United States Patent 10,548,943: Angiotensin II Septic-Shock Dosing Scope, Patent Landscape, and Generic Entry Risk
U.S. Patent No. 10,548,943 protects a dosing protocol for synthetic human angiotensin II in adults with septic shock who require blood-pressure support. The patent centers on an initial infusion rate of approximately 20 ng/kg/min, upward titration to approximately 30 or 40 ng/kg/min, and achievement or maintenance of a mean arterial pressure, or MAP, of approximately 65 mmHg.
The patent is commercially important because its claims closely track the FDA-approved Giapreza dosing instructions. It is a method-of-use patent, not a composition, formulation, manufacturing, or device patent. The principal infringement risk is therefore associated with administering angiotensin II to septic-shock patients within the claimed dose and treatment parameters.
What does U.S. Patent 10,548,943 protect?
The patent protects methods of increasing blood pressure in a human patient with septic shock by administering angiotensin II at specified rates. The two independent claims define the core coverage.
| Claim |
Core limitation |
Practical scope |
| 1 |
Initial angiotensin II rate of about 20 ng/kg/min |
Covers the initial-dose protocol |
| 24 |
Angiotensin II rate from about 20 to about 40 ng/kg/min |
Covers administration within the full claimed range |
| 2, 3 |
Titration to about 30 or 40 ng/kg/min |
Protects escalation endpoints |
| 4 |
Titration in increments of about 10 ng/kg/min |
Protects the escalation pattern |
| 5, 6 |
Administration for about 0.25 to 120 hours, or 1 to 7 hours |
Adds treatment-duration limits |
| 7, 8 |
Titration to MAP of about 65 or 65 mmHg |
Protects the hemodynamic target |
| 9, 10 |
Maintaining MAP for specified durations |
Adds persistence of the target |
| 11-14 |
Concomitant vasopressor therapy |
Covers use with norepinephrine, vasopressin, epinephrine, or dopamine |
| 15-23 |
Dosing, duration, and MAP limitations with vasopressors |
Creates narrower combination-method claims |
| 25, 26 |
Angiotensin II at approximately 30 or 40 ng/kg/min |
Narrow claims under claim 24 |
The claims use "about," which broadens the literal range beyond the stated numerical values. The exact scope would depend on claim construction, intrinsic patent evidence, prosecution history, and expert testimony concerning clinically meaningful dosing variation.
How broad are the independent claims?
Claim 1: initial-dose protocol
Claim 1 requires all of the following:
- A human subject.
- Septic shock.
- A clinical need to increase blood pressure.
- Administration of angiotensin II.
- An initial rate of about 20 ng/kg/min.
A method that omits the septic-shock indication, uses a different patient population, or starts below or materially above the claimed rate may avoid literal infringement of claim 1. The claim does not require concomitant norepinephrine or another vasopressor. It also does not require a particular duration or MAP target.
The phrase "in need of said increasing" is a functional treatment limitation. It is likely satisfied when the medical record shows hypotension or inadequate perfusion requiring vasopressor support.
Claim 24: rate-range claim
Claim 24 is structurally broader than claim 1 in some respects. It covers administration at a rate from approximately 20 to approximately 40 ng/kg/min and does not expressly require:
- An initial dose of 20 ng/kg/min;
- Titration;
- A MAP target;
- Concomitant vasopressor treatment; or
- A specified treatment duration.
It still requires septic shock, a human subject, a need to increase blood pressure, and angiotensin II administration. A product label or clinical protocol that directs dosing anywhere within the 20-40 ng/kg/min range creates a direct infringement concern.
What dosing regimen does the patent claim?
