[Federal Register Volume 80, Number 154 (Tuesday, August 11, 2015)]
[Proposed Rules]
[Pages 48044-48051]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-19655]



[[Page 48044]]

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DEPARTMENT OF JUSTICE

Drug Enforcement Administration

21 CFR Part 1308

[Docket No. DEA-419N]


Schedules of Controlled Substances: Placement of Eluxadoline Into 
Schedule IV

AGENCY: Drug Enforcement Administration, Department of Justice.

ACTION: Notice of proposed rulemaking.

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SUMMARY: The Drug Enforcement Administration proposes to place the 
substance eluxadoline (5-[[[(2S)-2-amino-3-[4-aminocarbonyl)-2,6-
dimethylphenyl]-1-oxopropyl][(1S)-1-(4-phenyl-1H-imidazol-2-
yl)ethyl]amino]methyl]-2-methoxybenzoic acid), including its salts, 
isomers, and salts of isomers, into schedule IV of the Controlled 
Substances Act (CSA). This proposed scheduling action is pursuant to 
the CSA which requires that such actions be made on the record after 
opportunity for a hearing through formal rulemaking. If finalized, this 
action would impose the regulatory controls and administrative, civil, 
and criminal sanctions applicable to schedule IV controlled substances 
on persons who handle (manufacture, distribute, dispense, import, 
export, engage in research, conduct instructional activities, or 
possess), or propose to handle eluxadoline.

DATES: Interested persons may file written comments on this proposal in 
accordance with 21 CFR 1308.43(g). Electronic comments must be 
submitted, and written comments must be postmarked, on or before 
September 10, 2015. Commenters should be aware that the electronic 
Federal Docket Management System will not accept comments after 11:59 
p.m. Eastern Time on the last day of the comment period.
    Interested persons, defined at 21 CFR 1300.01 as those ``adversely 
affected or aggrieved by any rule or proposed rule issuable pursuant to 
section 201 of the Act (21 U.S.C. 811),'' may file a request for 
hearing, notice of appearance, or waiver of hearing pursuant to 21 CFR 
1308.44 and in accordance with 21 CFR 1316.45, 1316.47, 1316.48, or 
1316.49, as applicable. Requests for hearing, notices of appearance, 
and waivers of an opportunity for a hearing or to participate in a 
hearing must be received on or before September 10, 2015.

ADDRESSES: To ensure proper handling of comments, please reference 
``Docket No. DEA-419N'' on all correspondence, including any 
attachments.
     Electronic comments: The Drug Enforcement Administration 
encourages that all comments be submitted electronically through the 
Federal eRulemaking Portal, which provides the ability to type short 
comments directly into the comment field on the Web page or to attach a 
file for lengthier comments. Please go to http://www.regulations.gov 
and follow the online instructions at that site for submitting 
comments. Upon completion of your submission you will receive a Comment 
Tracking Number for your comment. Please be aware that submitted 
comments are not instantaneously available for public view on 
Regulations.gov. If you have received a Comment Tracking Number, your 
comment has been successfully submitted and there is no need to 
resubmit the same comment.
     Paper comments: Paper comments that duplicate the 
electronic submission are not necessary and are discouraged. Should you 
wish to mail a paper comment in lieu of an electronic comment, it 
should be sent via regular or express mail to: Drug Enforcement 
Administration, Attn: DEA Federal Register Representative/ODL, 8701 
Morrissette Drive, Springfield, Virginia 22152.
     Hearing requests: All requests for hearing and waivers of 
participation must be sent to: Drug Enforcement Administration, Attn: 
Federal Register Representative/ODL, 8701 Morrissette Drive, 
Springfield, Virginia 22152. All requests for hearing and waivers of 
participation should also be sent to: Drug Enforcement Administration, 
Attn: Hearing Clerk/LJ, 8701 Morrissette Drive, Springfield, Virginia 
22152.

FOR FURTHER INFORMATION CONTACT: John R. Scherbenske, Office of 
Diversion Control, Drug Enforcement Administration; Mailing Address: 
8701 Morrissette Drive, Springfield, Virginia 22152; Telephone: (202) 
598-6812.

SUPPLEMENTARY INFORMATION: 

Posting of Public Comments

    Please note that all comments received in response to this docket 
are considered part of the public record. They will, unless reasonable 
cause is given, be made available by the Drug Enforcement 
Administration (DEA) for public inspection online at http://www.regulations.gov. Such information includes personal identifying 
information (such as your name, address, etc.) voluntarily submitted by 
the commenter. The Freedom of Information Act (FOIA) applies to all 
comments received. If you want to submit personal identifying 
information (such as your name, address, etc.) as part of your comment, 
but do not want it to be made publicly available, you must include the 
phrase ``PERSONAL IDENTIFYING INFORMATION'' in the first paragraph of 
your comment. You must also place the personal identifying information 
you do not want made publicly available in the first paragraph of your 
comment and identify what information you want redacted.
    If you want to submit confidential business information as part of 
your comment, but do not want it to be made publicly available, you 
must include the phrase ``CONFIDENTIAL BUSINESS INFORMATION'' in the 
first paragraph of your comment. You must also prominently identify 
confidential business information to be redacted within the comment.
    Comments containing personal identifying information and 
confidential business information identified as directed above will 
generally be made publicly available in redacted form. If a comment has 
so much confidential business information or personal identifying 
information that it cannot be effectively redacted, all or part of that 
comment may not be made publicly available. Comments posted to http://www.regulations.gov may include any personal identifying information 
(such as name, address, and phone number) included in the text of your 
electronic submission that is not identified as directed above as 
confidential.
    An electronic copy of this document and supplemental information to 
this proposed rule are available at http://www.regulations.gov for easy 
reference.

