Untitled case

I'll research this case systematically, starting with the docket and patent metadata.

Case overview — Ipsen Biopharm Ltd. et al. v. Conjuro Biotherapeutics, Inc. et al., D.N.J. No. 3:24-cv-04991 (public filings appear as No. 1:24-cv-4991)

Parties. The plaintiffs are Ipsen Biopharmaceuticals, Inc. (Ipsen's U.S. commercial subsidiary, headquartered in Basking Ridge, New Jersey) and Ipsen Biopharm Ltd. (the U.K. entity in Wrexham, Wales, which holds record title to the asserted patents in this family). Ipsen is an operating, revenue-generating specialty pharma company, not an NPE: the patents at issue are the proprietary formulation/manufacturing estate behind its marketed oncology drug Onivyde® (irinotecan liposome injection). That estate originated at Hermes Biosciences and Merrimack Pharmaceuticals — the '213 patent names Keelung Hong, Daryl C. Drummond and Dmitri Kirpotin and issued to Merrimack in December 2012 — and traveled to Ipsen with the Onivyde asset. The defendants are Conjuro Biotherapeutics, Inc. (some filings in the related-case record render the name "Conjupro") and an affiliated Chinese generics group, CSPC Pharmaceutical Group; they are a generic/505(b)(2) filer, not a product innovator in this space. This is therefore a classic brand-vs.-filer Hatch-Waxman/505(b)(2) pharmaceutical case rather than an NPE assertion.

Accused product and patents. The accused instrumentality is the "Proposed Conjuro Product" — an irinotecan liposome injection described in NDA No. 218923, filed under 21 U.S.C. § 355(b)(2) as a copy of Onivyde; infringement is pleaded under § 271(e)(2)(A) based on the NDA submission and the proposed labeling, with no element-by-element claim chart in the complaint. The complaint asserts a family of patents, of which the metadata patent U.S. 8,329,213 ("Liposomes useful for drug delivery") is the composition-of-matter backbone: a liposome whose interior aqueous space contains a sucrose octasulfate (SOS) salt of irinotecan — i.e., the copper-free, SOS-gradient loading technology that makes Onivyde's irinotecan retention and stability work (representative claim 11 is a composition claim to that SOS-irinotecan liposome). The co-asserted method patents build outward from that composition: U.S. 9,339,497 (methods of treating pancreatic cancer with liposomal irinotecan combination therapy — the NAPOLI-1 regimen), U.S. 9,717,724 (same family, claiming specific administration/infusion protocols for the combination), U.S. 10,980,795 (two-week-cycle dosing of liposomal irinotecan with 5-FU and leucovorin in metastatic pancreatic adenocarcinoma after gemcitabine progression), and U.S. 11,369,597 (later-issued method claims to patient populations and dosage regimens). Ipsen followed with a second D.N.J. suit, No. 1:24-cv-08723, asserting the then-newly-issued U.S. 12,059,497 ("Stabilizing camptothecin pharmaceutical compositions"), which claims a storage-stabilized SOS-irinotecan liposome defined by irinotecan:phospholipid ratio, drug:SOS gram-equivalent ratio, pH 7.25–7.5, and <20 mol% lyso-PC after six months at 2–8 °C — a deliberate hedge against design-arounds on the older composition claims.

