Why AstraZeneca Stock Is Crashing Today

British pharma giant AstraZeneca's (NYSE: AZN) comeback story took a major blow this morning after the company reported that the all-important Mystic trial assessing Imfinzi (durvalumab) in combination with tremelimumab missed its primary endpoint of improving progression-free survival in non-small cell lung cancer (NSCLC) patients. Astra's shares fell by a whopping 15.6% in pre-marketing trading on the back of this news, which is the steepest decline in the company's history.

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Astra's top-line has been cratering lately due to the loss of exclusivity for top-selling medicines such as the cholesterol drug Crestor. In response, the drugmaker has been investing heavily in its cancer immunotherapy pipeline, where the checkpoint inhibitor Imfinzi was supposed to take a leading role. This devastating clinical setback, however, puts a huge dent in the company's plan of reversing this downward trend and subsequently producing industry-leading levels of growth heading into 2023.

Source: Fool.com