Bass files 16th IPR petition as opposition continues to build

Managing IP is part of Legal Benchmarking Limited, 1-2 Paris Gardens, London, SE1 8ND

Copyright © Legal Benchmarking Limited and its affiliated companies 2025

Accessibility | Terms of Use | Privacy Policy | Modern Slavery Statement

Bass files 16th IPR petition as opposition continues to build

Kyle Bass has filed another IPR petition targeting a pharma company, taking aim again at the Vimovo pain reliever, while IPO has passed a resolution opposing the use of post-grant proceedings to manipulate the market

kyle20bass20150.jpg

The Coalition for Affordable Drugs has filed its 16th inter partes review (IPR) petition, taking aim for a second time at the Vimovo treatment made by Pozen and sold by Horizon Pharma in the US. Vimovo is an arthritis pain reliever.

Kyle Bass, who runs hedge fund Hayman Capital, and Erich Spangenberg, owner of nXn Partners, are behind the coalition. IP Nav is also involved.

I spoke to Bass last month for our June cover story and he made very clear that he is serious about taking on pharmaceutical and biotech companies through Patent Trial and Appeal Board proceedings and that he will not give up.

You can read the full story, including an analysis of Bass’s strategy, the response from IP practitioners and trade groups, and the potential action from Congress and the Board here (only available to subscribers and trialists – you can take out a trial to the site here).

Bass underlined that he is filing merit-based IPRs with the expectation of seeing the challenge through to a final decision by the PTAB. Hayman Capital says it will not accept settlement payments to drop its challenges.

Bass praised the IPR system. "It is very pro-competitive," he told me. "It was designed to mine-clear patent trolls in the tech space, and now it is allowing firms like ours to challenge patent squatters."

Pharma and bio patent owners have not taken lightly to Bass’s provocation. BIO labeled his strategy “a new door to abuse of the patent system”, and accused him of using PTAB proceedings to short sell stock.

Last week, the PATENT Act was reported to the full Senate and included a new provision allowed the PTAB to deny petitions “in the interest of justice”. This was likely drafted with PTAB strategies such as Bass's in mind. 

And this week IPO passed a resolution opposing the use of post-grant proceedings to manipulate the market.

The resolution said: “IPO believes it is an abuse to file AIA petitions for post grant proceedings by persons who have a significant bet against, or short, of the shares of the patent owners owning the patents challenged in the petitions; now, therefore, IPO urges the United States Patent and Trademark Office to use its discretion to deny petitions filed by such persons.”



Only 30% of our content is published on our blog – to access all of our content you need to be a subscriber.

We like to offer our loyal blog readers a special rate, so register your interest in coming on board as a subscriber and we will be in touch shortly.

  

more from across site and SHARED ros bottom lb

More from across our site

Lawyers at Lavoix provide an overview of the UPC’s approach to inventive step and whether the forum is promoting its own approach rather than following the EPO
Andrew Blattman, who helped IPH gain significant ground in Asia and Canada, will leave in the second half of 2026
The court ordering a complainant to rank its arguments in order of potential success and a win for Edwards Lifesciences were among the top developments in recent weeks
Frederick Lee has rejoined Boies Schiller Flexner, bolstering the firm’s capabilities across AI, media, and entertainment
Nirav Desai and Sasha S Rao at Sterne, Kessler, Goldstein & Fox explore how companies’ efforts to manage tariffs by altering corporate structures can undermine their ability to assert their patents and recover damages
Monika Żuraw, founder of Żuraw & Partners, discusses why IP should be part of the foundation of a business, and taking on projects that others walk away from
Lawyers say attention will turn to the UK government’s AI consultation after judgment fails to match pre-trial hype
Susan Keston and Rachel Fetches at HGF explain why the CoA’s decision to grant the UPC’s first permanent injunction demonstrates the court’s readiness to diverge from national court judgments
IP, M&A, life sciences and competition partners advised on deal that brings together brands such as ‘Huggies’ and ‘Kleenex’ with ‘Band-Aid’ and ‘Tylenol’
Stability AI, represented by Bird & Bird, is not liable for secondary copyright infringement, though Fieldfisher client Getty succeeds in some trademark claims
Gift this article