RBC Capital analyst Kennen MacKay thinks the data presented this morning by Roche's (RHHBY) Genentech could pressure shares of Puma Biotechnology (PBYI) today. Genentech announced the Phase III Katherine study met its primary endpoint, showing Kadcyla as a single agent reduced the risk of disease recurrence or death compared to Herceptin as an adjuvant treatment in people with HER2-positive early breast cancer who have residual disease present following neoadjuvant treatment. Kadcyla's ultimate entry into the HER2-positive adjuvant setting could complicate the positioning of Puma's Nerlynx, MacKay tells investors in a research note. He keeps a Sector Perform rating on shares of Puma, which are down 4%, or $1.55, to $41.14 in morning trading.