Request for Hearing, Notice of Appearance at Hearing, Waiver of an 
Opportunity for a Hearing or To Participate in a Hearing

    Pursuant to 21 U.S.C. 811(a), this action is a formal rulemaking 
``on the record after opportunity for a hearing.'' Such proceedings are 
conducted pursuant to the provisions of the Administrative Procedure 
Act (APA), 5 U.S.C. 551-559. 21 CFR 1308.41-1308.45; 21 CFR part 1316, 
subpart D. In accordance with 21 CFR 1308.44(a)-(c), requests for 
hearing, notices of appearance, and waivers of an opportunity for a 
hearing or to participate in a hearing may be submitted only by 
interested persons, defined as those ``adversely affected or aggrieved 
by any rule or proposed rule issuable pursuant to section 201 of the 
Act (21 U.S.C. 811).'' 21 CFR 1300.01. Such requests or notices must 
conform to the requirements of 21 CFR 1308.44(a) or (b), and 1316.47 or 
1316.48, as applicable, and include a

[[Page 48045]]

statement of interest of the person in the proceeding and the 
objections or issues, if any, concerning which the person desires to be 
heard. Any waiver must conform to the requirements of 21 CFR 1308.44(c) 
and 1316.49, including a written statement regarding the interested 
person's position on the matters of fact and law involved in any 
hearing.
    Please note that pursuant to 21 U.S.C. 811(a), the purpose and 
subject matter of a hearing is restricted to: ``find[ing] that such 
drug or other substance has a potential for abuse, and * * * mak[ing] 
with respect to such drug or other substance the findings prescribed by 
subsection (b) of section 812 of this title for the schedule in which 
such drug is to be placed * * *.'' All requests for hearing and waivers 
of participation must be sent to the DEA using the address information 
provided above.

Legal Authority

    The DEA implements and enforces titles II and III of the 
Comprehensive Drug Abuse Prevention and Control Act of 1970, as 
amended. 21 U.S.C. 801-971. Titles II and III are referred to as the 
``Controlled Substances Act'' and the ``Controlled Substances Import 
and Export Act,'' respectively, and are collectively referred to as the 
``Controlled Substances Act'' or the ``CSA'' for the purpose of this 
action. The DEA publishes the implementing regulations for these 
statutes in title 21 of the Code of Federal Regulations (CFR), chapter 
II. The CSA and its implementing regulations are designed to prevent, 
detect, and eliminate the diversion of controlled substances and listed 
chemicals into the illicit market while ensuring an adequate supply is 
available for the legitimate medical, scientific, research, and 
industrial needs of the United States. Controlled substances have the 
potential for abuse and dependence and are controlled to protect the 
public health and safety.
    Under the CSA, each controlled substance is classified into one of 
five schedules based upon its potential for abuse, its currently 
accepted medical use in treatment in the United States, and the degree 
of dependence the substance may cause. 21 U.S.C. 812. The initial 
schedules of controlled substances established by Congress are found at 
21 U.S.C. 812(c), and the current list of all scheduled substances is 
published at 21 CFR part 1308.
    Pursuant to 21 U.S.C. 811(a)(1), the Attorney General may, by rule, 
``add to such a schedule or transfer between such schedules any drug or 
other substance if he * * * finds that such drug or other substance has 
a potential for abuse, and * * * makes with respect to such drug or 
other substance the findings prescribed by subsection (b) of section 
812 of this title for the schedule in which such drug is to be placed * 
* *.'' The Attorney General has delegated scheduling authority under 21 
U.S.C. 811 to the Administrator of the DEA. 28 CFR 0.100.
    The CSA provides that scheduling of any drug or other substance may 
be initiated by the Attorney General (1) on her own motion; (2) at the 
request of the Secretary of Health and Human Services (HHS); or (3) on 
the petition of any interested party. 21 U.S.C. 811(a). If finalized, 
this action would impose the regulatory controls and administrative, 
civil, and criminal sanctions of schedule IV controlled substances for 
any person who handles eluxadoline.

Background

    Eluxadoline is a new molecular entity with central nervous system 
opioid properties. It has not been marketed in any country. Eluxadoline 
has mixed mu opioid receptor (MOR) and kappa opioid receptor (KOR) 
agonist and delta opioid receptor (DOR) antagonist properties. 
Recently, the Food and Drug Administration (FDA) approved eluxadoline 
as a prescription drug for the treatment of irritable bowel syndrome 
with diarrhea (IBS-d). Eluxadoline will be marketed as 75 and 100 
milligrams (mg) oral tablets under the trade name of Viberzi.

Proposed Determination To Schedule Eluxadoline

    Pursuant to 21 U.S.C. 811(a)(1), proceedings to add a drug or 
substance to those controlled under the CSA may be initiated by request 
of the Secretary of the HHS.\1\ The HHS provided the DEA with a 
scientific and medical evaluation document (dated May 5, 2015) prepared 
by the FDA entitled ``Basis for the Recommendation to Place Eluxadoline 
and Its Salts into schedule IV of the Controlled Substances Act'' and a 
scheduling recommendation. Pursuant to 21 U.S.C. 811(b), this document 
contained an eight-factor analysis of the abuse potential of 
eluxadoline as a new drug, along with the HHS' recommendation to 
control eluxadoline under schedule IV of the CSA.
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    \1\ As set forth in a memorandum of understanding entered into 
by the HHS, the Food and Drug Administration (FDA), and the National 
Institute on Drug Abuse (NIDA), the FDA acts as the lead agency 
within the HHS in carrying out the Secretary's scheduling 
responsibilities under the CSA, with the concurrence of the NIDA. 50 
FR 9518, Mar. 8, 1985. In addition, because the Secretary of the HHS 
has delegated to the Assistant Secretary for Health of the HHS the 
authority to make domestic drug scheduling recommendations, for 
purposes of this document, all subsequent references to 
``Secretary'' have been replaced with ``Assistant Secretary.''
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    In response, the DEA reviewed the scientific and medical evaluation 
and scheduling recommendation provided by the HHS, and all other 
relevant data, and completed its own eight-factor review document 
pursuant to 21 U.S.C. 811(c). Included below is a brief summary of each 
factor as analyzed by the HHS and the DEA, and as considered by the DEA 
in its proposed scheduling decision. Please note that both the DEA and 
the HHS analyses are available in their entirety under ``Supporting and 
Related Material'' in the public docket for this proposed rule at 
http://www.regulations.gov, under Docket Number ``DEA-419N''. Full 
analysis of, and citations to, the information referenced in the 
summary may also be found in the supporting and related material.
    1. The Drug's Actual or Relative Potential for Abuse: Eluxadoline 
is a new chemical entity that has not been marketed in the U.S. or in 
any other country. As such, there is no information available which 
details actual abuse of eluxadoline. However, the legislative history 
of the CSA suggests that the DEA consider the following criteria in 
determining whether a particular drug or substance has a potential for 
abuse: \2\
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    \2\ Comprehensive Drug Abuse Prevention and Control Act of 1970, 
H.R. Rep. No. 91-1444, 91st Cong., Sess. 1 (1970); 1970 U.S.C.C.A.N. 
4566, 4601.

