Dr. Falk Pharma GmbH v. Ellodi Pharmaceuticals, L.P.

Case Overview: Dr. Falk Pharma GmbH v. Ellodi Pharmaceuticals, L.P. (PGR2025-00086)

This Post-Grant Review (PGR) proceeding, filed by Dr. Falk Pharma GmbH against Ellodi Pharmaceuticals, L.P. before the United States Patent and Trademark Office's Patent Trial and Appeal Board (PTAB), challenges the validity of claims 1-34 of U.S. Patent No. 12,290,598. Dr. Falk Pharma GmbH is a German-based research-intensive family business specializing in developing and distributing innovative medicines for digestive and metabolic diseases, including inflammatory bowel disease and eosinophilic esophagitis (EoE). Ellodi Pharmaceuticals, L.P., established in 2020 by TPG Capital, is a specialty pharmaceutical company focused on advancing treatments for Eosinophilic Esophagitis (EoE), a rare and chronic allergic inflammatory condition. Ellodi's lead product, APT-1011, an orally disintegrating fluticasone formulation, is currently in Phase 3 clinical trials for EoE. While the PGR does not explicitly name an "accused product," the '598 patent broadly covers "Orally administered corticosteroid compositions," suggesting Ellodi's EoE treatment, APT-1011, is the underlying technology of commercial interest.

The asserted patent, U.S. Patent No. 12,290,598, titled "Orally administered corticosteroid compositions," describes orally disintegrating tablets (ODTs) containing a corticosteroid, such as budesonide or fluticasone propionate, for treating eosinophilic esophagitis. The claims of the '598 patent require the tablet to disintegrate within 60 seconds, deposit the drug topically in the esophagus, and possess a specific hardness of 4-48 N or a friability of not more than 1%. Dr. Falk is challenging these claims based on lack of written description under 35 U.S.C. § 112(a) and anticipation under 35 U.S.C. § 102 by an earlier patent, Perrett (Patent 8,771,729). The petitioner argues that the claimed hardness range of "4-48 N" lacks sufficient written description support in the original specification and that the '598 patent may not be entitled to its claimed priority date, thereby making additional prior art available. Furthermore, Dr. Falk asserts that the term "hardness" renders the claims indefinite under §112(b) due to the lack of a specified measurement method in the patent.

This PGR is currently pending before the PTAB, a specialized administrative tribunal within the USPTO, which handles challenges to patent validity. The choice of a PGR proceeding is significant as it allows for a broader range of invalidity grounds to be asserted compared to an Inter Partes Review (IPR), including challenges under 35 U.S.C. § 101 (patent eligibility) and § 112 (written description, enablement, definiteness), in addition to anticipation and obviousness. The case is notable due to its potential impact on the developing market for EoE treatments, a condition with a growing prevalence. Ellodi Pharmaceuticals' APT-1011 is a leading candidate in late-stage development, and the validity of its foundational patents could significantly influence its market position. There appears to be related litigation, with Ellodi Pharmaceuticals, L.P. having filed a district court case against Dr. Falk Pharma GmbH in the Eastern District of Virginia (1:24-cv-01392) on August 8, 2024. Such parallel proceedings between direct competitors in a specialized therapeutic area often indicate high-stakes intellectual property disputes over market exclusivity.## Case Overview: Dr. Falk Pharma GmbH v. Ellodi Pharmaceuticals, L.P. (PGR2025-00086)

This Post-Grant Review (PGR) proceeding, initiated by Dr. Falk Pharma GmbH against Ellodi Pharmaceuticals, L.P. before the United States Patent and Trademark Office's Patent Trial and Appeal Board (PTAB), challenges the validity of claims 1-34 of U.S. Patent No. 12,290,598. Dr. Falk Pharma GmbH is a German-based research-focused pharmaceutical company specializing in developing and distributing medicines for gastrointestinal and metabolic diseases, including inflammatory bowel disease and eosinophilic esophagitis (EoE). Ellodi Pharmaceuticals, L.P. is a specialty pharmaceutical company, formed in 2020 with backing from TPG Capital, dedicated to advancing treatments for Eosinophilic Esophagitis (EoE), a rare and chronic allergic inflammatory condition. Ellodi's primary asset, APT-1011, is an orally disintegrating fluticasone formulation currently in Phase 3 clinical trials for EoE. Although no "accused product" is explicitly named within the PGR filing itself, the '598 patent's subject matter of "Orally administered corticosteroid compositions" strongly suggests that Ellodi's APT-1011, or a similar therapeutic, is the product of commercial interest underlying this patent challenge.

