A week after filing in Europe, Bayer and partner Onyx Pharmaceuticals have asked regulators in the USA to approve Nexavar as a treatment for liver cancer.

The firms noted that that a supplemental New Drug Application for Nexavar (sorafenib) has been submitted to the US Food and Drug Administration for the treatment of patients with hepatocellular carcinoma (HCC), the most common form of liver cancer. The sNDA submission is based on positive data from the Phase III SHARP trial which demonstrated that the drug extended overall survival by 44% in patients with HCC versus placebo and the study revealed no significant differences in serious adverse event rates between Nexavar and placebo-treated groups.

Susan Kelley, vice president of oncology at Bayer Healthcare, said that the results are particularly meaningful “considering that death rates from liver cancer continue to increase", adding that after more than 100 clinical studies of many agents over three decades, Nexavar is the first to demonstrate “a significant survival benefit for patients with HCC, and, if approved, may fulfill a serious unmet need with a manageable toxicity profile”. The companies also confirmed that they are planning a sponsored Phase III study of Nexavar in the adjuvant treatment of HCC following the complete removal of early-stage liver cancer.

Nexavar is currently approved in more than 50 countries for the treatment of advanced kidney cancer and Bayer recorded revenues of 47 million euros from the drug in the first quarter. It is being studied alone and in combination with other therapies across many different cancer types, including melanoma, non-small cell lung and breast cancer.

Bayer pulls out of Nuvelo partnership

On a less pleasing note, at least for its partner, Bayer has confirmed that it has terminated its collaboration with the USA’s Nuvelo for the clotbuster alfimeprase. The German firm’s move is not overly surprising given that in December, the companies reported disappointing data from two Phase III trials of the drug (NAPA-2 and SONOMA-2) and suspended enrollment in follow-up studies.

Nuvelo noted that it has agreed to waive Bayer's obligation to provide 12 months’ notice before pulling out of the collaboration and the drug major will pay its US partner a lump sum of $15 million. As part of the deal, Bayer also has the one-time option to reacquire rights to alfimeprase upon initiation of a new clinical trial on the drug, focusing on stroke, and an additional $15 million payment.

Despite Bayer backing out, Nuvelo’s chief executive Ted Love said that based on a review of all clinical data and extensive consultations with data safety monitoring boards and regulatory authorities, “we believe that alfimeprase has the potential to offer many benefits, and we remain committed to its development". He added that "therapeutic options for stroke patients are limited [and] we believe that a safer, more efficacious intra-arterial therapy can change the treatment paradigm for these patients and that a product candidate such as alfimeprase holds the potential to rapidly restore flow and expand the treatment window beyond the current three-hour time frame."

A Phase II trial, which is expected to enroll around 100 patients, should begin in the second half of 2007, Nuvelo said, noting that it is investigating whether a single, higher, more concentrated dose of alfimeprase would generate results in another indication, catheter occlusion. However the company's enthusiasm was not shared by investors who have bailed out of the firm and left the share price down 18% at $2.73.