FDA’s approval of Bayer AG/Algeta ASA’s Xofigo (radium Ra 223 dichloride) for the treatment of castration-resistant prostate cancer in patients with symptomatic bone metastases will pave the way for the launch of the first alpha particle-emitting radioactive therapeutic agent.

The approval, which came three months ahead of the drug’s expected PDUFA date, brings yet another new treatment to the competitive prostate cancer market, which has seen several new entrants in the last two years. But, unlike the hormone therapies Xtandi and Zytiga and immune therapy Provenge that recently have launched, Xofigo specifically will target the critically ill subset of patients whose cancer has metastasized to the bones.

In the Phase III trial, ALSYMPCA, on which the approval was based, patients treated with Xofigo experienced a survival benefit of 14 months versus 11.2 months for those in the placebo arm and a delay in first symptomatic skeletal event (SSE) Also see "Phase III Results For Bayer/Algeta's Alpharadin Hint Of Labeling Down The Line" - Pink Sheet, 27 September, 2011.. Labeling for the product mentions both clinical benefits under the Clinical Studies section, although the drug does not carry an indication specifically for the prevention of SSEs. Use of the drug isn’t limited to either the pre- or post-chemo setting.

Bayer and Algeta will co-promote the drug together and share profits in the U.S. under a 2009 collaboration. They expect to launch Xofigo within two weeks. Bayer maintains sole commercial rights to the drug in the rest of the world.

The wholesale acquisition cost of Xofigo is $11,500 per injection. The drug is administered every four weeks over the course of six months, translating to a total cost of therapy of $69,000 per patient. That price appears in line with other recent oncology entries, which together have raised the pricing bar and begun to raise alarms among payers, physicians and patients Also see "Many New Oncology Drugs In 2012, With Prices That Test The Limits" - Pink Sheet, 28 January, 2013..

The price comes in higher than the cost of Astellas Pharma Inc./Medivation Inc.’s Xtandi (enzalutamide) and Johnson & Johnson’s Zytiga (abiraterone acetate) per month, but because the recommended dosing regimen is limited to six months, the total cost of therapy is similar, Algeta and Bayer said. Xtandi launched in September 2012 at a cost of $7,450 for a 30-day supply, or about $59,600 for the eight-month dosing scheme in the pivotal AFFIRM trial, while Zytiga costs $5,800 for 30 days, or $46,552 for eight months.

Algeta CEO Andrew Kay pointed out, however, that Zytiga is used on average for 15 months. He said the price of Xofigo is midway between the cost of Zytiga and Provenge in the pre-chemo setting and new chemotherapy.

“The pricing we have come to is clearly within the range of the new and current therapies that are available for castration-resistant prostate cancer,” said Shannon Campbell, Bayer VP & general manager, oncology. The companies will provide co-pay assistance for patients who are under-insured or uninsured so that for those on commercial insurance, the majority of patients will not pay more than $150 for the entire course of treatment.

The price falls between some recent analyst forecasts. Wedbush analyst David Nierengarten speculated the price would be about $72,000 for a six-month treatment in a recent note, while Deutsche Bank analyst Richard Parkes expected it to be significantly lower, $48,000 for a six-month course of treatment.

Xofigo also may compete with Amgen Inc.’s bone-building drug Xgeva (denosumab), a RANK ligand inhibitor approved for the prevention of skeletal-related events in patients with bone metastases. But Xgeva has not demonstrated an improvement in survival in patients.

Algeta’s First Commercial Launch

Bayer and Algeta will jointly launch the drug in the U.S. with dedicated field forces divided regionally. The teams will target urologists, oncologists and radiation oncologists, who typically administer radioactive medicines out of nuclear medicine departments. Marketing radiotherapeutics poses specific challenges, mainly manufacturing radioactive materials and administering them to patients safely. One issue is that administration sites have to be licensed to sell the product.

But Campbell said those challenges are mainly administrative. “Right now, we probably have 20 to 30 sites licensed,” she said. The companies have dedicated licensing specialists working with sites to ensure a smooth process and expect the number of licensed sites to grow rapidly.

For Algeta, the launch represents the company’s entry into the commercial market. The Oslo, Norway-based drug developer established U.S. operations in Cambridge, Mass., where it has hired 80 employees, including medical liaisons, marketing and sales reps.

Algeta stands to receive €50 million from Bayer upon the first commercial sale of Xofigo. It already received €50 million upon regulatory filing, cash it used to build its U.S. organization. Bayer partnered with Algeta on the drug in 2009, paying €42.5 million upfront and agreeing to more than €500 million in milestones [See Deal]. A regulatory application for the drug also is pending in Europe, where Algeta would be eligible for tiered double-digit royalties on sales of the product.

“It was very important for us in our ambitions to establish Algeta as a world class oncology company to have R&D continuing in Norway, to have the exclusive worldwide rights to our future products based on thorium, and to have a commercial footprint in the U.S., where we can not only sell Xofigo but also launch our future tumor-targeting thorium products,” Kay said of the company’s decision to maintain co-commercialization rights in the U.S.

Xofigo is the first of a new wave of radiopharmaceuticals that could reach the market, designed to target diseased tissue with a limited impact on healthy cells Also see "Radiotherapeutics Market Snapshot: This Sector Is Getting Hot" - Pink Sheet, 3 December, 2012.. The mechanism of action of Xofigo is the alpha particle-emitting isotope radium-223, which mimics calcium and targets the bone, particularly areas of high bone turnover, which are areas of metastases.

Bayer/Algeta’s Xofigo Brings New Mechanism To Prostate Cancer Field

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