    (1) There is evidence that individuals are taking the drug or 
drugs containing such a substance in amounts sufficient to create a 
hazard to their health or to the safety of other individuals or to 
the community;
    (2) There is significant diversion of the drug or substance from 
legitimate drug channels;
    (3) Individuals are taking the substance on their own initiative 
rather than on the basis of medical advice from a practitioner 
licensed by law to administer such drugs in the course of his 
professional practice; or
    (4) The drug or drugs containing such a substance are new drugs 
so related in their action to a drug or drugs already listed as 
having a potential for abuse to make it likely that they will have 
the same potentiality for abuse as such substance, thus making it 
reasonable to assume that there may be significant diversions from 
legitimate channels, significant use contrary to or without medical 
advice, or that it has a substantial capability of creating hazards 
to the health of the user or to the safety of the community.

    Both the HHS and the DEA note that three of the above mentioned 
four criteria (1, 2, and 3) do not apply to eluxadoline for the 
following reasons. Eluxadoline is a new molecular entity

[[Page 48046]]

and has not been marketed in any country. Accordingly, it has not been 
diverted from legitimate sources, and individuals have not taken this 
substance in amounts sufficient to create a hazard to public health or 
safety. Therefore, criterion 4 is the only one that applies to 
eluxadoline.
    Eluxadoline acts as a high affinity agonist at MORs and KORs and as 
an antagonist at DORs. Eluxadoline produced opioid agonistic effects 
such as centrally mediated analgesia, sedation, motor impairment, 
respiratory depression, and death in some animals. Eluxadoline 
generalized to morphine in a drug discrimination study in monkeys 
suggesting its MOR agonist properties. Monkeys self-administered 
eluxadoline indicating its rewarding properties.
    Receptor binding and functional profile studies demonstrate that 
eluxadoline has KOR agonistic activity. Pentazocine (schedule IV opioid 
analgesic) and butorphanol (schedule IV opioid analgesic) are the two 
currently marketed opioid drugs with KOR agonist activity. Pentazocine 
and butorphanol were initially approved for market as non-controlled 
drugs. However, subsequent reports of their actual abuse supported 
control as schedule IV drugs under the CSA. Clinical studies indicated 
that pentazocine and butorphanol have been shown to cause greater 
dysphoria and to be less abusable than the schedule II opioids.
    In human abuse potential studies, eluxadoline produced both 
positive and negative responses. The maximal effects of eluxadoline on 
Drug Liking are greater than that of placebo, but less than that of 
oxycodone (schedule II). Eluxadoline produced small statistically 
significant increases in several positive subjective responses such as 
visual analog scale (VAS) scores for Take Drug Again, Subjective Drug 
Value, Good Drug Effects, High, and the Addiction Research Center 
Inventory-Morphine Benzedrine Group (ARCI-MBG, Euphoria). The positive 
subjective responses to eluxadoline were most often statistically 
significantly less than those produced by oxycodone. Eluxadoline 
produced a high rate of euphoria in human abuse potential studies. 
However, these euphoric effects of eluxadoline are less than that of 
oxycodone.
    Eluxadoline at all doses elicited a small but significant increase 
in the VAS score for Drug Disliking. Eluxadoline also produced a 
statistically significant increase in VAS Bad Drug Effects, ARCI 
Lysergic Acid Diethylamide (ARCI-LSD, Dysphoria), but did not cause a 
significant increase in Drowsiness and Sedation. These results are also 
similar to those produced by pentazocine in a published study which 
reported a statistically significant increase in the VAS score for Bad 
Drug Effects and the score for ARCI-LSD (Dysphoria). Eluxadoline 
produced dysphoric effects consistent with kappa agonist activity 
related effects produced by pentazocine and butorphanol.
    In summary, eluxadoline appears to be so related in its action to 
substances already listed as having potential for abuse, and which have 
been controlled in schedule IV of the CSA, to make it likely that 
eluxadoline will have the same potential for abuse as those substances.
    2. Scientific Evidence of Its Pharmacological Effects, If Known: 
The HHS, in its scientific and medical evaluation document, reviewed 
data from pre-clinical and clinical studies on eluxadoline. The HHS' 
findings are summarized below.
Pre-Clinical In Vitro Pharmacological Studies
    Eluxadoline has high affinity at the MOR, KOR, and DOR. Eluxadoline 
lacked significant affinity for other binding sites including those 
associated with abuse potential. Similar to butorphanol (schedule IV), 
eluxadoline acted as an agonist at both MOR and KOR, but acted as an 
antagonist at DOR. Pentazocine (schedule IV) also has agonist activity 
at KOR.
Pre-Clinical In Vivo Studies
    In the Irwin test (a test of general behavioral responses), there 
were no noticeable behavioral changes produced by eluxadoline at three 
subcutaneous doses of 500, 1000, or 2000 mg/kg in mice. Similarly, 
there were no changes in motor activity, reflexes, excitation, body 
tone, righting reflex, and rotorod tests or in body temperature in rats 
following oral administration of eluxadoline (30 or 300 mg/kg). 
However, intravenous administration of eluxadoline HCl (5, 10 and 20 
mg/kg/day) in rats for 14 days followed by a 14-day recovery period 
produced classic opioid-related behaviors including general arousal, 
handling reactivity, stereotypy, tail pinch response, touch response, 
changes in posture, gait, mobility, righting reflex, respiration, and 
hindlimb splay. In a toxicity study in Cynomolgus monkeys, animals 
treated with eluxadoline (50, 100, and 200 mg/kg/day) or vehicle via 
oral gavage for nine months, followed by a four-week recovery period 
(for the vehicle and 200 mg/kg groups), exhibited no changes in 
behavior during the 39-week treatment period. In a dose-finding study, 
daily intravenous administration of 20 mg/kg eluxadoline for seven days 
produced opioid-associated behaviors (decreased respiration and periods 
of unconsciousness). These effects were severely pronounced following 
40 mg/kg dose. All animals in the highest dose group (40 mg/kg reduced 
to 30 mg/kg on the second day of the dosing after one animal died) 
exhibited opioid overdose symptoms such as decreased activity, 
unresponsiveness, decreased body temperature and respiration rates. 
Opioid antagonist naloxone (0.1 mg/kg) was administered either 
subcutaneously or intravenously to more or less severely affected 
animals, respectively. Upon reducing the eluxadoline dose from 40 mg/kg 
to 30 mg/kg, all animals continued to respond with opioid overdose 
symptoms.
    In a hot-plate test for studying anti-nociceptive effects in mice, 
oral administration of eluxadoline up to doses of 1000 mg/kg showed no 
significant analgesic responses. However, subcutaneous administration 
of both 10 and 50 mg/kg eluxadoline caused significant increases in hot 
plate latencies and produced concurrent opioid-associated behaviors 
such as Straub tail and increased limb tone.
    As mentioned in the HHS scientific and medical evaluation and 
scheduling recommendation, drug discrimination tests in animals serve 
as an important experimental method for predicting whether the effects 
of a given test drug will be similar to that of a standard training 
drug used in the study. In drug discrimination studies conducted in 
Rhesus monkeys trained to discriminate between subcutaneously 
administered morphine (1 mg/kg) and vehicle using shock stimulus 
termination procedure, intravenous administration of 17.8 mg/kg dose of 
eluxadoline HCl produced full generalization to morphine (1 mg/kg) in 
the only monkey tested. When this same monkey was tested at 10 mg/kg, 
there was no generalization. However, the 10 mg/kg dose of eluxadoline 
produced full generalization in a different monkey. The lowest doses of 
eluxadoline at 1.0 (n = 1) and 3.2 mg/kg (n = 2) produced no 
generalization (<20%) to morphine. Eluxadoline, as a mu and kappa 
opioid agonist, produces an interoceptive cue similar to that of mu 
opioid agonist, morphine (schedule II). These data are similar to those 
from several published human studies in which butorphanol (schedule IV, 
mu and kappa opioid agonist), pentazocine (schedule IV, kappa opioid 
agonist) and tramadol (schedule IV, mu opioid agonist

