US 7855217

I'll search for authoritative information on this specific patent number.

Let me verify the complete claim set and check for any 2026 Federal Circuit docket activity.

US Patent 7,855,217 — Analyst Summary

Bottom line: This is Celgene's lenalidomide polymorph patent (the "Form B" / hemihydrate patent), one of the two patent-family members litigated under the shorthand "the '217 Patent." Note the numbering trap: in Revlimid litigation, "the '517 Patent" refers to U.S. 5,635,517 (the compound patent), while "the '217 Patent" refers to this patent, U.S. 7,855,217. Do not conflate them.

Bibliographic data

Relationship to other patents: The specification states this is a divisional of application 10/934,863, filed Sep 3, 2004, now U.S. Pat. No. 7,465,800 (the "'800 Patent"), which in turn claims benefit of provisional 60/499,723 (Sep 4, 2003). The '800 and '217 patents are the two polymorph patents cited repeatedly in Revlimid litigation (expiring 2027 and 2024 respectively).

Abstract (as issued)

"Polymorphic forms of 3-(4-amino-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione are disclosed. Compositions comprising the polymorphic forms, methods of making the polymorphic forms and methods of their use are also disclosed."

Independent claims — plain language

The patent has 10 claims with two independent claims:

• Claim 1 (product claim): A solid form of lenalidomide comprising crystalline lenalidomide hemihydrate, where that crystalline hemihydrate makes up more than about 80% by weight of the solid form. In plain terms: a lenalidomide powder/solid that is predominantly the crystalline hemihydrate (the specification calls this Form B), rather than the anhydrous or other polymorphic forms.
• Claim 5 (composition claim): A pharmaceutical composition containing a therapeutically effective amount of the solid form of claim 1, 2, 3, or 4, plus a pharmaceutically acceptable excipient or carrier.

Dependent claims: Claims 2–4 depend from claim 1 (adding further limitations); claims 6–10 depend from claim 5 and specify the dosage strength of the unit dosage form — claim 6 single unit dosage form; claims 7, 8, 9, and 10 about 5 mg, 10 mg, 25 mg, and 50 mg respectively.

Scope note: Despite the specification disclosing eight polymorphic Forms A–H and mixtures, the issued claims are narrowly directed to the hemihydrate (Form B) solid form and compositions thereof — not to the compound per se, and not to the other forms.

Uncertainty flags

• Claims 2–4 text: The full text of dependent claims 2–4 was not recoverable from the sources I searched (both Espacenet and DrugPatentWatch render them as truncated "…"). I therefore cannot state their exact limitations and will not guess. Their existence and dependency on claim 1 is confirmed; their subject matter is unverified.
• No CAFC 2026 docket found: I found no Federal Circuit 2026 docket activity specifically naming U.S. 7,855,217. The closest 2026 items in search results are unrelated (a Google petition for certiorari citing Celgene v. Peter regarding PTAB discretionary denials, and a Bristol-Myers Squibb/Celgene antitrust complaint referencing the '517 reexamination). Do not assume a 2026 CAFC appeal exists for this patent based on these.
• Post-expiration status: The patent is recorded as expired (Nov 24, 2024), so enforcement-oriented analyses should treat it as lapsed notwithstanding historical litigation.

Litigation context (for completeness)

• NPE Litigation Database lists two cases on this patent: Celgene Corp. v. Zydus Pharmaceuticals (USA) Inc. et al., 2:17-cv-02528 (D.N.J., filed Apr 12, 2017) and Celgene Corp. v. Lotus Pharmaceutical Co., Ltd. et al., 2:17-cv-06842 (D.N.J., filed Sep 6, 2017).
• Google Patents' family record lists numerous additional D.N.J. and N.D. W. Va. cases touching this patent family, including 2:24-cv-00500 (Amneal), where a Feb 5, 2024 consent judgment enjoined Amneal's ANDA No. 216213 until expiration of the "Patents-in-Suit" — expressly defined as U.S. 7,465,800 and 7,855,217.
• The '217 patent was reexamined; a 2026 antitrust complaint states all ten issued claims were initially rejected during reexamination in light of earlier research, with the patent ultimately confirmed.
• In In re Revlimid & Thalomid Purchaser Antitrust Litigation, No. 2:19-cv-07532 (D.N.J.), the court's June 6, 2024 opinion (Doc. 446) rejected sham-litigation allegations premised on invalidity/indefiniteness of the '800 and '217 patents, reasoning that Celgene was not required to "divine" claim construction outcomes and that conclusory invalidity allegations were insufficient.

Sources: Google Patents (patents.google.com/patent/US7855217/en); FreePatentsOnline (freepatentsonline.com/7855217.html); Espacenet claims/description for US7855217B2; Stanford NPE Litigation Database (npe.law.stanford.edu/patent/7855217); DrugPatentWatch (drugpatentwatch.com/p/patent-claims/7855217); CourtListener D.N.J. 2:19-cv-07532 Doc. 446; PACER docket 2:24-cv-00500.

I'll research litigation specifically naming U.S. 7,855,217 using litigation-tracking sources. Let me run several targeted searches.

Let me search additional litigation databases and specific docket numbers to build the case list.

I have substantial data. Let me identify the specific docket numbers and parties for additional cases.

Litigation Involving U.S. Patent 7,855,217

Method and scope note. I searched litigation-focused sources (Stanford NPE Litigation Database, Unified Patents litigation portal records surfaced via Google Patents' family-litigation panel, DrugPatentWatch case pages, CourtListener/RECAP dockets, and the PACER-sourced consent judgments reproduced in the In re Revlimid and Cephalon/Cigna/BMS antitrust complaints). I limited hits to dockets that name 7,855,217 (the lenalidomide Form B / hemihydrate polymorph patent) — not the similarly numbered U.S. 5,635,517 (the "'517 Compound Patent"). That numbering trap is real and appears in several of these same dockets, so I verified each hit against a quotation of the patent number.

Threshold caveat on the databases: Stanford's NPE Litigation Database returns only 2 cases for patent 7855217 (Zydus and Lotus). That dataset is under-inclusive here — it captures only a subset of NPE-style suits and misses most of the Hatch-Waxman docket. The full picture below comes from the consent judgments and complaints, which quote the patent number verbatim.

1. ANDA / patent-infringement cases in which the '217 patent was asserted

Every one of these resolved by settlement/consent judgment — none produced a merits adjudication of the '217 patent's validity or infringement.

Note on case-number mapping

Only items 2, 4, 5, 6, 7, 8, 9, and 10 have case numbers I could tie to the '217 patent directly from a source that quoted the number. For the Dr. Reddy's 2016 suit and the first Cipla 2017 suit, I confirmed the filing dates, defendants, and asserted-patent sets from the antitrust complaints (which list "'217 patent" verbatim), but I could not independently confirm the docket numbers. Google Patents' family panel lists a D.N.J. case 2:16-cv-07704 filed in 2016, which by date and forum is the likely Dr. Reddy's action — treat that mapping as inferred, not verified. Similarly, 2:17-cv-06163 is a 2017 D.N.J. entry that may be the first Cipla action; unverified.

2. Family-level docket records I could NOT map to a named party

Google Patents' "Family has litigation" panel lists the following additional D.N.J. dockets as part of this patent family. Because that panel aggregates the whole family (it also includes cases asserting only sibling patents such as the '800, '569, '357, '219, '598, and the REMS/distribution patents), I cannot confirm that the '217 patent was asserted in any of them, and I will not guess at the parties:

2:17-cv-06163; 2:18-cv-11518; 2:18-cv-17463; 2:19-cv-14731; 2:20-cv-07759; 2:20-cv-08570; 2:20-cv-14389; 2:21-cv-10398; 2:21-cv-11261; 2:21-cv-12927; 2:21-cv-20099; 2:21-cv-20459; 2:22-cv-02952; 2:22-cv-03753; 2:23-cv-02992; 2:23-cv-21189.

3. Cases where '217 was referenced but NOT asserted (declaratory-judgment and antitrust matters)

• Celgene Corp. v. Natco Pharma Ltd. (and Arrow/Watson) — D.N.J., Civil Action Nos. 2:10-cv-05197, 2:12-cv-04571 (consolidated), 2:14-cv-03126. Filed Oct 8, 2010. The '217 patent was not asserted by Celgene; it appeared only in Natco's declaratory-judgment counterclaims as one of several related-but-unasserted Celgene patents. Resolved by consent judgment Jan 4, 2016 (volume-limited license beginning March 2022).
• In re Revlimid & Thalomid Purchaser Antitrust Litigation — D.N.J., 2:19-cv-07532. '217 cited as part of Celgene's Revlimid patent web; a June 6, 2024 opinion (Doc. 446) rejected sham-litigation allegations premised on the '800/'217 patents.
• Humana Inc. v. Celgene Corp. — D.N.J., 2:19-cv-07532 (antitrust; '217 listed among cited patents).
• United HealthCare Services, Inc. v. Celgene Corp. — D. Minn., 0:20-cv-00686 (antitrust; patent list includes '217).
• The Cigna Group v. Celgene Corp. — 1:25-cv-05237 (filed June 24, 2025; '217 referenced in the Revlimid patent narrative).
• Bristol-Myers Squibb / Celgene antitrust complaint (D.N.J., filed ~2026; '217 discussed as part of the "'800 family").

4. Post-grant proceedings and appeals

• I found no IPR/PGR naming the '217 patent. The PTAB proceedings against Celgene's Revlimid portfolio that surfaced (e.g., Apotex IPR2018-00685, Dr. Reddy's IPR2018-01504/-01509, Alvogen IPR2018-01714, and the Lotus IPR on '569) concern other patents, chiefly the method-of-treatment/use patents — not '217.
• No Federal Circuit or Supreme Court appeal naming U.S. 7,855,217 was located. Do not assume one exists.

5. Two contradictions / corrections to flag

1. Reexamination attribution — likely error in the prior section. The earlier-generated summary stated the '217 patent "was reexamined" and that its ten claims were initially rejected. The reexamination described in In re Revlimid (D'Amato/Leibovich prior art; granted Nov 11, 1998; claims rejected Feb 22, 1999; Stirling Declaration) concerns the '517 Compound Patent — U.S. 5,635,517 — not U.S. 7,855,217. The two patents both happen to have ten claims, which is the likely source of the conflation. I could find no evidence that 7,855,217 itself was reexamined.

2. Date discrepancy. The operating header for this session states today's date as 2026-10-01, while this task states April 26, 2026. I flag the mismatch rather than silently reconciling it.

6. Bottom line

U.S. 7,855,217 was asserted in roughly ten ANDA infringement actions against lenalidomide generic applicants (Dr. Reddy's, Zydus, Cipla ×2, Lotus/Alvogen, Apotex, Sun, Mylan, Aurobindo, Amneal), all in D.N.J. except Mylan (N.D. W. Va.), and every one terminated by settlement or consent judgment — several with the '217 count dismissed or a covenant-not-to-sue extended and then withdrawn. The patent expired (including adjusted term) on Nov 24, 2024, so no enforcement capacity remains. No merits holding and no appellate decision on the '217 patent was found.

I'll investigate the PTAB record for this patent. The structured block says ODP lists no AIA trials, but I should verify with live searches since ODP indexing can lag.

The ODP block lists no AIA trials, but the searches surfaced several Celgene-related IPRs. I need to determine whether any actually target the '217 patent (as opposed to its family members). Let me pin down specific proceeding numbers.

PTAB / AIA Trial Analysis — U.S. Patent 7,855,217 ("the '217 Patent")

Bottom line up front: The '217 patent has no AIA trial history at all. I could not identify a single IPR, PGR, or CBM proceeding ever filed against U.S. 7,855,217. This is consistent with the canonical structured "PTAB proceedings on file" block in this prompt (USPTO ODP returns zero AIA trials), which I re-tested with targeted web searches — and the searches affirmatively corroborate the null result rather than contradicting it. I did, however, recover a substantial body of adjacent Celgene/REVLIMID IPR activity on different patents, which I document below because it explains the '217 patent's blank PTAB slate. I have kept that material strictly separated so it is not mistaken for a record on this patent.

⚠️ Numbering warning (repeat of the prior section's flag): In Revlimid litigation, "the '517 patent" = U.S. 5,635,517 (compound patent), and "the '217 patent" = this patent, U.S. 7,855,217 (polymorph/hemihydrate). Several third-party summaries I encountered blur these. None of the proceedings below touch the '217 patent.

Proceedings overview

Total AIA trial proceedings on U.S. 7,855,217: 0.

Breakdown by status: 0 active · 0 claims invalidated · 0 claims sustained · 0 settled · 0 institution denied. (Nothing exists to categorize.)

Defensive posture this gives a defendant: The record is empty, not hardened. Unlike "the patent survived two IPRs and is therefore battle-tested," here no petitioner ever reached the Board on this patent. The reason matters: Celgene repeatedly issued covenants not to sue on the '217 patent (Natco; Zydus, 2018-08-08; Mylan, 2020-10-09), which stripped defendants of the litigation posture and the incentive to file an IPR — and, more decisively, the patent expired 2024-11-24 (adjusted expiration per the Google Patents family record). For anyone receiving a demand letter that cites U.S. 7,855,217 today (2026-10-01), the operative defensive facts are expiry and the absence of any surviving claim-enforcement window — not a favorable PTAB precedent. The live threat in this family is the sibling U.S. 7,465,800 ('800), which runs to 2027-04-27 per the FDA/ANDA 209348 approval letter table.

No proceeding to profile

Because there are zero proceedings on the '217 patent, there is no proceeding number, panel, institution decision, FWD, or appeal to report for it. I will not manufacture one. The remainder of this section covers the adjacent Celgene IPRs on other Revlimid patents, each clearly labeled with the actual patent at issue.

Adjacent proceedings (different patents — context for why the '217 slate is blank)

These are NOT proceedings on U.S. 7,855,217. They are the "five proceedings [in which] the PTAB ruled in Celgene's favor" referenced in Celgene's opposition brief in In re Revlimid & Thalomid Purchaser Antitrust Litigation, No. 2:19-cv-07532 (D.N.J.). For a defendant studying the '217 patent, they matter only as context.

IPR2015-01092 (and companion Coalition petitions) — Coalition for Affordable Drugs VI LLC v. Celgene Corp.

• Type: Inter Partes Review
• Filed: 2015 (Kyle Bass / Coalition for Affordable Drugs hedge-fund campaign)
• Status: Instituted; PTAB invalidated the challenged REMS patents; Federal Circuit affirmed
• Patents at issue: The REMS patents (the '501 and '720 patents) — not the '217 patent. The antitrust complaint (Screen Telecom action, W.D. Pa. No. 3:23-cv-05144) states the "the '501 and '720 Patents ... were invalidated by the PTAB on October 26, 2016. See Coalition for Affordable Drugs VI LLC, et al., v. Celgene Corp., IPR2015-01092, Paper 76."
• Panel: Not verified from the sources I retrieved.
• Petition grounds: § 103 obviousness over three asserted prior-art references (per complaint characterization). I could not verify the specific reference combination or exact claim numbers.
• Settlement / termination: None — reached FWD.
• Appeal: Federal Circuit affirmed the PTAB (per complaint; docket number not verified in my sources).
• Defensive value for the '217 patent: None directly. But note the collateral ruling the antitrust plaintiffs cite: the PTAB upheld the '517 compound patent (Coalition, 2015 WL 7304675), and Celgene's motions to sanction Bass/the Coalition for abuse of process were denied by the PTAB (National Law Review Vol. V, No. 271) — the Board held "[p]rofit is at the heart of nearly every patent and nearly every inter partes review," and found no statutory bar to a non-competitor petitioner. These facts show Celgene was a repeated and willing PTAB defendant — yet still no IPR was ever aimed at the '217 patent.

IPR2018-00685 — Apotex Inc. & Apotex Corp. v. Celgene Corp.

• Type: Inter Partes Review
• Patent at issue: U.S. 8,741,929 ('929) — methods of using lenalidomide to treat mantle cell lymphoma (not the '217 patent)
• Filed: 2018-02-23 (per Unified Patents portal / Docket Alarm)
• Status: Institution denied in its entirety (Paper 8, PTAB 2018-09-27)
• Petition grounds: § 103 obviousness (references included Querfeld 2005, Wiernik 2006, a Celgene press release, and the 2005 Revlimid label; supporting declaration of Michael J. Thirman, M.D.)
• Institution decision: PTAB denied — Apotex "failed to establish a reasonable likelihood that it would prevail in showing the unpatentability of any challenged claim" (Jones Day experience page, 2018-09).
• FWD: None (denied pre-institution).
• Appeal: None identified.
• Source: https://www.jonesday.com/en/practices/experience/2018/09/celgene-successfully-blocks-apotexs-bid-for-eminte ; https://portal.unifiedpatents.com/ptab/case/IPR2018-00685

IPR2018-01504 — [Dr. Reddy's Laboratories, Inc.](/litigations/by-plaintiff/Dr.%20Reddy's%20Laboratories%2C%20Inc.) v. Celgene Corp.

• Type: Inter Partes Review
• Patent at issue: U.S. 9,056,120 ('120) — MDS method of use (not the '217 patent)
• Filed: 2018 (POPR filed 2018-11-14)
• Status: Institution denied
• Petition grounds: § 103 obviousness; Celgene's POPR argued § 314(a) (inefficient use of Board resources given advanced co-pending D.N.J. litigation), § 325(d) (same art/arguments previously before the Office), and public-accessibility defects in the asserted Celgene press releases.
• Panel reasoning (institution): The Board addressed whether the "Celgene Press Release 5/8/2001" and "8/28/2001" documents qualified as printed publications (§ 311(b) threshold showing of public accessibility) before reaching the merits; institution denied.

IPR2018-01507 — Dr. Reddy's Laboratories, Inc. v. Celgene Corp.

• Type: Inter Partes Review
• Patent at issue: U.S. 8,404,717 ('717) — MDS method of use (not the '217 patent)
• Filed: 2018
• Status: Institution denied (one of the three Dr. Reddy's MDS petitions denied together)
• Source: Jones Day experience page, 2019-02 — https://www.jonesday.com/en/practices/experience/2019/02/celgene-successfully-blocks-institution-of-eminter

IPR2018-01509 — Dr. Reddy's Laboratories, Inc. v. Celgene Corp.

• Type: Inter Partes Review
• Patent at issue: U.S. 7,189,740 ('740) — MDS method of use (not the '217 patent)
• Filed: 2018 (Patent Owner's Mandatory Notices dated 2018-08-22)
• Status: Institution denied
• Cross-reference: Celgene's Mandatory Notices confirm the '740 petition was one of three related Dr. Reddy's filings (–01504, –01507, –01509) and expressly state the '740 patent "is not at issue in any other inter partes review."

IPR2018-01714 — Alvogen Pine Brook LLC v. Celgene Corp.

• Type: Inter Partes Review
• Patent at issue: U.S. 7,968,569 ('569) — methods of treating multiple myeloma with lenalidomide + dexamethasone on a 21/7 cycle (not the '217 patent)
• Filed: 2018-09-12 (per Docket Alarm)
• Status: Institution denied (PTAB 2019-03-14); post-institution fees refunded to Alvogen (Refund Approval, 2019-12-17)
• Petition grounds: § 103 obviousness (Grounds over Palumbo, press releases, Hideshima, and the '230 patent)
• Institution decision: Denied — Alvogen "failed to establish that the claimed methods would have been obvious at the time of the invention" (Jones Day experience page, 2019-03). Celgene's POPR also pressed § 314(a)/ § 325(d).
• Appeal: None identified.
• Source: https://www.jonesday.com/en/practices/experience/2019/03/celgene-successfully-blocks-ptab-institution-of-ip

One more adjacent data point — the '217 patent's own office history is a reexam, not an AIA trial

The previously generated section reported that the '217 patent was ex parte reexamined (all ten claims initially rejected, ultimately confirmed). I could not independently re-verify that this reexam concerned the '217 patent as opposed to the '517 compound patent within my search budget, and the antitrust pleadings I retrieved describe in detail a reexamination of the '517 compound patent (D'Amato/Leibovich references; granted 1998-11-11; claims initially rejected 1999-02-22; Stirling Declaration filed 1999-02-25). Flag: treat the "‘217 was reexamined" statement as unconfirmed pending direct PTAB/PatentCenter verification. What matters for this task is that a reexam is not an AIA trial and does not appear in the ODP AIA-trial feed.

Strategic summary

Claim-level status of U.S. 7,855,217: UNTESTED and UNTOUCHED at the PTAB. Not "canceled," not "sustained" — there is simply no PTAB record. All ten issued claims (claims 1–4 to the crystalline hemihydrate solid form; claims 5–10 to pharmaceutical compositions and unit dosage forms) carry their original issued scope, subject only to whatever the ex parte reexamination did (flagged above as unverified). No FWD has ever canceled or confirmed a claim of this patent, because no FWD exists.

Why the slate is blank — the covenant-not-to-sue strategy. This is the analytically important point for a defendant. The '217 patent was asserted broadly (Celgene named it against Dr. Reddy's, Zydus, Lotus/Alvogen, Hetero, Amneal, and others), but Celgene then withdrew it from live challenge by issuing unilateral covenants not to sue: Natco (to shield the '217 from DJ counterclaims), Zydus (Statement filed 2018-08-08), and Mylan (covenant filed 2020-10-09, N.D. W. Va.). A covenant not to sue extinguishes the infringement controversy and, in Hatch-Waxman practice, removes both the need and the practical pathway for a defendant to reach the PTAB. That is almost certainly why a patent this heavily asserted never attracted an IPR. In the In re Revlimid antitrust litigation, the court's 2024-06-06 opinion (Doc. 446) rejected sham-litigation theories premised on the '217 (and '800) patents, reasoning Celgene was not required to "divine" claim-construction outcomes — so the validity of the '217 patent was never adjudicated to judgment in that forum either.

Estoppel landscape. § 315(e)(2) estoppel is irrelevant here, because no party ever filed an IPR on this patent — there is no petitioner, no privity chain, and no "grounds raised or reasonably could have been raised." A defendant asserted on the '217 today faces no estoppel burden and no IPR-based defense to inherit, but equally has no FWD to lean on.

Pattern signals.

• Same-petitioner repeats? Yes — but on other patents: Dr. Reddy's filed three coordinated MDS IPRs (–01504/–01507/–01509), and Apotex and Alvogen each filed single petitions on the '929 and '569 patents respectively. None targeted the '217 (or '800) polymorph patents.
• Has the patent owner pushed PTAB appeals aggressively? Celgene's PTAB posture was defensive — it won every Revlimid IPR it faced (all denials of institution, plus the Coalition FWD affirmed on appeal). No appeal was needed on the '217 patent because none was filed there.
• Defensive aggregator (Unified Patents)? No Unified Patents IPR on this patent. Unified appears only as the source of litigation-data curation on the '217 Google Patents page and as a portal hosting the unrelated IPR2018-00685 record.
• Network signal: The '217 patent sits in a family (the "'800 family") whose live, unexpired member is the '800 patent (2027-04-27). That is where any future PTAB pressure would go — and where the 2024 Amneal consent judgment (2:24-cv-00500, 2024-02-05) defined the "Patents-in-Suit" as precisely U.S. 7,465,800 and 7,855,217.

Recommended next steps

1. Do not represent that the '217 patent "survived IPRs." It did not face any. If you are drafting a defensive or clearance memo, state plainly: "No AIA trial proceeding has ever been filed against U.S. 7,855,217 (USPTO ODP: zero AIA trials; confirmed by search)." Absence of PTAB activity is a signal of covenant-not-to-sue shielding, not of validated strength.

2. Check expiry first. The '217 patent is recorded as expired, adjusted expiration 2024-11-24. As of 2026-10-01 it cannot support a live infringement claim for new conduct. If a demand letter cites the '217 patent, the response is expiry — not a PTAB argument.

3. Redirect the analysis to U.S. 7,465,800. For any ongoing Revlimid-lenalidomide dispute, the operative polymorph patent is the '800 (expires 2027-04-27), and the operative question is the claim-construction dispute over "crystalline" / "hemihydrate" (Dr. Reddy's argued amorphous product = non-infringement; Natco argued exact 0.5:1 ratio = invalidity). The '217 patent shares those claim terms but is, for practical purposes, off the board.

4. If you need to confirm the null result authoritatively, pull the AIA-trial feed directly from USPTO Patent Trial and Appeal Board End-to-End (PTAB E2E) and the ODP API for application 12/335,395 / patent 7,855,217, and cross-check the "family has litigation" links on the Google Patents '217 page. My searches found no proceeding number, panel, institution decision, FWD, or CAFC appeal attributable to this patent.

5. Flag for legal review: the earlier section's statement that the '217 patent itself was ex parte reexamined (ten claims initially rejected, then confirmed) is not independently verified by my searches and should be confirmed via PatentCenter before it is relied upon. The reexamination described in the antitrust pleadings I retrieved concerned the '517 compound patent, not the '217.

Confidence statement. High confidence that zero AIA trial proceedings exist for U.S. 7,855,217 (structured ODP block + corroborating searches). High confidence in the patent numbers/dates for the adjacent IPRs listed above. Unverified: exact judge panels, precise claim numbers, and specific reference combinations for the adjacent 2018 Celgene IPRs (most were denied pre-institution, so no FWD/panel merit opinion exists to quote); the Federal Circuit docket numbers for the affirmed Coalition/REMS decision; and the alleged ex parte reexamination of the '217 patent. I have not fabricated any proceeding number or disposition.

I'll research the assignment chain for this patent using multiple sources.

Let me dig into the specific recorded assignment and check for any post-issuance transfers (BMS acquisition, etc.).

Let me try to pin down the specific reel/frame for the Celgene assignment and check for any BMS or reexamination-related recordings.

Assignment Chain Analysis — US 7,855,217

Important caveat up front: I was unable to retrieve the actual reel/frame numbers or the correspondent of record for the assignments on this patent. The USPTO Assignment Center (assignmentcenter.uspto.gov) and the legacy Assignment Search (assignment.uspto.gov) are session-based query tools that do not expose stable deep-linkable record pages, and my searches surfaced only aggregated legal-events data (Google Patents) — not a raw Assignment Division record. The reel/frame numbers below are therefore marked as unverified. Everything I could confirm is stated as confirmed; everything I could not is flagged. I did not fabricate any recording data.

Inventors

Named on the issued patent (face):

Additional assignors appearing on the recorded assignment but NOT named as inventors on the '217 patent face:

Pattern note (unusual, flag this): The recorded assignment for application 12/335,395 lists five assignors (Cameron, Chen, Jaworsky, Muller, Saindane), while the issued '217 patent names only three inventors (Jaworsky, Chen, Muller). This is consistent with the assignment document being executed against the parent application 10/934,863 (whose inventive entity most likely included Cameron and Saindane) and carried forward into the divisional — not with a defect on the '217 patent. I could not verify the '800 patent's inventor list to confirm this.

Departure pattern: Cannot determine. I found no data on inventor departure dates from Celgene. Note that Chen and Muller are career Celgene scientists associated with the IMiD franchise across two decades, which argues against a "all inventors departed within 12 months → portfolio fire-sale" pattern. But this is inference, not a documented finding.

Original assignee

Celgene Corporation (86 Morris Avenue, Summit, NJ / earlier Warren, NJ) — the assignee named on the issued patent and the only assignee ever recorded.

• Product embodying the claims: Yes. Celgene commercialized REVLIMID® (lenalidomide), NDA 021880, and the '217 patent was Orange Book–listed for it. The claimed subject matter (crystalline lenalidomide hemihydrate = "Form B") is the commercial API form used in the approved product — so this is a textbook case of a polymorph patent covering the shipped drug substance.
• Primary line of business: Research-based pharmaceutical company (oncology, hematology, immunology/inflammation).
• Current status: Operating — but no longer independent. Celgene was acquired by Bristol-Myers Squibb in an all-cash/stock transaction announced January 3, 2019 and completed November 20, 2019; Celgene became a wholly owned BMS subsidiary. Celgene did not dissolve.
• Ownership implication: Because the acquisition was structured as a stock purchase/merger making Celgene a wholly owned subsidiary, title to the '217 patent remained with Celgene Corporation as legal owner — no assignment to BMS was legally required or recorded, and none appears in the patent's legal events.

Assignment timeline

The assignment record is sparse. Based on Google Patents' legal-events tab (which mirrors the USPTO Assignment Division's indexed events), there is exactly one recorded assignment event on this patent, plus the original application-filing ownership entry.

2008-12-15 (recorded; execution date not retrieved) — Reel/Frame UNVERIFIED

• Conveyance: Assignment of Assignors' Interest ("SEE DOCUMENT FOR DETAILS")
• Assignor(s): Louise M. Cameron; Roger Shen-Chu Chen; Markian S. Jaworsky; George W. Muller; Manohar T. Saindane
• Assignee: Celgene Corporation
• Correspondent: Not retrieved. (Not exposed in the sources I could access. This is the single most important gap — see below.)
• Context: Original inventor-to-company assignment — routine prosecution-chain recordation accompanying the filing of divisional application 12/335,395. Not a fire-sale, not a transfer-to-asserter.

That is the entire chain. I found no post-issuance assignment of any kind — no transfer to an LLC, no security agreement, no name-change record for the Celgene→BMS transition, no defensive-aggregator transfer. The legal events list on Google Patents shows only filing → publication → grant → expiry, with no intervening ownership events after the 2008 recording.

Note on a possible parent-case recording: A related Celgene assignment in an unrelated case appears at Reel 013982/0697, recorded 2003-04-23 (brief: "Assignment of Assignor's Interest," assignee Celgene Corporation, 7 Powder Horn Drive, Warren, NJ). This is NOT evidence for the '217 patent — it surfaced from a different litigation record and I could not tie it to application 12/335,395. I mention it only to warn against conflating it with the '217 chain.

Timeline diagram

timeline
    title Ownership of US 7855217
    2003 : Provisional 60499723 filed
    2004 : Parent 10934863 filed
    2008 : Divisional 12335395 filed
         : Inventors assign rights to Celgene
    2010 : Patent 7855217 issues Dec 21
    2017 : Celgene sues Zydus and Lotus
    2019 : Celgene becomes BMS subsidiary
    2024 : Patent expires Nov 24

NPE / troll-pattern signals

Corroborating litigation context (operating-company, not NPE):

• Celgene's own covenant in Celgene v. Lotus/Alvogen represents that "Celgene hereby represents and warrants that it owns all right, title, and interest in United States Patent No. 7,855,217" (dated Aug 8, 2018) — directly confirming unbroken ownership.
• Celgene v. Apotex consent judgment (D.N.J. 2:18-cv-00461, entered Apr 30, 2019) confirms Celgene asserted claims 1–10 of the '217 patent and that those claims were held valid and enforceable (though Apotex's product was found non-infringing).
• Amneal consent judgment (Jan–Feb 2024, 2:24-cv-00500) enjoined Amneal until expiry of the "'800 and '217" patents.
• U.S. 7,855,217 expired November 24, 2024 (adjusted expiration), so it is no longer enforceable regardless of ownership.

Verdict

Operating-company assertion.

The chain is a single, unbroken inventor-to-company assignment to Celgene Corporation, recorded around 2008-12-15 in connection with divisional application 12/335,395. Celgene is a practicing pharmaceutical manufacturer whose REVLIMID product embodies the claimed lenalidomide hemihydrate, it asserted the patent in its own name against generic competitors beginning with the April 2017 Zydus and Lotus complaints, and it still owns the patent today as a wholly owned Bristol-Myers Squibb subsidiary following the November 20, 2019 acquisition. Not one indicator of an NPE holding pattern is present — no shell LLC, no asserter entity, no cascading transfers, no pre-suit assignment, no defensive-aggregator exit.

Residual uncertainty: Because I could not retrieve the actual reel/frame or correspondent of record, I cannot fully exclude a second, unindexed recording. To close this gap, verify directly:

• USPTO Assignment Center: https://assignmentcenter.uspto.gov/ (search "7855217" or application "12/335,395")
• Legacy Assignment Search: https://assignment.uspto.gov/patent/index.html

If either returns additional entries beyond the December 2008 Celgene recording, this verdict should be re-run.

I'll search for the prior art citations on this specific patent.

Let me look for the specific "References Cited" section on this patent.

I have the FreePatentsOnline list of US Patent References. Let me get the complete front-page citation list including foreign references and non-patent literature.

Prior-Art Analysis — US Patent 7,855,217 B2

Method note and scope caveat

I retrieved the citation record for US 7,855,217 B2 (app. 12/335,395; filed Dec 15, 2008; issued Dec 21, 2010; priority Sept 4, 2003). The authoritative full text supplied in the prompt omits the front-page "References Cited" block, so the citation list below was reconstructed from (a) the FreePatentsOnline front-page record for US 7,855,217 (freepatentsonline.com/7855217.html), and (b) a court filing (D.N.J. 2:…, CourtListener njd.364322.1.0.pdf) that reproduces the printed front pages of the Revlimid-family patents. Both sources rendered the bottom of the reference list truncated, so I flag where the list is incomplete rather than guess at missing entries. I could not reach USPTO PatentCenter/PatFT directly within this session; Espacenet, Google Patents, and FPO were used as the authoritative mirrors. No similar patent numbers were substituted for 7855217.

Because the issued claims are narrowly directed to the crystalline hemihydrate ("Form B") of lenalidomide, the §102 analysis turns on whether a single reference discloses that crystalline hemihydrate.

A. References cited on the face of US 7,855,217

Additional references listed on the front page (partially visible / truncated): the FPO record continues with further entries beginning "2…" that were cut off. A companion court filing reproducing the front pages of the Revlimid-family patents lists US 5,593,990 A (D'Amato, Jan 1997), US 5,629,327 A (D'Amato, May 1997), US 6,235,756 B1 (D'Amato, May 2001) in the same reference block. Because I could not confirm these three belong to the '217 front page specifically (as opposed to the '517 or '230 front page reproduced in the same document), I list them as unverified candidates, not confirmed citations. If confirmed, all three are D'Amato angiogenesis/thalidomide-analog references and would likewise fail to disclose the crystalline lenalidomide hemihydrate (same reasoning as item 10).

B. Bottom-line §102 assessment

None of the verified face-of-patent references appears to anticipate any of claims 1–10 under 35 U.S.C. §102. The reason is structural:

• Claim 1 requires a solid form in which crystalline lenalidomide hemihydrate constitutes >80% by weight. No cited reference — compound patent ('517, '230), method-of-use applications, or process applications — discloses a crystalline hydate/polymorph of lenalidomide, a hemihydrate stoichiometry, or any XRPD/TGA/KF characterization that would inherently disclose the Form B crystal. Anticipation requires disclosure of every limitation in a single reference, and the "crystalline hemihydrate" limitation is absent everywhere.
• Claim 5 (composition) inherits the claim-1 solid-form limitation and thus fails for the same reason; the D'Amato/Zeldis/Muller composition and method references disclose the compound in compositions but not the crystalline hemihydrate as the recited solid form.
• Claims 6–10 (single unit dosage forms at ~5/10/25/50 mg) inherit claim 5's limitation.
• References 4–7 and 9–14 are post-priority publications, so they are not §102(a)/(b) art at all; the family members (4–7, and the '800 parent) also lack §102(a)(2)/102(e) effect because they share the same Sept 4, 2003 priority.
• Reference 3 (the '800 parent) is the same invention's earlier family member — a related document, not prior art to its own divisional.

This is consistent with the patent having been confirmed on reexamination despite the initial rejections of all ten claims (per the antitrust pleading in In re Revlimid & Thalomid Purchaser Antitrust Litig., No. 2:19-cv-07532 (D.N.J.)).

C. Caveats and contradictions to flag

1. Incomplete citation list. The face-of-patent "References Cited" block could not be retrieved in full (FPO and the court filing both truncate it). Items 15+ and any foreign patent documents / non-patent literature (NPL) entries are not verified. Typical NPL in this family includes DiMartino et al., J. Thermal Anal. 48:447-458 (1997) and Knapman, Modern Drug Discoveries (2000), both cited in the specification as general polymorph-art background — but I did not confirm they appear in the '217 front-page NPL block, so I do not assert them as citations here.
2. Do not conflate identifiers. The user's instruction to interpret IDs literally matters here: the cited US 5,635,517 (item 1) is the compound patent, distinct from this patent's number 7,855,217. The prior summary already flagged this ('517 = compound patent; '217 = this polymorph patent). No contradiction with the earlier section; this analysis reinforces it.
3. No contradiction found between this citation analysis and the previously generated sections — claims 1–10 and the two-independent-claim structure match the Espacenet claim text I retrieved.
4. Alleged (not established) invalidity art. The Revlimid antitrust complaint (CourtListener njd.498914.1.0_1.pdf) alleges the polymorph claims are invalid over "publicly available prior art and research from decades earlier" and non-disclosed art, and that the claims are obvious variants of the '517 compound. Those are litigation allegations, not adjudicated prior art, and the complaint itself notes the reexam confirmed the claims. They do not identify a specific §102 reference I could verify.
5. Reexamination. If the actual reexam rejections applied specific §102 references, those are the most probative prior art for this patent — but I could not retrieve the reexam record in this session.

Sources: Google Patents (patents.google.com/patent/US7855217/en); FreePatentsOnline (freepatentsonline.com/7855217.html); Espacenet claims for US7855217B2; CourtListener D.N.J. filings (njd.364322.1.0.pdf, njd.498914.1.0_1.pdf); DrugPatentWatch patent-family record for US7855217.

I'll ground this analysis in the prior-art references of record for the '217 patent. Let me pull that data.

Good — I have the '217 claim set confirmed. Now let me pull the actual prior-art of record (the "(56) References Cited" and reexamination art), plus the European opposition outcome, which is the best-documented obviousness challenge to this family.

Let me nail down two decisive points: the outcome of the European appeal T 1443/15 (which addressed the identical Form B hemihydrate claim), and whether the '217 patent itself — as opposed to the '517 compound patent — was reexamined.

Obviousness Analysis — U.S. Patent 7,855,217 B2 under 35 U.S.C. § 103

Note on the "Prior Art section of this page": The Google Patents page for US7855217B2 does not carry a "References Cited" (56) exhibit in the fetched text. Its only "Prior art" field is the keyword string: isoindol; piperidine; dihydro; oxo; polymorph — i.e., five classification-style terms, not references. I therefore build the § 103 record from three grounded sources: (a) references the specification itself cites or admits, (b) references identified in the litigation/opposition record for this family, and (c) the general state of the polymorph art as of the Sept. 4, 2003 priority date. Where I could not retrieve the actual PTO (56) list, I say so.

1. The claims to be tested

Confirmed verbatim from the Espacenet claims rendering:

Two structural features drive the whole analysis:

1. The claims recite no analytical fingerprint. Claim 1 requires only "crystalline … hemihydrate" at >80 wt%. It does not require the XRPD peaks at 16, 18, 22 and 27 degrees 2θ that Celgene later had to add in Europe (see § 7 below). The broadest U.S. claim is therefore materially broader than the narrowest European claim that survived to the appeal stage.
2. The compound itself is old. The specification states: "U.S. Pat. Nos. 6,281,230 and 5,635,517, both to Muller et al., disclose 3-(4-amino-1-oxo-1,3 dihydro-isoindol-2-yl)-piperidine-2,6-dione…" (col. 1). That is an admission on the face of the patent that the compound, its synthesis, its pharmaceutical compositions, and its therapeutic uses are prior art. The sole asserted contribution is the solid-state form.

2. The prior-art record

2.1 References cited or admitted in the '217 specification

The last row is important: the patent concedes that the entire methodological toolkit for finding the claimed form — including slurrying — was known in the art. Every technique the '217 uses to make Form B (hexane/toluene/water recrystallization; water slurry; 75 °C, 6–24 h) is drawn from that admitted toolkit.

2.2 References from the family's litigation/opposition record

2.3 The general polymorph art at the priority date (skilled-art knowledge)

• Haleblian & McCrone, "Pharmaceutical Applications of Polymorphism," J. Pharm. Sci. 58(8):911–929 (1969) — the canonical teaching that a drug substance can exist in polymorphic, solvate and hydrate forms, and that the form must be characterized and selected.
• Guillory, "Generation of Polymorphs, Hydrates, Solvates, and Amorphous Solids," in Polymorphism in Pharmaceutical Solids (Brittain ed., 1999) — teaches that hydrates are routinely produced by recrystallization from water and aqueous solvent systems, and by slurry equilibration.
• Byrn, Pfeiffer & Stowell, Solid-State Chemistry of Drugs (2d ed. 1999); Bernstein, Polymorphism in Molecular Crystals (2002); Brittain, Polymorphism in Pharmaceutical Solids (1999) — routine screening methodology and the predictive relationship between hydrogen-bonding capacity and hydrate formation.

3. Level of ordinary skill

A person of ordinary skill would be a medicinal or pharmaceutical chemist (or formulation scientist) with an advanced degree and several years' experience in solid-state pharmaceutical chemistry, familiar with XRPD, DSC, TGA and Karl Fischer analysis, and with routine polymorph screening (solvent recrystallization, anti-solvent addition, slurry equilibration, evaporation, thermal cycling). This definition follows from the characterization methods the patent itself recites in Example 6 (Shimadzu XRD-6000, TA 2050/2950 TGA, TA 2920 DSC, VTI SGA-100 moisture balance) — all standard equipment, which supports a "routine experimentation" characterization of the work.

4. Combination 1 — Muller '517 + Muller '230 + polymorph-screening art → claim 1

This is the strongest and cleanest § 103 combination.

What each reference supplies:

• '517 and '230 supply every element of claim 1 except the crystalline form: the compound (lenalidomide), a pharmaceutical composition containing it and a carrier (→ claim 5), and unit dosage disclosure (→ claim 6).
• DiMartino and Knapman (admitted prior art inside the '217 itself) supply the reason to look: polymorphs differ in solubility, stability, flowability, compressibility and bioavailability; finding a new form "can provide a variety of advantages." That is literally the motivation statement the applicant wrote into its own Background.
• Guillory / Byrn / Brittain / Bernstein / Haleblian-McCrone supply the method: hydrate and solvate forms are generated by recrystallization from — and slurrying in — water and aqueous solvents.

Why a POSA would have been motivated to combine them (the KSR analysis):

1. Design incentive, same field, known problem. Having selected lenalidomide as a development candidate, the artisan must select a solid form to manufacture a capsule (the '230 patent already claims pharmaceutical compositions). Choosing a crystalline form is not optional; it is a required step in development. KSR, 550 U.S. 398, 417, 421 (2007) (predictable solutions; design incentives; "a finite number of identified, predictable solutions").
2. Predictable solution set. The artisan screening a basic, lactam- and arylamine-bearing compound against a routine panel of solvents (aqueous and organic) expects to find (i) an anhydrous form and (ii) one or more hydrates, most commonly the hemihydrate or monohydrate. Hydrate stoichiometries are not random; a hemihydrate is a routine, expected outcome of water/vapor equilibration.
3. The patent's own protocol proves routineness. Form B was obtained "by crystallization from the solvents hexane, toluene and water" and from a water slurry. The '217's own "preferred process parameters" — "a stirred 10 volume water slurry at ~75 °C for 6–24 hours" — are textbook slurry-equilibration conditions, exactly the routine practice taught by Guillory.
4. Reasonable expectation of success. Under In re O'Farrell, 853 F.2d 894, 903 (Fed. Cir. 1988), and KSR, a finite, predictable set of candidates with a reasonable expectation of success supports obviousness. Here the artisan had a specific, predictable target (the hemihydrate) and a routine method to reach it.

Claim 1's "greater than about 80% by weight" limitation does not rescue it. The '217 itself defines "substantially pure" as >80 wt% of one form (col. 4). That threshold is an arbitrary purity floor, not a technical contribution; and it is met by any crystalline hemihydrate product of a routine aqueous crystallization followed by ordinary filtration and drying. A purity/phase-dominance recitation that follows automatically from the disclosed process adds no inventive weight.

5. Combination 2 — Inherency route ('517/'230 Example + aqueous isolation) → claim 1

Where the polymorph produced by a prior-art process is not expressly named, § 103 permits inherency to supply the missing limitation — PAR Pharm., Inc. v. TWI Pharms., Inc., 773 F.3d 1186, 1194–95 (Fed. Cir. 2014) ("inherency may supply a missing claim limitation in an obviousness analysis").

The theory:

• The '517/'230 synthesis Example produces lenalidomide via catalytic hydrogenation of the 3-(4-nitro…) precursor, followed by conventional isolation. The compound patent itself teaches the compound's preparation.
• If that isolation/crystallization is performed from aqueous or water-wet solvent — the ordinary practice — the product obtained is a hydrate. The '217 specification itself concedes the commercial reality: "Three batches were produced as apparent mixtures of polymorphs in the non-micronized API," and it identifies Form B as "the desired polymorph for the active pharmaceutical ingredient (API)" that "has been used in the formulation of API into drug product for clinical studies."
• The EPO record shows Mylan and Teva submitted testing that following Example 1 of the '517 patent yields a defined crystalline form (Form A). Extending that reasoning to the hydrate (Form B) merely requires the additional, ordinary step of aqueous isolation — and the applicant's own specification concedes that Form B converts/recrystallizes freely in water.

Strength: Moderate. Inherency requires "necessarily present," not "probably or possibly" (Akamai Techs. v. Cable & Wireless, 344 F.3d 1186, 1192 (Fed. Cir. 2003)). The D.N.J. expressly noted the "battle of the experts" on this point in In re Revlimid & Thalomid Purchaser Antitrust Litig., No. 2:19-cv-07532 (D.N.J. June 6, 2024), Doc. 446, at 234–38 — and held only that it did not establish sham litigation (a pleading standard), not that the patents are non-obvious. Do not cite that opinion as a merits holding of validity.

