Three companies—McKesson, Cencora, and Cardinal Health—account for over 90% of the wholesale drug distribution market in the United States. Since 2019, U.S. spending on oncology drugs has risen from approximately $65 billion to $99 billion in 2023, representing nearly 45% of global oncology drug spending. In 2023, U.S. pharmaceutical expenditures reached $722.5 billion, with oncology drugs accounting for approximately 14% of total drug spending. By 2028, U.S. annual oncology spending is projected to reach $180 billion. These trends are driven by an aging population, increasing cancer incidence, and the development of innovative immunotherapies and targeted treatments. As such, it is not surprising that these companies have sought to expand their presence within the oncology sector with the strategic acquisition and consolidation of large, oncology-focused provider networks.
In the past few years, three major acquisitions have reshaped the oncology care sector: Cardinal Health’s acquisition of Integrated Oncology Network (ION), Cencora and TPG’s joint acquisition of OneOncology, and McKesson’s controlling stake in Florida Cancer Specialists & Research Institute (FCS). These acquisitions reflect a broader trend toward vertical integration, value-based care, and enhanced support for independent oncology practices.
McKesson Acquires Controlling Interest in Florida Cancer Specialists
McKesson, who acquired US Oncology Network for $2.2 billion in 2010, has continued to grow its footprint within the oncology provider space. When acquired, US Oncology Network was made up of 1,300 oncologists, supplying over $2 billion worth of drugs annually. Today, the business includes more than 2,550 oncologists at over 600 sites in 31 states.
Most recently, in August 2024, McKesson announced a $2.5 billion deal to acquire a controlling interest (70%) in Core Ventures, the administrative and business services arm of FCS, one of the nation’s largest, independent communities of oncology providers. FCS, with over 250 physicians and nearly 100 locations, will remain independently owned and join the US Oncology Network, McKesson’s flagship oncology platform. McKesson announced the transaction closed on June 3, 2025.
The provider-side expansion further supports McKesson’s specialty drug distribution, as oncology drugs are primarily distributed through specialty distribution channels. Furthermore, McKesson has attributed part of its 2025 growth within its pharmaceutical division to “growth in the distribution of specialty products, including higher volumes in oncology.”
Cencora & TPG Acquire OneOncology
In June 2023, TPG and Cencora (formerly AmerisourceBergen) completed their $2.1 billion acquisition of OneOncology, a rapidly growing network of community oncology practices. Founded in 2018, OneOncology aimed to empower independent oncology practices by offering clinical, operational, and technological resources to support physician-led cancer care. As part of the deal structure, TPG would take a majority stake, with Cencora and OneOncology’s leadership and affiliated practices assuming a minority share to ensure continued physician-led governance. The transaction includes a put option allowing TPG to sell its remaining interest to Cencora at a valuation of 19x OneOncology’s trailing 12-month adjusted EBITDA on the third anniversary of the deal, implying a current EBITDA of about $110 million.
Cencora also holds a call option to purchase TPG’s stake at the same multiple between the third and fifth anniversaries. This put/call structure reflects Cencora’s long-term strategy of full ownership, leveraging TPG’s capital to fuel the network’s expansion in a rapidly growing oncology market—projected to reach $180 billion in U.S. spending by 2028—while aligning with the broader consolidation trend among distributors.
OneOncology has since continued to expand post-acquisition, notably acquiring United Urology Group (UUG) in October 2024 and partnering with New York Oncology and Hematology (NYOH) starting in July 2025. UUG is a leading urology management services organization that supports over 250 providers across multiple states. On April 22, 2025, OneOncology announced a partnership with NYOH, a physician-owned practice with over 60 providers across various locations throughout New York’s Capital Region. President of NYOH, Todd Doyle, MD, stated, “Our OneOncology partnership will bring us capital, expertise, and proven solutions to grow our practice and continue meeting the needs of our patients and their families.”
While not oncology-focused, Cencora also announced its acquisition of Retina Consultants of America in November 2024 for $4.6 billion. Cencora CEO Bob Mauch stated, “Following our recent investment in OneOncology, the addition of RCA will allow us to expand our management services organization (MSO) solutions and drive differentiated value across the health care system for manufacturers, providers, and patients,” further instilling the strategic importance of OneOncology’s role in the Cencora’s MSO solutions in specialty care.
Cardinal Health Acquires Integrated Oncology Network
In December 2024, Cardinal Health closed its acquisition of ION for $1.1 billion in cash. ION, a physician-led network, comprised over 100 providers with more than 50 locations across 10 states. As part of the acquisition, ION will join Cardinal Health’s Navista, an oncology practice alliance that aims to support independent oncology practices with advanced analytics and value-based care solutions.
March 2024 saw Cardinal Health acquire Specialty Networks for $1.2 billion in cash. Specialty Networks is a healthcare services platform that supports over 11,500 providers across 1,200 independent practices. Cardinal Health CEO Jason Hollar emphasized the importance of these acquisitions: “Driving growth in specialty continues to be a top priority, and we’ve made investments to expand our offerings through both Navista and our acquisition of Specialty Networks. With their proven model providing extensive support of community oncology across the cancer care continuum and healthcare ecosystem, we’re confident Integrated Oncology Network will further accelerate our oncology strategy and enable us to create value for providers and patients.”
The ION acquisition will enhance Cardinal’s ability to offer a comprehensive suite of services and complement Cardinal’s acquisition of Specialty Networks, reinforcing its commitment to community oncology by strengthening the link between its downstream and upstream services.
Vertical Integration
The recent acquisitions of ION, OneOncology, and FCS illustrate a deliberate vertical integration strategy by major drug distributors—including Cardinal Health, Cencora (formerly AmerisourceBergen), and McKesson—to solidify their presence in the oncology care sector. These three wholesalers control over 90% of the entire pharmaceutical wholesale market. By acquiring established oncology practice networks, these distributors are vertically integrating drug distribution and clinical care, such as Cardinal Health’s Navista, while securing downstream demand for their drugs. Ultimately, this integration strategy reflects a shift from being mere suppliers to controlling multiple stages of the oncology care model.
Conclusion
The oncology care landscape has undergone significant transformation through recent acquisitions, as major healthcare players like McKesson, Cencora, and Cardinal Health pursue a strategy of vertical integration to expand their influence in community-based cancer care. The acquisitions of ION by Cardinal Health, OneOncology by TPG and Cencora, and Florida Cancer Specialists by McKesson highlight a strategic push to consolidate the oncology value chain, from drug distribution to care delivery. By integrating community oncology practices, it appears that these companies aim to streamline operations, enhance data-driven care, and secure a larger share of the rapidly growing oncology market.
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