Pharma BD Deal Intelligence

Alexion Pharmaceuticals Inc. / Portola Pharmaceuticals, Inc.

2020 · Acquisition/Merger · $1.4B · Complete

Outcome grade pending — assessed 5 years post-close.

Full analysis, sources & comparables →

The coverage arc

May 03, 2018 FDA Press Release Bullish

The U.S. Food and Drug Administration today granted accelerated approval to Andexxa (coagulation factor Xa [recombinant], inactivated-zhzo), the first and only…

May 05, 2020 Reuters Neutral

Alexion Pharmaceuticals said on Tuesday it would buy Portola Pharmaceuticals for about $1.41 billion to add the only approved reversal agent for the side…

May 15, 2023 CDC Heart Disease — Atrial Fibrillation Neutral

Atrial fibrillation affects an estimated 6 million people in the United States, with prevalence projected to rise to over 12 million by 2030. AF increases…

Source summaries from our enrichment pipeline; follow links for originals.

All 18 sources with sentiment breakdown →

Alexion acquired Portola Pharmaceuticals for $18.00/share in cash, ~$1.41B total; announced May 5, 2020 and completed July 2, 2020 via tender offer (~79.7% of shares tendered) and back-end merger. The deal added Andexxa/Ondexxya (andexanet alfa), the only approved reversal agent for Factor Xa inhibitors (Eliquis, Xarelto), expanding Alexion beyond Soliris into hematology. Activist investor Elliott Management publicly criticized the deal as value-destructive. The thesis ultimately did not hold: andexanet never approached its projected blockbuster sales (peaking near $219M globally in 2024, only ~$81M of it US). Alexion itself was acquired by AstraZeneca (completed July 2021), folding Andexxa into AstraZeneca Rare Disease. The ANNEXA-I confirmatory randomized trial (2024) met its hemostasis endpoint (63.9% vs 52.4% good/excellent hemostasis) but showed materially higher thrombosis (14.6% vs 6.9%) and thrombosis-related deaths. In December 2025 AstraZeneca voluntarily withdrew Andexxa's US biologics license application effective Dec 22-23, 2025 after the FDA concluded its serious thromboembolic risks outweighed its benefit and a path from conditional to traditional approval could not be reached.

Did it work? Outcome assessment

Strategic verdict
Partially Achieved
Financial impact
Dilutive
Pipeline outcome
Mixed

Key facts

Related deals — scored

DealYearValueOutcome
Alexion Pharmaceuticals Inc. / Portola Pharmaceuticals, Inc. (this deal)2020$1.4B
Alexion Pharmaceuticals Inc. / Synageva BioPharma2015$8.4B36
Alexion Pharmaceuticals Inc. / Wilson Therapeutics AB2018$855M20
Alexion Pharmaceuticals Inc. / Syntimmune, Inc.2018$1.2B14
Alexion Pharmaceuticals Inc. / Achillion Pharmaceuticals, Inc.2019$1.2B
Amgen Inc. / Micromet Inc.2012$1.2B88
Servier / Shire plc (Oncology Business)2018$2.4B88

Compare all 7 side-by-side →

See the full interactive analysis, sources & comparables →