A combination of cancer drugs from Seagen and Merck & Co. has shown early success in a large clinical trial, results that help confirm the pairing’s ability to treat a wide range of bladder cancer patients.
The trial has enrolled around 1,000 participants who have urothelial cancer that’s grown or spread to other parts of the body, and who have yet to receive treatment. These patients were given either chemotherapy or a pairing of Merck’s Keytruda and a drug developed by partners Seagen and Astellas, called Padcev.
On Friday, the companies said the study hit its two primary goals, as patients who were given the combination as opposed to chemo have gone significantly longer without their disease progressing while also living longer. More detailed data weren’t released, but the companies intend to present the results at an upcoming medical conference.
“This study has the potential to be practice changing and offer a new standard of care for first-line metastatic bladder cancer,” said Roger Dansey, president of research and development at Seagen, in a statement.
The combination of Keytruda and Padcev received conditional approval from the Food and Drug Administration earlier this year, based on a smaller trial that found it shrank tumors in nearly two-thirds of treated participants. The larger study is meant to affirm those results and support a full approval. Dansey said Seagen plans to discuss the new findings with regulators “in order to get this medicine to patients as soon as possible.”
Padcev was first cleared for the U.S. market in late 2019, just a couple weeks after Seagen and Astellas had agreed to collaborate with Merck and study their respective drugs together.
That initial approval, though, was for a smaller segment of the bladder cancer population. Eligible patients needed to be adults with locally advanced or metastatic urothelial cancer, who had previously received a platinum-containing chemotherapy and another type of cancer therapy known as PD-1/L1 inhibitor, which is the class of drugs that includes Keytruda.
Since then, Seagen and Astellas have been trying to expand Padcev’s use.
The two companies share marketing costs and profits related to the sale of Padcev in the U.S. Last year, Seagen recorded $451 million worth of net sales from the drug.
But Wall Street believes Padcev could make much more. Umer Raffat, an analyst at the investment firm Evercore ISI, wrote in a note to clients that the drug, at its peak, may generate $7 billion in annual sales for Seagen. Key to that estimate is its use in “first-line” — or never before treated — patients.
“This was a must-win trial,” Raffat wrote, referring to the larger study of Padcev and Keytruda. He noted, too, how the results presented Friday were from an interim analysis. That the combination was able to show a positive effect on overall survival before the trial has fully completed “bodes well.”
Raffat wrote that Padcev is expected to generate $2.5 billion in the U.S. from a first-line bladder cancer indication.
The new results are also important to Pfizer, which is currently trying to close a proposed $43 billion acquisition of Seagen.
In his own note to clients, analyst Dane Leone of Raymond James wrote that Friday’s announcement clears “one of the last remaining debates surrounding the pending Seagen merger with Pfizer ...”
He added that it “should provide both management teams with confidence that the revenue forecasts for the Seagen drug portfolio ... remain a viable expectation.” Those forecasts are approximately $10 billion in revenue in 2030.
Seagen, which has four marketed products, recorded $1.7 billion in net product sales in 2022, up 23% from the year prior.