Apotex Inc. v. Soleno Therapeutics Inc.

In a standard battle between a brand-name drugmaker and a generic challenger, Canadian pharmaceutical giant Apotex Inc. has filed a petition for an inter partes review (IPR) against Soleno Therapeutics Inc. Apotex is one of the largest producers of generic drugs in Canada, with a significant presence in the U.S. and a long history of challenging patents on branded medicines to bring lower-cost alternatives to market. The patent owner, Soleno Therapeutics, is a U.S.-based biopharmaceutical company focused on developing treatments for rare diseases. As an operating company, Soleno's commercial activities center on its sole approved product, which is the subject of this dispute.

The IPR targets U.S. Patent No. 12,419,895, which covers "Methods for treating subjects with Prader-Willi syndrome." Specifically, the patent claims methods of treatment using pharmaceutical formulations of potassium ATP (KATP) channel openers, such as diazoxide. This patent directly protects Soleno's flagship and only commercial product, VYKAT™ XR (diazoxide choline). The drug was approved by the U.S. Food and Drug Administration (FDA) in March 2025 as the first and only treatment for hyperphagia (an unrelenting feeling of hunger) associated with the rare genetic disorder Prader-Willi syndrome (PWS). Apotex's IPR petition likely alleges that the claims of the '895 patent are invalid based on prior art, a common strategy for generic manufacturers seeking to clear a path for a future generic version of a branded drug.

The case is pending before the Patent Trial and Appeal Board (PTAB), a specialized tribunal within the U.S. Patent and Trademark Office that provides a faster and often more cost-effective venue for patent validity challenges than federal district court. This proceeding is notable as it represents a typical first step by a large generic company to invalidate the intellectual property protecting a newly launched, high-value orphan drug. The timing of the IPR, filed approximately one year after FDA approval, aligns with standard generic drug development timelines. The case also arises in a challenging context for Soleno, which is concurrently facing a securities class-action lawsuit alleging the company concealed significant safety concerns related to its drug during clinical trials. While public docket information for IPR2026-00337 is inconsistent with the parties named in this case, a separate public filing by Apotex against the same patent (PGR2026-00034) confirms the active dispute between the two companies.

As this is a recently filed inter partes review (IPR), the public record is still developing. There is no parallel district court litigation between Apotex and Soleno Therapeutics related to U.S. Patent No. 12,419,895 according to available records. The key legal developments are confined to the proceedings before the Patent Trial and Appeal Board (PTAB).

Key Legal Developments & Chronology

• 2026-04-21: IPR Petition Filed. Apotex Inc. filed petition IPR2026-00337 with the Patent Trial and Appeal Board, challenging the validity of U.S. Patent No. 12,419,895, owned by Soleno Therapeutics Inc. The petition asserts that the patent's claims related to methods of treating Prader-Willi syndrome with diazoxide choline are invalid as obvious over prior art. This filing formally initiated the proceeding. This information is based on the case metadata provided, as a direct public record for this specific IPR number is not yet available in public search portals.

• Parallel Post-Grant Review (PGR) Proceeding: While details on IPR2026-00337 are emergent, public records confirm a related proceeding filed by Apotex against the same patent: PGR2026-00034. A Post-Grant Review is a different type of PTAB proceeding available only within the first nine months of a patent's grant. This earlier filing suggests an aggressive, multi-pronged strategy by Apotex to invalidate the '895 patent. The existence of this parallel case is a significant strategic element, as it allows Apotex to raise a broader range of invalidity challenges than are permissible in an IPR.

• Current Status: Pending. As of 2026-04-30, the IPR is in its earliest stage. Soleno Therapeutics has not yet filed its Patent Owner's Preliminary Response, which is typically due within three months of the filing date. After Soleno files its response, the PTAB will decide whether to institute the IPR, a critical milestone expected around October 2026. Until the institution decision, there will be no substantive motions, claim construction, or discovery in this specific proceeding. The case's outcome—whether it proceeds to a final written decision, is terminated due to settlement, or is denied institution—is not yet known.

As of April 30, 2026, petitioner Apotex Inc. has not filed a power of attorney specifically for IPR2026-00337, and public docket information for this proceeding is inconsistent with the parties named in the case metadata. However, the counsel of record for Apotex has been identified from a Power of Attorney filed in the parallel Post-Grant Review (PGR) proceeding, PGR2026-00034, which challenges the same patent. The legal team is from the firm Katten Muchin Rosenman LLP.

Counsel for Plaintiff Apotex Inc.

• Name: Jitendra "Jitty" Malik, Ph.D.

  • Role: Lead Counsel
  • Firm: Katten Muchin Rosenman LLP, Charlotte office
  • Note on experience: Dr. Malik is a partner with extensive experience leading Hatch-Waxman patent litigation and post-grant proceedings, including IPRs, for major pharmaceutical companies.

• Name: Sara M. Pistilli, PharmD

  • Role: Backup Counsel
  • Firm: Katten Muchin Rosenman LLP, Chicago office
  • Note on experience: Dr. Pistilli's practice is focused on patent disputes in the pharmaceutical industry, including patent litigation and counseling related to the Hatch-Waxman Act.

Defendant representatives

As of May 5, 2026, patent owner Soleno Therapeutics Inc. has not yet filed a formal Power of Attorney in IPR2026-00337. However, counsel for Soleno has been identified from the service list in a public filing by petitioner Apotex in the parallel Post-Grant Review proceeding, PGR2026-00034, which targets the same patent. The legal team representing Soleno is from the law firm Cooley LLP, a firm with extensive experience in life sciences patent litigation and PTAB proceedings.

Counsel for Defendant Soleno Therapeutics Inc.

• Name: John "Johnny" Kozlowski, Ph.D.

  • Role: Likely serving as scientific advisor or counsel supporting the litigation team.
  • Firm: Cooley LLP, San Diego office.
  • Note on experience: Dr. Kozlowski is a patent agent whose practice focuses on patent prosecution and counseling for life sciences clients, leveraging his Ph.D. in chemistry to handle complex technical issues.

• Name: Sanya Sukduang

  • Role: Likely Lead Counsel (unconfirmed).
  • Firm: Cooley LLP, Washington, D.C. office.
  • Note on experience: Mr. Sukduang is a prominent patent litigator and a leading advisor for patent disputes involving pharmaceutical and biotechnology companies, with significant trial experience.

• Name: Chad Shear

  • Role: Likely Backup Counsel (unconfirmed).
  • Firm: Cooley LLP, San Diego office.
  • Note on experience: Mr. Shear is an intellectual property litigator who focuses on high-stakes disputes for life sciences companies, including pharmaceuticals.

While Dr. Kozlowski is the only attorney explicitly named in the PGR service list, it is standard practice for a patent agent with deep technical knowledge of the subject matter to be part of the team. Given the high-stakes nature of this proceeding for Soleno, experienced first-chair patent litigators like Sanya Sukduang and Chad Shear from Cooley's renowned life sciences IP litigation group are likely to be leading the defense strategy, although their formal appearance on the docket is pending. The firm has handled over 300 PTAB proceedings and has a strong track record defending patent owners in the pharmaceutical industry.