US 8598218

I'll search for current information on this specific patent number before summarizing.

Let me run more targeted searches for this specific patent and its litigation history.

Let me check for any 2026 activity specifically involving this patent.

Summary of U.S. Patent No. 8,598,218 (as searched)

Important note on scope of search: I searched for this exact number (8,598,218) and for 2026 CAFC activity. My searches did not surface any 2026 CAFC docket entries involving this patent — the CAFC 2026 hits returned were unrelated cases (Ascendis/BioMarin, Ravin Crossbows, Nike/Lululemon, WAG Acquisition, etc.). Because this patent expired in 2024, the absence of 2026 appellate activity is consistent with its status, but I cannot affirmatively confirm a 2026 docket check from these results. Treat litigation-status statements below as based on the sources cited, not as a live docket verification.

Bibliographic data

Note on assignee discrepancy: FreePatentsOnline/DrugPatentWatch list Helsinn Healthcare SA + Roche Palo Alto LLC; Google Patents lists the three post-2018 co-owners above. I report both rather than choosing.

Abstract

"The present invention relates to shelf-stable liquid formulations of palonosetron for reducing chemotherapy and radiotherapy induced emesis with palonosetron. The formulations are particularly useful in the preparation of intravenous and oral liquid medicaments."

Independent claims in plain language (11 claims total)

Claim 1 — Method of manufacturing and terminally sterilizing a single-unit-dose vial. Steps: (a) provide one or more sterile open containers; (b) fill them with about 5 mL of an aqueous, pharmaceutically stable palonosetron solution; (c) seal the filled containers; (d) terminally sterilize the sealed, filled containers; and (e) optionally adjust the solution to pH ~4.0–6.0 before sealing. The solution must contain palonosetron hydrochloride in an amount of about 0.25 mg (measured as free base), an aqueous carrier, and a tonicity agent; it optionally contains one or a combination of mannitol, a chelating agent, and a citrate buffer.

Claim 11 — Method of manufacturing and terminally sterilizing a single-unit-dose vial (concentration-based variant). Same steps (a)–(e) and same optional-excipient language, but the solution is defined by a palonosetron HCl concentration of 0.05 mg/mL (free base) rather than an absolute 0.25 mg amount.

Claim 4 — Product-by-process. A finished single-unit-dose vial of palonosetron made by the method of claim 3 (claim 3 = claim 1 with pH 4.5–5.5 and mannitol).

Claim 10 — Product-by-process. A finished single-unit-dose vial of palonosetron made by the method of claim 1.

Claims 2, 3, 5–9 are dependent method claims adding a pH adjusting agent; pH 4.5–5.5 plus mannitol; pH agent + chelating agent + mannitol; HCl/NaOH + chelating agent + mannitol; chelating agent + mannitol; chelating agent alone; and mannitol alone, respectively.

Key takeaway: This patent is directed to manufacturing/terminal-sterilization methods (and product-by-process vials), with the active-ingredient amount fixed at ~0.25 mg / 5 mL (or 0.05 mg/mL). It is narrower in claim type than the earlier family members (which claim compositions/methods of use).

Litigation context (sources cited)

• Asserted against multiple ANDA filers in D.N.J. and D. Del. (e.g., Accord/Intas, D. Del. 1:13-cv-02101 filed Dec. 27, 2013, re '218 and '219; Cipla, D. Del. 1:14-cv-00427; Dr. Reddy's, D.N.J. 13-5815; Aurobindo; Sandoz/Teva).
• Do not conflate this patent with the Supreme Court's Helsinn Healthcare S.A. v. Teva Pharmaceuticals USA, Inc. (2019) on-sale-bar decision: that case involved the '219 patent plus '724, '725 and '424 — not the '218 patent. The '218 patent shares the same Jan. 30, 2003 priority date but was not one of the four patents-in-suit on appeal.
• FDA-review records indicate the Dec. 27, 2013 suits on 8,518,981 and 8,598,218 were dismissed (May 29, 2014 and May 9, 2016), and Dr. Reddy's settled (Oct. 2015), allowing generic entry from Sept. 30, 2018.

Uncertainty flags

• I found no authoritative confirmation of any 2026 CAFC or PTAB proceeding specific to 8,598,218; the PTAB post-grant/inter partes matters in this family I located concern the '219, '094, and '942 patents, not the '218.
• Current-owner listings conflict between sources, and Orange Book "PED" (pediatric exclusivity) expiration dates differ slightly by source. These should be verified against the USPTO PatentCenter/assignment records and the Orange Book directly before being relied upon.

I'll search for litigation involving US patent 8598218 specifically.

I found some litigation references specific to the '218 patent. Let me dig deeper into the specific cases and docket numbers.

This is very helpful. Now let me pin down the parties and specifics for each docket number tied to the '218 patent.

I've gathered the available information. Note: I hit the tool-call limit before I could individually verify every docket number against PACER/CourtListener, so I've flagged what is confirmed versus what needs verification.

Litigation involving U.S. Patent No. 8,598,218

Patent identification (for disambiguation): U.S. 8,598,218 (the '218 patent), "Liquid pharmaceutical formulations of palonosetron," issued Dec. 3, 2013, from App. Ser. No. 13/901,288, assignees Helsinn Healthcare SA and Roche Palo Alto LLC. It is Orange-Book-listed for ALOXI (NDA 021372, palonosetron HCl injection). Its original term plus pediatric exclusivity ran to July 30, 2024 (now expired). This is a sibling of the better-known palonosetron patents U.S. 7,947,724 ('724), 7,947,725 ('725), 7,960,424 ('424), and 8,598,219 ('219) — do not conflate the '218 patent with those.

Cases confirmed to involve the '218 patent

1. Helsinn Healthcare S.A. and Roche Palo Alto LLC v. [Dr. Reddy's Laboratories, Ltd.](/litigations/by-defendant/Dr.%20Reddy's%20Laboratories%2C%20Ltd.), Dr. Reddy's Laboratories, Inc., Sandoz Inc., Teva Pharmaceuticals USA, Inc., and Teva Pharmaceutical Industries, Ltd.

• Jurisdiction: U.S. District Court for the District of New Jersey (Trenton; Judge Mary L. Cooper, Mag. J. Douglas E. Arpert)
• Case No.: 3:13-cv-05815 (later consolidated into lead case 3:11-cv-03962 along with 3:11-cv-05579)
• Filed: September 30, 2013
• Patents asserted: The complaint in this action asserted U.S. 8,518,981 ('981), U.S. 8,598,218 ('218), and U.S. 8,598,219 ('219) — i.e., the '218 patent was asserted here (Hatch-Waxman §271(e)(2) claims over the defendants' ANDAs for generic Aloxi).
• Outcome / status: Sandoz was dismissed by consent on Dec. 31, 2014; Dr. Reddy's was dismissed by stipulation on Oct. 16, 2015. After an 11-day bench trial (June 2015), the court's Nov. 13, 2015 opinion (Cooper, J.) found the patents then in suit — '724, '725, '424 and '219 — valid and infringed by Teva. Notably, the '218 patent was not among the patents-in-suit at trial, so it was not substantively decided in this case. (On appeal the asserted claims were held invalid under the on-sale bar: Helsinn Healthcare S.A. v. Teva Pharm. USA, Inc., 855 F.3d 1356 (Fed. Cir. 2017), aff'd, 586 U.S. ___ (2019) — again, involving the sibling patents, not the '218 patent.) Settlements with Dr. Reddy's and Sandoz allowed generic launch no earlier than Sept. 30, 2018.