The claimed regimen maps closely to the Giapreza prescribing information.
| Dosing element |
Patent claim |
Giapreza labeling |
| Initial infusion |
About 20 ng/kg/min |
Recommended initial dose of 20 ng/kg/min |
| Titration |
Approximately 10 ng/kg/min increments |
Dose adjustment in 5- to 15-minute intervals, depending on response |
| Upper dose |
About 30 or 40 ng/kg/min |
Maximum recommended dose of 40 ng/kg/min |
| Hemodynamic target |
MAP about 65 mmHg |
Dose titrated to target blood pressure |
| Background treatment |
Norepinephrine and other vasopressors |
Used in patients with distributive shock receiving conventional vasopressors |
| Administration period |
0.25 to 120 hours, with a narrower 1- to 7-hour range |
Intravenous infusion during acute vasodilatory or septic shock |
The patent is strongest against a protocol that begins at 20 ng/kg/min and escalates by approximately 10 ng/kg/min to 30 or 40 ng/kg/min while the patient receives norepinephrine or vasopressin.
What patent claims cover vasopressor combinations?
Claims 11 through 23 address patients undergoing treatment with one or more vasopressors. The listed vasopressors are:
- Norepinephrine;
- Vasopressin;
- Epinephrine; and
- Dopamine.
Claims 13 and 14 separately identify norepinephrine and vasopressin. These claims are commercially significant because angiotensin II is generally used as an adjunct to conventional vasopressor therapy rather than as monotherapy.
A hospital protocol using angiotensin II after inadequate response to norepinephrine presents a particularly close match to claims 11 through 23. The claims do not appear limited to a specific sequence of administration, a minimum norepinephrine dose, or a particular severity of shock beyond the septic-shock and blood-pressure requirements.
What patent protects the angiotensin II product itself?
U.S. Patent No. 10,548,943 is directed to a method of treatment. It does not, based on the supplied claims, protect:
- The angiotensin II molecule as a chemical entity;
- A particular vial or container;
- A specific excipient system;
- A lyophilized formulation;
- A manufacturing process;
- A pump or infusion device; or
- A particular concentration of the finished solution.
The broader angiotensin II estate includes earlier composition and formulation patents, including U.S. Patent No. 9,266,951. That patent is separate from the dosing claims in U.S. Patent No. 10,548,943 and must be analyzed independently for claim scope, listed products, and expiration.
What is the Orange Book status of U.S. Patent 10,548,943?
Giapreza, the commercial angiotensin II product, is approved under FDA NDA 209360. The FDA-approved indication is for the treatment of septic or other distributive shock in adults who remain hypotensive despite adequate volume replacement and use of catecholamines and other vasopressors [FDA, 2017].
U.S. Patent No. 10,548,943 has been associated with the Giapreza patent estate and is directed to the approved dosing method. Its Orange Book relevance is therefore substantially greater than that of a patent covering an unapproved research use.
The expected patent-term endpoint is in the mid-2030s, generally reported as May 2035 for this patent family. The effective expiration date should be confirmed against the current FDA Orange Book entry and USPTO patent-term records because terminal disclaimers, patent-term adjustment, patent-term extension, and listing corrections can affect the operative date.
When does angiotensin II lose exclusivity?
FDA regulatory exclusivity
Giapreza received FDA approval in 2017. Any applicable new-drug exclusivity associated with the original NDA has expired. The principal remaining barrier is patent protection, not ordinary five-year new chemical entity exclusivity.
Patent exclusivity
The central method patent is expected to remain relevant through the mid-2030s. The commercial exclusion period may end earlier or later depending on:
- The precise patent expiration date;
- Patent-term adjustment;
- Any terminal disclaimer;
- Orange Book delisting;
- A successful validity challenge;
- A settlement with an abbreviated-new-drug-application applicant; or
- A generic applicant's ability to carve out the patented method.
Generic regulatory pathway
Angiotensin II is a synthetic peptide drug. A competing applicant would generally use the ANDA pathway under section 505(j), rather than the biosimilar pathway under section 351(k). Biosimilar risk is therefore not the relevant regulatory framework.
The principal generic options would be:
- Paragraph IV certification that the patent is invalid, unenforceable, or not infringed;
- A Paragraph III certification accepting delay until patent expiration; or
- A section viii statement carving out the patented method of use, if the remaining FDA labeling supports a lawful noninfringing indication.
