Novartis' Sandoz unit says it has initiated two more late-stage trials on biosimilar versions of Amgen’s white blood cell stimulators Neupogen and Neulasta.

The first trial is evaluating Sandoz's biosimilar of Neupogen (filgrastim) versus Amgen's drug  in breast cancer patients eligible for myelosuppressive chemotherapy treatment. Novartis said the study is expected to support extension of commercialisation to the USA, potentially the largest market for biologics. Sandoz's filgrastim biosimilar is already marketed as Zarzio in more than 30 countries outside the USA.

The biosimilar version of Neulasta (pegfilgrastim) is being conducted in breast cancer patients undergoing myelosuppressive chemotherapy, and "represents the next major step in the Sandoz global biosimilar development programme", the company said.

Jeff George, Sandoz global chief, said the firm is "already the clear global leader in biosimilars overall and in each of our three marketed products, with approximately 50% total segment share in the highly regulated markets of North America, Europe, Japan and Australia". In addition to Zarzio, Sandoz markets biosimilars of Pfizer's Genotropin (somatropin) as Omnitrope and Johnson & Johnson's anaemia drug Eprex (epoetin alfa), sold as Binocrit.

Ameet Mallik, head of Sandoz biopharmaceuticals, added that a late-stage trials for a biosimilar of Roche's Rituxan (rituximab) is ongoing and the  pipeline, consists of eight-10 copycat biologics.