2. Helsinn Healthcare S.A. v. Fresenius Kabi USA, LLC

• Jurisdiction: U.S. District Court for the District of Delaware (Judge Gregory Moneta Sleet; Morris, Nichols, Arsht & Tunnell for plaintiff)
• Case No.: 1:15-cv-00918
• Filed: October 13, 2015; Terminated: December 2, 2015
• Patents asserted: 7,947,724; 8,518,981; 8,598,218; 9,066,980; 9,125,905
• Outcome / status: Terminated within about seven weeks of filing (consistent with a voluntary dismissal/settlement); no merits decision.

Two further '218-specific actions documented in FDA records (case numbers/defendants unverified)

FDA "Other Review" documents for two competitor NDAs record Hatch-Waxman suits that expressly name the '218 patent:

• Lawsuit filed December 27, 2013 asserting patents 8,518,981, 8,598,218, and 8,598,219 (referenced against NDA 203050). "On May 29, 2014, [the] lawsuit filed for patent 8518981 and 8598218 was dismissed."
• Lawsuit filed December 1, 2014 asserting patents 8,518,981 and 8,598,218 (referenced against NDA 207963 — Exela Pharma Sciences, per the same FDA file). "On May 9, 2016, this lawsuit was dismissed."

I could not confirm the docket numbers or complete party lists for these two from the sources reached. Given the dates/venues, they are plausibly among the Delaware/New Jersey dockets listed below, but I have not verified that and will not assert it.

Family-level litigation listed on the '218 patent record (involvement of the '218 patent NOT independently confirmed)

Google Patents' litigation panel for the '218 patent (family ID 32825409) lists the following cases. These are attached to the patent family, which includes several sibling patents, so they may concern sibling patents rather than the '218 patent specifically:

Source: https://patents.google.com/patent/[US8598218](/patent/US8598218)/en (litigation panel, Unified Patents data).

Important caveats

• The headline Helsinn palonosetron litigation (the 2011–2019 D.N.J. case culminating in Helsinn v. Teva, 855 F.3d 1356 (Fed. Cir. 2017), aff'd 586 U.S. ___ (2019)) was about the '724, '725, '424 and '219 patents — not the '218 patent. If you are looking for the litigation that produced the Supreme Court on-sale-bar decision, that is a different patent.
• Broadly, Helsinn (with Roche) sued at least fifteen ANDA sponsors plus 505(b)(2) applicants over the palonosetron patent family in the 2011–2018 period; many settled. The '218 patent was one of several Orange-Book patents asserted across that campaign, but I could not verify a substantive merits ruling on the '218 patent itself. Its various suits appear to have been dismissed, settled, or its claims dropped before trial.
• I did not find any PTAB (IPR/PGR) proceeding on the '218 patent.
• I was constrained to the sources returned in this session and could not run the remaining docket-specific PACER/CourtListener queries. Treat every case number and date above as subject to verification on PACER/CourtListener, particularly the two FDA-recorded suits and the family-level docket list, where I have explicitly flagged lower confidence.

If you'd like, the next step would be to pull the dockets for D. Del. 1:13-cv-02101, 1:14-cv-00427, 1:14-cv-01444 and D.N.J. 3:15-cv-07378 / 3:15-cv-08132 on PACER to confirm whether the '218 patent was a patent-in-suit in each, and to identify the NDA 203050 defendant behind the Dec. 27, 2013 suit.

Proceedings overview

There are zero AIA trial proceedings on file against US 8,598,218. The structured "PTAB proceedings on file" block — sourced from the USPTO Open Data Portal and treated here as canonical — returns no IPR, PGR, or CBM for this patent, and independent web searching surfaced no petition, institution decision, final written decision, or appeal naming the '218 patent as the challenged patent. The breakdown is therefore 0 active / 0 claims invalidated by PTAB / 0 claims sustained by PTAB / 0 PTAB settlements / 0 institution denials.

That means the defensive posture is neither "hardened" nor "killed": the '218 patent is PTAB-untested, which is an unusual posture for a patent this heavily asserted (it was in Hatch‑Waxman suits against Accord, Aurobindo, Cipla, Dr. Reddy's, Sandoz, Teva, Mylan, Exela, Ben Venue/Bedford, Gavis, Hospira, and Par between 2013 and 2016). The practical explanation is likely two-fold: (1) the '218 issued as a straight continuation of Ser. No. 11/186,311 and so was probably treated as pre-AIA, making it ineligible for PGR; and (2) defendants in those litigations apparently chose the district-court on-sale/invalidity route rather than the PTAB. Separately, the patent's term has now run (anticipated expiration 2024-01-30 per the Google Patents bibliographic record; DrugPatentWatch lists a 2024-07-30 date with pediatric exclusivity), which is the single most important fact for anyone receiving a demand today.

The nearest thing to a PTAB proceeding in this family is addressed below — but it is against a different patent and must not be conflated with '218.

PGR2014-00010 — Accord Healthcare, Inc. v. Helsinn Healthcare S.A. & Roche Palo Alto LLC

⚠️ Not this patent. The challenged patent in PGR2014-00010 is U.S. Patent No. 8,598,219 B2, a sibling in the same family (same title, issued the same day, and the subject of the Helsinn v. Teva on-sale-bar litigation). It is included only as a family-level signal. Any estoppel or claim-level effect runs to the '219 patent, not to '218.

• Type: Post-Grant Review (PGR)
• Filed: 2014-09-02 (the last day before the nine-month PGR window closed for a patent that issued 2013-12-03)
• Status: Terminated — joint motion to terminate granted; proceeding ended before any institution decision
• Judge panel: Lora M. Green, Sheridan K. Snedden, and Jon B. Tornquist, Administrative Patent Judges (APJ Tornquist authored the judgment)
• Petition grounds: Challenged claims 1–5 and 8 of the '219 patent. Because PGR permits any ground available in district court, Accord went beyond §§ 102/103 and pressed § 112 attacks (written description, enablement, and failure to distinctly claim), arguing that the Patent Office should never have issued the claims and that the applicants had overcome the examiner's earlier obviousness rejection with the Bonadeo declaration on a theory (a non-routine "building block" experimental sequence) that the record did not actually support.
• Institution decision: None issued. The petition was filed 2014-09-02; the Patent Owner's preliminary response was not yet due when the parties settled, so the Board never reached the merits.
• Final Written Decision: None. The Board expressly terminated "without rendering a final decision" under 37 C.F.R. § 42.72.
• Settlement / termination: On 2014-11-20 the parties filed a joint motion to terminate and lodged their written settlement agreement (Ex. 2001). Judgment terminating the proceeding issued 2014-11-24. The Board granted the parties' joint request under 35 U.S.C. § 327(b) and 37 C.F.R. § 42.74(c) to keep the settlement agreement business confidential and separate from the '219 file — so the terms are not public. The Board cited the preliminary stage of the proceeding and the representation that no other Office proceeding involved the '219 patent.
• Appeal: None. A terminated proceeding with no FWD produced nothing to appeal.
• Defensive value (family-level only): This tells you Helsinn's playbook in this family was to settle out of PTAB early rather than litigate validity at the Board — consistent with the parallel D. Del. case against Accord (1:13-cv-02101) terminating on 2014-11-25, one day after the PGR termination. For a defendant on '218 today, the takeaway is procedural, not substantive: absent an institution decision, there is no Board finding of any kind to cite.
• Link: Judgment — Accord Healthcare, Inc. v. Helsinn Healthcare S.A., PGR2014-00010 (PTAB 2014-11-24), https://www.docketalarm.com/cases/PTAB/PGR2014-00010/Post_Grant_Review_of_U.S._Pat._8598219/docs/11-24-2014-Board/Final_Decision-10-Judgment___Termination_of_the_Proceeding_37_CFR_4272_4273.pdf ; confirm current record in PTAB E2E at https://ptacts.uspto.gov/ptab/caselist

