US-based AbbVie Inc., (NYSE: ABBV), the company behind the first-in-class Bruton’s tyrosine kinase (BTK) inhibitor Imbruvica (ibrutinib), has taken legal action against BeiGene’s (NASDAQ: BGNE) BTK inhibitor Brukinsa (zanubrutinib). The lawsuit was filed by AbbVie subsidiary Pharmacyclics in the Delaware District Court on the day it was awarded a new patent for Imbruvica, US Patent No. 11,672,803 (the ’803 Patent), which covers the use of an oral BTK inhibitor for treating chronic lymphocytic leukemia and small lymphocytic lymphoma (CLL/SLL). No official announcements have been made by either company regarding the lawsuit, and BeiGene’s Hong Kong share price fell by 12.43% following the news.
Imbruvica’s History and Market Performance
Imbruvica, originally discovered by Celera Genomics, was acquired by Pharmacyclics in a 2006 deal. The drug received its first approval to treat mantle cell lymphoma (MCL) in 2013 and has since added 11 other indications, including CLL in 2014 and CLL/SLL in 2016. Imbruvica’s remarkable performance in treating blood cancers, particularly CLL, led AbbVie to invest USD 21 billion in 2016 to acquire a controlling stake in Pharmacyclics. By 2020, Imbruvica generated USD 6.6 billion in sales, making it the fourth top-selling cancer drug that year, with forecasts predicting USD 10 billion in annual revenues by 2024.
Competition in the BTK Inhibitor Space
AstraZeneca entered the BTK market with Calquence (acalabrutinib) in 2017, followed by BeiGene’s Brukinsa, which was first approved in the US in November 2019 for MCL and later for CLL/SLL. Both drugs aim to provide more targeted BTK inhibition compared to Imbruvica. BeiGene conducted a head-to-head clinical trial comparing Brukinsa with Imbruvica in CLL, with final data in December 2022 showing significant improvements in progression-free survival and reduced toxicity for Brukinsa. This has led to an increasing preference for Calquence and Brukinsa over Imbruvica among US physicians. In 2022, AstraZeneca’s Calquence reached over USD 2 billion in sales, while Brukinsa generated USD 564.7 million, contrasting with a 21% year-on-year decline in AbbVie’s Imbruvica sales to USD 3.4 billion.
