Roche's (VTX:ROG) Perjeta (pertuzumab) spurs confidence in experts about its success in the adjuvant setting APHINITY trial for HER2-positive (HER2+) breast cancer but with a pause due to statistical complexities.
Neoadjuvant trials are said to be largely predictive of success in the adjuvant setting, according to an analyst report. While experts agreed they also cautioned against extrapolating neoadjuvant results, owing to the complexity of large trials.
Another analyst report noted that pathologic complete response (pCR) rate benefits seen in Perjeta's neoadjuvant trial seem to be predictive for long-term survival in both settings. Yet, interviewed experts said, while pCR rates are meant to indicate a survival improvement, this has not been proven in a large Phase III study. They also pointed to the failure of Novartis' (VTX:NOVN) Tykerb (lapatinib) in the adjuvant setting despite prior approval as a neoadjuvant therapy.
Nonetheless, experts were optimistic about Perjeta's potential as an additional drug in the adjuvant setting. Perjeta was the first drug to receive an accelerated approval based on the improvement in pCR rates in its neoadjuvant trial and efficacy in the metastatic setting is proven, they explained.
Phase III APHINITY (NCT01358877) results are expected in 2H16, according to analyst reports. The trial is comparing Herceptin (trastuzumab) and chemotherapy with or without Perjeta and has invasive disease free survival (DFS) as the primary endpoint.
Forecasted sales for Perjeta in 2022 are estimated to be USD 5.4bn, according to BioPharm Insight data. Sales in 2015 were CHF 1.44bn (USD 1.48bn), according to Roche's 2015 financial report.