Posture, venue and why it matters. The action was filed in August 2024 in the District of New Jersey (a related-case certification under L. Civ. R. 11.2/40.1 is dated August 23, 2024), assigned to Chief Judge Renée Marie Bumb with Magistrate Judge Matthew J. Skahill (the "(RMB)(MJS)" designation). Venue is not an accident: Ipsen Biopharmaceuticals is a New Jersey resident, D.N.J. is the home district for a large share of U.S. pharmaceutical patent filings, and its judges handle ANDA/505(b)(2) cases routinely and quickly — a real advantage when the practical leverage is the statutory 30-month stay of FDA approval triggered by the suit. The case is notable on three counts: (1) it is the first generic/505(b)(2) challenge to Onivyde's liposomal-irinotecan franchise, a product Ipsen acquired from Merrimack and has since expanded into first-line metastatic pancreatic cancer (the NALIRIFOX regimen), so the outcome sets the U.S. generic-entry date for a drug with growing oncology revenue; (2) it illustrates the modern pharma plaintiffs' playbook of stacking later-issued method and stability patents on top of an older composition patent, including serial suits as new patents issue; and (3) it is a U.S.–China pharma confrontation (CSPC-affiliated filer versus a French multinational), which makes it a bellwether for whether Chinese generic entrants can crack complex liposomal formulation IP. Parallel PTAB activity against the Ipsen liposomal-irinotecan family is plausible and would materially affect the litigation, but I was not able to verify any specific IPR numbers in this session.

Sourcing and open items

• Complaint analysis and patent-by-patent mapping: Ex Parte AI Lab, D.N.J. No. 1:24-cv-04991, Ipsen Biopharma Inc. v. Conjupro BioTherap Inc.; second suit on the '497 patent: No. 1:24-cv-08723.
• Related-case certification identifying "Ipsen Biopharmaceuticals, Inc., et al. v. Conjuro Biotherapeutics, Inc., et al., Civil Action No. 24-4991 (RMB)(MJS) (D.N.J.)" and reproducing U.S. 12,059,497: Ipsen v. CSPC filing.
• '213 patent bibliographic data (title, inventors, assignee Merrimack, app. 13/416,204, issued Dec. 11, 2012): SumoBrain record for US 8,329,213; Google Patents US8329213B2.
• Docket-number discrepancy (flag): the case metadata supplied to me says 3:24-cv-04991 (Trenton vicinage numbering), while the public filing materials I could reach for this dispute use 1:24-cv-4991 (Camden). Because the '213 patent and the Onivyde/NDA 218923 subject matter match exactly, I have treated them as the same matter, but I could not confirm the number, filing date, or assignment directly on PACER, and I could not verify whether the action was originally filed in Trenton and reassigned.
• Not verified in this session: the precise issue date of the original complaint; the exact claim(s) of the '213 patent charted (the complaint pleads "one or more claims"); the current status of any motion practice, claim construction, or settlement; whether a stay of NDA 218923 approval has been imposed; the '213 patent's priority date and expiration (needed for any generic-entry-date analysis); and any IPR/PGR filings against U.S. 8,329,213, 9,339,497, 9,717,724,

I'll research this case systematically, starting with the docket and patent identification.

Case identification (with a correction to the metadata)

The litigation behind this docket flag is Ipsen Biopharmaceuticals, Inc. and Ipsen Biopharm Ltd. v. Conjupro Biotherapeutics, Inc., CSPC Pharmaceutical Group Limited, and CSPC Ouyi Pharmaceutical Co., Ltd.

One correction worth recording: the D.N.J. docket number appearing in public sources is No. 1:24-cv-04991 (RMB)(MJS) — Camden vicinage, Chief Judge Renee Marie Bumb with Magistrate Judge Matthew J. Skahill — not "3:24-cv-04991." The defendants' own counterclaims plead the case as "Civil Action No. 24-4991 (RMB)(MJS)." The vicinage prefix in the case metadata appears to be an artifact of litigation-database normalization (Unified Patents/Google Patents, which is the source of the existing summary). Substance is otherwise consistent: D.N.J., filed 2024-04-15, §271(e)(2)(A) case over U.S. Patent No. 8,329,213. (Justia docket, companion case; KOTRA dispute record)

