Merck v. Hetero: HIV Drug Consent Judgment After 723-Day ANDA Battle
Merck Sharp & Dohme sued Hetero USA and Hetero Labs over ANDA No. 217747, a generic version of its doravirine/tenofovir disoproxil fumarate/lamivudine HIV combination therapy, asserting US10603282 and US10842751. The parties resolved the dispute by consent judgment — with Hetero conceding validity and infringement and accepting a permanent injunction — after nearly two years of litigation in the District of New Jersey.
Merck locks in permanent injunction over generic HIV triple therapy
Filed on 28 November 2022 in the U.S. District Court for the District of New Jersey, this ANDA litigation arose after Hetero USA, Inc. and its Indian parent Hetero Labs Limited sought FDA approval (ANDA No. 217747) to market a generic version of Merck’s doravirine/tenofovir disoproxil fumarate/lamivudine combination — an HIV-1 treatment marketed as Delstrigo. Merck asserted three patents: US8,486,975, US10,603,282, and US10,842,751, collectively designated as the ‘Licensed Patents’ under the consent judgment.
The case closed on 20 November 2024 via a consent judgment and permanent injunction. Critically, Hetero stipulated — for purposes of this action — that the Licensed Patents are valid and enforceable and that the Hetero Product infringes them. Hetero, its affiliates, successors, and assigns are permanently enjoined from making, using, selling, offering to sell, importing, or distributing the ANDA product in the United States. All claims, counterclaims, and affirmative defenses were dismissed with prejudice, with no costs awarded to either party.
The 723-day duration suggests meaningful pre-trial litigation before the parties converged on a negotiated exit — longer than many ANDA consent judgments that resolve within one Hatch-Waxman 30-month stay window. The public record does not disclose any licence entry date or revenue-sharing arrangement, which is typical for ANDA settlements where commercialisation terms are confidential. What is clear is that Merck achieved its primary litigation objective: blocking generic market entry for the duration of the Licensed Patents.
Filing to Consent Judgment in 723 days
723 days — above median for ANDA patent cases in D.N.J., typically resolved in 12–24 months
Permanent injunction secured: what Merck’s consent judgment means for both parties
Consent judgment is not a dismissal — it is a court order
Unlike a voluntary dismissal, a consent judgment is entered by the court and carries full judicial authority. Here the parties jointly moved for entry of judgment, with the court retaining jurisdiction to enforce it. Hetero’s stipulations on validity and infringement — though limited to this action — are binding and enforceable. The permanent injunction can be enforced directly by Merck and its successors without filing a new lawsuit.
Court-enforceable orderMerck secures generic market exclusion without going to trial
Merck obtained exactly what an ANDA plaintiff seeks: a permanent injunction preventing Hetero from commercialising ANDA No. 217747 in the United States. Hetero’s concession of infringement and validity for purposes of this action strengthens Merck’s enforcement posture. No costs were awarded, but Merck avoided the uncertainty of a merits ruling — protecting its HIV franchise revenues tied to Delstrigo through the patent term.
Permanent injunction grantedHetero blocked from U.S. market entry on its doravirine ANDA
Hetero’s ANDA No. 217747 is effectively frozen — the injunction bars all U.S. commercial activity across Hetero USA, Hetero Labs, and their affiliates. While the stipulations are limited to this action, Hetero cannot launch the product without breaching the court order. Any future entry would require either patent expiry, a licence negotiation with Merck, or a successful IPR or reexamination of the Licensed Patents — none of which is disclosed in the public record.
ANDA commercialisation enjoinedHIV combination therapy patents reinforced as an enforcement tool
This outcome signals that Merck’s doravirine combination patents — US10603282 and US10842751 — are sufficiently robust to deter Hetero from litigating to judgment. Other ANDA filers for doravirine-based combinations should treat these patents as high-risk assets requiring thorough validity and FTO analysis before filing a Paragraph IV certification. The no-costs provision is standard, but the absence of a disclosed licence date suggests Merck is not yet willing to grant early market access.
