Bayer has secured approval in Japan for Stivarga as a treatment for gastrointestinal stromal tumour (GIST) patients who have progressed after prior systemic therapy.
This is the second green light for Stivarga (regorafenib) in Japan after the country’s Ministry of Health, Labour and Welfare (MHLW) gave its blessing to use of the drug in unresectable, advanced or recurrent colorectal cancer (CRC) earlier this year.
Signs that Japan’s economy is on a recovery after years in the doldrums means that the country is once again being perceived by pharma companies as an important growth market for new products.
Bayer said the approval of Stivarga was based on the results of the phase III GRID trial, which demonstrated a statistically significant improvement in progression-free survival (PFS) compared to placebo in GIST patients who had progressed after treatment with Novartis’ Glivec (imatinib) or Pfizer’s Sutent (sunitinib).
Regorafenib is a multi-kinase inhibitor that blocks several enzymes that promote cancer growth and is one of four late-stage compounds that Bayer has predicted could collectively add €5bn to its revenues at peak.
The drug was originally developed by Onyx and was launched in the US last year for both GIST and CRC. Onyx – which is currently reported to be the target of a takeover bid from Amgen – co-markets the drug in the US with Bayer holding exclusive rights elsewhere.
Stivarge is starting to gain sales momentum – Bayer booked $61m from the product in the second quarter, a 15 per cent rise on the first three months of the year – and it has been predicted to be a $1bn product at peak, with Onyx receiving a 20 per cent royalty on sales.
To maintain sales momentum Bayer is also undertaking a comprehensive programme of additional testing for Stivarga, with the first of two planned phase III trials starting earlier this year in second-line liver cancer patients after progression on Bayer and Onyx’ Nexavar (sorafenib).
The second phase II trial will include patients with colorectal cancer following resection of liver metastasis and is due to get underway before the end of this year.