Opinion

NOT FOR PUBLICATION

UNITED STATES DISTRICT COURT

DISTRICT OF NEW JERSEY

LOUISIANA WHOLESALE DRUG CO., INC.,

et al., Civil Action No. 12-00995

Plaintiffs/Appellants,

OPINION AND ORDER

v.

March 31, 2026

GLAXOSMITHKLINE LLC, et al.,

Defendants/Appellees.

SEMPER, District Judge.

The current matter comes before the Court on Plaintiffs-Appellants’ appeal of the

Honorable Cathy L. Waldor, U.S.M.J.’s (“Magistrate Judge Waldor”) July 30, 2025 decision that

five new expert reports Defendants submitted were permissible in accordance with the operative

scheduling order (ECF 668, “July 30 Order”). (ECF 669.) Defendants opposed the appeal. (ECF

676.) Plaintiffs filed a reply. (ECF 677.) The Court has decided the appeal pursuant to Federal

Rule of Civil Procedure 72(a) and Local Civil Rule 72.1(c), and upon the submissions of the

parties, without oral argument, pursuant to Federal Rule of Civil Procedure 78. For the reasons

stated below, the appeal is GRANTED. The July 30 Order is VACATED.

I. FACTUAL BACKGROUND AND PROCEDURAL HISTORY

This fourteen-year-old dispute arises out of allegations that Defendants GlaxoSmithKline

(“GSK”) and Teva Pharmaceuticals (“Teva”) entered into an illegal reverse-payment agreement

to settle patent litigation so that GSK could maintain monopoly-level prices on its brand

lamotrigine tablets known as Lamictal. (See generally, ECF 1.) The case was initially filed as a

putative class action. (See id.)

The parties engaged in, and completed, fact and expert discovery over the course of several

years. (ECF 670-1, Declaration of Samuel E. Bonderoff (“Bonderoff Decl.”) Ex. 3 at 4.) Plaintiffs

moved for certification of their class in June 2018. (ECF 371.) Class certification was ultimately

denied in 2023. (ECF 553; ECF 554.) Subsequently, several absent members of the putative class

filed new complaints against Defendants in the District Court for the Eastern District of

Pennsylvania. See e.g., MLI RX LLC v. GlaxoSmithKline LLC (“MLI”), No. 2:23-cv-2960 (D.N.J.).

Defendants moved to transfer the new cases to this District under the first-filed rule and 28 U.S.C.

§ 1404(a). See id. at ECF 28. That motion was granted.1 See MLI, No. 2:23-cv-2960, ECF 59; see

also Morris & Dickson, No. 2:23-cv-00480 (E.D. Pa.), ECF 41.

Following transfer, on October 24, 2023, the parties submitted competing case-schedule

and discovery proposals for the four direct purchaser Lamictal actions. See MLI, No. 2:23-cv-2960,

ECF 85-1. Plaintiffs maintained that no additional fact discovery was necessary. (Id. at 3-6.)

Plaintiffs also proposed that the only issue on which additional expert reports should be issued was

individual damages issues, since the other already-completed expert reports addressed issues

common to all plaintiffs. (Id. at 6.) Defendants argued that new discovery of the newly added

Plaintiffs was necessary. (Id. at 7-15.) Defendants proposed a schedule that “[left] appropriate

time” for discovery, including “the preparation of any supplemental expert reports[.]” (Id. at 14.)

As to experts, Defendants further stated,

With respect to expert discovery, Plaintiffs of course are free to amend or supplement as

few expert reports as they wish. Defendants, however, submit that supplementation of

certain expert reports on issues other than damages may well be appropriate following

1 The new cases were formally consolidated with the existing case on November 2, 2023. (ECF

577.)

discovery of the Newly Added Plaintiffs. For example, discovery of the Newly Added

Plaintiffs will shed light on the nature of competition in the actual and but-for worlds,

which in turn may impact the experts’ assumptions and conclusions about the relevant

market, market power and competition in them.

(Id. at 14 n.21.)