The patent. US 8,329,213, "Liposomes useful for drug delivery," inventors Keelung Hong, Daryl C. Drummond, and Dmitri Kirpotin, assigned to Ipsen Biopharm Ltd., from App. No. 13/416,204. Claim 1 is a liposome composition with an aqueous interior containing sucrose octasulfate polyanion; claim 11 is the commercially relevant claim — a liposome whose interior contains a sucrose octasulfate salt of irinotecan. This is the composition-of-matter backbone for Onivyde® (irinotecan liposome injection), Ipsen's metastatic pancreatic adenocarcinoma product. Orange Book expiry for the '213 is 2027-01-06; it sits in the same family as US 8,147,867 (2028-08-29). (DrugPatentWatch claims page; TheraRadar Onivyde landscape)

Data-quality caution: search results for "8,329,213" on PTAB document repositories surface a different '213 — a Japanese published application ("JPAP '213") used as prior art in semiconductor material-handling IPRs. Those are unrelated to this case and should not be attributed to Ipsen.

---

Chronological developments

1. Filing and the first complaint — 2024-04-15 (Dkt. 1)

Ipsen filed a single complaint asserting eight patents against Conjupro/CSPC: the '213 patent plus US 9,339,497; 9,364,473; 9,452,162; 9,492,442; 9,717,724; 10,980,795; and 11,369,597. The trigger was Conjupro's NDA No. 218923 for an irinotecan liposome injection product ("Proposed Conjupro Product"), filed with a Paragraph IV certification; the statutory basis is 35 U.S.C. § 271(e)(2)(A). The docket's nature-of-suit is "Patent – Abbreviated New Drug Application (ANDA)," though the described filing is a 505(b)(2) NDA — a distinction that matters for stay mechanics but not for §271(e)(2) jurisdiction.

Notable for evaluating the pleadings: the '213 counts are pleaded at a high level of generality. The complaint does not identify which claims are asserted and contains no element-by-element claim chart; it alleges that the product "meets or embodies all elements of one or more claims," with representative reference to claim 11 (sucrose octasulfate salt of irinotecan encapsulated by a lipid membrane). (Complaint analysis, 1:24-cv-04991)

2. Service, answer, and counterclaims — 2024-08 through late 2024

Service was effected by waiver: the CSPC entities and Conjupro each returned waivers sent 2024-08-28, with answers due 2024-10-28 (Dkts. 8–10 in 24-8723). Plaintiffs' appearances include William C. Baton, Sarah Ann Sullivan, and Alexander Lee Callo (Dkts. 3–5). Defendants did not merely answer — they pleaded counterclaims for declaratory judgment of invalidity, unenforceability, and non-infringement covering the "Initial Patents-In-Suit," which in their notice-letter recitation include the eight asserted patents plus US 8,147,867, 10,456,360, and 10,993,914. The counterclaims also plead an Orange Book listing dispute, tracking whether Ipsen caused the FDA to list (and has failed to delist) the patents against NDA No. 207793. (Counterclaim pleading; Answer/counterclaims, 24-8723)

3. Second suit and consolidation — 2024-08-23 / 2024-10-18

Ipsen filed a second action, No. 24-8723, on 2024-08-23, asserting newly issued US 12,059,497 ("Stabilizing Camptothecin Pharmaceutical Compositions," issued 2024-08-13, expiring 2036-10-15) — a formulation-stability patent requiring specified irinotecan:phospholipid ratios, SOS gram-equivalent ratios of 0.85–1.2, pH 7.25–7.5, and <20 mol% lyso-PC after six months at 2–8°C. On 2024-10-18, Magistrate Judge Skahill entered an order consolidating 24-8723 into 24-4991 for all purposes, with all future filings in 24-4991 and 24-8723 administratively terminated (Dkt. 12). (Justia docket; '497 complaint analysis)

This is the strategically significant move in the case: Ipsen is running a rolling-patent strategy, layering each newly issued Orange Book patent into a single consolidated action rather than litigating serially.

4. Third suit and consolidation — 2025-07-22 / 2025-08-21

Following issuance of US 12,364,691 (2025-07-22), Ipsen filed No. 25-13647, and that case was consolidated into 24-4991 on 2025-08-21. The counterclaims filed in the consolidated action confirm all three cases are proceeding as one. The '691 is a member of the '724/'597 method-of-treatment family (U-2091 use code, expiration 2033-06-12).

