Specialty pharmaceutical and diagnostic company Prometheus Laboratories has commenced enrolment in a multicentre Phase IV trial evaluating Proleukin (high-dose interleukin-2 (HD IL-2)), along with vemurafenib therapy.

The study, which is scheduled to be conducted in approximately 25 sites in the US, is enrolling patients with BRAF V600 mutation-positive metastatic melanoma (mM).

HD IL-2 is administered as inpatient therapy in specialised hospitals, while vemurafenib is an oral outpatient therapy.

Prometheus oncology clinical development and medical affairs senior director Dr James Lowder said that until two years ago, approved systemic therapy for metastatic melanoma was limited.

"Immune-based therapy with the FDA-approved HD IL-2 has long been shown to produce meaningful and durable responses in a small percentage of patients with metastatic melanoma," Lowder said.

"The study, which is scheduled to be conducted in approximately 25 sites in the US, is enrolling patients with BRAF V600 mutation-positive metastatic melanoma (mM)."

"The recently FDA-approved vemurafinib produces rapid, but temporary, reductions in tumor size in a majority of patients with an activating mutation of the BRAF signaling protein."

In this open-label, two-arm study, patients will initially receive treatment with vemurafenib, sequenced with two courses of HD IL-2.

Cohort one will consist of 135 patients new to vemurafenib and HD IL-2 therapy, who will initially be treated with six weeks of vemurafenib alone, followed by two courses of HD IL-2 sequenced with continued vemurafenib.

Cohort two patients will receive seven to 18 weeks of vemurafenib before adding HD IL-2, and can be enrolled after starting vemurafenib.

The effect of more prolonged vemurafenib treatment on adverse events and efficacy will be explored in the second cohort.

The primary endpoint of the study is complete response (CR) at 26 weeks from the start of HD IL-2.

Patient assessment of overall response rate (OSS), progression-free survival (PFS) and overall survival (OS) will be followed in the PROCLAIM registry study, according to the company.