Source: s3://data.kl3m.ai/documents/govinfo/USCOURTS/USCOURTS-caDC-23-05200/USCOURTS-caDC-23-05200-0/pdf.json

Nature of Suit Code: 899
Nature of Suit: Other Statutes - Administrative Procedure Act/Review or Appeal of Agency Decision
Cause of Action: 

---

United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued September 25, 2024 Decided December 17, 2024

No. 23-5200

VANDA PHARMACEUTICALS, INC.,

APPELLANT

v.

UNITED STATES FOOD AND DRUG ADMINISTRATION, ET AL.,

APPELLEES

Appeal from the United States District Court

for the District of Columbia

(No. 1:22-cv-01432)

Paul W. Hughes argued the cause for appellant. With him 

on the briefs were Andrew Lyons-Berg and Tyler L. Bishop.

Steven A. Myers, Attorney, U.S. Department of Justice, 

argued the cause for appellees. On the brief were Brian M. 

Boynton, Principal Deputy Assistant Attorney General, Daniel 

Tenny and Anna M. Stapleton, Attorneys, Samuel Bagenstos, 

General Counsel, U.S. Department of Health and Human 

Services, and James Allred, Associate Chief Counsel, U.S. 

Food and Drug Administration.

Before: KATSAS and CHILDS, Circuit Judges, and 

EDWARDS, Senior Circuit Judge.

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 1 of 22
2

Opinion of the Court filed by Senior Circuit Judge

EDWARDS.

EDWARDS, Senior Circuit Judge: Companies seeking to 

market drugs in the United States must first obtain approval 

from the Food and Drug Administration (“FDA”). 21 U.S.C. 

§ 355(a). Seeking to expedite this process, Congress enacted a 

“fast track” approval program, pursuant to which the FDA shall

“facilitate the development and expedite the review” of a new 

drug if it “demonstrates the potential to address unmet medical 

needs” for a serious disease or condition. 21 U.S.C. 

§ 356(b)(1). The dispute in this case concerns a fast track 

request filed by Vanda Pharmaceuticals, Inc. (“Vanda”) with 

the FDA for tradipitant, an investigational new drug product 

that Vanda is developing for the treatment of gastroparesis. 

Vanda claims that the FDA’s denial of fast track designation 

for tradipitant was contrary to law, and arbitrary and capricious 

agency action.

Before Vanda’s fast track request was filed, the FDA had 

placed its drug on a partial clinical hold, as authorized by 21 

U.S.C. § 355(i)(3). The clinical hold prevents any long-term 

clinical studies on Vanda’s drug until long-term animal studies 

have been completed to assess its toxicological effects. When 

the FDA later assessed Vanda’s eligibility for fast track, the

clinical hold was a significant factor that led the agency to deny

Vanda’s request. The FDA essentially determined that, without 

long-term studies, Vanda could not “demonstrate” that its drug

had the “potential to address” the unmet need for long-term 

treatment of gastroparesis. 

Vanda challenges the FDA’s denial as arbitrary, 

capricious, and contrary to law under the Administrative 

Procedure Act (“APA”), 5 U.S.C. § 706(2)(A). It contends that 

the FDA erred in considering the clinical hold as a factor, 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 2 of 22
3

improperly defined the “unmet medical need” at issue to 

constitute long-term treatment only, and adopted a view of the 

fast track program that was at odds with agency practice.

The District Court granted summary judgment for the 

FDA and Vanda sought review in this court. While this appeal

was pending, Vanda also filed a complete New Drug 

Application (“NDA”) for its drug, which the FDA has since 

denied in its current form. This complete filing, the FDA 

argues, has mooted the question presented here. We disagree, 

and affirm the District Court’s decision on the merits. The FDA 

properly considered the drug’s development plan in assessing 

whether it qualified for fast track, and its denial of Vanda’s fast 

track application was neither contrary to law nor arbitrary and 

capricious.

I. BACKGROUND 

A. Statutory and Regulatory Framework

Before a new drug may be marketed in the United States, 

the FDA must first confirm that it is safe and effective. Food, 

Drug and Cosmetic Act (“FDCA”), 21 U.S.C. § 355(d). The

FDA process generally takes approximately ten months. 

Manufacturers seeking to better study their drugs before filing 

a marketing application may submit an Investigational New 

Drug Application (“IND”) to the FDA. Id. § 355(i)(1), 21 

C.F.R. § 312.20(a). The IND allows manufacturers to run 

clinical trials before obtaining marketing approval. However, 

if the FDA finds that the drug in question “represents an 

unreasonable risk to the safety” of test subjects, it may impose 

a clinical hold on such studies. 21 U.S.C. § 355(i)(3)(B). A 

clinical hold halts any further studies or trials until the 

manufacturer cures the issues that give the FDA pause.

