Second-quarter earnings reports, flowing fast in the last days of July, delivered a bevy of contrasting results, from A to V. Stymied by the pandemic, Aimmune Therapeutics Inc. booked exactly zero net sales during the quarter for its expected blockbuster peanut allergy treatment, Palforzia. Vertex Pharmaceuticals Inc. and Seattle Genetics Inc. beat top-line expectations, driven primarily by strong sales of new products.