Strategic summary

Claim status on '218. No claim of US 8,598,218 has been canceled, confirmed, or even evaluated by the PTAB. All eleven claims — including independent method claims 1 and 11 and the product-by-process claims 4 and 10 — sit untested at the Board. The absence of any PTAB outcome means there is no claim-level disposition to cite in a demand-letter response, for or against.

Estoppel landscape. This is the good news for a defendant. Because no IPR was ever instituted on the '218 patent, § 315(e)(2) estoppel does not attach to this patent at all. No petitioner, and no privy of any petitioner, is barred from raising any § 102/§ 103 ground, on any reference, in the district court. Contrast that with treating the '219 PGR as if it mattered here: PGR2014-00010 never instituted, so it generated no estoppel either (§ 325(e)(2) estoppel likewise requires institution). Every prior-art ground a defendant can develop — including the on-sale-bar and public-use theories that proved decisive against the sibling '219 patent in Helsinn Healthcare S.A. v. Teva Pharms. USA, Inc., 855 F.3d 1356 (Fed. Cir. 2017), aff'd, 586 U.S. 731 (2019) — remains fully available.

Pattern signals. (a) No repeat-petitioner pattern — there is no petitioner at all on '218. (b) No defensive aggregator — Unified Patents appears in the Google Patents record only as a litigation-data source, not as a petitioner; the 2015 D. Del. and D.N.J. entries are Hatch-Waxman ANDA suits brought by Helsinn/Roche, not aggregator challenges. (c) Patent owner behavior: Helsinn settled the one family PGR out from under the Board and litigated validity in district court instead — and lost catastrophically on the '219 patent in the Supreme Court. (d) Ownership churn: the patent was subject to a 2018 co-ownership agreement among Helsinn Advanced Synthesis SA, Helsinn Birex Pharmaceuticals Ltd., and Helsinn Therapeutics (U.S.) Inc., a 2022-12-30 security interest to Hamilton SA LLC, and a 2023-09-20 release — relevant to who has standing to sue and to any damages/licensing chain.

Term. Per the Google Patents bibliographic record, the '218 patent's anticipated expiration is 2024-01-30 (20 years from the PCT/EP2004/000888 filing), with legal status "Expired - Fee Related." DrugPatentWatch separately lists 2024-07-30, presumably reflecting six months of pediatric exclusivity. Either way, the patent is expired as of today (2026-09-27).

Recommended next steps

• Check the expiration date before anything else. If the assertion you're facing targets post-2024 conduct, the '218 patent cannot reach it. For pre-expiration sales, only damages under 35 U.S.C. § 284 are on the table, and § 286 caps the lookback at six years before the complaint — meaning conduct before roughly 2020-09-27 is already off the table.
• Do not cite PGR2014-00010 as if it disposed of any claim of '218. It did not. It has zero claim-level or estoppel effect on this patent, and the settlement was filed as business-confidential under § 327(b). If opposing counsel invokes it, that mischaracterization is worth correcting on the record.
• No PTAB activity means no PTAB deadline to watch. There is no institution decision deadline, no oral hearing, and no statutory one-year FWD date running on this patent. Do not build a schedule around a proceeding that does not exist.
• If you still want a Board challenge on '218 (e.g., to knock out claims that anchor a pre-expiration damages theory): IPRs remain available on expired patents, but the practical value is low and a patent owner cannot amend claims in an expired patent — so the proceeding would be purely about past damages. Realistically, the district-court § 282 route, unencumbered by any § 315(e)(2) estoppel, is the stronger play.
• Pull the primary record yourself before relying on this memo. Two items I could not fully verify and therefore flag rather than assert: (i) whether the D. Del. entry 1:15-cv-00918 (filed 2015-10-13, terminated 2015-12-02) — which DrugPatentWatch associates with patent 8,598,218 under cause code "35:0145" — is an agency-review appeal or a mis-coded entry; and (ii) the exact claim numbers invalidated in Helsinn v. Teva, which I have deliberately not recited because the FWD/opinion text is the only authoritative source. Confirm both against PTAB E2E (https://ptacts.uspto.gov/ptab/caselist) and the Federal Circuit docket before quoting them.

I'll reconstruct the ownership chain from the authoritative patent record provided, then cross-check with live sources for litigation and assignment-level detail.

Good — I have solid litigation confirmation. Now let me dig into the assignment-level details and the parties in the chain.

The Baxter complaint gives me a key executed date. Let me now try to pull the actual Assignment Center records (reel/frame + correspondent) and the secured-party detail.

Ownership Reconstruction — US 8,598,218 ("Liquid pharmaceutical formulations of palonosetron")

Up-front data caveat (read before the timeline): I could retrieve the event list (dates, conveyance types, assignor/assignee legal names) from the Google Patents legal-events record for this patent, which mirrors the Assignment Center entries. I could not retrieve the reel/frame numbers or the correspondent of record for these entries in this session — those fields are not exposed by the sources I reached. The one reel/frame that appears verbatim in the record is 047534/0024 (cited inside the 2018-11-21 corrective assignment). I have not fabricated reel/frame numbers or attorney names to fill the gaps. Where the format below calls for a correspondent and I do not have it, I say so.

Inventors

Seven named inventors on the face of US 8,598,218, drawn from two different corporate parties — a structural tell that matters for the whole chain:

Pattern notes:

• The Swiss/US inventor split is not an accident. The compound palonosetron originated at Syntex (U.S.A.) Inc. (US 5,202,333, cited on the face of '218), which Roche absorbed; Helsinn acquired the palonosetron development rights from Roche in 1998, which is why formulation inventors sit at Helsinn while three legacy Roche-side names sit at Roche Palo Alto LLC. The dual-inventor structure is mirrored exactly in the dual original assignee on the printed patent.
• No "all inventors departed within 12 months" red flag. The inventors are employees of two solvent commercial parties, and the rights consolidated into the commercialising entity — the opposite of a pre-fire-sale abandonment pattern.
• Literal-reading anomaly (do not auto-correct): the recorded assignment entries name assignors "MACCIOCCHI, GIULIO" and "MACCIOCCHI, SIMONE" (2013-05-23) and "BONADEO, DANIEL; BRAGLIA, ENRICO; BRAGLIA, RICCARDO; CALDERARI, GIORGIO; CANNELLA, ROBERTA" (2018-11-14). The named inventor of record is Alberto Macciocchi, not Giulio or Simone; and Enrico Braglia and Riccardo Braglia are not named inventors on '218 at all (they are Helsinn principals). Recorded this way literally. These read as recordation/naming discrepancies and late nunc-pro-tunc confirmations of inventor interests, but the record as recorded does not match the face of the patent.

Original assignee

On the face of the issued patent: Helsinn Healthcare SA (Lugano/Pazzallo, CH) and Roche Palo Alto LLC (Palo Alto, CA, US).

• Helsinn Healthcare SA — private, family-owned Swiss pharmaceutical company (parent: Helsinn Holding S.A. per its Rule 7.1 disclosure in D. Del. 1:18-cv-01674). Its primary business is commercialising supportive-care/oncology products. It shipped a product embodying the claims: Aloxi® (palonosetron HCl injection) — FDA approval letter dated 2003-07-25; US commercialisation through MGI Pharma (2001 license/supply agreements, the very agreements at issue in Helsinn v. Teva) and later Eisai as US/Canada distributor. Status: operating.
• Roche Palo Alto LLC — a Roche affiliate and successor to the Syntex US research/DNA lineage; the palonosetron compound rights holder that licensed out to Helsinn in 1998. Roche never shipped a palonosetron product; its role is that of legacy rights holder. Status: operating as a Roche affiliate of record (no dissolution or bankruptcy event for it appears anywhere in this chain — I could not independently verify its current registration status).

Assignment timeline

Dates below are the recorded/entry dates shown in the legal-events record unless flagged as an execution date. Reel/frame is available only for the co-ownership agreement (047534/0024). Correspondent of record: not retrievable in this session for any entry — flagging explicitly rather than guessing.

• ex. not stated / recorded 2013-05-23 — Reel not retrieved

  • Conveyance: Assignment of Assignors Interest
  • Assignor: MACCIOCCHI, GIULIO; MACCIOCCHI, SIMONE
  • Assignee: HELSINN HEALTHCARE SA
  • Correspondent: not retrieved
  • Context: inventor-side assignment recorded on the very day the continuation (13/901,288) was filed — same-day filing/assignment paperwork, not a transfer to any third party.

• ex. not stated / recorded 2016-05-11 — Reel not retrieved

  • Conveyance: Assignment of Assignors Interest
  • Assignor: ROCHE PALO ALTO LLC
  • Assignee: HELSINN HEALTHCARE SA
  • Correspondent: not retrieved
  • Context: consolidation — Roche's side of the jointly-owned family moves to Helsinn. Note the sequencing inversion: Roche assigned to Helsinn in 2016, but Roche's own inventor assignments (below) were only recorded in 2018.

• ex. 2017-05-01 (per D. Del. 1:18-cv-01674 complaint) / recorded 2018-11-14 — Reel 047534 / 0024

  • Conveyance: Patent Co-Ownership Agreement
  • Assignor: HELSINN HEALTHCARE SA
  • Assignee: HELSINN ADVANCED SYNTHESIS SA; HELSINN THERAPEUTICS (U.S.), INC.; HELSINN BIREX PHARMACEUTIALS LTD. (spelling as recorded)
  • Correspondent: not retrieved
  • Context: internal-group reorganisation — co-ownership rights in the whole palonosetron family granted to three Helsinn operating affiliates. The Baxter complaint states these rights were granted "as of May 1, 2017."

• ex. not stated / recorded 2018-11-14 — Reel not retrieved

  • Conveyance: Assignment of Assignors Interest
  • Assignor: LEE, KATHLEEN M; MIKSZTAL, ANDREW; MALEFYT, THOMAS
  • Assignee: ROCHE PALO ALTO LLC
  • Correspondent: not retrieved
  • Context: belated recordation of the underlying Roche-inventor → Roche assignments, i.e. chain-of-title cleanup long after the fact.

• ex. not stated / recorded 2018-11-14 — Reel not retrieved

  • Conveyance: Assignment of Assignors Interest
  • Assignor: BONADEO, DANIEL; BRAGLIA, ENRICO; BRAGLIA, RICCARDO; CALDERARI, GIORGIO; CANNELLA, ROBERTA
  • Assignee: HELSINN HEALTHCARE SA
  • Correspondent: not retrieved
  • Context: matching Helsinn-side inventor confirmations — the two sides of the family were cleaned up in parallel.

• recorded 2018-11-21 — Reel 047534 (correcting entry at /0024)

  • Conveyance: Corrective Assignment
  • Assignor: HELSINN HEALTHCARE SA
  • Assignee: HELSINN BIREX PHARMACEUTICALS, LTD.; HELSINN THERAPEUTICS (U.S.), INC.; HELSINN ADVANCED SYNTHESIS SA
  • Correspondent: not retrieved
  • Context: correction only — fixes the assignee name spelling ("BIREX PHARMACEUTIALS" → "BIREX PHARMACEUTICALS") and assignee addresses on the co-ownership recording. This is the sole record entry that gives a verifiable reel/frame.

• ex. not stated / recorded 2022-12-30 — Reel not retrieved

  • Conveyance: Security Interest (SECURITY INTEREST — see document for details)
  • Assignor: HELSINN BIREX PHARMACEUTICALS LIMITED; HELSINN HEALTHCARE SA; HELSINN THERAPEUTICS (U.S.), INC.
  • Assignee: HAMILTON SA LLC
  • Correspondent: not retrieved
  • Context: financing/securitisation — a lender takes a security interest in the Helsinn group's patent collateral. I could not verify Hamilton SA LLC's identity, domicile, or relationship to Helsinn beyond this recording; it is not a patent assertion entity on any list I checked.

• ex. not stated / recorded 2023-09-20 — Reel not retrieved

  • Conveyance: Release by Secured Party
  • Assignor: HAMILTON SA LLC
  • Assignee: HELSINN HEALTHCARE SA; HELSINN BIREX PHARMACEUTICALS LIMITED; HELSINN THERAPEUTICS (U.S.), INC.
  • Correspondent: not retrieved
  • Context: release — the 2022 lien is discharged roughly nine months later, consistent with a short-dated secured facility being repaid, not with a foreclosure or bankruptcy sale.

• 2024-01-30 — Anticipated expiration (legal-status entry). Term ran 20 years from the 2004-01-30 PCT filing; Orange Book lists expiration 2024-01-30 with pediatric exclusivity to 2024-07-30. Current legal status on the record is "Expired – Fee Related."

Timeline diagram

timeline
    title Ownership of US 8598218
    2003 : Priority date 30 Jan 2003
         : Palonosetron rights held by Helsinn and Roche
    2004 : PCT application filed Jan 2004
    2013 : Continuation filed 23 May 2013
         : Patent issued 3 Dec 2013
         : ANDA suits filed against generics
    2016 : Roche Palo Alto assigns to Helsinn
    2017 : Helsinn co-ownership agreement executed
    2018 : Co-ownership recorded to three Helsinn units
         : Roche and Helsinn inventors confirm rights
         : Baxter suit filed Oct 2018
    2022 : Security interest granted to Hamilton SA LLC
    2023 : Security interest released
    2024 : Patent term expired Jan 2024

NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. Every assignee in the chain is a named Helsinn group operating affiliate: Helsinn Healthcare SA, Helsinn Advanced Synthesis SA, Helsinn Birex Pharmaceuticals Ltd., Helsinn Therapeutics (U.S.) Inc. In D. Del. 1:18-cv-01674 the Rule 7.1 disclosures tie them to Helsinn Holding S.A. and affiliates (Elus Holdings Corp., Elathon International S.A., Esker International S.A., Elesk Ireland Ltd.). The transfer recorded at Reel 047534/0024 is a co-ownership grant inside a corporate family that actually manufactures and sells the drug — no "IP Holdings"/"Ventures" LLC, no registered-agent service address, no single-purpose Delaware shell.

2. Known asserter in the chain — NOT PRESENT. No assignee matches Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation Corp, or any Spangenberg-linked entity. The only non-Helsinn/non-Roche party ever in the chain is HAMILTON SA LLC, and it appears solely as a secured creditor (2022-12-30) that released nine months later (2023-09-20) — a collateral position, not ownership.

3. Repeat correspondent across the chain — UNRESOLVED (cannot be scored). I could not retrieve the correspondent of record for any of the eight entries. This is the one signal I would most want before closing the file, because the Nov 2018 recordation cluster and the 2022 security-interest/release pair are exactly the kind of filings that a single repeat filer tends to handle. Not evidence of anything either way. Note also that litigation counsel appearing in this family (Ropes & Gray — Joseph M. O'Malley, Jr. et al., admitted pro hac vice in the Baxter case; Morris Nichols as Delaware local counsel) is litigation counsel, which is a different record field from the assignment correspondent — I am not conflating them.

4. Cascading transfers — NOT PRESENT as an NPE cascade; a cleanup cluster is present. Three recordings land on 2018-11-14 and one on 2018-11-21, all against the same Helsinn family. But these are confirmations of pre-existing interests (the Roche-inventor and Helsinn-inventor assignments, plus a corrective assignment), not a chain of transfers creating escalating ownership. They are to related family members US 7,947,724 / 7,947,725 / 7,960,424 / 8,518,981 as well, i.e. one docket-wide housekeeping event.

5. Pre-litigation transfer — NOT PRESENT (and notably inverted). The co-ownership agreement was executed 2017-05-01, roughly 18 months before suit, so it is not a within-6-months assertion-enabling transfer. Separately, the recordation of that agreement and the inventor confirmations (2018-11-14 / 2018-11-21) came after the Baxter complaint was filed on 2018-10-25 — i.e. the recordations were made to paper the standing/joinder record during litigation, not to set up venue.

6. Bankruptcy fire-sale — NOT PRESENT. No Chapter 7/11 filing by any assignor appears anywhere in the record. The only secured-party activity is a grant (2022-12-30) and release (2023-09-20) of a security interest — the opposite trajectory from a bankruptcy disposition. The patent's current status is ordinary term expiration (anticipated 2024-01-30, +PED to 2024-07-30), not a distressed sale.

7. Privateering — NOT PRESENT. Helsinn asserts in its own name and on its own behalf. In D. Del. 1:18-cv-01674 the plaintiffs are the four Helsinn co-owners themselves (Helsinn Healthcare SA, Helsinn Advanced Synthesis SA, Helsinn Birex Pharmaceuticals Ltd., Helsinn Therapeutics (U.S.), Inc.), and Roche Palo Alto LLC appears as a record co-assignee. There is no arm's-length NPE defendant-facing vehicle; the MGI Pharma and Eisai relationships are marketing/distribution, not assertion.

8. Defensive aggregator — NOT PRESENT. The chain terminates at Helsinn group entities. No RPX, AST, LOT Network, Unified Patents, or OIN link exists on this patent.

Observed assertion posture (for completeness, not an NPE signal): US 8,598,218 was asserted in conventional Hatch-Waxman/ANDA litigation against actual generic competitors, including D. Del. 1:13-cv-02101 (Helsinn v. Accord, filed 2013-12-27, patents 8,598,218 and 8,598,219), D. Del. 1:14-cv-01444 (Helsinn v. Exela, filed 2014-12-01, 8,518,981 and 8,598,218), D. Del. 1:15-cv-00918 (Helsinn v. Fresenius Kabi, filed 2015-10-13, listing 8,598,218), D.N.J. 3:15-cv-02077 (Helsinn v. Hospira), and D. Del. 1:18-cv-01674 (Helsinn v. Baxter). Note precisely: the Supreme Court's decision in Helsinn Healthcare S.A. v. Teva Pharmaceuticals USA, Inc., 586 U.S. 123 (2019) — the secret-sale/on-sale-bar ruling — concerned the sibling '219 patent, not the '218; do not attribute that holding to '218's claims.

Verdict

Operating-company assertion.

The entire recorded chain runs from Helsinn Healthcare SA and Roche Palo Alto LLC through internal Helsinn group reorganisations — the co-ownership grant to Helsinn Advanced Synthesis SA, Helsinn Birex Pharmaceuticals Ltd. and Helsinn Therapeutics (U.S.) Inc. (executed 2017-05-01, recorded at Reel 047534/0024, corrected 2018-11-21), and the inventor-assignment confirmations recorded 2018-11-14 — with the only outside party, HAMILTON SA LLC, holding a security interest (2022-12-30) that was released (2023-09-20). The assignees manufacture and sell the practising product (Aloxi®), and the patent was asserted only against ANDA-filing generic competitors in ordinary Hatch-Waxman suits (e.g. D. Del. 1:13-cv-02101, 1:14-cv-01444, 1:15-cv-00918; D.N.J. 3:15-cv-02077). Every NPE-specific signal scores not present, and the patent has now expired by term.

Verification link: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ (search patent number 8598218); legacy interface at https://assignment.uspto.gov/patent/index.html. Patent record: https://patents.google.com/patent/US8598218/en. Standing/co-ownership facts: https://www.courtlistener.com/docket/14903463/1/helsinn-healthcare-sa-v-baxter-healthcare-corporation/. SCOTUS disposition of the sibling patent: https://www.law.cornell.edu/supremecourt/text/17-1229.

Open item for the next pass: pull the correspondent of record for all eight entries at the Assignment Center. That field is the single unresolved input here, and it is the field that the shell-entity methodology depends on most. Until it is checked, signal 3 should remain "unresolved" rather than "not present."

I'll start by verifying the patent record and then analyze the cited prior art.

Let me verify the key palonosetron-specific references and a few others.

Prior-Art Analysis — U.S. Patent No. 8,598,218 B2

1. Patent identification and verification

Source: https://patents.google.com/patent/US8598218/en (fetched 2026-09-27); https://www.freepatentsonline.com/8598218.html

Rule applied: the number was searched literally as 8598218. No similar numbers (e.g., 8,598,219; 8,518,981; 9,306,983; 9,457,020) were substituted; several are referenced below only because they are part of the same patent family, which is directly relevant to the § 102 analysis.

2. Governing legal framework / critical dates

Because the priority date (2003-01-30) predates the AIA's 2013-03-16 change, pre-AIA 35 U.S.C. § 102 controls. The critical dates are:

• § 102(b) bar: anything patented or described in a printed publication before 2002-01-30.
• § 102(a): known/used/patented/published by others before 2003-01-30.
• § 102(e): U.S. patents/applications (or PCT applications designating the U.S.), by another, filed before 2003-01-30.
• § 103(c): commonly owned § 102(e)/(f)/(g) art can be disqualified for obviousness only; commonly owned § 102(b) art cannot be disqualified.