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 3 of 22
4

Aiming to “hasten research of the safety and effectiveness 

of drugs” in some cases, Congress has enacted several 

programs to expedite the FDA’s review process. Abigail All. 

for Better Access to Developmental Drugs v. von Eschenbach, 

495 F.3d 695, 699, n.4 (D.C. Cir. 2007). One such program, for 

instance, designates a drug as a “breakthrough therapy” if 

“preliminary clinical evidence” indicates that the drug offers a 

“substantial improvement over existing therapies.” 21 U.S.C. 

§ 356(a)(1). Another expedited review pathway is “accelerated 

approval,” which may be granted if the FDA determines that 

the drug in question “has an effect” that is “reasonably likely 

to predict clinical benefit” for a condition, considering its 

“severity, rarity, or prevalence” and the “lack of alternative 

treatments.” Id. § 356(c)(1).

At issue here is the specific expedited program known as 

“fast track.” Enacted as part of the FDA Modernization Act of 

1997, the fast track statute provides that the FDA “shall take 

such actions as are appropriate to expedite the development and 

review” of a drug that is intended “for the treatment of a serious 

or life-threatening disease or condition” if the drug in question 

“demonstrates the potential to address unmet medical needs for 

such a disease or condition.” Id. § 356(b)(1), (b)(3). 

A fast track designation offers two main benefits to a drug 

manufacturer. First, the FDA will “facilitate the development” 

of the drug, usually by providing feedback in ongoing 

discussions with the manufacturer. Id. § 356(b)(1); FDA, 

Guidance for Industry: Expedited Programs for Serious 

Conditions – Drugs and Biologics, Joint Appendix (“J.A.”)

672. Second, fast track drugs are reviewed on an expedited 

schedule, and are considered for expedited review programs. 

These include the accelerated approval program under section

356(c) and “rolling review,” in which the FDA provides

feedback to the manufacturer on individual portions of the 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 4 of 22
5

application so that the developer may make any revisions 

before filing a complete NDA. 21 U.S.C. § 356(d)(1).

Applicants may request a fast track designation 

“concurrently with, or at any time after” their IND submission. 

Id. § 356(b)(2). In reviewing requests for fast track, the FDA 

requires that manufacturers list their drug’s proposed 

indication in the application. Where a drug may have more than

one indication, applicants may file multiple fast track requests

or list multiple indications in the same application. 

B. Factual Background 

In 2016, Vanda submitted an IND to begin studying its 

drug tradipitant for the treatment of gastroparesis, a chronic 

stomach condition with persistent symptoms that include 

abdominal pain, vomiting, and nausea. Vanda reported that 

preliminary studies on gastroparesis patients in a four-week 

drug trial showed that tradipitant had a statistically significant 

effect on one of the “core” symptoms of gastroparesis, nausea. 

There are two kinds of gastroparesis: idiopathic and 

diabetic. The FDA currently recognizes one approved drug for 

diabetic gastroparesis, which is only indicated for short-term 

use of up to three months due to risks of serious side effects 

after 12 months of use. There are no FDA-approved drugs 

specifically for idiopathic gastroparesis, although the treatment

of its symptoms – including nausea – is the same as for diabetic 

gastroparesis. 

Vanda’s relevant discussions with the FDA regarding 

tradipitant began in April 2018, when it submitted a proposal 

to extend its four-week clinical trial of the drug by 12 months. 

The FDA denied this proposal, requiring a nine-month animal 

study to assess the drug’s long-term toxicity before Vanda 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 5 of 22
6

could proceed with long-term studies in humans. Vanda 

refused to conduct such studies, citing its ethical opposition to 

nonrodent testing that requires sacrificing the animal. As a 

result of this refusal, the FDA imposed a partial clinical hold, 

as authorized by 21 U.S.C. § 355(i)(3), which prevents further 

long-term clinical studies until Vanda conducts the required 

animal studies. While the hold is in place, Vanda can still 

conduct short-term clinical studies. In a separate litigation, 

Vanda sought judicial review of the clinical hold and the 

District Court upheld the FDA’s order. Vanda Pharm., Inc. v. 

FDA (“Vanda I”), 436 F. Supp. 3d 256 (D.D.C. 2020). Vanda 

did not appeal this decision.

