Can Roche's Herceptin-Perjeta combo expand yet again? Check the impending data

Roche's Perjeta, a newer member of its massive breast cancer franchise, could get another boost if a Herceptin combo regimen performs in an upcoming trial.

It’s no secret that Roche’s breast cancer juggernaut is about to hit a snag, and pharma watchers well know that the Swiss drugmaker has been lining up new drugs and data to steer onto a new course.

The endeavor is crucial: The mighty Herceptin is due for U.S. biosimilar competition in the next few years, and it’s a 6.8 billion Swiss franc contributor to the company’s top line. Biosims in Europe are expected to erode sales beginning this year.

Thing is, however, one of Roche’s hoped-for successes—a combination of Herceptin follow-up Kadcyla and Roche’s new med Perjeta—fell short in a key breast cancer trial back in 2014, failing to beat Herceptin and chemo at progression-free survival.

What combo has worked? Herceptin and Perjeta. The duo is approved, alongside chemo, to treat metastatic breast cancer and early-stage breast cancer before surgery. And those combo nods are credited with pushing up sales of both meds.

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Now, Roche is hoping that the combo will deliver in yet another setting: breast cancer after surgery. The data is expected by the end of the quarter, and as market watchers report, hopes are high. EP Vantage noted early this year that an approval in that population would “substantially expand” the combo’s market. A breast cancer specialist told Bernstein analysts last year that the combo will need to deliver at least a 2% to 3% improvement over Herceptin and chemo alone.

Other analysts put it differently: As Bloomberg reports, citing Mirabaud Securities analysts, the new study would need to show that 90% of the women on the combo regimen were recurrence-free for at least two years.

That’s a high bar, but if the combo clears it, it would be an important payoff—particularly after Herceptin biosimilars hit in full force. Perjeta, first approved in 2012, has many years of branded sales before its patents expire. The drug delivered 26% growth in 2016, to 1.85 billion francs, putting it in fourth place for Roche, sales-wise.

Winning another indication for the Herceptin-Perjeta combo would help ensure that Perjeta keeps that growth coming as Herceptin and its fellow blockbusters Rituxan and Avastin start to suffer biosimilar sales erosion.

If the Kadcyla-Perjeta combo had delivered in that 2014 breast cancer trial as Roche had expected, following up Herceptin might have been easier. Then again, these drugs are pricey, and with more and more combo cancer treatments coming online, those prices will come in for more scrutiny.

Meanwhile, Roche has Tecentriq, its PD-L1 inhibitor that debuted last year, first in bladder cancer and then in non-small cell lung cancer. That launch is another story. But with Tecentriq in Roche’s stable, Perjeta won’t have to carry so much of the growth load. And don't count out Kadcyla, either. That med brought in more than 800 million francs last year—no small potatoes.