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prodrug) generalized to hydromorphone (schedule II, mu opioid agonist). 
Thus, these drug discrimination data demonstrate that mu opioid 
agonists will be recognized by animals and humans as having similar 
pharmacological properties to each other.
    Drug self-administration tests in animals are used to evaluate the 
rewarding effects of drugs. There is a good correlation between those 
drugs that are self-administered by animals and those that are abused 
by humans. The data from self-administration studies provide a measure 
for abuse potential. In a self-administration study with monkeys (n = 
5) trained to self-administer heroin (0.032 mg/kg/infusion in two 
monkeys or 0.01 mg/kg/infusion in three monkeys), the 0.32 and 1.0 mg/
kg/infusion doses of eluxadoline HCl did not produce self-
administration in one monkey trained to self-administer the higher 
0.032 mg/kg/infusion dose of heroin, or in three other monkeys trained 
to self-administer the lower 0.001 mg/kg/infusion dose of heroin. When 
the highest dose of eluxadoline HCI (3.2 mg/kg/infusion) was tested 
first in the two monkeys trained at the 0.032 mg/kg/infusion dose of 
heroin, the self-administration rate of eluxadoline HCl (10-19 
infusions/session) was less than that of heroin, but more than that of 
saline (2-4 infusions/session). The self-administration of eluxadoline 
in animals seems similar to that of the mu and kappa opioid agonist, 
butorphanol (schedule IV), a kappa opioid agonist, pentazocine 
(schedule IV) and another mu opioid agonist prodrug, tramadol (schedule 
IV).
Human Behavioral Studies
    In a clinical study, the abuse potential, safety, tolerability, and 
pharmacokinetics of orally administered eluxadoline (100, 300 and 1000 
mg) were compared with positive control drug, oxycodone (30 and 60 mg) 
in healthy non-dependent recreational opioid users. Of the subjects who 
received any study treatment, a total of 33 subjects completed the 
study. On the primary subjective measure of VAS Drug Liking, 
eluxadoline at the two supratherapeutic doses (300 and 1000 mg) 
produced statistically significant higher maximum (Emax) scores on Drug 
Liking compared to placebo. When compared to that of either dose of 
oxycodone on Drug Liking, all three tested doses of eluxadoline (100, 
300 and 1000 mg) showed statistically significant lower Emax scores. 
Eighteen of the 36 subjects who received eluxadoline showed a 
statistically significant positive response on Drug Liking with at 
least one of the eluxadoline doses tested. Data from the secondary 
subjective measures showed that oxycodone (30 and 60 mg) statistically 
significantly increased scores on other positive subjective responses 
such as the VAS for Overall Drug Liking, Take Drug Again, Subjective 
Drug Value, Good Drug Effects, High, and ARCI-MBG (Euphoria). At 
supratherapeutic oral doses (300 and/or 1000 mg), eluxadoline elicited 
statistically significant increases as compared to the placebo in 
positive subjective responses such as VAS for Take Drug Again, 
Subjective Drug Value, Good Drug Effects, High, and ARCI-MBG 
(Euphoria). The positive subjective responses to eluxadoline were most 
often statistically significantly less than those produced by either 
dose of oxycodone (30 and 60 mg). The HHS states that these results are 
similar to those produced by a kappa opioid agonist, pentazocine 
(schedule IV). Eluxadoline at all doses elicited a small but 
significant increase in the VAS score for Drug Disliking, but it 
happened one to two hours before the peak Drug Liking response. 
Furthermore, there were no statistically significant differences in 
Drug Disliking between eluxadoline and oxycodone (60 mg). Eluxadoline 
also produced a statistically significant increase in VAS Bad Drug 
Effects, and ARCI-LSD (Dysphoria), but did not cause a significant 
increase in Drowsiness and Sedation. These results are also similar to 
those produced by pentazocine in a published study which reported a 
statistically significant increase in the VAS score for Bad Drug 
Effects and the score for ARCI-LSD (Dysphoria).
    Oral administration of eluxadoline produced an increase in several 
classical opioid-like adverse events (AEs) associated with mu opioid 
agonists. Eluxadoline (ranging from 14-28%) produced euphoria in a 
dose-dependent manner and it was greater than that after placebo (5%) 
but less than that of oxycodone (ranging from 73-76%). Eluxadoline 
induced centrally-mediated responses such as somnolence (ranging from 
19-42%), and it overlaps with the rate reported for oxycodone (38-41%) 
and placebo (19%). Peripheral opioid-associated AEs such as dry mouth 
were also mentioned (11-19% for eluxadoline and 11-13% for oxycodone). 
Pruritus was also reported with a range of 8-11% for eluxadoline and 
54-70% for oxycodone. The above AEs support that eluxadoline produced 
typical opioid-like effects, although these are less frequent than 
reported for oxycodone.
    Another clinical study evaluated the abuse potential and safety of 
intranasal administration of crushed eluxadoline (100 and 200 mg) in 
comparison to crushed oxycodone HCl (crushed, 15 and 30 mg) in 31 
healthy adult, non-dependent recreational opioid users. On the primary 
subjective measure of Drug Liking VAS, eluxadoline (100 and 200 mg) 
failed to produce Emax scores on Drug Liking that were statistically 
different from that of placebo while oxycodone at both tested doses (15 
and 30 mg) produced statistically significant higher maximum (Emax) 
scores compared to placebo. Results for the secondary subjective 
measures show oxycodone (15 and 30 mg) significantly increased scores 
on positive subjective responses including the VAS for Overall Drug 
Liking, Take Drug Again, Subjective Drug Value, Good Drug Effects, 
High, and ARCI-MBG (Euphoria). Eluxadoline (100 and 200 mg) produced 
significant increases compared to placebo in these positive subjective 
responses. The positive subjective responses to eluxadoline were most 
often significantly less than those produced by either dose of 
oxycodone. Intranasal eluxadoline produced a small but statistically 
significant increase in the VAS for Drug Disliking while oxycodone did 
not. Eluxadoline also produced a significant increase in VAS Bad Drug 
Effects, ARCI-LSD (Dysphoria), Drowsiness, and Sedation. Oxycodone at 
both doses increased each of these negative subjective measurements, to 
a degree significantly greater than that of placebo but similar to the 
high dose of eluxadoline. Subjects identified eluxadoline as an opioid 
to a degree that was less than that of oxycodone. Intranasal 
administration of eluxadoline caused adverse events such as euphoria 
after the 100 mg (22%) and the 200 mg doses (19%). Rate of euphoria 
following eluxadoline was less than that of oxycodone at 15 mg (44%) 
and 30 mg (67%), and greater than placebo (0%). All incidences of 
euphoria produced by eluxadoline were mild in intensity.
    The clinical efficacy studies conducted with oral eluxadoline (75 
and 100 mg/BID) reported abuse-related AEs. The AE of euphoric mood was 
reported by only two IBS-d patients in the pooled Phase 2 and 3 safety 
trials (0.2% of population). The dose of eluxadoline for both these 
subjects was 100 mg BID. Similarly, the AE of ``feeling drunk'' was 
reported by only two subjects (0.1% of subjects in the 75 mg group and 
0.1% of subjects in the 100 mg group). Other than euphoria, anxiety 
(1.7%) and somnolence (0.7%)