In March 2019, Vanda requested that tradipitant be 

designated a “breakthrough therapy” for the treatment of 

gastroparesis under 21 U.S.C. § 356(a). Pointing to issues with 

the study’s conclusions and its findings of the drug’s 

effectiveness on nausea symptoms, the FDA denied this 

request. The FDA also advised Vanda that it was “considering 

an indication for the short-term relief of nausea in 

gastroparesis” and encouraged Vanda to “further evaluate 

tradipitant for this use” in future submissions. Letter from FDA 

Director Julie Beitz to Vanda Denying Appeal of Denial of 

Breakthrough Therapy Designation for Tradipitant (Feb. 28, 

2020) [hereinafter FDA Letter Affirming Breakthrough 

Therapy Designation Denial], J.A. 657.

Finally, in 2021, Vanda filed the fast track application that 

is the subject of this litigation. Rather than taking the FDA’s 

recommendation to tailor its application to short-term relief, 

Vanda once again framed tradipitant’s indication as for the 

symptoms of gastroparesis broadly. As with its previous 

applications, Vanda’s fast track request described the 

symptoms of gastroparesis as “chronic” and “persistent,” with 

most patients “requir[ing] long-term medications.” Vanda 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 6 of 22
7

Pharma., Inc., Request for Fast Track Designation 8-11 (Sep. 

28, 2021), J.A. 177-80.

The FDA denied Vanda’s fast track request. While it

conceded that gastroparesis is a serious condition with an 

unmet medical need, the agency found that the partial clinical 

hold prevented Vanda from demonstrating that its drug could 

address that need. This was because, being unable to conduct 

long-term studies, Vanda could not obtain the data necessary 

to demonstrate the product’s potential for the indication as 

described in its application – i.e., to treat the symptoms of 

gastroparesis, which are chronic, rather than to provide shortterm symptomatic relief.

In a contemporaneous internal memorandum, the FDA 

elaborated that the unmet medical need tradipitant purported to 

address was the long-term treatment of nausea symptoms, but 

that no data on the drug’s effectiveness for this indication could 

be generated while the clinical hold was in place. The FDA 

further observed that the approach to treating nausea in patients 

was the same whether the gastroparesis was diabetic or 

idiopathic. The FDA also noted issues with Vanda’s study’s 

methodology, including the use of rescue medication, which 

the FDA was concerned may have tainted the results of 

Vanda’s study. These internal notes, although not originally 

disclosed to Vanda, mirror feedback that Vanda had previously 

received from the FDA in connection with its breakthrough 

designation application.

The FDA’s memo also included an internal checklist that 

the FDA uses to assess fast track applications. The checklist 

contains six main items, including whether the condition is 

serious/life-threatening, and whether the product’s 

development program was designed to demonstrate an effect 

on a serious aspect of the condition. For these two items – items 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 7 of 22
8

1 and 2 – the FDA marked “yes” when assessing Vanda’s fasttrack application. But it marked “no” as to items 3 and 4, which 

ask if the product development plan addresses an unmet 

medical need and if the product shows potential to address an 

unmet medical need. Also relevant is item 5, which asks 

whether the data supporting the request comes from trials that 

are on clinical hold. Here, the FDA marked “yes.” The 

checklist then recommends that, for fast track approval, items 

1 through 4 must be answered “yes,” and that, if item 5 is 

marked “yes,” – i.e., if there is a clinical hold in place – the fast 

track application may not be granted.

In the face of the fast track denial and of the partial clinical 

hold, Vanda could then pursue one of two courses of action. 

First, it could file a new fast track application, tailored to the 

short-term treatment of gastroparesis symptoms, as the FDA 

suggested it do. Alternatively, it could conduct the required 

animal studies to lift the clinical hold and proceed with longterm studies to treat gastroparesis broadly. Vanda chose to 

pursue neither of these options, which have remained open in 

the course of this litigation. Instead, it filed suit in federal court 

challenging the fast track denial as arbitrary and capricious 

under the APA. While the District Court’s decision on crossmotions for summary judgment was pending, Vanda then 

submitted a complete NDA, requesting marketing approval of 

its drug – once again, indicated broadly to treat gastroparesis

symptoms. The District Court granted summary judgment in 

favor of the FDA. This appeal followed. 

After this appeal was filed, the FDA reviewed Vanda’s 

NDA and issued a Complete Response Letter denying the 

application in its current form, finding that Vanda does not 

provide substantial evidence of effectiveness for tradipitant for 

the treatment of either symptoms of gastroparesis more broadly 

or nausea specifically.

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 8 of 22
9

II. ANALYSIS

A. Standard of Review

This Court reviews appeals from summary judgments de 

novo, applying the standards set forth in Federal Rule of Civil 

Procedure 56(a). See, e.g., Celotex Corp v. Catrett, 477 U.S. 

