Kyle Bass launches IPR challenge against Imbruvica patent

Texas hedge fund manager Kyle Bass has sought another inter partes review (IPR), this time to challenge a patent covering Pharmacyclics’ cancer drug Imbruvica (ibrutinib).

Bass’s Coalition for Affordable Drugs, named as the lead petitioner in the challenge, has argued that US patent  number 8,754,090 is invalid for obviousness and that it was anticipated by a study published in 2009.

The challenge, filed on Monday (April 20), is the fourth IPR lodged by the coalition in four months—its other targets have been Acorda Therapeutics, Shire and Jazz Pharmaceuticals.

Pharmacyclics’s ‘090 patent covers a method for treating mantle cell lymphoma, an aggressive form of cancer. It markets the drug with Janssen Pharmaceutica.

The patent was issued last year and is due to expire in June 2031. The remaining nine patents covering the drug will expire in December 2026.

The US Food and Drug Administration (FDA) approved Imbruvica in 2013, designating it as a “breakthrough” therapy, which speeds up the development and review process for new drugs.

Imbruvica was one of just three drugs to receive this designation that year—the others were Gilead’s Sovaldi and Genentech’s Gazyva.

Pharmacyclics said it expects US sales of Imbruvica to be near the $1 billion mark by the end of this year.

Imbruvica has received two further breakthrough therapy designations since its initial FDA approval: to treat patients with chronic lymphocytic leukaemia who have received prior treatment, and to treat Waldenström’s macroglobulinemia, a rare form of cancer that starts in the immune system.

AbbVie, which is not a named defendant, acquired Pharmacyclics earlier this year for $21 billion.

Neither Bass nor Pharmacyclics responded to a request for comment.