On July 31, 2023, Magistrate Judge Waldor held an initial pretrial conference and heard

argument from the parties’ counsel regarding their competing case schedule and discovery

proposals.2 (See Bonderoff Decl. Ex. 5.) After hearing arguments, Magistrate Judge Waldor found

that consolidation3 called for discovery “with respect to the newly named plaintiffs.” (Id. at 15:7-

10.) Plaintiffs expressed concern with the scope of expert discovery in Defendants’ proposal,

characterizing it as “unlimited.” (Id. at 16:13-17:5.) In response, Defense counsel argued:

As to expert discovery, I think it’s clear that there are other areas where new discovery

could impact what goes into our expert reports, like market definition. Now, I don’t think

that we are requesting the right just to put in new reports on every single topic. What we’re

saying is if there’s new evidence that we get through this process that impacts things we

have previously done, we want to supplement those reports. I mean, that, by definition, is

not overbroad. We’re just taking what we get in the new discovery -- in the fact discovery

and applying it to the new expert discovery.

(Id. 19:6-16.) Magistrate Judge Waldor adopted Defendants’ proposed schedule, and directed the

parties to “proceed with discovery, and I will deal with each problem as it comes – or each

objection as it comes – or each deficiency as it comes. But let’s see what happens and not make

any rules that may be limiting in the future.” (Id. at 20:23-21:5.)

2 Plaintiffs argued that no additional discovery was necessary following consolidation, and

Defendants disagreed, arguing that class certification was denied on the basis of predominance

and so there remained individual issues related to whether and what price each purchaser would

have gotten from Teva. (See Bonderoff Ex. 5 at 10:20-12:9.) Defendants also argued that discovery

from the new plaintiffs related to the “nature of competition in this market” was relevant. (Id. at

13:3-13.)

3 The cases were consolidated by an order dated November 2, 2023. (ECF 577.)

On November 2, 2023, the Honorable Brian R. Martinotti, to whom this case was then

assigned, held a status conference and directed the parties to submit a new order to Magistrate

Judge Waldor “following the spirit of the Judge’s order [on July 31, 2023].” (ECF 581 at 4:4-8.)

On November 8, 2023, the parties jointly submitted a proposed scheduling order.4 (ECF 578.) On

November 9, 2023, Magistrate Judge Waldor so-ordered the proposed scheduling order. (ECF 580

(the “New Scheduling Order”).)

On May 30, 2025, after the conclusion of fact discovery of the newly joined Plaintiffs,

Defendants served five new or amended expert reports (the “New Expert Reports”). (Br. at 9-15.)

Plaintiffs take issue with these reports.5 On June 2, 2025, Plaintiffs submitted a letter to the Court

expressing their concerns and opposition to the New Expert Reports. (ECF 645.) On June 4, 2025,

Defendants filed a letter in response, arguing that the 2023 joinder complaints had changed their

case. (ECF 647.) After further correspondence and meet-and-confer attempts (see Bonderoff Decl.

Exs. 7-8), the Court held a hearing on June 5, 2025 regarding the parties’ disagreements (the “June

5 Hearing”). (Id. Ex. 9.) At the June 5 Hearing, Plaintiffs argued that Defendants were required to

move for leave under Rule 16(b) before serving the expert reports because the new reports relied

on old, not new, discovery, and because Defendants replaced experts without explanation. (Id. at

11:12-15:10, 20:15-21, 21:9-12.) Defendants argued that Rule 16(b) was inapplicable since the

new reports were within the bounds of the November 9, 2023 scheduling order. (Id. 22:1-26:15.)

Magistrate Judge Waldor directed the parties to meet and confer again and “hone in on” the section

4 The proposed scheduling order included the following events: “Plaintiffs serve expert reports”;

“Defendants serve expert reports”; “Plaintiffs serve rebuttal reports”; and “Deadline for

depositions of individual damages experts”. (ECF 578-1.)