[[Page 48048]]

were the most commonly reported abuse-related AEs. There were a few 
other central nervous system-associated AEs observed in clinical 
trials. These included headache (4.0-4.5%), dizziness (2.2-3.2%), and 
fatigue (1.9-2.6%). Thus there was a very low incidence of euphoria-
related AEs in these clinical studies. It is not uncommon for patients 
participating in clinical studies to exhibit a low rate of euphoria-
related AEs compared to participants in Phase I human abuse potential 
studies. This difference may be due to the underlying disease state of 
the patient population in clinical studies versus the healthy subject 
population in human abuse potential studies.
    3. The State of Current Scientific Knowledge Regarding Eluxadoline: 
The chemical name of eluxadoline is 5-[[[(2S)-2-amino-3-[4-
aminocarbonyl)-2,6-dimethylphenyl]-1-oxopropyl][(1S)-1-(4-phenyl-1H-
imidazol-2-yl)ethyl]amino]methyl]-2-methoxybenzoic acid. The molecular 
formula of eluxadoline is 
C32H35N5O5 and its 
molecular weight is 569.65. Eluxadoline has two asymmetric carbons, and 
there are at least four different optical isomers. Because eluxadoline 
contains a primary amine and a carboxylic acid in its structure, the pH 
of the solution will determine whether the primary amine will be 
protonated (positively charged) and the carboxylic acid will be 
deprotonated (negatively charged). The synthesis of eluxadoline 
requires a high level of expertise and knowledge in organic chemistry. 
The tablets could be cracked and easily crushed by users with a tablet 
crusher or a mortar and pestle. However, the unique physicochemical 
properties of eluxadoline may present a challenge to isolate 
eluxadoline for purposes of abuse.
    The half-life of eluxadoline is approximately five hours, with high 
inter-subject variability. Eluxadoline has a low oral bioavailability 
due to poor GI permeability and moderate hepatic first-pass extraction 
involving OATP1B1-mediated hepatic uptake of eluxadoline. Co-
administration with food lowered systemic exposures. Biliary excretion 
accounted for over 80% of overall elimination, while there is a minimal 
elimination by renal excretion.
    4. History and Current Pattern of Abuse: Because eluxadoline is a 
new molecular entity and has not been marketed in any country, 
information as to the history and current pattern of its abuse is not 
available. Data from pre-clinical and clinical studies indicated that 
eluxadoline shares pharmacological similarities with schedule IV drugs 
such as pentazocine and butorphanol and has similar abuse potential 
(see factors 1 and 2). Pentazocine and butorphanol were initially 
approved for market as non-controlled drugs. However, subsequent 
reports of actual abuse of pentazocine and butorphanol supported 
control as schedule IV drugs under the CSA. It is likely that 
eluxadoline, upon approval for marketing, will be abused for its 
rewarding effects.
    Eluxadoline generalized to the stimulus effects of morphine 
(schedule II) in animal drug discrimination studies. These 
discriminative stimulus effects are similar to that for butorphanol, a 
schedule IV mu and kappa opioid receptor agonist and for pentazocine, a 
schedule IV kappa opioid receptor agonist. In two human abuse potential 
studies, eluxadoline produced both positive and negative subjective 
responses. The maximal effects of eluxadoline on Drug Liking are 
greater than that of placebo, but less than that of oxycodone (schedule 
II). Eluxadoline at all doses elicited a small but significant increase 
in the VAS score for Drug Disliking. The negative subjective responses 
of eluxadoline may be reflective of its kappa opioid receptor agonist 
properties and these are similar to those of schedule IV opioids, 
butorphanol and pentazocine. These dysphoric effects may indicate a 
lower abuse potential of a substance. In human abuse potential studies 
oral or intranasal administration of eluxadoline produced euphoria with 
a degree less than that of oxycodone.
    As of May 20, 2015, no reports for eluxadoline were identified in 
either the National Forensic Laboratory Information System (NFLIS),\3\ 
or System to Retrieve Information on Drug Evidence (STRIDE).\4\
---------------------------------------------------------------------------

    \3\ NFLIS is a program of the DEA that collects drug 
identification results from drug cases analyzed by other Federal, 
State, and local forensic laboratories.
    \4\ STRIDE collected the results of drug evidence analyzed at 
DEA laboratories and reflects evidence submitted by the DEA, other 
Federal law enforcement agencies, and some local law enforcement 
agencies. On October 1, 2014, STARLiMS replaced STRIDE as the DEA 
laboratory drug evidence data system of record.
---------------------------------------------------------------------------

    5. The Scope, Duration, and Significance of Abuse: Because 
eluxadoline is a new molecular entity and has not been marketed in any 
country, information as to the scope, duration and significance of its 
abuse is not available. Both pre-clinical and clinical studies indicate 
that eluxadoline shares pharmacological similarities with schedule IV 
drugs such as butorphanol and pentazocine and has similar abuse 
potential. Pentazocine and butorphanol were initially marketed as 
uncontrolled drugs. However subsequent reports of abuse of butorphanol 
and pentazocine led to their control as schedule IV drugs under the 
CSA. Thus, if eluxadoline were to be marketed as a non-controlled drug, 
it is likely to be abused for its rewarding properties. If 
uncontrolled, it is also likely that individuals seeking opioids will 
abuse eluxadoline as a substitute for other opioids that are controlled 
under the CSA.
    In human abuse potential studies, eluxadoline produced both 
positive and negative subjective responses. The maximal effects of 
eluxadoline on Drug Liking are greater than that of placebo, but less 
than that of oxycodone (schedule II). Eluxadoline at all doses elicited 
a small but significant increase in the VAS score for Drug Disliking. 
The negative subjective responses of eluxadoline may be reflective of 
its kappa opioid receptor agonist properties and these are similar to 
those of schedule IV opioids, butorphanol and pentazocine. These 
dysphoric effects may indicate a lower abuse potential of eluxadoline.
    6. What, If Any, Risk There Is To the Public Health: Data from pre-
clinical and clinical studies indicate that eluxadoline has abuse 
potential similar to schedule IV opioids such as butorphanol and 
pentazocine. Abuse potential of a drug is considered a risk to the 
public health. Available information suggests that if eluxadoline were 
to be marketed as a non-controlled drug, it would be abused for its 
rewarding properties. The major concern regarding eluxadoline's risk to 
public health is based on animal studies in monkeys treated with 
eluxadoline, where the animals exhibited opioid overdose symptoms such 
as decreased activity, unresponsiveness, decreased body temperature, 
and decreased respiration rates. Severe sedation and slumping were also 
observed in monkeys following self-administration with eluxadoline. 
Furthermore, opioid-like effects of eluxadoline may not be reversible 
unless adequate or repeated administration of opioid antagonists such 
as naloxone or naltrexone is performed.
    7. Its Psychic or Physiological Dependence Liability: Several pre-
clinical studies both on Cynomolgus monkeys and rats treated with 
different doses of eluxadoline followed by various recovery or drug 
discontinuation periods showed no behavioral changes during the 
treatment period. There were also no behaviors suggestive of withdrawal 
during the observed recovery periods. Thus, chronic administration of 
eluxadoline

[[Page 48049]]

did not result in withdrawal signs in laboratory monkeys and rats. 
However, monkeys self-administered eluxadoline. This suggests that 
eluxadoline has sufficient rewarding effects to induce reinforcement. 
In human subjects, the abuse-related AEs reported in clinical studies 
found that eluxadoline produced a low incidence of euphoria, ``feeling 
drunk,'' anxiety, somnolence, headache, abdominal pain, dizziness, and 
fatigue, which are suggestive of its ability to produce psychic 
dependence.
    8. Whether the Substance is an Immediate Precursor of a Substance 
Already Controlled Under the CSA: Eluxadoline is not an immediate 
precursor of any substance controlled under the CSA.
    Conclusion: Based on consideration of the scientific and medical 
evaluation conducted by the HHS and its recommendation, and after 
considering its own eight-factor analysis, the DEA has determined that 
these facts and all relevant data constitute substantial evidence of 
potential for abuse of eluxadoline. As such, the DEA hereby proposes to 
schedule eluxadoline as a controlled substance under the CSA.