317, 322 (1986). Under Rule 56(a), summary judgment is 

warranted if the movant shows that “there is no genuine dispute 

as to any material fact and the movant is entitled to judgment 

as a matter of law.” 

When reviewing agency decisions under the APA, we set 

aside agency actions if we determine that they are “arbitrary, 

capricious, an abuse of discretion, or otherwise not in 

accordance with law.” 5 U.S.C. § 706(2)(A). An agency “acts 

arbitrarily or capriciously if it ‘has relied on factors which 

Congress has not intended it to consider, entirely failed to 

consider an important aspect of the problem, offered an 

explanation for its decision that runs counter to the evidence 

before the agency, or is so implausible that it could not be 

ascribed to a difference in view or the product of agency 

expertise.’” Am. Wildlands v. Kempthorne, 530 F.3d 991, 997-

98 (D.C. Cir. 2008) (quoting Motor Vehicle Mfrs. Ass’n v. State 

Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983)).

Where the question is whether the agency action was 

consistent with statutory authorization, our task is to determine 

whether the agency acted consistently with the “best reading” 

of the statute. Loper Bright Enterprises v. Raimondo, 144 S. 

Ct. 2244, 2263 (2024). This judicial inquiry includes a 

determination as to whether the statute in question “delegates 

discretionary authority” to the agency and whether the agency

“engaged in reasoned decisionmaking within [the] boundaries” 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 9 of 22
10

of that statutory delegation. Id. (internal quotation marks and 

citations omitted).

B. Finality and Mootness

As a threshold matter, it is not clear that the denial of fast

track review is a final action that is subject to judicial review.

See Bennett v. Spear, 520 U.S. 154, 177-78 (1997). This is 

because normally “[a] preliminary, procedural, or intermediate 

agency action or ruling” is only “subject to review on the 

review of the final agency action.” Yaman v. U.S. Dep’t of 

State, 634 F.3d 610, 613 (D.C. Cir. 2011) (per curiam) (quoting 

5 U.S.C. § 704).

This final order rule codifies the understanding that 

“[p]remature review squanders judicial resources,” and that 

litigants are generally “best served by a system which prohibits 

piecemeal appellate consideration of rulings that may fade into 

insignificance by the time proceedings conclude.” CSX 

Transp., Inc. v. Surface Transp. Bd., 774 F.3d 25, 31 (D.C. Cir. 

2014) (internal quotation marks and citations omitted). Thus, 

we normally “reserv[e] judicial review until the end of an 

adjudication,” when a judgment has been rendered on the 

merits of the matter before the agency – in this case, until the 

final completed NDA is ultimately denied. Id.; see also Holistic 

Candlers & Consumers Ass’n v. FDA, 664 F.3d 940, 943 (D.C. 

Cir. 2012) (finding that FDA warning letters are not reviewable 

final agency actions because they “neither mark the 

consummation of the agency’s decisionmaking process nor 

determine the appellants’ legal rights or obligations”). 

Neither party contends that the FDA’s Complete 

Response Letter denying the NDA in its current form is a final 

agency action, as it “simply afford[s] [Vanda] the opportunity 

to provide additional information before the agency makes a 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 10 of 22
11

final decision on the application.” Nostrum Pharms., LLC v. 

FDA, 35 F.4th 820, 825 (D.C. Cir. 2022) (holding that a 

“complete response letter is an interim step in the FDA’s 

consideration of an application” and, therefore, not a final 

agency action under 21 U.S.C. § 355(h)). Indeed, the Complete 

Response Letter is not at issue in this case.

It is thus unclear under applicable law whether the FDA’s 

denial of fast track review of Vanda’s application, on its own, 

is a final order. We leave this question for another day,

however, because the FDA does not claim the disputed action 

taken on Vanda’s fast track request was not a final action 

subject to judicial review. As finality is not jurisdictional under 

the APA, we therefore need not decide this matter. See Marcum 

v. Salazar, 694 F.3d 123, 128 (D.C. Cir. 2012). Rather than 

challenge finality, the FDA alleges a different justiciability bar, 

contending that the fast track issue should be dismissed as 

moot. We disagree. 

We are “obliged to address the issue” of mootness because 

it “goes to the jurisdiction of this court.” Row 1 Inc. v. Becerra, 

92 F.4th 1138, 1143 (D.C. Cir. 2024) (internal quotation marks 

and citation omitted). A claim is moot when “the issues 

presented are no longer ‘live’ or the parties lack a legally 

cognizable interest in the outcome.” Already, LLC v. Nike, Inc., 

568 U.S. 85, 91 (2013) (quoting Murphy v. Hunt, 455 U.S. 478, 

481 (1982) (per curiam)). Intervening events may moot a claim 

if they “make it impossible to grant the prevailing party 

effective relief.” Lemon v. Geren, 514 F.3d 1312, 1315 (D.C. 