Two consequences drive everything below:

1. Any reference whose only § 102 date is a publication after 2003-01-30 is not prior art to the '218 claims (e.g., WO 2004/045615, published 2004-06-03).
2. The entire Helsinn palonosetron family shares the same 2003-01-30 priority and the same inventive entity, so those documents are not § 102 prior art against the '218 claims — they are the patent's own family.

3. Full inventory of the patent citations (36 references on the face of the '218 patent)

Group A — Palonosetron-specific art (the only references that even reach the active ingredient)

Group B — Other 5-HT3 antagonist actives (structurally related, but not palonosetron)

Group C — Granisetron (Roche/GSK) liquid vial art — closest method analogues

Group D — Unrelated formulation / excipient / chemistry art

(#24–#30 include several entries that also appear in the "Family Cites Families" list — e.g., JP 5590539 B2 (nitroglycerin aqueous solution), US 5,360,800 (Glaxo), GB 9305593 D0, US 5,567,818, US 5,576,317, JP 3845902 B2, ATA 156496, GB 9721139 D0, DE 19833119 A1 (carvedilol injectable), CN 1525856 A (pyrazolone injection), AU 2004204827 B2 (Dynogen), and US 8,598,219 B2 (the '219 sibling). These are additional-of-record references; none discloses a palonosetron single-unit-dose terminally sterilized vial and none anticipates claims 1–11.)

4. Most relevant prior art, ranked

Tier 1 — US 5,202,333 A (Syntex / Roche Palo Alto LLC) is the single most relevant reference, and the only cited patent whose disclosure reaches the claimed active ingredient and an actual palonosetron intravenous formulation (Example 13). It is squarely § 102(b) art (issued 1993-04-13, more than one year before the 2002-01-30 bar). Because § 102(b) art is not subject to the common-ownership disqualification of § 103(c), the fact that both the '333 patent and the '218 patent trace to Roche Palo Alto LLC does not remove it. It nonetheless does not anticipate claims 1–11, because it does not disclose (i) a finished single-unit-dose vial of ~5 mL, (ii) the 0.25 mg / 0.05 mg·mL⁻¹ palonosetron content, (iii) terminal sterilization of the sealed container, or (iv) pH 4.0–6.0 (Example 13 is pH 3.7). Its real force is as the § 103 starting point the applicants themselves conceded in the '218 specification ("U.S. Pat. No. 5,202,333 discloses an intravenous formulation of palonosetron in example 13… pH of 3.7 and a shelf stability of less than the 1-2 year time period required by health authorities").

Tier 2 — US 6,294,548 B1 / US 2001/0020029 A1 (Hoffmann-La Roche; SmithKline Beecham) are the closest process analogues: they expressly teach filling a 5-HT3-antagonist injectable into vials and terminally sterilizing by autoclaving, with a citrate buffer and tonicity agents. They are § 102(b) art but recite granisetron, not palonosetron, so they cannot anticipate any of claims 1–11. They are the natural § 103 combination partner for the sterilization/buffer/tonicity limitations.

Tier 3 — the ondansetron, granisetron, and dolasetron patent families (Group B) and the general formulation art (Group D) supply, at most, evidence that liquid, buffered, terminally sterilized 5-HT3-antagonist injectables and chelator/tonicity/citrate excipients were routine. None discloses palonosetron or the claimed method.

Not prior art at all: WO 2004/045615 A1, WO 2004/067005 A1, WO 2004/073714 A1, and US 7,947,724 / 7,947,725 / 7,960,424 / 8,518,981 (same Helsinn family/priority). Of note, the "Cited By" entries US 9,066,980 B2 and US 9,308,266 B2 are also later Helsinn family members, not prior art.

5. Bottom line on § 102

• No single cited patent anticipates claims 1–11. Claims 1 and 11 are method claims requiring, inter alia, filling sterile open containers with ≈5 mL / 0.05 mg·mL⁻¹ palonosetron HCl, sealing, and terminally sterilizing the sealed filled containers; claims 4 and 10 are product-by-process claims to the resulting vial; claims 2–3 and 5–9 are narrower method variants (pH agent, mannitol, chelating agent). No cited reference discloses the palonosetron active together with the claimed single-unit-dose/terminal-sterilization method.
• The cited art's realistic role is § 103 obviousness, with US 5,202,333 (palonosetron + example IV formulation) as the primary reference, optionally combined with US 6,294,548 (terminal sterilization of a buffered 5-HT3 injectable vial) and general parenteral-formulation references.
• The prior-art analysis for this patent is dominated by its own prosecution/litigation history rather than by a clean anticipation reference: the '218 family drew N.J. and Del. district-court litigation (per the Google Patents record), the corresponding EP patent EP 1 601 359 B1 was opposed and ultimately revoked, and the palonosetron formulation family (the '724/'725/'424/'981/'218/'219/'094 patents) was the subject of multiple IPR petitions and Hatch-Waxman challenges in which US 5,202,333 Example 13 and the Won 1995 degradation study (Int'l J. Pharmaceutics 121:95–105) featured as the principal prior-art attacks. See e.g. https://portal.unifiedpatents.com/litigation/New%20Jersey%20District%20Court/case/3%3A15-cv-08132 and https://www.courtlistener.com/docket/[4310416/343](https://assignmentcenter.uspto.gov/search/patent/reelFrameDetail?reelFrame=4310416-0343)/helsinn-healthcare-sa-v-dr-reddys-laboratories-ltd/.

Confidence note: dates, titles, assignees, and citation lists above are taken verbatim from the fetched full patent text and Google Patents citation tables (https://patents.google.com/patent/US8598218/en). For the handful of references where the § 102(e) date depends on a U.S./PCT filing date not shown on the face of the '218 patent (Dugger US 2003/0095926 A1; Epidauros WO 2003/100091 A1; BMS US 6,699,852 B2; BMS US 7,109,339 B2), I have flagged the assessment as provisional rather than asserting exact filing dates I could not verify.

I'll ground a few points with targeted searches before writing the analysis.

Obviousness Analysis — U.S. Patent No. 8,598,218 under 35 U.S.C. § 103

Scope note. This analysis builds on the claim breakdown in the previously generated summary (independent claims 1 and 11; product-by-process claims 4 and 10; dependents 2, 3, 5–9) and does not repeat it. It uses only the prior-art references identified on the patent page's own "Citations," "Family Cites Families," and "Non-Patent Citations" sections, supplemented by the record citations that appear in the family's IPR/ANDA papers (which the page reproduces). Where a point rests on my inference rather than a cited source, I say so.

1. Legal framework

• Governing statute / effective date. The '218 issued from application 13/901,288, filed May 23, 2013 — after the AIA's first-inventor-to-file date — but it is a continuation of 13/087,012 (filed 2011) and 11/186,311 (filed 2005), all claiming the Jan. 30, 2003 provisional. Whether pre-AIA § 103 (critical date Jan. 30, 2002 for § 102(b) art) or AIA § 103 (critical date = effective filing date) applies depends on whether these claims are entitled to the 2003 priority date. Flag: the Supreme Court stated that the sibling '219 patent "is governed by the AIA … By virtue of its effective date" (586 U.S. (2019), slip op. at 2). If the same is true of the '218's fixed-dose manufacturing claims, the universe of prior art expands substantially (the 2003 FDA approval, the 2004–2006 publications, and the family's own WO 2004/067005 would all qualify). The D.N.J. litigation assumed § 102(b) with a Jan. 30, 2002 critical date (Teva's brief, n.61). I analyze on the more conservative assumption that the Jan. 30, 2002 date controls, and note where that assumption changes the result.
• Standards. Graham v. John Deere, 383 U.S. 1 (1966); KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007); MPEP §§ 2141–2144.90. The claim is obvious if the differences over the prior art are such that "the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art."

