Johnson & Johnson's Darzalex ambitions take a hit with scrapped I-O trials

Analysts predict Darzalex could rack up $8.5 billion in peak sales. (Johnson & Johnson)

Drugmakers have raced to pair their cancer drugs with immuno-oncology therapies, hoping to see an improved benefit from a combination. But that’s not how things are looking for Darzalex partners Genmab and Johnson & Johnson.

J&J’s Janssen nixed a pair of studies testing the standout cancer-fighter alongside members of the PD-1/PD-L1 class after a pairing of Darzalex and Roche product Tecentriq failed to show a benefit over solo Tecentriq treatment in previously treated nonsmall lung cancer patients, Genmab said over the weekend.

What’s more, a data monitoring committee noted an increase in “mortality-related events” in the study’s combo arm.

The findings prompted Janssen to discontinue not only that phase 1b/2 study, but also a phase 1 trial examining Darzalex alongside J&J PD-1 candidate JNJ-63723283 in multiple myeloma patients.

“Janssen has informed health authorities about these events and has contacted its partner companies conducting daratumumab and anti-PD-(L)1 combination studies to discuss ceasing enrollment and dosing of the combination while the data is being further investigated,” Genmab said in a statement.

RELATED: Johnson & Johnson's Darzalex snags landmark myeloma approval in first-line patients

Genmab’s shares took a beating on the news, which scuttled investors’ hopes for eventual Darzalex sales in solid tumors.

“This was clearly the big upside for Genmab in the near-term,” Bernstein analyst Wimal Kapadia wrote in a note to clients, noting that “the cherry on top” for the multiple myeloma star “has disappeared.”

Given Darzalex’s potential in blood cancer, though, the “failure has minimal impact to numbers and valuation,” in Kapadia’s view. Earlier this month, the drug snagged an approval—in combination with Takeda’s Velcade and prednisone—in first-line multiple myeloma patients who are transplant ineligible, making it the first monoclonal antibody to score an OK in newly diagnosed patients. That greenlight put the drug on a path to major top-line expansion, with analysts predicting the therapy could reach $8.5 billion in peak sales.