Bayer and partner Onyx Pharmaceuticals are celebrating after regulators in the USA gave the green light to Stivarga for the treatment of metastatic colorectal cancer.

Specifically, the US Food and Drug Administration has approved Stivarga (regorafenib) tablets for the treatment of patients with mCRC who have been previously treated with currently available therapies (including fluoropyrimidine-, oxaliplatin- and irinotecan-based chemotherapy, an anti-VEGF therapy and, if KRAS wild type, an anti-EGFR therapy). The approval of the oral multi-kinase inhibitor is based on results from a Phase III study that demonstrated a statistically significant improvement in overall survival (6.4 months versus 5.0) and progression-free survival (2.0 months vs 1.7) compared to placebo in patients with mCRC whose disease had progressed after approved standard therapies.

There are a number of colorectal cancer drugs already on the market, including Roche's Avastin (bevacizumab), Eli Lilly/Merck KGaA/Bristol-Myers Squibb's Erbitux (cetuximab) and Amgen’s Vectibix (panitumumab). Just last month, the FDA gave the green light to Sanofi/Regeneron's (ziv-aflibercept) injection in combination with FOLFIRI (5-fluorouracil, leucovorin and irinotecan) chemotherapy.

The US approval of Stivarga, which came one month ahead of its Prescription Drug User Fee Act goal date, "is an important milestone for Bayer as it marks the first approval of this innovative cancer treatment to fulfill a significant unmet medical need", said the firm's healthcare chief Joerg Reinhardt. The drug will carry a boxed warning noting that severe and fatal liver toxicity occurred in patients treated with Stivarga during clinical studies.

Last month, regorafenib was also filed in the USA for a second indication, that of gastrointestinal stromal tumours. The drug was at the centre of a row between Bayer and Onyx which was settled in October 2011. Before then, in May 2009, Onyx sued over the rights to the drug, claiming it is a variant of the two firms' liver and kidney cancer drug Nexavar (sorafenib), while Bayer always insisted that regorafenib is not covered by a collaboration the companies signed in 1994.

The settlement recognised that regorafenib is a Bayer compound, while Onyx will receive a 20% royalty. The US biotech will not have to pay any development and commercialisation costs and will co-promote Stivarga.

Japan approval for Eylea

More good news for Bayer came with the announcement that Eylea (aflibercept) has been approved for the treatment of wet age-related macular degeneration by Japan's Ministry of Health, Labour and Welfare.

Last week, the therapy, which is partnered with Regeneron, was issued with a positive opinion by the European Medicines Agency's Committee for Medicinal Products for Human Use for wet AMD and was also approved by the FDA for the treatment of macular oedema following central retinal vein occlusion (CRVO).