Phase 3 Efficacy and Safety Laboratory Classroom Study in Pediatrics (6-12) With ADHD Using CTx-1301

Inclusion Criteria:

1. Male or female subjects between 6 and 12 years of age (inclusive) at the time ofconsent.

2. Subject must have a body weight between the 5th and 95th percentile (≥5th percentileand ≤95th percentile) for their respective age and sex.

3. Subject is unsatisfied with his/her current pharmacological therapy for treatment ofADHD or not currently receiving pharmacological therapy for ADHD. Inclusion ofsubjects who are naïve to pharmacological therapy for ADHD or are newly diagnosedwith ADHD is permitted.

4. