Halozyme Therapeutics, Inc. has announced interim results from a proof of concept Phase I/II clinical trial evaluating the activity and local tolerability of HTI-501, an investigational biologic, for use in aesthetic dermatology. The data were presented at the 9th Annual World Congress of Cosmetic Dermatology in Athens, Greece.

The trial is being conducted in healthy adult females with oedematous fibrosclerotic panniculopathy (i.e. cellulite). The Phase I dose-escalation section of the trial was completed in 2012, while the ongoing Phase II section is designed to assess the pharmacologic activity of HTI-501 and extend the safety assessment to multiple injections in a treatment area.

The primary endpoint is physician assessment at day 28, supported by secondary endpoints of subject self-evaluations and objective measurements of changes to the skin topography.

The interim results from 12 of the planned 34 evaluable patients from this trial indicates pharmacologic activity at the primary 28 day observation point, with 83% of subjects (10 out of 12) showing improvement from the pre-treatment assessment, with a median improvement of 53% (P=0.006) by the primary physician assessment.

In comparison, 75% of subjects (9 out of 12) showed improvement with a median improvement of 22% (P=0.009) for the vehicle injection control at the same observation point. The objective measure (skin topography) for the treated area showed modest improvement in 80% of evaluable subjects (8 out of 10) treated with HTI-501 (P=0.042), but was not significantly changed for the vehicle control (P=0.84) or a post-hoc evaluation of non-injected areas.

To query the robustness of any study conclusions, an independent blinded panel evaluation of images will be performed on the evaluable subjects at 1 and 6 months post-treatment.

‘In the initial patients treated thus far, the response to treatment with HTI-501 has been encouraging. We are particularly interested in subsequent 3- and 6-month observations, which have shown further improvement in some subjects treated thus far,’ said Francisco Perez, MD, immediate past-President of World Congress of Cosmetic Dermatology and principal clinical investigator.

‘We look forward to completing enrollment this summer and conducting final follow-up observations early next year.’

The HTI-501 enzyme and its formulation have been well tolerated so far in this trial at all doses and formulations tested, with no serious or severe adverse events.

The most common side-effects have been mild-to-moderate transient injection site discomfort and mild-to-moderate injection site bruising, resolving within approximately 2 weeks without intervention.