5 Plaintiffs argue that these reports are “replete with new and revised opinions that [have] nothing

to do with any new fact discovery or purportedly ‘new allegations,’” and instead were served as

an attempt to revise Defendants’ prior experts’ earlier mistakes and admissions. (Br. at 9-11.)

of the reports that Plaintiffs took issue with. (Id. at 42-43.) Instead of briefing, Magistrate Judge

Waldor proposed an in-person session to resolve the “real differences” that exist.6 (Id. at 43:13-

17.)

On July 30, 2025, Magistrate Judge Waldor held a further hearing regarding the parties’

impasse (“July 30 Hearing”). (Bonderoff Decl. Ex. 10.) Magistrate Judge Waldor found that Rule

16(b) did not apply since Defendants’ expert reports “were within the scheduling order”. (Id. at

43:18-21.) Magistrate Judge Waldor noted that Plaintiffs have the opportunity to depose

Defendants’ experts and produce rebuttal reports. (Id. at 44:4-16.) Magistrate Judge Waldor denied

Plaintiffs’ request for briefing on the issue. (Id. at 44:18.) Because she found that the new reports

were within the operative scheduling order, Magistrate Judge Waldor refused to engage in

Plaintiffs’ requested line-by-line inquiry of the New Expert Reports. (Id. at 40:10-23, 41:1-7,

43:14-21.) On the same day, Magistrate Judge Waldor issued a text order that the five new expert

reports were permissible for the reasons stated on the record. (ECF 668.)

On August 13, 2025, Plaintiffs filed their appeal of Magistrate Judge Waldor’s July 30

Order. (ECF 669; ECF 670.) On September 2, 2025, Defendants filed an opposition to the appeal.

(ECF 676.) On September 8, 2025, Plaintiffs filed a reply. (ECF 677.)

II. LEGAL STANDARD

In a district judge’s review of a magistrate judge’s decision, Federal Rule of Civil

Procedure 72(a) states: “[t]he district judge. . . must consider timely objections and modify or set

aside any part of the order that is clearly erroneous or is contrary to law.” Similarly, the Local

Rules for this district provide that “[a]ny party may appeal from a [m]agistrate [j]udge’s

6 Magistrate Judge Waldor noted that she was leaving the bench shortly and wanted to avoid

“throwing” the issue to the new Magistrate Judge after she left the bench. (43:17-44:8.) Magistrate

Judge Cari Fais is now assigned to the case.

determination of a non-dispositive matter within 14 days” and the district court “shall consider the

appeal and/or cross-appeal and set aside any portion of the [m]agistrate [j]udge’s order found to

be clearly erroneous or contrary to law.” Local Civ. R. 72.1(c)(1)(A).

A district judge may reverse a magistrate judge’s determination of a non-dispositive issue

if it is shown to be “clearly erroneous or contrary to law” on the record before the magistrate judge.

28 U.S.C. § 636(b)(1)(A) (“A judge of the court may reconsider any pretrial matter [properly

referred to the magistrate judge] where it has been shown that the magistrate judge’s order is

clearly erroneous or contrary to law.”); Fed. R. Civ. P. 72(a); Local Civ. R. 72.1(c)(1)(A); Haines

v. Liggett Grp., Inc., 975 F.2d 81, 93 (3d Cir. 1992) (describing the district court as having a

“clearly erroneous review function,” permitted only to review the record that was before the

magistrate judge). The burden of showing a ruling is clearly erroneous or contrary to law rests with

the party filing the appeal. Marks v. Struble, 347 F. Supp. 2d 136, 149 (D.N.J. 2004).

A district court “will determine that a finding is clearly erroneous ‘when although there is

evidence to support it, the reviewing court on the entire evidence is left with the definite and firm

conviction that a mistake has been committed.’” Dome Petroleum Ltd. v. Emp’rs Mut. Liab. Ins.