5. Pre-trial motions of substance

None verified. I found no public record of a Rule 12(b)(6) motion, a §1404(a) transfer motion, a motion to stay pending IPR, or a summary-judgment motion in this consolidated action. Given the posture (a §271(e)(2) case with DJ counterclaims and a rolling-patent consolidation through at least August 2025), the absence of dispositive motion practice is unsurprising; Hatch-Waxman cases typically proceed to bench trial on the patent merits after claim construction.

6. Claim construction (Markman)

Not verified — no evidence the case has reached Markman. No claim-construction order or hearing date surfaced. This is a genuine gap rather than a negative finding, and it is the single most important item to confirm on PACER. If a Markman has issued, the "scope question" flagged in the complaint-level analysis for the '213 — whether the claim-11 "sucrose octasulfate salt of irinotecan" limitation reaches a product formulated with residual/released species, and the numerical-ratio limitations in the '497 — is where the case would be won or lost.

7. Discovery milestones

Not verified. Nothing in the public record I could reach describes discovery cutoff, expert disclosures, fact-discovery disputes, or ESI orders. The only docket activity in the public snippets is service, appearances, and consolidation orders.

8. Trial, verdict, post-trial motions

None. No trial date, verdict, JMOL/new-trial motion, or fee motion is documented. The case remains pre-trial.

9. Final disposition / present posture

Pending and active. No settlement, dismissal, consent judgment, or appeal appears in the record. Third-party patent-landscape data current as of 2026-05-15 still lists the '691 and '213 among 14 Orange Book patents for Onivyde, consistent with live litigation. (TheraRadar) I could not confirm events after approximately August 2025; treat the 2026 posture as unresolved.

Stay clock: the '213's practical leverage here is the 30-month stay generated by the 2024-04-15

I'll research this case, starting with the docket and patent.

Counsel of Record for Plaintiffs — Ipsen Biopharmaceuticals, Inc. et al. v. Conjupro Biotherapeutics, Inc. et al.

Case identification (now verified — corrects the earlier unverified summary)

Sources: Paragraph IV certification/Onivyde case entry (paragraphfour.com); Ipsen's complaint in 24-8723 and Defendants' counterclaims, both of which recite C.A. No. 24-4991 (RMB)(MJS) and the consolidation orders (paragraphfour.com/wp-content/uploads/2024/04/njdc24cv8723A.pdf); Patsnap case record for 1:24-cv-08723 (reciting the consolidation order language); ai-lab.exparte.com complaint analysis for 1:24-cv-04991 (identifying the '213 patent as an asserted composition patent, claim 11 asserted against the "Proposed Conjupro Product").

---

Plaintiffs' counsel of record

The signature block on Ipsen's complaints, and the docket-derived counsel lists, show a two-tier structure typical of D.N.J. Hatch-Waxman practice: a New York boutique as substantive/lead counsel ("of counsel" on the signature block) and Saul Ewing LLP, Newark, as local counsel of record.

1. Brian V. Slater — lead counsel (substantive); listed "OF COUNSEL" on the complaint caption block

• Sterlington LLP, One World Trade Center, 85th Floor, New York, NY 10007 (212-433-2993); brian.slater@sterlingtonlaw.com
• Commercial/patent litigation boutique; Paragraph Four's docket summary names Slater as the plaintiffs' lead lawyer for this action ("Plaintiff Lawyer/Firm: Brian Slater/Sterlington"). I did not independently verify his specific prior ANDA wins from a firm bio — treat the "notable past cases" element as unconfirmed.

2. Gregory B. Sephton — of counsel (substantive)

• Sterlington LLP, New York (same address); gregory.septon@sterlingtonlaw.com
• Second-chair / brief-writing role in the Ipsen ANDA program (also appears on the 24-8723 complaint).

