Facing the dual challenges of performance growth pressure and the impending patent expiration of its core product, pharmaceutical giant Merck (MRK) has taken a key step seen as crucial to reversing its decline by acquiring clinical-stage biotechnology company Cidara Therapeutics (CDTX) for approximately $92 billion in cash. This major acquisition aims to inject new vitality into Merck’s product pipeline, particularly to address the potential revenue cliff after its blockbuster cancer drug Keytruda loses patent protection in 2028.
For Merck, acquiring biotechnology companies with mid-to-late-stage drug candidates is a more efficient and less risky path compared to internal R&D. The centerpiece of this acquisition is Cidara’s lead candidate, CD388, a potential long-acting antiviral drug for influenza. This drug is designed to address several major shortcomings of current flu vaccines: vaccine production relies on pre-season predictions of circulating strains, where inaccuracies can significantly reduce effectiveness; vaccine efficacy wanes as the flu season progresses; and elderly and immunocompromised populations respond poorly to traditional vaccines.
CD388 is designed to target two main types of influenza virus and multiple strains, potentially offering sustained protection throughout the flu season, even for high-risk groups. Clinical data supports its promise: a Phase II study showed CD388 provided statistically significant protection against influenza over 24 weeks, with effects persisting through week 28. Recognizing its potential, the U.S. Food and Drug Administration has granted CD388 Fast Track designation to accelerate its development.
Merck’s recent performance pressure stems partly from declining demand for its core growth driver – the HPV vaccine Gardasil product line – particularly in markets like China and Japan. The company’s total global sales in the third quarter grew only 4% year-over-year to $17.3 billion, with Gardasil sales falling 24%, highlighting the urgency of finding new growth drivers.
A more profound challenge is the patent expiration of its “cash cow” Keytruda in 2028, which will expose it to intense competition from generics. Furthermore, other Phase III therapies are already attempting to challenge its position in key indications like lung cancer. The addition of CD388 could help Merck strengthen its anti-infectives portfolio while preparing for the post-Keytruda era.
Beyond this acquisition, Merck is also bolstering its market position through other means. For instance, the newly approved subcutaneous formulation of Keytruda significantly reduces administration time while maintaining efficacy, and its unique patent protection helps manage future competition. Meanwhile, the pulmonary arterial hypertension drug Winrevair and the pneumococcal vaccine Capvaxive, both approved last year, have shown growth potential, with Q3 sales reaching $360 million and $244 million, respectively.