Cir. 2008) (internal quotation marks and citation omitted). 

While the party invoking mootness “bears the initial burden of 

proving that no live controversy exists,” N. Am. Butterfly Ass’n 

v. Wolf, 977 F.3d 1244, 1258 (D.C. Cir. 2020) (internal 

quotation marks and citation omitted), this court still has the

“independent obligation to ensure that appeals before us are not 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 11 of 22
12

moot.” Planned Parenthood of Wis., Inc. v. Azar, 942 F.3d 512, 

516 (D.C. Cir. 2019) (internal quotation marks and citation 

omitted).

The FDA contends that the denial of fast track review is 

not a live issue at this juncture because any benefits of fast track 

are inapplicable once the complete NDA has been filed. But 

fast track is not an “all or nothing” package: that Vanda cannot 

at this stage benefit from all of the features of the fast track 

program, such as rolling review, does not mean it has no 

concrete interest in the program. Because Vanda can still 

benefit from other advantages the program confers, including 

expedited review and facilitation opportunities, it retains a 

“legally cognizable interest” in the resolution of the question 

before us here. Already, 568 U.S. at 91.

First, now that the FDA has denied Vanda’s NDA in its 

current form, Vanda may continue to discuss how to move 

forward with its application, and will benefit from facilitation 

of the drug’s development in these negotiations. We see no 

reason why a fast track designation would confer no relief in 

this ongoing process, and why it would therefore be 

“impossible for a court to grant any effectual relief” to Vanda 

if we determine that it should prevail on the merits. Knox v. 

Serv. Emps. Int’l Union, Loc. 1000, 567 U.S. 298, 307 (2012)

(internal quotation marks and citation omitted). Even if the 

benefits of such facilitation discussions are marginal in the face 

of the substantial feedback Vanda has already received, this 

concrete interest, “however small,” means that the case is not 

moot. Id.

Second, while the application is in continued revision, fast

track status would still confer the concrete benefit of expedited 

“review of the application” under section 356(b). Should 

Vanda prevail on the merits, it would thus obtain the 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 12 of 22
13

“opportunity to pursue a benefit” of expedited review of its 

application, which is a “constitutionally cognizable” interest.

CC Distribs., Inc. v. United States, 883 F.2d 146, 150 (D.C. 

Cir. 1989). 

The FDA argues that completed NDAs are only 

reviewable in an expedited fashion under “priority review,” a 

separate review program which assesses whether the drug in 

question would provide a significant improvement in safety 

and effectiveness. It points to the fact that in filing its NDA,

Vanda concurrently requested priority review of its application. 

But the fact that a complete NDA may benefit from priority 

review does not necessarily mean that it cannot also qualify for 

fast track. In fact, fast track applications may be filed “any time 

after” the IND is submitted. 21 U.S.C. § 356(b)(2). Nor are 

these two expedited review pathways interchangeable because, 

as the FDA acknowledges, an application meeting the criteria 

for fast track would not necessarily qualify for priority review. 

Thus, Vanda could still receive the benefit of expedited review 

“of the application” if it meets the fast track statutory criteria, 

which are different from those for priority review. 

Finally, even if the fast track status were a moot issue, the 

facts here involve an agency action “capable of repetition yet 

evading review.” Del Monte Fresh Produce Co. v. United 

States, 570 F.3d 316, 322 (D.C. Cir. 2009). This exception to 

the mootness doctrine applies “where (1) the challenged action 

is in its duration too short to be fully litigated prior to cessation 

or expiration, and (2) there is a reasonable expectation that the 

same complaining party will be subject to the same action 

again.” Kingdomware Techs., Inc. v. United States, 579 U.S. 

162, 170 (2016) (cleaned up). 

Because fast track applications must be reviewed within 

60 days, 21 U.S.C. § 356(b)(3), the challenged action here is 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 13 of 22
14

“too short to be fully litigated prior to its cessation or 

expiration.” Del Monte, 570 F.3d at 322 (noting that “agency 

actions of less than two years’ duration cannot be ‘fully 

litigated’ prior to cessation or expiration”). And because the 

FDA has made it clear that it invites Vanda to submit a 

modified application for tradipitant indicated for short-term 

symptoms of gastroparesis, there is “a reasonable expectation 

that” any subsequent fast track applications will be subject to 

the same assessment process that Vanda alleges is improper 

here. Id.

