Roche’s HER2-targeting antibody drug conjugate (ADC) Kadcyla has claimed a new approval in Europe in early breast cancer, ahead of looming competition in the market.
The EMA has cleared Kadcyla (ado-trastuzumab emtansine) for the adjuvant or post-surgery treatment of adults with HER2-positive early breast cancer, who still have some residual signs of invasive cancer cells despite treatment before surgery with taxane and other HER2 drugs like Roche’s Herceptin (trastuzumab).
The new indication – approved in 27 countries at last count – has led to a renewed growth spurt for Kadcyla, which has long been the under-performing element out Roche’s three HER2 antibodies, lagging behind Herceptin and Perjeta (pertuzumab).
For some time the standard adjuvant treatment for early breast cancer patients has been to continue therapy using their pre-surgery (neoadjuvant) HER-2 drug for at least a year.
The new approval is based on the KATHERINE trial, which compared Kadcyla to Herceptin in this group of patients and found that the risk of invasive breast cancer recurrence or death from any cause was reduced by 50% with the ADC.
After three years’ follow-up, around 88% of people treated with Kadcyla did not have their breast cancer return, compared to 77% of the Herceptin group.
“Optimal treatment is vital for every patient with early-stage breast cancer, a setting where cures are possible,” said Levi Garraway, Roche’s chief medical officer.
“This approval of Kadcyla will allow many more women with HER2-positive early breast cancer to be given a transformative treatment that may cut the risk of their disease returning or progressing, he added.
Kadcyla was approved for this new indication by the US FDA in May, and according to Roche thousands of American women are already being given this treatment.
That has helped drive a 40% increase in Kadcyla sales in the first nine months of the year to around $1bn, having narrowly failed to clear the blockbuster threshold in 2018 from its other use in patients who relapse after or don’t respond to Herceptin.
Kadcyla’s resurgence has helped support Roche’s HER2 franchise as Herceptin – now off-patent – has started to feel the effects of biosimilar competition.
Kadcyla and the rest of Roche’s franchise are facing the threat of competition from a new generation of HER2-targeting drugs, initially in later-line breast cancer therapy, and the new indication also provides some breathing space for Kadcyla.
Among the rivals is Daiichi Sankyo and AstraZeneca’s trastuzumab deruxtecan (DS-8201), another ADC currently under regulatory review for patients with advanced HER2-positive breast cancer that have failed Kadcyla therapy, but which is in development for earlier treatment lines.
Also on the horizon is Seattle Genetics’ oral HER2 drug tucatinib, which recently cleared the phase 3 HER2CLIMB trial as an add-on to Herceptin plus Roche’s chemotherapy Xeloda (capecitabine) in patients previously treated with Roche’s trio of HER2 drugs.
Seattle also has ambition to extend tucatinib into earlier lines of therapy. HER2CLIMB-02 will compare tucatinib to placebo in combination with Kadcyla in HER2-positive breast cancer patients who have received prior treatment with a taxane and Herceptin.