2 The technology
Description of the technology
Talimogene laherparepvec (Imlygic, Amgen) is derived from the herpes simplex virus type-1. It is a modified form of the virus that kills cancer cells. It is injected directly into cutaneous, subcutaneous and nodal lesions that are visible on the skin, palpable, or detectable with ultrasound guidance. The company states that talimogene laherparepvec has 2 complementary mechanisms of action: replication that causes cell rupture/lysis and death (intracellular or direct effect) and post-lysis release of tumour-derived antigens and granulocyte macrophage colony-stimulating factor (GM-CSF), stimulating a systemic immune response from antigen-presenting cells upon distant tumour sites (extracellular or indirect effect).
Marketing authorisation
Talimogene laherparepvec has a marketing authorisation in the UK for the treatment of adults with 'unresectable melanoma that is regionally or distantly metastatic (stage 3B, 3C and 4M1a) with no bone, brain, lung or other visceral disease'.
Adverse reactions
The most common adverse reactions in clinical trials of metastatic melanoma were flu-like symptoms (very common), injection-site reactions (very common) and cellulitis (common and potentially serious). For full details of adverse reactions and contraindications, see the summary of product characteristics.
Recommended dose and schedule
Administered by intralesional injection at an initial dose of 1,000,000 plaque forming units (PFU) per ml, followed by doses of 100,000,000 PFU per ml at 3 weeks and then every 2 weeks.
Price
The acquisition cost of talimogene laherparepvec is £1,670 per 1 ml vial of either 1,000,000 plaque forming units (PFU) per ml or 100,000,000 PFU per ml (excluding VAT; company's submission).
The company has agreed a patient access scheme with the Department of Health. This scheme provides a simple discount to the list price of talimogene laherparepvec, with the discount applied at the point of purchase or invoice. The level of the discount is commercial in confidence. The Department of Health considered that this patient access scheme does not constitute an excessive administrative burden on the NHS.