We therefore proceed to the merits of Vanda’s claim. 

C. The FDA’s Denial of Vanda’s Fast Track Application 

Was Not Contrary to Law 

Vanda first argues that the text of section 356(b) prohibits 

the FDA from considering a clinical hold or other elements of 

the drug’s development program when assessing a fast track 

application. We disagree. 

There are some provisions in the FDCA that are relatively 

clear in indicating how the FDA should designate certain 

products. See, e.g., Genus Med. Techs. LLC v. FDA, 994 F.3d 

631, 633 (D.C. Cir. 2021) (interpreting FDCA provisions for 

designation of products as “drugs” or “devices” where the 

statute defined each term and rejecting the FDA’s 

interpretation as inconsistent with the relevant statutory 

definitions). The same is not true with respect to the fast track 

provision in the FDCA. Rather, the statute leaves it for the FDA 

to determine whether a drug “demonstrates the potential to 

address unmet medical needs,” 21 U.S.C. § 356(b)(1), (b)(3), 

and it does not define these terms. The statute merely 

encourages the FDA to “utilize innovative and flexible 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 14 of 22
15

approaches to the assessment of products” that address “unmet 

medical needs.” Id. § 356(e)(1). 

Vanda contends that the FDA could not consider the 

clinical hold because the statute’s text allows the FDA to only 

consider the “drug,” not the drug’s development program. In 

other words, Vanda argues that because the statutory language 

requires the FDA to assess whether the drug demonstrates the 

potential to address unmet medical needs, the FDA

impermissibly deviated from the statute when it considered the 

drug’s development program, including whether a clinical hold 

was in place. This is an untenable distinction. 

The statute places the burden on an applicant to 

“demonstrate” that its drug meets the fast track criteria. To 

assess whether this standard is met, the FDA obviously must 

consider how the application puts forth the drug’s capacity to 

address the indicated need. In doing so, the FDA may consider 

past studies that have been conducted and how future studies 

may further offer evidence of the drug’s efficacy. See 

Prohibition Juice Co. v. FDA, 45 F.4th 8, 26 (D.C. Cir. 2022) 

(explaining that the FDA shall deny an application where the 

statute “requires that applicants make a certain showing before 

their products can be approved” and the “applicant[s] fail[] to 

make that showing”). Vanda points to no statutory language to 

the contrary. Moreover, the fast track provision requires the 

FDA to assess not only whether the drug currently addresses 

unmet needs, but whether it has the “potential” to address them. 

This language mandates an inherently prospective analysis. See 

Potential, OXFORD ENGLISH DICTIONARY (2d ed. 1989). The 

drug’s development plan, including what past and future 

studies may demonstrate about the potential of the drug, are 

plainly relevant and permissible considerations. 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 15 of 22
16

Vanda’s self-serving interpretation of the statute is both 

under- and overinclusive. It would preclude the FDA from 

considering a drug’s development plan at all, even where it 

might be lenient to an applicant whose drug has yet to show 

results and who can only demonstrate its potential through a 

development plan that may in the future prove the drug’s 

effectiveness. Simultaneously, Vanda would require that the 

FDA grant fast track to all applications that show that the drug 

might in the future serve an unmet need, even if current studies 

do not show that it is effective and future studies cannot be 

conducted. Such a construction of the statute would render 

superfluous the FDA’s role in determining whether a drug 

“demonstrates” the potential defined by the statute, as it would 

make virtually all drugs intended for treating the qualifying 

conditions eligible for fast track. See Donnelly v. FAA, 411 

F.3d 267, 271 (D.C. Cir. 2005) (“We must strive to interpret a 

statute to give meaning to every clause and word, and certainly 

not to treat an entire subsection as mere surplusage.”). 

The best reading of the statute indicates that, in enacting 

the fast track, Congress intended to benefit drugs that are not 

yet fully effective but that can demonstrate their potential

effectiveness in addressing an unmet medical need in the 

future. Assessing the drug’s development plan, including 

whether future studies may be conducted to demonstrate its 

potential or cure current data issues, is perfectly consistent with 

that goal. By considering all available evidence, the FDA thus 

lives up to the statutory mandate that it “utilize innovative and 

flexible approaches” to determine whether to grant fast track 

status, especially where current data on the drug’s effectiveness 

may be scarce at the time the FDA is evaluating it for fast track. 

