The FDA has issued a complete response letter to Celltrion for its application for Herzuma (trastuzumab biosimilar) for the treatment of patients with gastric cancer. This comes after the FDA issued a warning to the company in January over its manufacturing facility. The company claims that it expects to resubmit soon. Comment: Herceptin lost patent protection in the EU and Japan in 2014, with further patent expiries expected in the US in 2019. Biosimilar versions of Herceptin are anticipated to compete strongly with the branded drug for sales; global sales of Herceptin totaled $6.78bn in 2016.