3. Charles M. Lizza — local counsel of record (New Jersey); senior member of the D.N.J. team

• Saul Ewing LLP, One Riverfront Plaza, Suite 1520, Newark, NJ 07102 (973-286-6700); clizza@saul.com
• Listed first on the complaint signature block and in Patsnap's docket-derived counsel list; a long-tenured Newark IP litigator who is a recurring local counsel in D.N.J. ANDA matters.

4. William C. Baton — local counsel of record (New Jersey)

• Saul Ewing LLP, Newark; wbaton@saul.com
• Co-signatory on the complaints; one of the most frequent D.N.J. Hatch-Waxman local counsel.

5. Sarah A. Sullivan — local counsel team (associate)

• Saul Ewing LLP, Newark; sarah.sullivan@saul.com

6. Alexander L. Callo — local counsel team (associate)

• Saul Ewing LLP, Newark; alexander.callo@saul.com

In-house: No Ipsen in-house attorney appears as counsel of record on the docket entries I reviewed. Ipsen's legal function is not listed as appearing; do not assume an in-house appearance without checking the docket.

---

Important caveats

• What I actually reviewed: the signature blocks and recitals in (a) Ipsen's August 23, 2024 complaint in 24-8723, (b) Defendants' answers/counterclaims in 24-8723 and 25-13647, and (c) secondary docket-derived records (Patsnap, Paragraph Four, ExParte's complaint analysis). All of these identify the same six attorneys as Ipsen's counsel and cross-reference 24-4991. I did not pull the 24-4991 docket sheet itself from PACER, so I cannot confirm (i) that no additional attorney has since entered an appearance (e.g., a later pro hac vice admission or a substituted firm), or (ii) the exact pro hac vice status of Slater and Sephton. Pro hac vice applications for the Sterlington lawyers are likely on the 24-4991 docket but I did not see them.
• No sealing issue identified as to counsel; the complaints and answers are public. Confidential Access materials under the Conjupro Notice Letter would be sealed, but that does not affect counsel identification.
• Do not confuse the Ipsen-side and Conjupro-side teams. Defendants are represented by Fox Rothschild LLP (Gerard P. Norton, Jonathan R. Lagarenne, Paul W. Kalish, Joe G. Chen, Jonathan J. Madara — Princeton, NJ; Howard S. Suh and Erxin Du, New York) with separate IPR counsel. Those names should not be attributed to plaintiffs.
• Related PTAB activity (context, not '213-specific): Conjupro filed IPR 2025-00505 on U.S. 11,344,552 (instituted, oral argument set 5/19/26); Apotex filed IPR 2025-01531 on the '552 patent (joined). I found no IPR Challenging the '213 patent in the sources reviewed — so state that as "none located," not "none exists."
• '213 significance: it is the earliest-expiring asserted patent in the consolidated actions (est. Jan. 6, 2027 per Paragraph Four's Orange Book listing), so it is the near-term gating patent for Conjupro's NDA approval date even though the later '497-family patents drive the 2033–2036 runway.

I'll start by identifying the case caption and parties, since the existing summary leaves those unverified.

The Chrome Hearts result is a different court's docket number. Let me pin down what US 8,329,213 covers and search the patent-specific litigation data.

Short answer

I could not verify a single defense attorney of record, and I won't guess at names. My searches hit a hard step limit before I could pull the docket, and every free-text hit for "24-cv-04991" resolved to unrelated cases in other courts. Below is what is actually verified, what the number collision is, and exactly where the counsel names will be found.

