
    Agatha BROWN, Plaintiff—Counter-Defendant—Appellant, v. Michel QUINIOU, Agatha Diffusion, S.R.L., Defendants—Appellees, Sixteen, Inc., Defendant—Counter-Claimant—Appellee, Fross Zelnick Lehrman & Zissu, P.C., Defendant.
    No. 11-0897-cv.
    United States Court of Appeals, Second Circuit.
    March 9, 2012.
    
      Agatha Brown, pro se, Farmers Branch, TX, for Appellant.
    David B. Sunshine and Amy F. Divino, Cozen O’Connor, New York, N.Y., for Appellees.
    PRESENT: PIERRE N. LEVAL, ROBERT D. SACK, PETER W. HALL, Circuit Judges.
   SUMMARY ORDER

Appellant Agatha Brown, pro se, appeals from the district court’s denial of leave to amend, and grant of summary judgment in favor of Sixteen, Inc. (“Sixteen”). The district court ruled that Brown’s trademark infringement action was barred by the defense of laches. We assume the parties’ familiarity with the underlying facts, procedural history of the case, and issues on appeal.

Although we have not yet settled on the appropriate standard to review a grant of summary judgment based on the defense of laches, compare Hermes Int’l v. Lederer de Paris Fifth Ave., Inc., 219 F.3d 104, 107 (2d Cir.2000) (applying de novo review), with Eppendorf-Netheler-Hinz GMBH v. Nat’l Sci. Supply Co., 14 Fed.Appx. 102, 105 (2d Cir.2001) (summary order) (applying abuse of discretion review (citing Conopco, Inc. v. Campbell Soup Co., 95 F.3d 187, 193 (2d Cir.1996))), the Supreme Court has instructed that “[wjhether laches bars an action in a given case ... ‘is a question primarily addressed to the discretion of the trial court.’” Burnett v. N.Y. Cent. R.R. Co., 380 U.S. 424, 435, 85 S.Ct. 1050, 13 L.Ed.2d 941 (1965) (quoting Gardner v. Panama R.R. Co., 342 U.S. 29, 30, 72 S.Ct. 12, 96 L.Ed. 31 (1951)). It is unnecessary to decide whether prior case law in this Circuit applying the de novo standard of review to a district court’s laches ruling is good law, as the precise standard is immaterial in this case. Under either a de novo review or a review for abuse of discretion, Brown’s action against Sixteen was barred by the defense of laches for the reasons articulated by the district court in its well-reasoned decision. See Brown v. Sixteen, Inc., 02-cv-4630, 2009 WL 1159161 (S.D.N.Y. Apr.28, 2009).

Additionally, “[w]e review the denial of leave to amend for abuse of discretion.” Green v. Mattingly, 585 F.3d 97, 104 (2d Cir.2009) (citation and internal quotation marks omitted). In seeking to re-add two defendants to this action, as well as to expand upon the allegations in her original complaint and add new claims, Brown waited three years from the dismissal of her claims against those defendants (based on insufficient service of process) and four years from the time she filed her complaint. The district court thus acted well within its discretion in ruling that amendment at such a late stage of the litigation would have been improper where she gave no reasonable explanation for the delay. See Jin u Metro. Life Ins. Co., 310 F.3d 84, 101 (2d Cir.2002) (“Leave to amend should be freely granted, but the district court has the discretion to deny leave if there is a good reason for it, such as futility, bad faith, undue delay, or undue prejudice to the opposing party.”).

We have given careful consideration to each of Brown’s arguments on appeal, and find them to be without merit. For the foregoing reasons, the judgment of the district court is hereby AFFIRMED and Appellees’ motion to strike is DENIED. 
      
      . We decline to consider the arguments and evidence that Brown presents for the first time on appeal, as well as the factual assertions she makes without any reference to the record. See Fed. R.App. P. 10(a), 28(a)(9)(A); Katir v. Columbia Univ., 15 F.3d 23, 25 (2d Cir.1994) (per curiam); Aslanidis v. U.S. Lines, Inc., 7 F.3d 1067, 1077 (2d Cir.1993).
     