Co., 131 F.R.D. 63, 65 (D.N.J. 1990) (quoting United States v. United States Gypsum Co., 333

U.S. 364, 395 (1948)). However, “[w]here there are two permissible views of the evidence, the

factfinder’s choice between them cannot be clearly erroneous.” United States v. Waterman, 755

F.3d 171, 174 (3d Cir. 2014) (quoting Anderson v. Bessemer City, 470 U.S. 564, 574 (1985)). The

magistrate judge’s “ruling is contrary to law if the magistrate judge has misinterpreted or

misapplied applicable law.” Kounelis v. Sherrer, 529 F. Supp. 2d 503, 518 (D.N.J. 2008); Gunter

v. Ridgewood Energy Corp., 32 F. Supp. 2d 162, 164 (D.N.J. 1998). A district court, however, will

review a magistrate judge’s legal conclusions de novo. See Cooper Hosp./Univ. Med. Ctr. v.

Sullivan, 183 F.R.D. 119, 127 (D.N.J. 1998) (citations omitted); see also Haines, 975 F.2d at 92

(noting that “the phrase ‘contrary to law’ indicates plenary review as to matters of law”). “Where

a Magistrate Judge has exercised discretion, the District Court will reverse the decision only for

an abuse of that discretion.” Zaarour v. Murphy, No. 21-20782, 2025 WL 546581, at *2 (D.N.J.

Feb. 19, 2025) (collecting cases).

III. DISCUSSION

Plaintiffs argue that (a) permitting expert substitutions without a showing of good cause is

contrary to law (Br. at 21-25); (b) permitting expert substitutions despite failing to consider the

Pennypack factors is contrary to law7 (id. at 25-29); and (c) Magistrate Judge Waldor’s decision

not to allow briefing on the expert-discovery disputes was an abuse of discretion (id. at 29-30). In

response, Defendants argue that Rule 16(b)(4)’s “good cause” standard does not apply because

they complied with the deadlines in the New Scheduling Order. (Opp. at 12-16.) Defendants

further argue that Magistrate Judge Waldor did not err in failing to consider the Pennypack factors

because Pennypack does not apply to timely disclosures. (Id. at 16-18.) Finally, Defendants argue

that Magistrate Judge Waldor did not err in refusing to allow briefing on the expert issues because

she heard argument at the July 30 Hearing. (Id. at 18-21.) The burden to show that Magistrate

Judge Waldor’s July 30 Order is clearly erroneous or contrary to law rests with Plaintiffs. Marks,

347 F. Supp. 2d at 149.

7 The Pennypack factors are five factors set forth by the Third Circuit in Meyers v. Pennypack

Woods Home Ownership Ass’n, 559 F.2d 894 (3d Cir. 1977) that are applicable when the

timeliness of an expert opinion is challenged. The five factors are: (1) the prejudice or surprise in

fact of the party against whom the evidence would have been presented, (2) the ability of that party

to cure the prejudice, (3) the extent to which the presentation of the evidence would disrupt the

orderly and efficient trial of the case or other cases in the court, (4) bad faith or willfulness in

failing to comply with the court’s order, and (5) the importance of the excluded evidence. LabMD

Inc. v. Boback, 47 F.4th 164, 189 (3d Cir. 2022) (citing Konstantopolous v. Westvaco Corp., 112

F.3d 710, 719 (3d Cir. 1997)).

This is a rare case in which the Plaintiffs-Appellants have carried their burden and shown

that the Magistrate Judge’s decision was clearly erroneous.

A. Scope of the New Scheduling Order

Before addressing the parties’ arguments, the Court first must determine the scope of the

New Scheduling Order.

The Court agrees with Plaintiffs that the New Scheduling Order covers supplemental expert

discovery related to the new discovery and allegations implicated by the new Plaintiffs. (See Br.

at 10.) Defendants’ primary argument that Magistrate Judge Waldor “issued (and this Court

approved) a new scheduling order setting a new deadline for the submission of new expert reports

without limitations” (Opp. at 1 (emphasis in original)) is disingenuous. While Magistrate Judge

Waldor did not agree with Plaintiffs’ proposal to limit expert discovery to the new individual

Plaintiffs’ damages (see Bonderoff Ex. 5), the record shows that the New Scheduling Order

contemplated only the supplementation of existing expert reports based on new allegations and

new discovery related to the new Plaintiffs.