What is verified (and what the number is not)

Two important corrections to the existing summary:

• The docket number collides with unrelated cases. Web hits for "24-cv-04991" return Chrome Hearts LLC v. [e-commerce sellers] (GBC, trademark, N.D. Ill.) and Skillz Platform Inc. v. Voodoo SAS (No. 1:24-cv-04991-VSB, S.D.N.Y., defense counsel Harold K. Gordon of Jones Day). Neither is a D.N.J. patent case; neither should be imported into this file. The Jones Day/Voodoo name in particular is exactly the kind of false positive that would corrupt a counsel list — I am explicitly not using it.
• The filing date is not reconciled. D.N.J. Trenton-vicinage numbers ending in 04991 were issued in roughly mid-2024, whereas the patent-specific database shows an April 15, 2024 filing. Either the D.P.W. row is a companion/earlier Ipsen case or one of the two data points is stale. This needs to be settled from the docket itself before any counsel attribution.

Best-supported inference (flagged as inference, not finding)

Given the assignee and the subject matter, the likely plaintiff is Ipsen Biopharm Ltd., and '213 (liposomal irinotecan / Onivyde-lineage delivery claims) is the type of patent asserted against an ANDA or 505(b)(2) filer. If that holds, the defendants are generic or specialty pharma companies, and the defense side will almost certainly be staffed as: national Hatch-Waxman counsel + mandatory D.N.J. local counsel under L. Civ. R. 101.1 + in-house IP counsel named on the Rule 7.1 disclosure. That is a structural expectation about how such a case is defended — it is not evidence of who was retained here, and I am not supplying names to fill those slots.

Where the answer actually lives (ordered retrieval plan)

1. PACER / CourtListener RECAP for D.N.J. 3:24-cv-04991 — pull the docket sheet and read the first ~15 entries. The universe of papers that names defense counsel:
   • D.E. 1 complaint (caption gives the defendant's full corporate name, which is what you need to search firms against);
   • each defendant's NOTICE of Appearance;
   • Rule 7.1 corporate disclosure statement — this is the single highest-yield document, since it is signed by counsel with firm, address, phone, and email (the Skillz/Voodoo hit above is a textbook example of that format);
   • any waiver of service or answer/Rule 12 motion;
   • a scheduling order or Rule 16 pretrial order, which lists "Counsel of Record" for both sides and identifies lead trial counsel;
   • the Joint Claim Construction and Prehearing Statement (L. Pat. R. 4.3), which designates lead and backup counsel in a patent case.
2. D.N.J. ECF Case Locator / CM/ECF — confirm the assigned judge and magistrate, since vicinage (Trenton, 3:xx) tells you which local-counsel pool appears most often.
3. Firm press releases and "representing" announcements — search "Ipsen Biopharm" AND "8,329,213", and "Ipsen" AND "Onivyde" AND "ANDA" AND 2024, targeting Law360, Reuters Legal, and the Hatch-Waxman firm blogs that routinely post "we represent X in D.N.J. litigation over U.S. Patent No. 8,329,213."
4. PTAB side-channel — if any IPR petition was filed against '213, the petition's mandatory real-party-in-interest and related-matter disclosures name the district court case, the parties, and lead counsel for petitioner. This is often the fastest way to get defense-side counsel without PACER.
5. Sealing check — if the complaint was filed with a motion to seal (common in ANDA cases where the complaint attaches the Paragraph IV notice letter), the caption and appearances are still public; only exhibits are sealed. If a defendant has been served but has not yet appeared, there may be no defense counsel of record at all, which is a legitimate finding rather than a gap.

What I will not do

I am not going to produce a table of attorney names, firms, office cities, and "notable past cases" for this docket, because I have zero verified sourcing for any of those fields in 3:24-cv-04991. Inventing a plausible-looking Jones Day or D.N.J.-local roster is precisely the failure mode this assignment warns against, and the number collision above shows how easily a wrong name enters the record.

Bottom line: defense counsel of record in D.N.J. 3:24-cv-04991 is unverified. The verified anchor points are patent '213, Ipsen Biopharm as assignee, and a D.N.J. § 271 action — enough to run a targeted PACER pull and a Rule 7.1/disclosure-statement read, which should yield the complete counsel list in a single docket session. If you can run that PACER query or paste the docket sheet text, I'll build the annotated counsel table from it immediately.