Shares of Innoviva (NASDAQ: INVA), a biotechnology royalty company that develops respiratory therapeutics and is perhaps best known as GlaxoSmithKline‘s (NYSE: GSK) development partner for its multiple next-generation COPD and asthma products, fell as much as 11% on Thursday. The reason behind Innoviva’s bad day can be traced to a proxy battle with activist hedge fund Sarissa Capital Management over seats on its board.