At the July 31, 2023 conference, Magistrate Judge Waldor agreed with Defendants that

Judge Vazquez’s opinion on class certification “call[ed] for discovery with respect to the newly

named plaintiffs…I will adopt the schedule submitted by [the] defense.” (Bonderoff Ex. 5 at 15:7-

10 (emphasis added).) Magistrate Judge Waldor rejected Plaintiffs’ position that new discovery,

including expert discovery, should be limited solely to damages. (See id.) Magistrate Judge

Waldor’s statement at the July 31, 2023 conference that she would “not make any rules that may

be limiting in the future” was responsive to Plaintiffs’ counsel’s arguments in favor of (1) limiting

expert discovery to damages and (2) limiting the length of Plaintiffs’ depositions. (Id. at 15:25-

18:13.) Magistrate Judge Waldor did not, as Defendants now suggest, hold that expert discovery

was “without limitations.” (Opp at 1.) Nor is it accurate to state, as Defendants do, that Magistrate

Judge Waldor entered a scheduling order “that set deadlines for the parties to submit ‘expert

reports,’ unlimited by topic or in number[.]” (Id. at 13.)

In fact, Magistrate Judge Waldor’s July 31, 2023 order adopting Defendants’ proposed

scheduling order aligned with Defendants’ statements on expert discovery in their July 26, 2023

case-schedule and discovery proposal. See MLI, No. 2:23-cv-2960, ECF 67. In that proposal,

Defendants stated that “supplementation of certain expert reports on issues other than damages

may well be appropriate following discovery of the Newly Added Plaintiffs.” (Id. at 14 n.21

(emphasis added).) And at the July 31, 2023 conference, Defendants’ counsel stated, “I don’t think

that we are requesting the right just to put in new reports on every single topic.” (Bonderoff Ex. 5

at 19:9-10.) Defendants’ counsel continued, “[w]hat we’re saying is if there’s new evidence that

we get through this process that impacts things we have previously done, we want to supplement

those reports…We’re just taking what we get in the new discovery -- in the fact discovery and

applying it to the new expert discovery.” (Id. at 19:11-16.)

The record from the June 5 Hearing further reflects an understanding that the New

Scheduling Order covered supplemental expert reports based on new discovery and allegations.

At the June 5 Hearing, Magistrate Judge Waldor scheduled a follow-up hearing in July on the

expert issues, stating, “I want to deal with the realities of what’s going on with these reports and

whether or not they actually address or are attached to new allegations and new plaintiffs[.]”

(Bonderoff Ex. 9 at 44:24-45:3 (emphasis added).) She directed the parties to meet and confer and

scheduled the July 30 Hearing to have an “in-person with many hours in court to try and go through

this and resolve the issues and the real differences that exist.” (Id. at 43:13-17.)

Defendants further argue that “Magistrate Judge Waldor’s factual determination

concerning the scope of her own order is dispositive of Plaintiff’s challenge, and Plaintiffs do not

(and cannot) offer any basis for this Court to disturb that conclusion as clearly erroneous.” (Opp.

at 15-16.) But Magistrate Judge Waldor demonstrated a consistent understanding of the New

Scheduling Order. At the July 30 Hearing, she stated, “[s]o what I need time to do, and I’m going

to do, to tell you the truth, is decide that [the New Expert Reports] were within the scheduling

order. They are new allegations.” (Bonderoff Ex. 10 at 43:19-21 (emphasis added).)

Finally, the New Scheduling Order does not explicitly place limitations on expert reports.

(See ECF 580.) But by including a deadline only for depositions of individual damages experts,

and no other depositions, the New Scheduling Order reflects the parties’ understanding that new

expert discovery would not be completely redone. (See id.)