Findings for Schedule Placement

    The CSA establishes five schedules of controlled substances known 
as schedules I, II, III, IV, and V. The statute outlines the findings 
required in placing a drug or other substance in any schedule. 21 
U.S.C. 812(b). After consideration of the analysis and recommendation 
of the Assistant Secretary for Health of the HHS and review of all 
available data, the Administrator of the DEA, pursuant to 21 U.S.C. 
812(b), finds that:

    (1) The drug or other substance has a low potential for abuse 
relative to the drugs or other substances in schedule III. 
Eluxadoline has a low potential for abuse relative to the drugs or 
other substances in schedule III. The overall abuse potential of 
eluxadoline is comparable to the schedule IV substances such as 
pentazocine and butorphanol.
    (2) The drug or other substance has a currently accepted medical 
use in treatment in the United States. Recently, the FDA approved 
eluxadoline as a prescription drug for the treatment of irritable 
bowel syndrome with diarrhea (IBS-d). Therefore, eluxadoline has a 
currently accepted medical use in treatment in the United States.
    (3) Abuse of the drug or other substance may lead to limited 
physical dependence or psychological dependence relative to the 
drugs or other substances in schedule III. Abuse of eluxadoline may 
lead to limited psychological dependence similar to that of schedule 
IV drugs, but less than that of schedule III drugs.

    Based on these findings, the Administrator of the DEA concludes 
that eluxadoline, including its salts, isomers and salts of isomers, 
whenever the existence of such salts, isomers, and salts of isomers is 
possible, warrants control in schedule IV of the CSA (21 U.S.C. 
812(b)(4)).

Requirements for Handling Eluxadoline

    If this rule is finalized as proposed, eluxadoline would be subject 
to the CSA's schedule IV regulatory controls and administrative, civil, 
and criminal sanctions applicable to the manufacture, distribution, 
dispensing, importing, exporting, research, and conduct of 
instructional activities involving schedule IV substances, including 
the following:
    1. Registration. Any person who handles (manufactures, distributes, 
dispenses, imports, exports, engages in research, or conducts 
instructional activities with) eluxadoline, or who desires to handle 
eluxadoline, would be required to be registered with the DEA to conduct 
such activities pursuant to 21 U.S.C. 822, 823, 957, and 958 and in 
accordance with 21 CFR parts 1301 and 1312. Any person who currently 
handles eluxadoline, and is not registered with the DEA, would need to 
submit an application for registration and may not continue to handle 
eluxadoline as of the effective date of the final rule, unless the DEA 
has approved that application for registration, pursuant to 21 U.S.C. 
822, 823, 957, 958, and in accordance with 21 CFR parts 1301 and 1312.
    2. Security. Eluxadoline would be subject to schedule III-V 
security requirements and would need to be handled and stored pursuant 
to 21 U.S.C. 821, 823, 871(b) and in accordance with 21 CFR 1301.71-
1301.93.
    3. Labeling and Packaging. All labels and labeling for commercial 
containers of eluxadoline on or after finalization of this proposed 
rule would need to comply with 21 U.S.C. 825 and 958(e), and be in 
accordance with 21 CFR part 1302.
    4. Inventory. Every DEA registrant who possesses any quantity of 
eluxadoline on the effective date of the final rule would be required 
to take an inventory of all stocks of eluxadoline on hand as of the 
effective date of the rule, pursuant to 21 U.S.C. 827 and 958, and in 
accordance with 21 CFR 1304.03, 1304.04, and 1304.11(a) and (d).
    Any person who becomes registered with the DEA after the effective 
date of the final rule must take an initial inventory of all stocks of 
controlled substances (including eluxadoline) on hand on the date the 
registrant first engages in the handling of controlled substances, 
pursuant to 21 U.S.C. 827 and 958 and in accordance with 21 CFR 
1304.03, 1304.04, and 1304.11(a) and (b).
    After the initial inventory, every DEA registrant would be required 
to take an inventory of all controlled substances (including 
eluxadoline) on hand, on a biennial basis, pursuant to 21 U.S.C. 827 
and 958, and in accordance with 21 CFR 1304.03, 1304.04, and 1304.11.
    5. Records. All DEA registrants would be required to maintain 
records with respect to eluxadoline pursuant to 21 U.S.C. 827 and 958, 
and in accordance with 21 CFR parts 1304, 1307, and 1312.
    6. Prescriptions. All prescriptions for eluxadoline or products 
containing eluxadoline would need to comply with 21 U.S.C. 829, and be 
issued in accordance with 21 CFR parts 1306 and 1311, subpart C.
    7. Importation and Exportation. All importation and exportation of 
eluxadoline would need to be in compliance with 21 U.S.C. 952, 953, 
957, and 958, and in accordance with 21 CFR part 1312.
    8. Criminal Liability. Any activity involving eluxadoline not 
authorized by, or in violation of, the CSA, occurring on or after 
finalization of this proposed rule, would be unlawful, and may subject 
the person to administrative, civil, and/or criminal sanctions.

Regulatory Analyses

Executive Orders 12866 and 13563

    In accordance with 21 U.S.C. 811(a), this proposed scheduling 
action is subject to formal rulemaking procedures performed ``on the 
record after opportunity for a hearing,'' which are conducted pursuant 
to the provisions of 5 U.S.C. 556 and 557. The CSA sets forth the 
procedures and criteria for scheduling a drug or other substance. Such 
actions are exempt from review by the Office of Management and Budget 
(OMB) pursuant to section 3(d)(1) of Executive Order 12866 and the 
principles reaffirmed in Executive Order 13563.