The patent at issue, U.S. Patent No. 12,290,598, is titled "Orally administered corticosteroid compositions." It generally describes orally disintegrating tablets (ODTs) that contain a corticosteroid, such as budesonide or fluticasone propionate, specifically for the treatment of eosinophilic esophagitis. Key technical features claimed in the patent include tablets designed to disintegrate within 60 seconds, deliver the drug topically to the esophagus, and possess a specific hardness range of 4-48 N or a friability of not more than 1%. Dr. Falk Pharma GmbH has challenged the validity of these claims on multiple grounds, including a lack of written description under 35 U.S.C. § 112(a) and anticipation under 35 U.S.C. § 102, citing an earlier patent, Perrett (U.S. Patent No. 8,771,729). A core argument for the written description challenge centers on the "4-48 N" hardness range, which the petitioner contends lacks adequate support in the original specification, potentially affecting the patent's priority date and allowing more prior art to be considered. Additionally, Dr. Falk argues that the term "hardness" renders the claims indefinite under §112(b) due to the absence of a specified measurement method in the patent.

This case is currently pending at the United States Patent and Trademark Office's Patent Trial and Appeal Board, a specialized administrative tribunal. The PTAB's PGR process is a significant venue because it permits challenges to patent validity based on a broader array of grounds than other post-grant proceedings, including written description and indefiniteness, which are central to Dr. Falk's petition. The case is notable for its direct relevance to the emerging market for eosinophilic esophagitis treatments. With Ellodi Pharmaceuticals' APT-1011 in late-stage development as a potential first FDA-approved orally disintegrating treatment for EoE, the outcome of this PGR could have substantial implications for market competition and access to therapies for this rare condition. Furthermore, the existence of a parallel patent infringement lawsuit filed by Ellodi Pharmaceuticals, L.P. against Dr. Falk Pharma GmbH in the Eastern District of Virginia (Case No. 1:24-cv-01392), initiated on August 8, 2024, underscores the high-stakes nature of this intellectual property dispute between two pharmaceutical companies vying in the gastrointestinal disease space.

The provided case, PGR2025-00086, is a Post-Grant Review (PGR) proceeding before the United States Patent and Trademark Office's Patent Trial and Appeal Board (PTAB), not a district court patent infringement litigation. This PGR was filed by Dr. Falk Pharma GmbH, challenging claims 1-34 of U.S. Patent No. 12,290,598, owned by Ellodi Pharmaceuticals, L.P..

While a district court case, Ellodi Pharmaceuticals, LP v. Dr. Falk Pharma GmbH, Case No. 1:24-cv-01392, was filed on August 8, 2024, in the Eastern District of Virginia, its nature of suit is categorized as a "Contract - Other Contract" and a "Diversity-Contract Dispute," not a patent infringement action. Therefore, the information below pertains specifically to the PGR proceeding, as there is no active patent infringement litigation identified for patent 12,290,598 between these parties.

Key Legal Developments and Current Posture of PGR2025-00086:

• Filing of PGR Petition (2025-09-19): Dr. Falk Pharma GmbH filed the PGR petition challenging the validity of claims 1-34 of U.S. Patent No. 12,290,598. The grounds for the challenge include lack of written description under 35 U.S.C. §112(a) and anticipation under 35 U.S.C. §102, specifically by U.S. Patent No. 8,771,729 to Perrett. The '598 patent relates to orally administered corticosteroid compositions, such as orally disintegrating tablets (ODTs) containing budesonide or fluticasone propionate, for treating eosinophilic esophagitis.

• Briefing on Discretionary Denial (2026-01-13): As of January 13, 2026, the Petitioner, Dr. Falk Pharma GmbH, filed a "Petitioner's Sur-reply to Patent Owner's Discretionary Denial Brief" (Document #14). This indicates that the PTAB was still actively considering whether to institute the PGR trial, including arguments related to discretionary denial, after the initial petition and patent owner's preliminary response.

• Institution Decision (Pending): A decision on institution for PGR2025-00086 would typically be expected within six months of the petition's filing date (September 19, 2025), placing the expected decision around March 2026. Given the filing of a sur-reply in January 2026, the institution decision would occur after that date. As of October 20, 2025, the USPTO Director personally determines whether to institute IPR and PGR trials. The status of an institution decision for PGR2025-00086 has not yet been publicly disclosed in the available search results.

• Current Posture: The PGR proceeding remains pending. The next significant development will be the PTAB's decision on whether to institute a trial. If the trial is instituted, the process will move to discovery, a hearing, and eventually a Final Written Decision. If institution is denied, the PGR proceeding will terminate. The projected deadline for final written decisions in PGRs filed in 2025 is between June and November 2026 for cases that have instituted trial.

Dr. Falk Pharma GmbH, the petitioner in the Post-Grant Review (PGR) case PGR2025-00086, is represented by attorneys from Knobbe, Martens, Olson, & Bear, LLP. While direct counsel listings for PGR2025-00086 are not explicitly available in public search results, related PTAB proceedings and district court cases involving the same parties indicate the following attorneys are likely representing Dr. Falk Pharma GmbH:

• Nathanael Luman (Lead Counsel)

  • Firm: Knobbe, Martens, Olson, & Bear, LLP (California office likely, based on firm's strong California presence and prior listings)
  • Experience: Luman has represented Dr. Falk Pharma GmbH as counsel in related proceedings, including IPR2024-01197, where Dr. Falk Pharma GmbH was also the Petitioner. He was also listed as counsel for Dr. Falk Pharma GmbH in a district court case against Ellodi Pharmaceuticals, LP. His experience includes patent litigation and post-grant proceedings.

• Eric S. Furman (Counsel)

  • Firm: Knobbe, Martens, Olson, & Bear, LLP
  • Experience: Furman is listed as counsel for Dr. Falk Pharma GmbH in the related IPR2024-01197 proceeding.

• Phillip J. Minnick (Counsel)

  • Firm: Knobbe, Martens, Olson, & Bear, LLP
  • Experience: Minnick is listed as counsel for Dr. Falk Pharma GmbH in the related IPR2024-01197 proceeding.

• Christy Lea (Counsel)

  • Firm: Knobbe Martens Olson & Bear LLP (California office likely)
  • Experience: Lea was listed as counsel for Dr. Falk Pharma GmbH in the district court case Ellodi Pharmaceuticals, LP v. Dr. Falk Pharma GmbH.

As of the current date, no specific "local counsel" or "in-house counsel" roles have been explicitly identified for Dr. Falk Pharma GmbH in the provided public records for this PGR. The PTAB filings typically list the primary attorneys handling the case, who are often lead counsel from their respective firms. The filings are not sealed, and counsel has appeared, as evidenced by the related IPR filings.

I'll research counsel of record for the patent owner/respondent, Ellodi Pharmaceuticals, L.P., in PGR2025-00086 and related proceedings.

Key finding: Cooley LLP appears as Ellodi's counsel. Let me verify the current roster and the reported 2026 lead counsel substitution.

Counsel of Record — Respondent/Patent Owner Ellodi Pharmaceuticals, L.P. (PGR2025-00086)

Threshold correction to the request. PGR2025-00086 is not a patent infringement case; it is a Post-Grant Review before the PTAB. The party you are asking about — the "defendant"-side party — is Ellodi Pharmaceuticals, L.P., the Patent Owner/respondent adverse to petitioner Dr. Falk Pharma GmbH. (The earlier-generated section of this case file is correct that the only district-court case between these parties, Ellodi Pharms., LP v. Dr. Falk Pharma GmbH, No. 1:24-cv-01392 (E.D. Va.), is docketed as a contract/diversity action, not an infringement action, and Ellodi is the plaintiff there.) Below is Ellodi's PTAB counsel of record, which is where counsel has actually appeared.

Counsel of record (Cooley LLP, as listed in the PGR service certificates)

Petitioner's mandatory-notice and service certificates in PGR2025-00086 identify Ellodi's counsel at Cooley LLP as follows (service address Ellodi_IPR@cooley.com):

Sources: Petitioner's Supplemental Mandatory Notice served Sept. 23, 2025 in PGR2025-00086, listing ssukduang@cooley.com, jdavies@cooley.com, jcousin@cooley.com, iagarwal@cooley.com, Ellodi_IPR@cooley.com (PTAB P-TACTS document, https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1556815](/patent/1556815)/download-documents?artifactId=TxJ51F-E6FQaeMozWteNvkymkVuuYT7dNSbjqrbvmxskwMY6Xsy8F0w); PTAB email correspondence in the related IPRs bearing Sukduang's Cooley signature block (https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1556395](/patent/1556395)/download-documents?artifactId=OqhEVl1fCidufj2ao1B3xoWZg-m0YeOUUrlvrQJEAPCr_pKymicV5Ik); PTAB e-mail of Jan. 29, 2026 copying Ellodi_IPR@cooley.com (https://ptacts.uspto.gov/ptacts/public-informations/petitions/[1556811](/patent/1556811)/download-documents?artifactId=S-DOeA-kDC9tgUzFXPqTp9jcOpSV_ZHCw02Vio2Ew1zRb2x0HBhT6c0).

⚠️ Unresolved: the April 2026 lead-counsel substitution

Two independent search results indicate there has been a change in Ellodi's lead counsel that I could not fully verify:

1. Secondary reporting states that in April 2026 the Board granted Patent Owner's unopposed motion to withdraw existing lead counsel and substitute new lead counsel in PGR2025-00086 under 37 C.F.R. § 42.10 — but the reporting does not name the withdrawing or incoming attorney (https://www.legaltechdaily.com/2026/04/ptab-grants-unopposed-lead-counsel-substitution-in-pgr2025-00086/).
2. Sukduang and Davies left Cooley for Norton Rose Fulbright (announced Feb. 9, 2026; effective Feb. 3, 2026 per their own notices of change of firm affiliation filed in D. Del. and M.D.N.C.) — https://www.globenewswire.com/news-release/2026/02/09/[3234912](/patent/3234912)/0/en/norton-rose-fulbright-increases-ip-disputes-muscle-with-two-washington-dc-partners.html and https://storage.courtlistener.com/recap/gov.uscourts.ded.83482/gov.uscourts.ded.83482.458.0_1.pdf.

The obvious inference is that the April 2026 substitution was the mechanism by which the Ellodi engagement moved (either to Norton Rose Fulbright with Sukduang/Davies continuing, or to remaining Cooley attorneys Cousin/Agarwal as lead/backup). I could not locate a primary document confirming which. I am therefore not naming a current lead counsel as fact. To close this, pull from the PTAB docket: the Power of Attorney filed by Patent Owner on Oct. 10, 2025, and the April 2026 Order granting the § 42.10 motion (docket listing at https://ipverse.greyb.com/ptab-web/cases/case-details/PGR2025-00086 and https://gaeflexstaging-dot-docketupdate.appspot.com/cases/PTAB/PGR2025-00086/Dr._Falk_Pharma_GmbH_v._Ellodi_Pharmaceuticals/). No counsel listings are sealed in this proceeding; the gap is a reporting gap, not a sealing issue.

Contradiction to flag against the existing case summary

The previously generated "Key legal developments" section states that institution was pending with an expected decision around March 2026, and describes the posture as of October 2025. Current docket aggregators instead list PGR2025-00086 as "Trial Instituted" (IP Verse, updated May 2026: https://ipverse.greyb.com/competitive-analysis/company/ellodi-pharmaceuticals; Docket Alarm case page: https://gaeflexstaging-dot-docketupdate.appspot.com/cases/PTAB/PGR2025-00086/Dr._Falk_Pharma_GmbH_v._Ellodi_Pharmaceuticals/). That is consistent with merits-stage activity on the docket (Patent Owner's Brief in Support of Discretionary Denial, Nov. 24, 2025; Board order staying the certificate-of-correction request, Dec. 18, 2025; Patent Owner exhibit submissions Dec. 26, 2025; joint notice of Jan. 29, 2026 regarding adverse judgments in IPR2025-00052/54/55/56). The earlier section's "pending institution" characterization should be treated as superseded.

Also worth noting for the counsel picture

• The same Cooley team (same four attorneys, same Ellodi_IPR@cooley.com service address) represented Ellodi across IPR2024-01197 and IPR2025-00052/54/55/56. In those sibling IPRs Ellodi ultimately disclaimed all claims and requested adverse judgment (e.g., the '729 patent disclaimer and adverse-judgment request filed Oct. 22, 2025, in IPR2024-01197), a fact Dr. Falk is now pressing in PGR2025-00086 — which makes the counsel transition in the PGR unusually consequential.
• No in-house counsel for Ellodi has appeared on the PTAB docket in this proceeding, and no local-counsel designation is required at the PTAB (unlike district court).