in rats treated with a murine monoclonal antibody-ricin A chain immunotoxin (IT). Female Sprague-Dawley rats received intravenous doses of IT at a dose of 5 mg/kg body weight alone or in combination with CY at a dose level of either 10 or 20 mg/kg body weight. The IT was given as one or two courses consisting of five consecutive daily intravenous injections (days 0 to 4, or days 0 to 4 and days 21 to 25 of the study). Cyclophosphamide was given on days 2, 4, 6, 13, and 17 of the study to the group receiving a single course of IT; additional doses of CY were administered on days 23, 25, and 27 to the group receiving two courses of IT. On days 4, 14, 21, 28, and 35, animals from each group were evaluated for antibodies to murine IgG and ricin A chain, and for clinical laboratory parameters and histopathology. Animals receiving IT alone developed significant titers of both anti-murine and anti-ricin A chain antibodies. Compared with the response in the animals receiving single-course IT, the response to both of the components of the IT was significantly increased on days 28 and 35 in the animals receiving a second course of IT. The groups receiving a combination of either one or two courses of CY and IT demonstrated a significantly decreased antibody response to both the murine IgG and the ricin A chain compared with the group receiving IT alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Regulatory agency concerns in the manufacturing and testing of monoclonal antibodies for therapeutic use.

Monoclonal antibody-based therapeutic products are subject to the same regulatory review procedures and submissions requirements as more traditional pharmaceutical agents. In addition, the FDA often asks for specific information on the unique aspects of the manufacture, characterization, and testing of these products. Agency concern begins with the origin of the hybridoma cell line and continues through preclinical safety testing and clinical trials. Specific regulatory issues are often decided on a case-by-case basis with the FDA reviewers. Implementing an effective strategy for identifying and addressing these issues and concerns is a critical part of the development process.

Distinctive patterns of release of neuroendocrine peptides after nasal challenge of allergic subjects with ryegrass antigen.

The concentrations of the neuropeptides substance P, somatostatin, and calcitonin gene-related peptide in human nasal secretions were quantified by radioimmunoassays, concurrently with that of histamine, in the course of nasal challenge of allergic and control subjects with ryegrass antigen to examine contributions of neuromediation of the tissue response. Each of the neuropeptides and histamine were detected in nasal lavage fluid prior to challenge. In allergic patients, but not normal controls, antigen evoked significant increases of 3-fold in histamine at 15-60 min, 1.5- to 4-fold in calcitonin gene-related peptide at 15 min-24 hr, and more than 2-fold in somatostatin at 6 hr, without altering the concentration of substance P in nasal lavage fluid. The identity of the neuropeptides was confirmed chromatographically. Thus calcitonin gene-related peptide may mediate nasal congestion directly and somatostatin may be one of the factors regulating the late involvement of basophils and mast cells in allergic rhinitis.

Therapy of patients with malignant melanoma using a monoclonal antimelanoma antibody-ricin A chain immunotoxin.

We conducted a trial of a murine monoclonal antimelanoma antibody-ricin A chain immunotoxin (XOMAZYME-MEL) in 22 patients with metastatic malignant melanoma. The dose of immunotoxin administered ranged from 0.01 mg/kg daily for 5 days to 1 mg/kg daily for 4 days (total dose: 3.2 to 300 mg). Side effects observed in most patients were a transient fall in serum albumin with an associated fall in serum protein, weight gain, and fluid shifts resulting in edema. In addition, patients experienced mild to moderate malaise, fatigue, myalgia, decrease in appetite, and fevers. There was a transient decrease in voltage on electrocardiograms without clinical symptoms, change in serial echocardiograms or elevation of creatine phosphokinase MB isozyme levels. Symptoms consistent with mild allergic reactions were observed in three patients. The side effects were related to the dose of immunotoxin administered and were generally transient and reversible. Encouraging clinical results were observed, even after a single course of a low dose of immunotoxin. In addition, localization of antibody and A chain to sites of metastatic disease was demonstrated by immunoperoxidase staining of biopsy specimens. Additional studies are being conducted to continue the evaluation of safety and efficacy of immunotoxin therapy for malignancy.