Roche's Perjeta is one of the first drugs to take advantage of a new regulatory pathway in the US that is designed to get new drugs for early-stage breast cancer to market quicker.
Perjeta (pertuzumab) has been granted priority review by the FDA for use before surgery (neoadjuvant treatment) in women with HER2-positive breast cancer, setting it up for approval in the new indication by the end of October 2013.
There are currently no drugs specifically approved in the US for neoadjuvant therapy of breast cancer, an approach designed to reduce the size of a tumour before surgical excision in order to make it easier to remove or avoid too much damage to breast tissue.
Perjeta was approved as a treatment for advanced-stage HER2-positive breast cancer in the US a year ago, in Europe last month and in Japan a few days ago, adding to Roche's dominant anti-HER2 franchise which also includes blockbuster Herceptin (trastuzumab) and follow-up Kadcyla (ado-trastuzumab emtansine).
Much of the buzz around the company's portfolio at the moment centres on Kadcyla as the first antibody-drug conjugate (ADC) approved for breast cancer, but Perjeta stands to make a sizeable contribution if it can secure approval in the neoadjuvant setting.
The drug posted sales of 50m Swiss francs ($53m) in the first quarter of the year thanks to its use in combination with Herceptin and chemotherapy, with signs that take-up in Europe will also be strong following its approval there in March. Kadcyla contributed 18m Swiss francs from its first few weeks on the market as a second-line therapy after Herceptin in the first three months of the year.
Roche filed the application for Perjeta on the back of two phase II studies - NEOSPHERE and TRYPHAENA - as well as longer-term safety data from the phase III trials that supported the drug's approval in later-stage patients.
Another ongoing study called APHINITY is enrolling around 4,800 early-stage HER2-positive patients in the adjuvant (post-surgery) setting and will gauge the effect of adding Perjeta to Herceptin and standard regimens of adjuvant chemotherapy.
Analysts have previously predicted sales of Perjeta could reach $600m to $1bn within the next five years, which could help offset possible generic competition to Herceptin, which starts to lose patent protection in 2014.
One key factor could be the high cost of Perjeta plus Herceptin, which has been put at nearly $190,000 for an 18-month course on a price additive basis. Roche said recently that it would be looking at capping measures to help ease the combination through reimbursement discussions.