Tumor-associated hyaluronan limits efficacy of monoclonal antibody therapy.

Despite tremendous progress in cancer immunotherapy for solid tumors, clinical success of monoclonal antibody (mAb) therapy is often limited by poorly understood mechanisms associated with the tumor microenvironment (TME). Accumulation of hyaluronan (HA), a major component of the TME, occurs in many solid tumor types, and is associated with poor prognosis and treatment resistance in multiple malignancies. In this study, we describe that a physical barrier associated with high levels of HA (HA(high)) in the TME restricts antibody and immune cell access to tumors, suggesting a novel mechanism of in vivo resistance to mAb therapy. We determined that approximately 60% of HER2(3+) primary breast tumors and approximately 40% of EGFR(+) head and neck squamous cell carcinomas are HA(high), and hypothesized that HA(high) tumors may be refractory to mAb therapy. We found that the pericellular matrix produced by HA(high) tumor cells inhibited both natural killer (NK) immune cell access to tumor cells and antibody-dependent cell-mediated cytotoxicity (ADCC) in vitro. Depletion of HA by PEGPH20, a pegylated recombinant human PH20 hyaluronidase, resulted in increased NK cell access to HA(high) tumor cells, and greatly enhanced trastuzumab- or cetuximab-dependent ADCC in vitro. Furthermore, PEGPH20 treatment enhanced trastuzumab and NK cell access to HA(high) tumors, resulting in enhanced trastuzumab- and NK cell-mediated tumor growth inhibition in vivo. These results suggest that HA(high) matrix in vivo may form a barrier inhibiting access of both mAb and NK cells, and that PEGPH20 treatment in combination with anticancer mAbs may be an effective adjunctive therapy for HA(high) tumors.

A recombinant human hyaluronidase sustained release gel for the treatment of post-surgical edema.

BACKGROUND: Edema commonly accompanies surgical procedures and when excessive, can adversely affect surgical outcomes. The skin extracellular matrix, including one of its primary components, hyaluronan (HA), is a significant barrier to effective drainage of accumulated edematous fluid. Recombinant human hyaluronidase (rHuPH20) is a human hyaluronidase that acts transiently and locally to depolymerize HA. A non-liposomal gel formulation that provides a sustained release of rHuPH20 was tested in vivo in a preclinical murine model of acquired lymphedema. METHODS: Lymphedemic mice were injected 24 hours before surgery, and at 2 and 12 days following surgery with rHuPH20 sustained release gel (PH20 SR gel). Quantitative assessment of treatment response indicated that a single dose of PH20 SR gel resulted in accelerated resolution and reduced severity of post-surgical edema as compared to the gel vehicle (control). RESULTS: Statistically significant enzymatic degradation of HA was demonstrated up to 5 mm from the injection site, and histological analysis confirmed removal of HA up to 72 hours following PH20 SR gel administration. CONCLUSIONS: These results demonstrate sustained hyaluronidase enzymatic activity that promotes diffusion of accumulated post-surgical edematous fluid, suggesting that PH20 SR gel may be a useful adjuvant in promoting postoperative edema resolution.

Recombinant human hyaluronidase PH20 (rHuPH20) facilitates subcutaneous infusions of large volumes of immunoglobulin in a swine model.

Many patients with primary immunodeficiency disease (PIDD) require lifelong immunoglobulin (Ig) replacement therapy. Home-based subcutaneous (SC) infusion provides advantages to patients with PIDD compared to hospital-based intravenous infusion. One limitation of current practice with SCIg infusion is the need for small-volume infusions at multiple injection sites on a frequent basis. A method was developed for large-volume SC infusion that uses preinfusion of recombinant human hyaluronidase (rHuPH20) to facilitate fluid dispersion. Miniature swine was used as a preclinical model to assess the effects of rHuPH20-facilitated infusions, of a single monthly dose, on fluid dispersion, infusion-related pressure, swelling, induration, and tissue damage. Preinfusion of vehicle (control) or rHuPH20 (75 U/g Ig) was performed simultaneously on contralateral abdominal sites on each animal, followed by infusion of 300 mL 10 % Ig (30 g) at each site. Compared to control infusions, rHuPH20 significantly reduced infusion pressure and induration (p < 0.05) and accelerated postinfusion Ig dispersion. Histological evaluation of infusion site tissue showed moderate to severe swelling for the control. Swelling after rHuPH20-facilitated infusion was mild on day 1 and had completely resolved shortly thereafter. Laser Doppler imaging of control infusion sites revealed local cutaneous hypoperfusion during Ig infusion, which was reduced almost 7-fold (p < 0.05) with the use of rHuPH20. These results demonstrate that rHuPH20-facilitated Ig infusion is associated with improved dispersion of Ig, resulting in reduced tissue pressure, induration, and reduced risk of tissue damage from mechanical trauma or local ischemia, thus enabling SC administration of large volumes of Ig at a single site.