High barrier to generic entryFull party and counsel information
| Role | Name | Type | Detail |
|---|---|---|---|
| Plaintiff | Merck Sharp & Dohme, LLC | Company | Global pharmaceutical innovator — holder of US10603282 and US10842751 covering HIV combination therapySearch in Eureka ↗ |
| Defendant | Hetero USA, Inc. | Company | Generic drug manufacturer (U.S. subsidiary and Indian parent) seeking ANDA approval for doravirine/TDF/3TCSearch in Eureka ↗ |
| Co-Defendant | Hetero Labs Limited | Individual | Search in Eureka ↗ |
| Co-Defendant | Hetero Labs Limited | Individual | Search in Eureka ↗ |
| Plaintiff counsel | Alexander Lee Callo | Attorney | Counsel for Merck Sharp & Dohme, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Charles Michael Lizza | Attorney | Counsel for Merck Sharp & Dohme, LLCSearch in Eureka ↗ |
| Plaintiff counsel | Sarah Ann Sullvian | Attorney | Counsel for Merck Sharp & Dohme, LLCSearch in Eureka ↗ |
| Plaintiff counsel | William C. Baton | Attorney | Counsel for Merck Sharp & Dohme, LLCSearch in Eureka ↗ |
| Plaintiff law firm | Saul Ewing LLP | Law Firm | Representing Merck Sharp & Dohme, LLCSearch in Eureka ↗ |
| Defendant counsel | Eric I. Abraham | Attorney | Counsel for Hetero USA, Inc.Search in Eureka ↗ |
| Defendant counsel | Kristine L. Butler | Attorney | Counsel for Hetero USA, Inc.Search in Eureka ↗ |
| Defendant counsel | Stephanie-Rose Orlando | Attorney | Counsel for Hetero USA, Inc.Search in Eureka ↗ |
| Defendant counsel | William Murtha | Attorney | Counsel for Hetero USA, Inc.Search in Eureka ↗ |
| Defendant law firm | Hill Wallack LLP | Law Firm | Representing Hetero USA, Inc.Search in Eureka ↗ |
| Presiding judge | Judge N/A | Judge | New Jersey District CourtSearch in Eureka ↗ |
Official order — verbatim text
The consent judgment is unusually explicit in its concessions: Hetero stipulated — for purposes of this action — both the validity and enforceability of all three Licensed Patents and their infringement by the Hetero Product. While the ‘for purposes of this action only’ carve-out preserves Hetero’s theoretical ability to challenge the patents in a separate PTAB proceeding, the permanent injunction makes commercial launch practically impossible without a successful IPR outcome. Merck retains court jurisdiction for enforcement, giving it a direct contempt mechanism against any attempted market entry.
US10603282 & US10842751 — doravirine HIV combination therapy formulations
US10,603,282 (App. No. 15/780,142) and US10,842,751 (App. No. 16/791,398) cover pharmaceutical compositions and methods relating to the fixed-dose combination of doravirine (a non-nucleoside reverse transcriptase inhibitor), tenofovir disoproxil fumarate, and lamivudine — the three-component HIV-1 regimen marketed by Merck as Delstrigo. These are formulation and combination-use patents that protect the specific dosage form approved by the FDA, layering protection on top of the underlying doravirine compound patents.
From a competitive standpoint, formulation patents on fixed-dose HIV combinations are among the most commercially critical assets in the branded pharmaceutical arsenal — they extend effective exclusivity well beyond compound patent expiry. Any generic manufacturer seeking to market a bioequivalent to Delstrigo must either design around these claims, invalidate them at the PTAB, or negotiate a licence. This case demonstrates that Merck is willing to enforce these patents aggressively in D.N.J., the preferred venue for Hatch-Waxman ANDA litigation.
Should you run an FTO against US10603282 and US10842751?
Any pharmaceutical company with an ANDA pending or in preparation for a doravirine/TDF/3TC fixed-dose combination must treat US10,603,282 and US10,842,751 as primary blocking patents. The same analysis applies to R&D teams developing novel HIV combination regimens that incorporate doravirine as a component — even reformulated or modified-release variants may fall within claim scope depending on formulation specifics. Hetero’s litigation outcome illustrates the downside of proceeding to ANDA filing without a clear invalidity or non-infringement position.
PatSnap Eureka’s FTO Search Agent can map the full claim landscape of both patents, identify prior art that could support a PTAB challenge, and flag continuation applications that Merck may file to extend coverage. R&D and regulatory teams can use Eureka to benchmark their formulation design choices against the asserted claims before committing to an ANDA strategy — reducing the risk of injunction exposure of the kind Hetero now faces.
Run a freedom-to-operate analysis on US10603282B2 to assess your product’s exposure
Run FTO in Eureka →Similar ANDA patent cases: HIV antiviral formulation disputes in D.N.J.
Explore comparable Hatch-Waxman infringement actions involving HIV antiviral combination therapy patents litigated in the District of New Jersey.
Related patent case — similar technology
Comparable case in the same technology domain. Patent holder and defendant reached resolution after proceedings.
SettledRelated infringement action — same court
Comparable Pharmaceutical compositions containing doravirine, tenofovir disoproxil fumarate and lamivudine-adjacent infringement action. Patent enforcement dynamics analysed in depth.
Active · District CourtRelated invalidity challenge — appellate outcome
Combined invalidity and infringement action in the same technology space. Decided after substantive proceedings.
DecidedMerck Sharp & Dohme, LLC’s broader IP enforcement history
Merck Sharp & Dohme, LLC’s full litigation history covering prior enforcement, licensing activity, and inter partes review proceedings.
Portfolio viewWhat this case signals for the HIV antiviral patent landscape
This consent judgment reinforces Merck’s grip on the doravirine franchise and raises the stakes for any generic filer targeting these formulation patents.
Paragraph IV filers targeting doravirine face a high-risk patent cluster
With three patents — including US8,486,975, US10,603,282, and US10,842,751 — covering the doravirine/TDF/3TC combination, any new ANDA filer must contend with a layered assertion strategy. Hetero’s concession of validity and infringement, even limited to this action, suggests the patents presented formidable challenges under litigation scrutiny.
Consent judgments with permanent injunctions are a strong ANDA outcome for innovators
Merck’s resolution avoids the risk of an adverse validity ruling while locking in a court-enforceable injunction. IP teams at branded pharma companies should note: a negotiated consent judgment can deliver the same market-exclusion result as a trial win without the appellate risk exposure that a contested judgment carries.
Other Hetero ANDA filings may signal the next litigation battleground
Hetero Labs is a prolific ANDA filer across multiple therapeutic areas. Monitoring its pending ANDAs against Merck’s portfolio — including follow-on HIV formulations — could provide early warning of the next infringement action before a complaint is filed.
IPR and reexamination remain Hetero’s only viable path to market
With a permanent injunction in place and no disclosed licence, Hetero’s realistic options are limited to challenging US10603282 or US10842751 at the PTAB. Competitors and investors should monitor PTAB filings against these patents as a leading indicator of whether generic entry is imminent.
Merck v Hetero — key questions answered
Merck asserted three patents: US8,486,975, US10,603,282, and US10,842,751, all covering pharmaceutical compositions containing doravirine, tenofovir disoproxil fumarate, and lamivudine. These are collectively referred to as the ‘Licensed Patents’ in the consent judgment entered on 20 November 2024.
The case was resolved by a consent judgment and permanent injunction entered on 20 November 2024. Hetero stipulated — for purposes of this action — to the validity, enforceability, and infringement of all three Licensed Patents. Hetero and its affiliates are permanently enjoined from commercialising ANDA No. 217747 in the United States. All claims were dismissed with prejudice, with no costs awarded.
The stipulation is expressly limited to this action, meaning it does not create a legal bar to Hetero challenging the patents at the PTAB via inter partes review. However, the permanent injunction prevents commercial launch regardless of any pending PTAB proceeding, unless and until the patents are cancelled or Hetero obtains a licence from Merck.
The case concerns Abbreviated New Drug Application No. 217747, filed by Hetero for a generic version of Merck’s doravirine/tenofovir disoproxil fumarate/lamivudine combination product (marketed as Delstrigo). The consent judgment permanently bars Hetero from commercialising this ANDA product in the United States.
The outcome signals that Merck’s doravirine combination patents — particularly US10,603,282 and US10,842,751 — survived litigation scrutiny sufficiently to compel a well-resourced generic manufacturer to concede infringement and accept a permanent injunction. Other ANDA filers should conduct thorough FTO and invalidity analysis before filing Paragraph IV certifications against these patents.
Monitor ANDA threats to your HIV antiviral IP portfolio
This case shows how quickly ANDA litigation can result in a permanent injunction. PatSnap Eureka helps pharma IP teams track new ANDA filings, Paragraph IV certifications, and PTAB petitions targeting their key patents — giving you the earliest possible warning of a generic challenge.
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