Dynavax (DVAX) shares have pulled back about 30% since the U.S. approval of Heplisav, the first and only two-dose hepatitis B vaccine that has demonstrated "superiority in efficacy and comparability" in safety to the standard of care, GlaxoSmithKline's (GSK) Engerix-B, William Blair analyst Katherine Xu tells investors in a research note. The analyst attributes the selloff to Dynavax electing to launch Heplisav on its own and the Street having insufficient confidence in the launch. She believes Heplisav has peak U.S. sales prospects of $600M and "provides a valuation floor." Xu also sees catalysts on the oncology side of the business. She maintains an Outperform rating on Dynavax with a $40 per share fair value estimate.

GSK announced positive results from the pivotal EAGLE-1 phase III trial for gepotidacin, a potential first-in-class oral antibiotic with a novel mechanism of action for uncomplicated urogenital gonorrhoea in adolescents and adults. These results will be presented on 30 April 2024 at the European Society of Clinical Microbiology and Infectious Diseases, ESCMID, Global in Barcelona, Spain. The results from EAGLE-1 are based on a primary endpoint of microbiological response at the Test-of-Cure visit 3-7 days after treatment. The trial showed that gepotidacin was non-inferior with 92.6% success rates when compared to 91.2% success rates for intramuscular ceftriaxone plus oral azithromycin combined therapy, a leading combination treatment regimen for gonorrhoea. The safety and tolerability profile of gepotidacin in the EAGLE-1 trial was consistent with results seen in phase I and II trials. The most commonly reported adverse events in gepotidacin subjects were gastrointestinal. All AEs were mild or moderate except for one severe, unrelated event in each treatment arm and one unrelated serious event in the gepotidacin arm.