On May 9 after the market closed, Puma Biotechnology (NASDAQ:PBYI) reported 1Q19 results. Nerlynx net sales came in much lower than expected and showed a sequential decline of 25%, causing management to lower full-year net sales guidance from $268M to $230M. The stock sold off heavily the next day and has continued to slide.
Source: PBYI 1Q19 earnings slides
Several minor reasons were given for the lower than expected sales, such as a higher gross-to-net reduction than previous quarters, unfilled sales positions in certain territories, and some patients completing the treatment and