Zauberkugel: Pfizer’s Seagen Acquisition

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BioPharm International, BioPharm International, April 2023, Volume 36, Issue 04
Pages: 6

What can we take away from Pfizer's acquisition of Seagen?

Does Pfizer’s outbidding of Merck in the acquisition of Seagen consolidate gains for patients given the up and down history of the antibody drug conjugate (ADC) field and funnel new oxygen into novel applications? Or does this merger winnow down alternatives and close commercial paths for otherwise promising but currently overlooked ADC entities?

The history of gemtuzumab ozogamicin—first approved in 2000, removed from most markets in 2010 (except Japan), then reapproved by FDA and the European Medicines Agency (EMA) in 2017 (based on that Japanese data)—underscores the bifurcated belief in the ADC approach itself. This drug was the product of a collaboration between Celltech and Wyeth that began in 1991. The former being acquired by UCB in 2004, the latter acquired by Pfizer in 2009 (1). The German Nobel laureate, Paul Ehrlich, came up with ADCs way back in 1900, famously describing it as Zauberkugel, a “magic bullet” due to its potential to target only cancerous cells, leaving healthy cells free to go about their normal lives.

“Four of the 12 total FDA-approved and marketed ADCs [are] using its [Seagen’s] technology … Seagen’s portfolio includes four approved medicines that are first- or best-in-class in their respective indications across solid tumors and hematologic malignancies, including three ADCs: ADCETRIS (brentuximab vedotin), PADCEV (enfortumab vedotin), and TIVDAK (tisotumab vedotin) ” (2, 3).

My own take is this acquisition is a magic bullet for filling Pfizer’s innovation duties in their oncology portfolio. They can “bolt on” much of their small-molecule knowhow as an added bonus, for other therapeutic indications, potentially expanding physicians toolboxes. Equally, it’s a win for patients generally, as Seagen said on a call “there’s opportunities, not just with immune checkpoint blockers, but to increase further the antibodies, but also the linkers, as well as the payloads ... to expand across many novel tumor types, not only hematologic.” So, more types of magic bullet for more patients over time.


1. Sorkin, A.; Wilson, D. Pfizer Agrees to Pay $68 Billion for Rival Drug Maker Wyeth. The New York Times. Jan 25, 2009.


2. Pfizer. Pfizer Analyst and Investor Call to discuss Proposed Acquisition of Seagen, March 13, 2023.

3. Pfizer. Pfizer Invests $43 Billion to Battle Cancer. Press Release. March 13, 2023.

About the author

Chris Spivey is editorial director for Pharmaceutical Technology.

Article details

BioPharm International
Vol. 36, No. 4
April 2023
Pages: 6


When referring to this article, please cite it as C. Spivey. The Commercial Message mRNA Products Send. BioPharm International 2023 36 (4).