6. Claims 5–10 — composition and dosage strengths

These fall even more readily than claim 1, and by a two-step route that is the paradigm of KSR:

• Claim 5 = [obvious solid form of claim 1] + [pharmaceutically acceptable excipient or carrier]. The excipient/carrier element is expressly disclosed in '517/'230 ("pharmaceutical compositions" of lenalidomide). Combining a known active solid form with a known excipient is the "combination of familiar elements according to known methods… yields no more than one would expect." KSR, 550 U.S. at 416. Anticipation/obviousness of the composition follows from the compound patent plus the obviousness of the form.
• Claim 6 (single unit dosage form) — capsules/tablets are the disclosed and conventional dosage form for an oral immunomodulatory drug; the '230 patent discloses unit dosage forms. Routine design choice.
• Claims 7–10 (about 5, 10, 25, 50 mg) — these are standard oral unit strengths for an immunomodulatory agent, reached by routine dose-ranging. Nothing in the claims ties these strengths to any special or unexpected property of Form B. Under MPEP § 2144.04 and KSR ("obvious to optimize"), a recitation of conventional dosage strengths, without a showing of a form-specific or dose-specific unexpected result, adds no patentable weight. Note also the specification's own disclosure that a single dosage form comprises Form B "in an amount of about 5, 10, 25 or 50 mg" — an admission that these four strengths are the standard, arbitrary set.

7. What the patent's own data do — and do not — show

A § 103 analysis for a new form of a known compound turns on whether the new form has unexpected properties (Pfizer, Inc. v. Apotex, Inc., 480 F.3d 1348 (Fed. Cir. 2007); Aventis Pharma Deutschland GmbH v. Lupin Ltd., 499 F.3d 1293 (Fed. Cir. 2007); Abbott Labs. v. Sandoz, Inc., 544 F.3d 1341 (Fed. Cir. 2008)). The '217's data cut against Celgene:

In other words, the '217 does not and cannot make the Pfizer v. Apotex-style showing. What remains is a "non-hygroscopic, easily-filtered hydrate" from a routine screen — a manufacturing convenience, not an unexpected result.

Contrast the two pro-validity cases the patentee would reach for: Sanofi-Synthelabo v. Apotex, 550 F.3d 1075 (Fed. Cir. 2008) (clopidogrel bisulfate — validity rested on extensive evidence that the specific salt form was selected from among thousands of salts on the basis of unexpected properties), and the notion that polymorph discovery is "unpredictable." Neither is available here, because the '217's own comparative data show Form B performing comparably to (or worse than) Form A.

8. Rebuttal arguments a patentee would raise — and their weaknesses

9. Contradictions and corrections to flag in the earlier sections

1. ⚠️ The "'217 reexamination" statement appears to be a misattribution. The earlier summary said: "The '217 patent was reexamined; a 2026 antitrust complaint states all ten issued claims were initially rejected during reexamination… with the patent ultimately confirmed." The complaint passage in question (BMS/Celgene antitrust complaint ¶ 195, and the parallel allegations at ¶¶ 262–279 of the Cigna/Pomalyst complaints) concerns "the '517 patent" — i.e., U.S. 5,635,517, reexamination 90/005,157, filed 14 Apr 1998, in which the PTO rejected all ten claims over the three D'Amato patents (U.S. 4,808,402-era family) plus Leibovich, and Celgene overcame the rejection with the Stirling Declaration (which, the complaints allege, tested "Compound 2" = pomalidomide, not a claimed compound). The '217 polymorph patent is a different, later, single-digit-claims-family document. The "ten issued claims" figure matched both patents and appears to have caused a conflation. I could not independently confirm from the sources retrieved whether U.S. 7,855,217 itself was ever the subject of an ex parte reexamination request. Treat the earlier "reexamined" statement as unverified and likely wrong; the documented reexamination is of the '517 compound patent.
2. WO 2005/023192 is not prior art (see § 2.2). A third-party aggregator listed it as prior art against the '217; it is the family's own PCT publication.
3. Claims 2–4 remain unrecoverable. Espacenet and FreePatentsOnline both truncate them. This analysis therefore covers claims 1 and 5–10 with confidence and claims 2–4 only structurally (they depend from claim 1 and add limitations).
4. The Google Patents "Prior art" field contains keywords, not references — worth stating explicitly, because it is not a substitute for the PTO (56) list, which I could not retrieve.

10. Conclusion on § 103

Claims 1–10 of U.S. 7,855,217 would, on this record, be vulnerable to a § 103 challenge, with claim 1 the keystone.

• Primary combination: Muller '517 + '230 (compound, compositions) + DiMartino (1997) + Knapman (2000) (admitted prior art in the '217's own Background, teaching that polymorphs matter and differ in solubility/stability/processability) + Guillory/Byrn/Brittain/Bernstein (teaching that hydrates are routinely obtained by recrystallization from, and slurrying in, water). Motivation: selecting a crystalline solid form is a mandatory pharmaceutical-development step; hydrates are a predictable and expected outcome for a hydrogen-bonding compound exposed to water; and the specification itself concedes the methods (water slurry, recrystallization from hexane/toluene/water, 75 °C, 6–24 h) were known. KSR supplies the legal glue.
• Secondary route: inherency — the '517/'230 synthetic Example plus ordinary aqueous isolation yields a hydrate, making claim 1's form "necessarily present" (PAR Pharm.; Akamai).
• Claims 5–10 fall with claim 1, plus the familiar-elements/excipient reasoning and the routine-optimization reasoning for the 5/10/25/50 mg strengths.
• No unexpected-results rebuttal is available: the '217's own data show Form A and Form B dissolving at the identical intrinsic rate (0.35 mg/cm²/min), Form B dissolving more slowly in the solubility study, and Form E, not Form B, being the most stable form in aqueous systems.

Caveats on confidence: (i) this is a paper analysis — I do not have the PTO (56) list, the prosecution history, or any litigation expert record; (ii) the Federal Circuit has repeatedly cautioned that polymorph obviousness must be proved with evidence of what a skilled artisan would expect, not merely the observation that screening methods were known (the D.N.J. quoted and applied this caution in the Revlimid/Thalomid sham-litigation ruling); and (iii) the patent is expired (adjusted expiration Nov 24, 2024), so this analysis is retrospective and of interest for the Form A family members that expire later (notably U.S. 7,465,800, ~Apr 2027).

Sources: Google Patents US7855217B2 (patents.google.com/patent/US7855217/en); Espacenet claims US7855217B2; FreePatentsOnline 7855217 and 8058443; EPO Board of Appeal decision T 1443/15 (epo.org/boards-of-appeal/decisions/pdf/t151443eu1.pdf); Luxembourg patent register entry for EP1667682 (revocation recorded 16 Nov 2020); In re Revlimid & Thalomid Purchaser Antitrust Litig., No. 2:19-cv-07532 (D.N.J. June 6, 2024), Doc. 446; BMS/Celgene antitrust complaints (D.N.J., filed 2026; hbsslaw.com Pomalyst and Revlimid complaints, ¶¶ 195, 262–279); GreyB/Pharsight Revlimid patent-expiry table; DrugPatentWatch patent-claim and family pages.