Titan could give Erleada a fighting chance

Johnson & Johnson is doing its best to extend its prostate cancer franchise in the face of Zytiga generics, and it now has a chance to move its follow-on agent Erleada into a new and more relevant use. The Titan trial in metastatic castration-sensitive prostate cancer (mCSPC) was stopped early for positive efficacy yesterday.

The Titan trial is not a head-to-head comparison against Zytiga. Still, Erleada will need to produce results that make it look better in mCSPC than J&J’s established prostate cancer drug, even in cross-trial comparison, as it moves to switch patients to its new product.

How Erleada stacks up against Zytiga is not yet known, since J&J did not give any numbers from the Titan study yesterday, instead saying detailed data would be presented at an upcoming medical meeting. The trial compared Erleada plus androgen deprivation therapy (ADT) versus ADT alone in patients with newly diagnosed disease, with the goal of showing a benefit on radiographic progression-free and overall survival.

A leader? 

Zytiga has already set the bar in the comparable Latitude and Stampede trials. In Latitude, Zytiga plus ADT reduced the risk of death by 38% and radiographic progression by 53%. Meanwhile, Stampede showed a 37% benefit with Zytiga on overall survival, and on three-year failure-free survival the benefit of Zytiga plus ADT was 71%.

Erleada could have a chance: at an interim analysis the Titan study’s independent data committee concluded that both endpoints had been met and said ADT-only patients could begin receiving Erleada, and the fact that the study hit both overall and progression-free survival suggests a profound benefit with Erleada.

But the Titan data will need to be significantly better than that seen in Latitude and Stampede to justify the extra cost of the new agent. Erleada is already approved for non-metastatic castrate-resistant prostate cancer, but it not clear how big this market is (Asco-GU – J&J’s Zytiga follow-on strategy crumbles on Spartan, 5 February 2018).

J&J is not even trying to move Erleada into metastatic castrate-resistant prostate cancer, the use for which Zytiga and Pfizer’s rival product, Xtandi, are already well established.

Meanwhile, other companies are piling into the metastatic castrate-resistant prostate cancer space, with Xtandi and Bayer's darolutamide also recently posting positive topline results in this setting, from the Arches and Arasens trials respectively.

It is not each other they need to beat, but rather the soon-to-be off-patent Zytiga.