21 U.S.C. § 356(e)(1). 

The FDA previously informed Vanda of numerous 

concerns it had about its tradipitant study. In the face of such 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 16 of 22
17

issues with existing data, the agency’s consideration of whether 

future studies might cure those problems is entirely consistent 

with the statute’s mandate. It was equally reasonable for the 

FDA to conclude that Vanda’s decision not to conduct 

additional studies required to lift the partial clinical hold meant 

that Vanda would not cure those issues and, thus, could not 

demonstrate tradipitant’s potential to address the unmet need 

that Vanda’s application identified. 

D. The FDA Did Not Act Arbitrarily and Capriciously in 

Denying Vanda’s Fast Track Application

On the record before us, we also conclude that the FDA

did not act arbitrarily or capriciously in assessing Vanda’s fast 

track application.

First, it was permissible for the FDA to assess tradipitant

as indicated for long-term symptoms of gastroparesis. The 

record – including Vanda’s own filings with the FDA – makes 

clear that gastroparesis is a chronic disease. Indeed, the fact that 

Vanda had previously sought to extend its clinical trials to 12 

months indicates that it was interested in tradipitant’s longterm effects. And, even after the FDA advised Vanda that it 

should tailor its future submissions more narrowly to shortterm symptoms, Vanda did not do so, continuing to list 

tradipitant’s indication as for the treatment of symptoms of 

gastroparesis broadly. The fact that Vanda chose not to follow 

that recommendation does not place the burden on the FDA to 

divine a more specific indication for the drug than what Vanda 

described in its application. 

Moreover, as Vanda itself acknowledged in its application, 

there is already a FDA-approved short-term treatment for 

gastroparesis. In light of this alternative treatment and of 

Vanda’s own description of the condition it set out to treat, the 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 17 of 22
18

FDA was reasonable in defining the unmet medical need as the 

need for long-term treatment of gastroparesis symptoms. And, 

because the clinical hold precludes Vanda from demonstrating 

that its drug will be an improvement on the current treatment’s 

toxic long-term side effects, it was also reasonable for the FDA 

to conclude that tradipitant could not demonstrate that it had 

the potential to meet that need. 

Second, it was also reasonable for the FDA not to address 

tradipitant’s indication to treat idiopathic gastroparesis 

separately, because the version of the disease is irrelevant to 

the drug’s effectiveness to treat chronic nausea symptoms. 

Vanda contends that, because idiopathic gastroparesis in 

particular has no FDA-approved treatment, the FDA should 

have granted fast track to tradipitant for that narrower 

indication. But the lack of any approved idiopathic 

gastroparesis treatment does not mean that tradipitant 

necessarily meets that need. In fact, the record shows that 

tradipitant’s only statistically significant effects are on the 

symptom of nausea, which manifests the same way in both 

idiopathic and diabetic gastroparesis. The FDA’s concerns with 

Vanda’s nausea findings and with the clinical hold’s 

foreclosure of long-term studies apply just as compellingly to 

an indication for idiopathic gastroparesis as they do for 

gastroparesis generally. 

Finally, Vanda argues that the FDA had already previously 

indicated that tradipitant had “potential,” and had already 

approved it for treatment in some circumstances, so the fast 

track denial was an arbitrary contradiction of the agency’s prior 

positions. This claim is without merit. An agency acts 

unreasonably when it deviates from prior positions “in similar 

situations,” which is plainly not the case here. Gen. Motors 

Corp. v. Nat’l Highway Traffic Safety Admin., 898 F.2d 165, 

174 (D.C. Cir. 1990). 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 18 of 22
19

Vanda first points to a letter in which an FDA director, 

while affirming the FDA’s denial of breakthrough therapy 

designation under the separate standard governed by section

356(a), states that she saw “a potential therapeutic role for 

tradipitant, particularly for the short-term relief of nausea in 

gastroparesis patients.” FDA Letter Affirming Breakthrough 

Therapy Designation Denial, J.A. 657. But this non-binding

statement assessed tradipitant’s merits under the separate 

standard of section 356(a), and thus cannot indicate a shift in 

agency position with regards to whether tradipitant met the 

different criteria for fast track under section 356(b). See Gen. 

Motors Corp., 898 F.2d at 174; Muwekma Ohlone Tribe v. 

Salazar, 708 F.3d 209, 216 (D.C. Cir. 2013) (finding no 

inconsistency where the agency’s positions did not involve 

treating “similar situations differently”). 