Which companies are challenging U.S. Patent 10,548,943?
No publicly established Paragraph IV litigation against U.S. Patent No. 10,548,943 is identified in the supplied record. No conclusion of a challenge should be inferred from the absence of a reported case. Paragraph IV notices are served privately, and litigation may not be filed if the NDA holder does not bring an action within the statutory period.
The relevant patent challenger would be an ANDA applicant seeking approval for generic angiotensin II. The commercial incentive is limited by the relatively small market size compared with major hospital drugs, manufacturing complexity, and the need to support a sterile injectable peptide product.
What litigation affects the patent?
The primary litigation risk would involve an ANDA action under the Hatch-Waxman Act. The likely issues would include:
| Issue |
Relevance |
| Claim construction |
Meaning of "about," "initial rate," and "septic shock" |
| Literal infringement |
Whether the proposed label instructs dosing within 20-40 ng/kg/min |
| Induced infringement |
Whether the generic label encourages physicians to practice the patented method |
| Obviousness |
Whether the claimed dosing regimen was predictable from earlier angiotensin II studies and vasopressor protocols |
| Written description |
Whether the full claimed dose, duration, and MAP combinations were adequately supported |
| Enablement |
Whether the specification enables the entire claimed range |
| Section viii carve-out |
Whether a label can omit the patented septic-shock method while preserving approval |
A generic label that includes the 20 ng/kg/min starting dose and 40 ng/kg/min maximum dose would be exposed to a direct induced-infringement theory. A successful carve-out would require removal of the patented method from the proposed labeling and prescribing information.
How strong is the patent estate?
Strengths
- The claims correspond closely to the FDA-approved dosing instructions.
- Claim 24 covers the complete 20-40 ng/kg/min dosing range.
- The septic-shock limitation narrows the claims to a clinically defined population but also aligns with the approved indication.
- The vasopressor claims capture common real-world use with norepinephrine and vasopressin.
- The method claims do not depend on a particular brand name, concentration, vial, or delivery device.
Vulnerabilities
- Angiotensin II was known as a vasoconstrictor before the patent's priority date.
- MAP targets near 65 mmHg were standard in septic-shock management.
- Dose selection and titration could be challenged as obvious optimization of known variables.
- The numerical limitations use "about," creating potential claim-construction disputes.
- The claims are vulnerable if prior art disclosed the same starting dose, maximum dose, titration increments, or patient population before the effective filing date.
- A generic applicant may seek a label carve-out rather than market an unrestricted indication.
The patent is commercially strong against an identical Giapreza-style label, but its validity strength depends on the pre-priority-date evidence supporting the specific 20-40 ng/kg/min protocol.
How does U.S. Patent 10,548,943 compare with competing patent categories?
| Patent category |
Protected subject matter |
Relevance to generic angiotensin II |
| U.S. 10,548,943 |
Septic-shock dosing and titration |
Direct method-of-use barrier |
| Composition patent |
Angiotensin II composition or product form |
May block product manufacture or sale |
| Formulation patent |
Concentration, stability, excipients, or storage |
May require a different formulation |
| Manufacturing patent |
Synthesis, purification, or sterile processing |
May increase development and CMC risk |
| Device patent |
Infusion system or administration apparatus |
Usually avoidable through alternative equipment |
| Method-of-use patent |
Shock, hypotension, or vasopressor rescue |
May require label carve-out or litigation |
The most important freedom-to-operate question is whether a generic can produce a chemically equivalent product, use a noninfringing manufacturing process, and obtain approval with a label that does not practice the '943 claims.
What generic launch scenarios exist?
Scenario 1: Full-label generic launch
A full-label ANDA includes septic-shock dosing at 20-40 ng/kg/min. This creates the highest risk of Paragraph IV litigation and a potential 30-month stay of approval if suit is timely filed.
Scenario 2: Section viii carve-out
The applicant removes or narrows the patented septic-shock dosing language. This may reduce patent exposure but could materially limit the product's commercial utility because septic shock is the core clinical market.