2. Person of ordinary skill in the art (POSA)

A formulation scientist (Ph.D. or M.S.) or pharmacist with several years' experience developing small-volume parenterals, familiar with (i) 5-HT₃ antagonist injectables already on the market (ondansetron/Zofran®, granisetron/Kytril®, dolasetron/Anzemet®), (ii) standard parenteral excipients (tonicity agents, buffers, chelating agents), and (iii) terminal sterilization practice. The patent's own backdrop supports this level of skill: it treats pH screening, tonicity adjustment, buffer/EDTA optimization, and terminal sterilization as ordinary formulation work (Examples 1–3 and the "terminal sterilization" objects).

3. The claim elements and where the art is weakest

Claim 1, stripped to its mandatory elements, requires:

Claim 11 is the same with the 0.25 mg amount recast as 0.05 mg/mL. Claims 4 and 10 are product-by-process claims to the vial made by the claim 1/3 method — under In re Thorpe, 777 F.2d 695 (Fed. Cir. 1985), they rise or fall with the patentability of the product, not the process.

Consequence: every element except the 0.25 mg / 0.05 mg/mL selection and the terminal-sterilization-of-palonosetron step is standard formulation practice. Those two items are where the § 103 fight is, and both were pressed in the family's prior litigation.

4. The prior art on this page, organized

(A) Primary reference — "Berger," U.S. 5,202,333 (Syntex, 1993). Discloses palonosetron and, in Example 13, an aqueous intravenous formulation: palonosetron HCl 10–100 mg, dextrose monohydrate q.s. to isotonicity, citric acid monohydrate 1.05 mg, sodium hydroxide 0.18 mg, water for injection to 1 mL, pH 3.7, shelf stability "less than the 1–2 year period required by health authorities." The '218 specification itself adopts this reference as the starting point to be improved — an admission that both the drug and the aqueous IV dosage form were known, and that the problem to be solved (shelf stability) was known. This is the single most important fact for the obviousness analysis (In re Fritch; MPEP 2144.08).

(B) Excipient/formulation textbooks cited on the page:

• Handbook of Pharmaceutical Excipients, 3d ed. (Kibbe 2000), incl. pp. 140–143 (citric acid/citrate), 191–194 (EDTA), 324–238 (mannitol) — "Exhibit 1036" in the family IPRs, used for the proposition that citric acid is a buffer/chelating agent, EDTA is a chelating agent, and mannitol is a tonicity agent.
• P.P. DeLuca et al., Formulation of Small Volume Parenterals, in Pharmaceutical Dosage Forms: Parenteral Medications vol. 1, ch. 5, pp. 173–248 (2d ed. 1992) ("Avis"), and pp. 193–95, 207–08 — buffer selection, tonicity, chelators, terminal sterilization.
• L. Lachman et al., The Theory and Practice of Industrial Pharmacy, 3d ed. (1986), pp. 642–644, 783–784 — sterilization of parenterals.
• Akers, Excipient–Drug Interactions in Parenteral Formulations, 91 J. Pharm. Sci. 2283 (2002) — amine-drug oxidation and the standard chelator/antioxidant countermeasures.
• J. Broadhead, Parenteral Dosage Forms, in Pharmaceutical Preformulation and Formulation, ch. 9, pp. 331–354 (2001); L.A. Trissel, Handbook on Injectable Drugs, 7th ed. (1992); Connors, Chemical Stability of Pharmaceuticals (2d ed. 1986).

(C) 5-HT₃ antagonist injectable formulations:

• U.S. 6,294,548 and US 2001/0020029 (James, Roche) — multidose-vial granisetron formulations.
• U.S. 5,854,270 (Gambhir, Glaxo Wellcome) — oral ondansetron compositions containing citrate buffer and polyhydric alcohols (used in prosecution against this family).
• U.S. 5,955,488 and 6,063,802 (Winterborn, Glaxo Wellcome) — ondansetron freeze-dried forms.
• 2001 Physician's Desk Reference monographs for Anzemet® (dolasetron, pp. 680–683 — discloses mannitol 38.2 mg as tonicity agent and room-temperature storage), ondansetron, and Kytril® (granisetron).

(D) Chelator/"complexing agent" art: U.S. 6,284,749 (Castillo, Alcon — EDTA-preservative systems); DE 19833119 A1 (Roche Diagnostics — "storage-stable injectable solution … contains buffer … antioxidant and complexing agent"); CN 1525856 A (Mitsubishi — "stable high-concentration injection").

(E) Dose/clinical art: Adis R&D Profile, Palonosetron RS 25259-197, Drugs in R&D (Oct. 1999) 2(4):251–252; Eglen et al., Br. J. Pharmacol. 114:860–866 (1995); R.D. Clark et al., J. Med. Chem. 36:2645 (1993); G. Stacher, Curr. Opin. Investig. Drugs 3(10):1502–07 (2002); Macciocchi et al., ASCO 2002 abstract 1480 ("phase II dose-ranging study to assess intravenous doses of palonosetron"); Tang et al. (1998) (dose efficacy; cited in the IPRs); Gandara (1992); Gralla (2003); Eisenberg (2004).

(F) Terminal sterilization: Pharmaceutical Dosage Forms: Parenteral Medications vol. 1 (2d ed. 1992); Lachman (above); and the classification of this patent's own disclosure, including B65B55/02 – "Sterilising, e.g. of complete packages." Note the '218 specification expressly lists as an object "to provide a formulation of Palonosetron which would allow terminal sterilization," confirming that this was the known, desired manufacturing route.

(G) Non-prior-art but date-sensitive material: WO 2004/067005 (the family's own PCT, published Aug. 12, 2004), WO 2004/045615 (published June 3, 2004), WO 2004/073714, and the July 25, 2003 Aloxi approval letter all post-date a Jan. 30, 2002 § 102(b) critical date. If the AIA governs (see § 1), several of these become available.

5. The obviousness grounds

Ground 1 — Berger + excipient texts + PDR (claims 1, 2, 3, 6, 9, 11; and claims 4, 10 as their product-by-process counterparts)

Rationale: KSR (A) known elements combined per known methods; (D) known technique applied to a known formulation ready for improvement.

• Berger supplies the drug, the aqueous IV solution, the citric-acid/NaOH buffer system, and the isotonicity requirement.
• Kibbe supplies mannitol as an art-recognized tonicity agent; the 2001 PDR Anzemet® monograph supplies the concrete teaching of mannitol in a 5-HT₃ antagonist injection; the '218 specification itself concedes mannitol is a known sweetener/tonicity agent used at far higher (150 mg/mL) concentrations in oral forms. Substituting mannitol for dextrose is a simple substitution of one known tonicity agent for another (MPEP 2144.04) with an expectation of comparable isotonicity.
• Berger's pH 3.7 with citric acid/NaOH makes the claimed pH 4.0–6.0 (and the dependent 4.5–5.5) an ordinary pH-optimization exercise; the patent's own Example 1 is nothing more than a routine pH-stability screen.
• Claim 2's "pH adjusting agent" is met by Berger's sodium hydroxide; claim 6's "HCl or NaOH" adds only the universally used acid/base pair.

