Phase I study of GRN1005 in recurrent malignant glioma.

PURPOSE: GRN1005 is a peptide-drug conjugate with the ability to penetrate the blood-brain barrier (BBB) and tumor cells by targeting the low-density lipoprotein receptor-related protein-1. We conducted a first-in-human phase I trial of GRN1005 in patients with recurrent glioma. METHODS: Patients received GRN1005 by intravenous infusion every 3 weeks. Doses were escalated using a modified Fibonacci scheme. Study objectives included safety, tolerability, identification of the maximum tolerated dose (MTD), pharmacokinetics, and preliminary evidence of efficacy. Tumor extracted from patients undergoing surgery following administration of GRN1005 was analyzed to determine whether therapeutic concentrations of GRN1005 were achieved. RESULTS: Sixty-three patients received GRN1005 at doses of 30 to 700 mg/m(2) every 3 weeks. Therapy was well tolerated with neutropenia, leucopenia, and fatigue as the most frequent drug-associated grade 3/4 or higher toxicities. The MTD was 650 mg/m(2) every 3 weeks. Dose-limiting toxicities were grade 3 mucositis and grade 4 neutropenia. There was no evidence of central nervous system toxicity or antibody production. Pharmacokinetic analysis showed that exposure to GRN1005 was dose proportional. We observed one complete and two partial responses. Eight of 27 patients dosed ≥ 420 mg/m(2) had stable disease, which lasted a median of 51 days. Therapeutic concentrations of GRN1005 and free paclitaxel were shown in tumor tissue of surgical patients dosed with ≥ 200 mg/m(2). CONCLUSION: GRN1005 delivers paclitaxel across the BBB and achieves therapeutic concentrations in tumor tissue. It has similar toxicity to paclitaxel and appears to have activity in recurrent glioma. The recommended phase II dose is 650 mg/m(2) every 3 weeks.

Once-daily administration of CJC-1295, a long-acting growth hormone-releasing hormone (GHRH) analog, normalizes growth in the GHRH knockout mouse.

Although the majority of children with isolated growth hormone (GH) deficiency have a good growth response to GH-releasing hormone (GHRH), the use of this therapeutic agent is limited by its very short half-life. Indeed, we have shown that, in mice with GHRH gene ablation (GHRH knockout; GHRHKO), even twice-daily injections of a GHRH analog are unable to normalize growth. CJC-1295 is a synthetic GHRH analog that selectively and covalently binds to endogenous albumin after injection, thereby extending its half-life and duration of action. We report the effects of CJC-1295 administration in GHRHKO animals. Three groups of 1-wk-old GHRHKO mice were treated for 5 wk with 2 microg of CJC-1295 at intervals of 24, 48, and 72 h. Placebo-treated GHRHKO mice and mice heterozygous for the GHRHKO allele served as controls. GHRHKO animals receiving daily doses of CJC-1295 exhibited normal body weight and length. Mice treated every 48 and 72 h reached higher body weight and length than placebo-treated animals, without full growth normalization. Femur and tibia length remained normal in animals treated every 24 and 48 h. Relative lean mass and subcutaneous fat mass were normal in all treated groups. CJC-1295 caused an increase in total pituitary RNA and GH mRNA, suggesting that proliferation of somatotroph cells had occurred, as confirmed by immunohistochemistry images. These findings demonstrate that treatment with once-daily administration of CJC-1295 is able to maintain normal body composition and growth in GHRHKO mice. The same dose is less effective when administered every 48 or 72 h.

Prolonged stimulation of growth hormone (GH) and insulin-like growth factor I secretion by CJC-1295, a long-acting analog of GH-releasing hormone, in healthy adults.

CONTEXT: Therapeutic use of GHRH to enhance GH secretion is limited by its short duration of action. OBJECTIVE: The objective of this study was to examine the pharmacokinetic profile, pharmacodynamic effects, and safety of CJC-1295, a long-acting GHRH analog. DESIGN: The study design was two randomized, placebo-controlled, double-blind, ascending dose trials with durations of 28 and 49 d. SETTING: The study was performed at two investigational sites. PARTICIPANTS: Healthy subjects, ages 21-61 yr, were studied. INTERVENTIONS: CJC-1295 or placebo was administered sc in one of four ascending single doses in the first study and in two or three weekly or biweekly doses in the second study. MAIN OUTCOME MEASURES: The main outcome measures were peak concentrations and area under the curve of GH and IGF-I; standard pharmacokinetic parameters were used for CJC-1295. RESULTS: After a single injection of CJC-1295, there were dose-dependent increases in mean plasma GH concentrations by 2- to 10-fold for 6 d or more and in mean plasma IGF-I concentrations by 1.5- to 3-fold for 9-11 d. The estimated half-life of CJC-1295 was 5.8-8.1 d. After multiple CJC-1295 doses, mean IGF-I levels remained above baseline for up to 28 d. No serious adverse reactions were reported. CONCLUSIONS: Subcutaneous administration of CJC-1295 resulted in sustained, dose-dependent increases in GH and IGF-I levels in healthy adults and was safe and relatively well tolerated, particularly at doses of 30 or 60 microg/kg. There was evidence of a cumulative effect after multiple doses. These data support the potential utility of CJC-1295 as a therapeutic agent.