The complaint

Rubicon Research Limited v. Indivior Inc., No. 1:26-cv-01444 (D. Del.), is a five-page complaint for declaratory judgment of noninfringement filed November 10, 2026, and marked as an ANDA case. Rubicon is an Indian company based in Thane, Maharashtra. The complaint alleges, on information and belief, that Indivior is a Delaware corporation with its principal place of business in North Chesterfield, Virginia. The complaint pleads the patent laws, the Declaratory Judgment Act, and 21 U.S.C. § 355, and venue under 28 U.S.C. §§ 1391(b)(1) and 1400(b).

The ANDA and the notice letter

According to the complaint, Rubicon submitted ANDA No. 221382 on April 18, 2026, seeking approval of a nalmefene hydrochloride nasal spray, EQ 2.7 mg base per spray, referencing OPVEE, which Indivior markets under NDA No. N217470. The ANDA included a Paragraph IV certification that the product does not infringe any valid claim of the two patents. The complaint says FDA acknowledged the ANDA and certification by letter dated May 14, 2026, effective April 20, 2026, and that Rubicon sent its notice letter on June 3, 2026, with an offer of confidential access to the ANDA. It alleges, on information and belief, that Indivior received the letter on June 4, 2026, says Indivior has not brought suit, and invokes 21 U.S.C. § 355(j)(5)(C)(i).

The patents

  • U.S. Patent No. 11,458,091, Compositions and Methods for the Treatment of Opioid Overdose, issued October 4, 2022, from Application No. 16/461,354. The complaint says the Orange Book lists an expiration of July 10, 2038. Claim 1 recites an intranasal formulation of about 3% (w/v) nalmefene hydrochloride with specified ranges of dodecyl maltoside, sodium chloride, disodium edetate, and benzalkonium chloride, a pH between 3.5 and 5.5, and a final volume of about 50 to 200 μL.
  • U.S. Patent No. 12,290,596, with the same title, issued May 6, 2025, from Application No. 17/881,306, filed August 4, 2022, with Indivior Inc. as applicant. The complaint says the Orange Book lists an expiration of August 4, 2042. Claim 1 is directed to a method of emergency treatment of a known or suspected opioid overdose by nasally administering about 100 μL of a specified nalmefene formulation, with recited pharmacokinetic and respiratory reversal parameters, and claim 2 to a method of treating remifentanil-induced respiratory depression with the same formulation and parameters.

The complaint alleges that Indivior is the owner of both patents by assignment according to USPTO records.

The claims for relief

Count I seeks a declaration that Rubicon's ANDA and ANDA product do not infringe any claim of the '091 patent, and Count II seeks the same for the '596 patent. The prayer asks for a judgment that the claims of both patents are not infringed by Rubicon's ANDA and ANDA product.

What to watch next

Watch for judge assignment, Indivior's answer or motion, and any infringement counterclaim under 35 U.S.C. § 271(e)(2).