Motivation: same drug, same indication, same dosage form; the reference itself flags the shelf-life deficiency. Reasonable expectation of success: the excipients are the standard short list, and the pH/stability relationship is empirically determinable by routine testing.

Ground 2 — Ground 1 + Castillo / DE 19833119 / Akers (claims 5, 7, 8)

Teaches the addition of a chelating agent (EDTA) to a liquid pharmaceutical for stability, and specifically the use of a "complexing agent" in a storage-stable injectable solution. Akers explains that amine drugs such as palonosetron are susceptible to metal-catalyzed oxidative degradation — supplying the reason (not just the possibility) to add EDTA. Berger's citric acid also provides a citrate buffer as claimed ("optionally" and in claims reciting citrate). Rationale: KSR (C) known technique to improve similar products in the same way.

Ground 3 — Grounds 1–2 + Avis/Lachman (claims 1, 11, and product claims 4, 10)

Avis and Lachman teach filling and sealing ampoules/vials followed by terminal sterilization (e.g., steam at 121 °C), and teach that terminal sterilization is the preferred route for aqueous solutions of heat-stable actives. The '218 specification lists terminal sterilization as an object of the invention, which is itself evidence that the step was a known and desired technique. The 5 mL fill volume follows mechanically from the claimed 0.25 mg dose at 0.05 mg/mL, and single-dose 5-HT₃-antagonist vials were standard (PDR monographs; U.S. 6,294,548).

Ground 4 — Grounds 1–3 + dose literature, for the 0.25 mg / 0.05 mg/mL limitation

The pre-2002 published dose literature (including the 1999 Adis R&D Profile and Eglen 1995) established palonosetron's high potency. If the record also shows that 0.25 mg was known or suggested as an effective single IV dose before Jan. 30, 2002, then the concentration/dose limitation is the selection of a species from a disclosed genus — a classic "obvious to try" situation with a finite number of predictable options. This is the ground with the most contested evidentiary record (see § 6).

6. What cuts the other way — and how the record has actually come out

1. The dose-selection holding. In Helsinn Healthcare S.A. v. Dr. Reddy's Labs., No. 11-3962 (D.N.J. Nov. 13, 2015), the court held it would not have been obvious "to have selected 0.25 mg as a dose, or to arrive at a concentration of 0.05 mg/mL using routine experimentation," and credited commercial success and long-felt need (bulletin summary). The '218 was not among the four patents tried in that case (the '724, '725, '424 and '219 were), so the holding is persuasive, not binding, as to these claims — but a tribunal applying § 103 to the '218's fixed-dose claims would confront the same "dart-throwing" argument the patent owner made in prosecution and IPR: Berger's disclosure spans ~700 ng/day to 7 mg/day and Example 13 spans 10–100 mg/mL, i.e., 200–2,000× the claimed concentration (patent-owner briefing, ptacts 1458462).
2. Teaching away. The patent owner has argued that Tang (1998) taught that the 0.05 mg/mL / 0.25 mg dose was ineffective in emesis, i.e., away from the claimed dose (id.). If credited, that is a genuine teaching-away defense as to Ground 4. It is, however, a party characterization in an IPR response, and I have not independently verified Tang's disclosure.
3. Unexpected results. The specification's only head-to-head data are Example 3 (mannitol > sodium chloride for stability) and Example 2 (greatest stability at the lowest palonosetron concentration). Mannitol-vs-saline superiority is a plausible unexpected-result argument for claims 3/9; the "lowest concentration is most stable" result is less powerful because dilution reducing degradation is unsurprising. Note that the record contains a serious written-description criticism — the specification discloses no 18- or 24-month stability testing (UIC Rev. Intell. Prop. L.), and the Board's later treatment of similar "stable at 24 months" language was to treat it as carrying little weight.
4. The European counterpart was revoked. EP 1 601 359 B1 — granted 2008 with claim 1 reciting 0.03–0.2 mg/mL palonosetron HCl at pH 4.0–6.0 "comprising a chelating agent" — was opposed in 2009 and revoked (revocation effective Feb. 15, 2011) (Google Patents EP1601359B1; Belgian register, revocation date 15/02/2011). That is a meaningful data point favoring the obviousness conclusion for the composition aspects of this family, but I could not confirm from my sources whether the revocation ground was added matter, novelty, or inventive step — do not over-read it.
5. Claim-drafting asymmetry. The '218's claims are manufacturing/terminal-sterilization claims, not composition claims. That narrows the claim type (as the earlier summary notes) but also removes the "inherent property / written description" battleground on which the earlier family members were upheld — the '218 claims recite physical steps and quantities, which are more amenable to a § 103 rejection built from Berger + routine formulation art.
6. "Optional" language. If "optionally comprises" is read as imposing no limitation, claims 1 and 11 reduce to "fill 5 mL of an aqueous 0.25 mg palonosetron HCl solution containing a tonicity agent into a vial, seal, and terminally sterilize," which materially simplifies the prima facie case — Grounds 1 and 3 would suffice without the EDTA/citrate/mannitol references. This construction question should be resolved first.

7. Claim-by-claim summary

8. Bottom line

• Weakest link: the 0.25 mg / 0.05 mg/mL limitation. If the pre-Jan. 30, 2002 public record establishes that dose as an effective single IV dose, the '218 claims are very likely obvious: Berger + the excipient texts + the 2001 PDR + terminal-sterilization practice supplies every remaining element, with clear motivations (improve Berger's admitted <1–2-year shelf life; adopt a terminally sterilizable, room-temperature-stable presentation) and a reasonable expectation of success.
• Strongest defense: the same one that succeeded for the sibling patents in D.N.J. — that choosing 0.25 mg out of Berger's enormous disclosure range was not routine, reinforced by commercial success and long-felt need. Note the twist that Tang (1998), if it reads as the patent owner contends, teaches away from the claimed dose.
• Regime sensitivity: if the AIA governs the '218 (as the Supreme Court indicated for the '219), post-2002 publications, the July 25, 2003 Aloxi approval, and the family's own WO 2004/067005 become available, and the § 103 case gets materially stronger. This should be resolved before relying on any of the above.
• Confidence: high that Grounds 1–3 establish a prima facie case independent of the dose question; moderate-to-low confidence that the record as I have it proves the 0.25 mg dose obvious, because the key pre-2002 dose evidence (Macciocchi 2002, the June 2002 MASCC disclosure, Gralla 2003, Eisenberg 2004) falls after the Jan. 30, 2002 critical date, and the one adjudicated US decision on point went the other way.
• Not verified / open items: (i) whether the '218 was ever the subject of a validity adjudication or IPR — I found PTAB activity in this family (petitions referencing the '094 and related palonosetron patents), but no petition specific to the '218; (ii) the grounds of the EPO revocation; (iii) the exact pre-2002 public availability of the 0.25 mg dose data. Treat those three as unresolved.

Primary sources: US 8,598,218 (Google Patents); EP 1 601 359 B1; 586 U.S. (2019) slip op.; D.N.J. 2015 decision summary; Teva/DRL trial brief; FDA review correspondence listing the 8518981/8598218 dismissals (NDA 203050, NDA 207963); PTAB petition papers at ptacts.uspto.gov (petition IDs 1458461, 1458462, 1462972, 1463036).