In any event, the FDA’s denial of both requests reflects a 

consistent position, as the agency asserted many of the same 

issues with the drug’s studies in both decisions. Immediately 

after the language Vanda quotes, the FDA director observed 

that “additional data would be needed” to support a 

breakthrough therapy designation. FDA Letter Affirming 

Breakthrough Therapy Designation Denial, J.A. 657. The 

director also added that Vanda’s application was for a broader 

indication than its data supported, as it was “for ‘the treatment 

of gastroparesis’, not for the treatment of a single symptom 

associated with gastroparesis.” Id. Instead, the agency advised 

that Vanda “should not submit a request for Breakthrough 

Therapy Designation to treat ‘gastroparesis’ based on a 

treatment effect for nausea alone.” Id. The FDA’s denial of 

Vanda’s fast track application is therefore consistent with its 

prior feedback to Vanda, including that its current data did not 

demonstrate the potential for tradipitant to treat gastroparesis 

symptoms generally. 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 19 of 22
20

Vanda’s second contention of a prior inconsistent agency 

position is equally unpersuasive. Vanda refers to the FDA’s 

prior approval of expanded access for tradipitant, which is not 

only governed by a different statutory standard under 21 U.S.C. 

§ 360bbb(b)(2), but is also wholly unrelated to expedited 

approval. The expanded access program allows physicians, 

subject to certain conditions, to request manufacturers to 

provide an unapproved, investigational drug for the treatment 

of specific patients, whom the physician in question will 

monitor. Id. § 360bbb(b). Unlike breakthrough therapy, 

accelerated approval, and fast track, expanded access does not 

expedite a drug’s approval process. It merely authorizes its use 

for certain patients in certain conditions if “the Secretary 

determines that there is sufficient evidence of safety and 

effectiveness to support the use of the investigational drug” in 

the unique case of each petitioning patient. Id. § 360bbb(b)(2). 

Vanda argues that because the FDA had already granted 

expanded access for tradipitant to eight individuals, some of 

whom have used the drug for over a year, tradipitant’s 

“potential” under section 356(b) is met, and the FDA’s fast 

track denial was therefore inconsistent with the expanded 

access grant. But authorization for expanded access takes no 

position on the drug’s marketing approval, likelihood of 

success, or potential to treat patients on a broader scale. There 

is no inconsistency between the FDA’s grant of expanded 

access and its denial of fast track where these two programs 

operate under different statutory standards and objectives. 

Finally, Vanda’s ethical objections to the required animal 

studies to lift the clinical hold, principled though they may be, 

are beside the point. Having fully litigated the propriety of the 

clinical hold in Vanda I, Vanda is estopped from raising any 

new challenges to the hold that it could have raised earlier. See 

Ashbourne v. Hansberry, 894 F.3d 298, 302 (D.C. Cir. 2018). 

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 20 of 22
21

Vanda attempts to circumvent res judicata by raising the novel 

argument that the FDA Modernization Act 2.0, Pub. L. No. 

117-328, enacted after Vanda I, now renders the clinical hold 

unreasonable. But we do not reach this claim because Vanda 

raises it for the first time on appeal, even though the relevant 

statute was enacted before the District Court reached its 

decision. See Zevallos v. Obama, 793 F.3d 106, 114 (D.C. Cir. 

2015). Vanda is welcome to raise this argument before the 

FDA as it continues to discuss tradipitant’s approval, as the 

FDA is better positioned to assess the reasonableness of 

scientific methodology than this court. See Smith v. Berryhill, 

587 U.S. 471, 488 (2019) (“[A] federal court generally goes 

astray if it decides a question that has been delegated to an 

agency if that agency has not first had a chance to address the 

question.”). 

In light of the evidence before it, the FDA reasonably 

interpreted Vanda’s fast track application as targeting the 

chronic symptoms of gastroparesis, which necessarily requires 

that tradipitant meet the unmet need for long-term treatment. 

The FDA’s focus on the drug’s effects on chronic symptoms is 

wholly consistent with the record and demonstrates a “rational 

connection between the facts found and the choice made.” State 

Farm, 463 U.S. at 43 (internal quotation marks and citation 

omitted); see also Growth Energy v. EPA, 5 F.4th 1, 16 (D.C. 

Cir. 2021) (per curiam) (“[B]ecause the agency examined the 

relevant data and articulated a satisfactory explanation for its 

action, we uphold its decision.” (internal quotation marks and 

citation omitted)). We therefore find that the FDA’s denial of 

Vanda’s fast track application was neither arbitrary nor 

capricious.

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 21 of 22
22

III. CONCLUSION

For the reasons set forth above, we affirm the District 

Court’s grant of summary judgment to the FDA. Vanda 

remains free to continue its negotiations with the agency, 

including to file an amended application pursuing a short-term 

indication for its drug, or to proceed to lift the partial clinical 

hold.

So ordered.

USCA Case #23-5200 Document #2089874 Filed: 12/17/2024 Page 22 of 22