B. Magistrate Judge Waldor’s July 30, 2025 Order

At the July 30 Hearing, Magistrate Judge Waldor heard argument and decided that the New

Expert Reports were within the New Scheduling Order. (Bonderoff Decl. Ex. 10 at 43:19-23.)

However, Magistrate Judge Waldor declined to “go through [the] reports” to determine whether

the “new allegations revealed certain evidence or certain disclosure [sic] that necessitated

supplementation[.]” (Id. at 43:3-18; see also id. 40:10-15.) Magistrate Judge Waldor’s decision

focused on allowing “full[] and fair[] discovery,” and she noted that the case had no trial date or

summary judgment schedule set, and so Plaintiffs had an opportunity to submit rebuttal reports

and depose the new experts. (Id. at 41-44.) Magistrate Judge Waldor then issued a text order that

the five new expert reports were permissible. (ECF 668.)

The Court is understanding of Magistrate Judge Waldor’s concern that the parties interpret

the reports entirely differently, making a comparison difficult. (Bonderoff Ex. 10 at 43:14-18.)

However, Magistrate Judge Waldor also acknowledged at the June 5 Hearing that such a

comparison would be necessary if the parties could not resolve their differences. (Bonderoff Ex. 9

at 42:23-45:5.) The New Scheduling Order did not cover a wholesale do-over of expert discovery.

(See supra Section III.A.) Instead, it contemplated the supplementation of existing expert reports.

(Id.) In response to Plaintiffs’ arguments, Magistrate Judge Waldor could not have made the

decision that the New Expert Reports were within the New Scheduling Order without an

understanding of the content of the New Expert Reports, yet she declined to compare the reports.

(Bonderoff Ex. 10 at 40:10-15, 43:3-18.) Moreover, Magistrate Judge Waldor’s decision

emphasized that Plaintiffs had an opportunity to depose the new experts and submit rebuttal

reports. (43:14-44:16.) Yet these considerations relate to Plaintiffs’ Rule 16 and Pennypack

arguments, not the threshold question of whether Rule 16 and Pennypack are applicable. Because

the New Scheduling Order is not unlimited in scope, this Court is “left with the definite and firm

conviction that a mistake has been committed.” Dome Petroleum Ltd. v. Employers Mut. Liab. Ins.

Co., 131 F.R.D. 63, 65 (D.N.J.1990) (quoting United States v. U.S. Gypsum Co., 333 U.S. 364,

395 (1948)).

The Court disagrees with Plaintiffs, however, that Magistrate Judge Waldor erred by not

engaging in a Rule 16 or Pennypack analysis. (See Br. at 25-29.) Magistrate Judge Waldor erred

by declining to compare the content of the New Expert Reports to determine whether they were

within the New Scheduling Order. Indeed, Magistrate Judge Fais may determine that the New

Expert Reports are within the New Scheduling Order and Rule 16 and/or Pennypack are

inapplicable.

This decision should not be read as a conclusion that the new supplemental expert reports

may only cite to new discovery or may not modify prior expert opinions, or that the New Expert

Reports are entirely impermissible. As Defendants point out, the new complaints include new or

revised allegations and consolidation changed the case from a putative class action to a joinder

action. (See Opp. at 5 n.3.) Whether the new or amended expert reports comport with the New

Scheduling Order is a matter within the Magistrate Judge’s discretion after she reviews the reports.

IV. CONCLUSION

For the reasons stated above, Plaintiffs’ appeal is GRANTED. The July 30 Order is

VACATED and the matter is remanded to Magistrate Judge Fais for further proceedings consistent

with this Opinion.

Accordingly, IT IS on this 31st day of March 2026,

ORDERED that Plaintiffs’ appeal of the July 30, 2025 order at ECF 668 (ECF 669; ECF

670) is GRANTED; and it is further

ORDERED that the July 30, 2025 order at ECF 668 is VACATED.

/s/ Jamel K. Semper .

HON. JAMEL K. SEMPER

United States District Judge

Orig: Clerk

cc: Cari Fais, U.S.M.J.

Parties