Executive Order 12988

    This proposed regulation meets the applicable standards set forth 
in Sections 3(a) and 3(b)(2) of Executive Order 12988 to eliminate 
drafting errors and ambiguity, minimize litigation, provide a clear 
legal standard for affected conduct, and promote simplification and 
burden reduction.

Executive Order 13132

    This proposed rulemaking does not have federalism implications 
warranting the application of Executive Order

[[Page 48050]]

13132. The proposed rule does not have substantial direct effects on 
the States, on the relationship between the national government and the 
States, or the distribution of power and responsibilities among the 
various levels of government.

Executive Order 13175

    This proposed rule will not have tribal implications warranting the 
application of Executive Order 13175. It does not have substantial 
direct effects on one or more Indian tribes, on the relationship 
between the Federal government and Indian tribes, or on the 
distribution of power and responsibilities between the Federal 
government and Indian tribes.

Regulatory Flexibility Act

    The Administrator, in accordance with the Regulatory Flexibility 
Act (RFA), 5 U.S.C. 601-612, has reviewed this proposed rule and by 
approving it certifies that it will not have a significant economic 
impact on a substantial number of small entities. The purpose of this 
proposed rule is to place eluxadoline, including its salts, isomers, 
and salts of isomers, into schedule IV of the CSA. No less restrictive 
measures (i.e., non-control, or control in schedule V) enable the DEA 
to meet its statutory obligations under the CSA. In preparing this 
certification, the DEA has assessed economic impact by size category 
and has considered costs with respect to the various DEA registrant 
business activity classes.
    Eluxadoline is a new molecular entity which has not yet been 
marketed in the United States or any other country. Although the 
manufacturer is expected to enjoy market exclusivity for many years, 
the DEA has no basis to determine the level of contracted or outsourced 
manufacturing activities or the breadth of the distribution network. 
Furthermore, due to the wide variety of unidentifiable and 
unquantifiable variables that could potentially influence the 
dispensing and distribution rates of new pharmaceutical drugs, the DEA 
is unable to determine the number of potential small entities that 
might handle eluxadoline. However, the DEA estimates that all persons 
who would handle, or propose to handle, eluxadoline are currently 
registered with the DEA to handle schedule IV controlled substances, 
because it is a pharmaceutical controlled substance intended for 
medical treatment. Accordingly, the number of DEA registrations 
authorized to handle schedule IV controlled substances is a reasonable 
estimate for the maximum number of eluxadoline handlers. Therefore, the 
DEA estimates that 1.6 million (1,554,254 as of June 2015) controlled 
substance registrations, representing approximately 427,584 entities, 
would be the maximum number of entities affected by this rule. The DEA 
estimates that 418,141 (97.8%) of 427,584 affected entities are ``small 
entities'' in accordance with the RFA and SBA size standards.
    The DEA anticipates that prospective eluxadoline handlers already 
handle other schedule IV controlled substances and that the cost impact 
as a result of placing eluxadoline in schedule IV would be nominal. As 
the anticipated eluxadoline handlers already handle other scheduled IV 
controlled substances, they already have DEA registrations and the 
required security and recordkeeping processes, equipment, and 
facilities in place, and would only require a nominal increase in 
security, inventory, recordkeeping and labeling costs.
    As discussed above, while the DEA does not have a basis to estimate 
the number of affected entities, the DEA estimates that the maximum 
number of affected entities is 427,584 of which 418,141 are estimated 
to be small entities. Since the affected entities are expected to 
handle other schedule IV controlled substances and maintain security 
and recordkeeping facilities and processes consistent with schedule IV 
controlled substances, the DEA estimates any economic impact will be 
nominal. Because of these facts, this proposed rule will not result in 
a significant economic impact on a substantial number of small 
entities.

Unfunded Mandates Reform Act of 1995

    In accordance with the Unfunded Mandates Reform Act (UMRA) of 1995, 
2 U.S.C. 1501 et seq., the DEA has determined and certifies that this 
action would not result in any Federal mandate that may result ``in the 
expenditure by State, local, and tribal governments, in the aggregate, 
or by the private sector, of $100,000,000 or more (adjusted for 
inflation) in any one year.'' Therefore, neither a Small Government 
Agency Plan nor any other action is required under UMRA of 1995.

Paperwork Reduction Act of 1995

    This action does not impose a new collection of information 
requirement under the Paperwork Reduction Act of 1995, 44 U.S.C. 3501-
3521. This action would not impose recordkeeping or reporting 
requirements on State or local governments, individuals, businesses, or 
organizations. An agency may not conduct or sponsor, and a person is 
not required to respond to, a collection of information unless it 
displays a currently valid OMB control number.

List of Subjects in 21 CFR Part 1308

    Administrative practice and procedure, Drug traffic control, 
Reporting and recordkeeping requirements.

    For the reasons set out above, the DEA proposes to amend 21 CFR 
part 1308 as follows:

PART 1308--SCHEDULES OF CONTROLLED SUBSTANCES

0
1. The authority citation for 21 CFR part 1308 continues to read as 
follows:

    Authority: 21 U.S.C. 811, 812, 871(b), unless otherwise noted.

0
2. Amend Sec.  1308.14 by adding paragraph (g)(3) to read as follows:


Sec.  1308.14  Schedule IV.

* * * * *
    (g) * * *

(3) Eluxadoline (5-[[[(2S)-2-amino-3-[4-aminocarbonyl)-           (9725)
 2,6-dimethylphenyl]-1-oxopropyl][(1S)-1-(4-phenyl-1H-
 imidazol-2-yl)ethyl]amino]methyl]-2-methoxybenzoic
 acid) (including its optical isomers) and its salts,
 isomers, and salts of isomers..........................
 



[[Page 48051]]

    Dated: August 5, 2015.
Chuck Rosenberg,
Acting Administrator.
[FR Doc. 2015-19655 Filed 8-10-15; 8:45 am]
 BILLING CODE 4410-09-P