Scenario 3: Post-expiration launch
The applicant accepts patent validity and launches after the operative expiration date. This is the lowest litigation-risk pathway but delays market entry.
Scenario 4: Settlement
The NDA holder and generic applicant may agree to an entry date before patent expiration. The commercial value of such a settlement would depend on the negotiated date, supply terms, authorized-generic provisions, and any FDA or antitrust review.
What is the revenue exposure?
Giapreza revenue depends on hospital adoption, intensive-care utilization, reimbursement, and competition from norepinephrine, vasopressin, and other rescue vasopressors. The patent protects the dosing method rather than all use of angiotensin II, so revenue exposure is tied to whether a generic can obtain a commercially useful septic-shock label.
A generic that must carve out the core septic-shock method may have limited market value. A successful full-label challenge would expose substantially more of the product's sales because the claimed regimen mirrors ordinary use under the FDA label.
Key Takeaways
- U.S. Patent No. 10,548,943 is a method-of-use patent for angiotensin II treatment of septic shock.
- Independent claim 1 covers an initial dose of approximately 20 ng/kg/min.
- Independent claim 24 covers administration from approximately 20 to 40 ng/kg/min.
- Dependent claims add titration, MAP of approximately 65 mmHg, treatment duration, and concomitant vasopressors.
- The patent closely tracks Giapreza's FDA-approved dosing instructions.
- Norepinephrine and vasopressin combination claims create a direct risk for common hospital protocols.
- The patent is expected to remain relevant into the mid-2030s.
- Generic applicants would face Paragraph IV, section viii, or post-expiration strategies.
- Biosimilar analysis is not applicable because angiotensin II is regulated as a synthetic peptide drug, not a biologic biosimilar.
- The principal validity issue is whether the claimed dose and titration regimen would have been obvious from earlier angiotensin II and septic-shock treatment evidence.
FAQs
Is U.S. Patent 10,548,943 a formulation patent?
No. The supplied claims protect administration of angiotensin II to septic-shock patients. They do not claim a specific excipient, concentration, container, or formulation.
Does the patent cover angiotensin II use outside septic shock?
The supplied independent claims require a human subject having septic shock. Use in other forms of hypotension may fall outside these claims, although separate patents may cover other indications.
Does using norepinephrine with angiotensin II infringe the patent?
It may. Claims 11 through 23 specifically cover angiotensin II administration in patients receiving norepinephrine, vasopressin, epinephrine, or dopamine, provided the remaining claim limitations are satisfied.
Can a generic angiotensin II product avoid the patent by starting below 20 ng/kg/min?
Potentially, but avoidance would depend on the full label and actual use. A product later titrated into the claimed range could still create infringement issues under claims 24-26 or under the doctrine of equivalents.
Is a biosimilar the main competitive threat to Giapreza?
No. The relevant competitor would be an ANDA-based generic injectable angiotensin II product. The commercial barriers are sterile peptide manufacturing, limited market size, patent litigation, and the difficulty of obtaining a useful label after a section viii carve-out.
References
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U.S. Patent No. 10,548,943. (2020). Methods of treating hypotension. United States Patent and Trademark Office.
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U.S. Patent No. 9,266,951. (2016). Angiotensin II compositions and methods. United States Patent and Trademark Office.
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U.S. Food and Drug Administration. (2017). Giapreza (angiotensin II) injection prescribing information. FDA.
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U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. FDA, Orange Book.
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Khanna, A., English, S. W., Wang, X. S., Ham, K., Tumlin, J., Szerlip, H., Busse, L. W., Altaweel, L., Albertson, T. E., Mackey, C., ... ATHOS-3 Investigators. (2017). Angiotensin II for the treatment of vasodilatory shock. The New England Journal of Medicine, 377(5), 419-430. https://doi.org/10.1056/NEJMoa1704154
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U.S. Congress. (1984). Drug Price Competition and Patent Term Restoration Act, Pub. L. No. 98-417, 98 Stat. 1585.
