A trio of small drug developers are queuing up to go public as the years-long open window for biotech IPOs continues to falter. Viventia Bio, developing treatments for cancer, and Kura Oncology each filed to raise $86 million, while Dutch oncology biotech Merus lined up for a $60 million debut. Meanwhile, most of the past month's biotech debutantes have priced their IPOs at significant discounts, as marketwide concerns about drug pricing and R&D success have driven down valuations across the biopharma industry. Viventia | Kura | Merus