Hyaluronan-Irinotecan improves progression-free survival in 5-fluorouracil refractory patients with metastatic colorectal cancer: a randomized phase II trial.

PURPOSE: The objective of this study was to conduct a randomised phase II study in second-line metastatic colorectal cancer with the purpose of confirming preliminary clinical data indicating that the formulation of irinotecan with the drug carrier, hyaluronan (HA) reduced toxicity of the drug. METHODS: Irinotecan-naïve patients were randomized to receive either irinotecan (350 mg/m(2)) or HA-Irinotecan (HA 1,000 mg/m(2) and irinotecan at 350 mg/m(2)) every 3 weeks for a maximum of eight cycles. RESULTS: Seventy-six patients (41 HA-Irinotecan and 35 irinotecan-alone) were enrolled. There was no significant difference in any individual, or overall, grade 3 or 4 toxicity. There was a trend for increased diarrhea in the HA-Irinotecan-treated patients (20 versus 9%; P = 21), potentially explained by a disproportionate number of baseline toxicity-associated risk factors in this treatment group. The median number of cycles completed was six for HA-Irinotecan patients and two for irinotecan-alone patients (P = 0.005). When compared to the control arm, HA-Irinotecan patients had a significantly longer median progression-free survival of 5.2 versus 2.4 months (P = 0.017) and time to treatment failure (4 vs. 1.8 months; P = 0.007). Median overall survival was 10.1 months for HA-Irinotecan compared to 8.0 months for irinotecan patients (P = 0.196). CONCLUSION: Further studies are required to define the safety of the formulation of irinotecan with HA. While this study was not adequately powered to demonstrate survival differences, these phase II data indicated HA-Irinotecan to be a promising therapy demonstrating improved efficacy compared to irinotecan-alone.

A pilot human evaluation of a formulation of irinotecan and hyaluronic acid in 5-fluorouracil-refractory metastatic colorectal cancer patients.

BACKGROUND: Preclinical data demonstrate that the polysaccharide hyaluronic acid (HA) acts as a macromolecular carrier for chemotherapeutic drugs. In these studies the formulation of HA and irinotecan reduced treatment-related toxicity and improved efficacy via the preferential delivery of irinotecan to the tumor and lymph nodes. This study was designed as a first-in-man investigation of the safety and pharmacokinetics of irinotecan when administered within the HA-Irinotecan formulation. METHODS: 5-Fluorouracil refractory metastatic colorectal cancer patients were intravenously treated with HA-Irinotecan (300 mg/m(2) irinotecan with 1,000 mg/m(2) HA) on day 1 of a 21-day cycle. After safety was demonstrated, the irinotecan dose was increased to 350 mg/m(2) with maintenance of the HA at 1,000 mg/m(2). RESULTS: Twelve patients were treated with HA-Irinotecan. Overall toxicity was low, with an 8 and 17% incidence of grade lll/lV diarrhea and neutropenia, respectively. No grade III/IV nausea or vomiting was observed. Seventeen percent of patients had a partial response and 50% experienced stable disease, indicating that the efficacy of the irinotecan was maintained. Median survival was 16.6 months, while median progression-free survival was 6.2 months. CONCLUSION: HA-Irinotecan containing standard doses of irinotecan can be safely administered to patients. Comparison to historical irinotecan data suggests HA-Irinotecan may have a greater margin of safety without compromising anticancer activity.

Gene expression, synthesis and degradation of hyaluronan during differentiation of 3T3-L1 adipocytes.

The high molecular weight glycosaminoglycan hyaluronan (HA) is an essential component of the extracellular matrix (ECM), however, the link between HA regulation and development of the adipocyte ECM, which is essential for differentiation, remains undefined. Hyaluronan synthase gene expression, HA synthetic rate and molecular weight during differentiation of 3T3-L1 pre-adipocytes were compared to undifferentiated 3T3-L1 pre-adipocytes and non-adipogenic NIH/3T3 fibroblasts. In the 3T3-L1 pre-adipocytes, the predominant genes associated with HA metabolism were found to be HA synthase-2 (Has-2) and hyaluronidase-2 (Hyal-2) demonstrating a co-regulation of expression which was stimulated by adipogenic induction consequently resulting in increased synthesis of high molecular weight HA (>10 MDa) and its simultaneous degradation. Accumulation of HA correlated positively with cell number, although synthetic rate was inversely related suggesting a regulatory feedback mechanism. Within 24h post-induction, pre-adipocytes responded with a higher HA synthetic rate and later, accumulated cytoplasmic lipid. In contrast, undifferentiated pre-adipocytes had a reduced HA synthetic rate during clonal expansion and did not accumulate lipid. HA was continuously and rapidly metabolised throughout 3T3-L1 adipogenesis, where terminal differentiation coincided with the increased generation of low molecular weight, angiogenic HA fragments, a likely prerequisite for concurrent neovascularisation of adipose tissue. This study has highlighted a relationship between HA metabolism and adipocyte differentiation, suggesting that the balance between the formation and regulation of the adipocyte extracellular matrix is finely coordinated in a growth phase-specific dependent manner.

An arthritogenic monoclonal antibody to type II collagen, CII-C1, impairs cartilage formation by cultured chondrocytes.

Antibodies to type II collagen (CII) cause articular damage in collagen-induced arthritis (CIA) in mice as judged by passive transfer to naive animals of mAb to CII. We tested the hypothesis that mAb degrade cartilage structure by reacting with functionally important regions of the collagen molecule by examining the effects of an arthritogenic mAb to CII, CII-C1, on cultured bovine chondrocytes at high density, at days 7 and 14. The effects were compared of CII-C1, an isotype-matched control mAb, or medium alone, on chondrocyte proliferation and viability, cell morphology, matrix structure by light and electron microscopy, and matrix synthesis by metabolic labelling with 3H-proline for collagen or 35SO4 for proteoglycans. Chondrocytes in culture remained viable, proliferated, and produced an extracellular matrix in which CII was the major collagen. The addition of CII-C1, but not a control mAb, increased the synthesis of CII and proteoglycan, and caused disorganization of the extracellular matrix and thin collagen fibrils ultrastructurally. Moreover, using a cell-free assay, CII-C1 inhibited the normal self-assembly of collagen fibrils from CII in solution. The finding that the mAb to CII, CII-C1 has striking degradative effects in vitro on cartilage synthesis suggests that antibodies to collagen perpetuate the chronic phase of CIA and that, in mice at least, such antibodies are an important component of pathogenesis.