Amgen is buying cancer and infectious disease vaccines firm BioVex for $425 million in cash and potentially another $575 million in regulatory and sales milestones. BioVex’ lead candidate, OncoVEXGM-CSF, is currently being evaluated in a Phase III multinational study in metastatic melanoma, and a separate Phase III study in squamous cell carcinoma of the head and neck (SCCHN).
The boards of both firms have approved the acquisition, which—subject to regulatory clearance—is expected to close during the first quarter of 2011. BioVex will then be a wholly owned subsidiary of Amgen.
“Amgen is ideally positioned to leverage the potential of OncoVEX in multiple solid tumor indications, given their impressive oncology franchise and expertise in biologics manufacturing and development,” comments Philip Astley-Sparke, BioVex CEO.
OncoVEXGM-CSF is a first-in-class oncolytic vaccine designed to selectively kill cancer cells and also induce an anticancer immune response. Previous clinical trials enrolled patients with breast cancer, melanoma, head and neck cancer, and pancreatic cancer, and have all demonstrated clinical activity, BioVex notes. The ongoing Phase III OPTiM study in metastatic melanoma is designed to assess the efficacy and safety of treatment with OncoVEXGM-CSF compared with subcutaneously administered GM-CSF in 360 patients with unresectable Stage III (b-c) and Stage IV (M1a-c) melanoma. The primary endpoint is the rate of durable (maintained for six months) objective response.
The Phase III study has been initiated following promising data from a Phase II trial evaluating OncoVEXGM-CSF as standalone therapy. This trial showed that 20% of patients ultimately achieved a complete response, and 28% of patients achieved an overall objective response (complete response or partial response). Such responses, including the complete resolution of uninjected visceral deposits, have been maintained for up to nearly four years to date.
In December 2010, BioVex started a Phase III study in the U.K. and U.S. evaluating OncoVEXGM-CSF as first-line treatment of patients with locally advanced SCCHN. The trial will enroll 528 previously untreated patients with locally advanced disease. It aims to demonstrate a statistically significant increase in two-year event-free survival (relapse, progression, or death) for patients treated with chemoradiation plus OncoVEXGM-CSF in comparison with chemoradiation therapy alone.
In a previous Phase I/II study in SCCHN, OncoVEXGM-CSF was administered by direct injection into tumor-containing lymph nodes, in combination with standard first-line chemoradiotherapy every three weeks, for four cycles prior to surgical resection. The results showed that 93% of OncoVexGM-CSF-treated patients had a complete pathological response at surgery, with five patients achieving a complete response after only two or three OncoVEXGM-CSF doses. None of the patients demonstrated loco-regional recurrence in the neck at a median follow-up of 30 months.
In March 2010, BioVex started a U.K.-based Phase I study evaluating its ImmunoVEXHSV2 vaccine for genital herpes. ImmunoVEXHSV2 comprises an engineered form of the genital herpes virus, HSV-2, from which genes that collectively interfere with the functions of the immune system have been deleted. The resulting vaccine expresses all but four of the approximately 80 HSV-2 proteins, which the firm says should maximize the breadth of the anti-HSV immune response generated without expressing the genes encoding immune-inhibiting proteins. The firm notes that preclinical studies in an industry-standard preclinical model of genital herpes showed the candidate completely prevented disease, and in addition considerably reduced the level of viral shedding following exposure, which could reduce any window of infectivity from an infected individual.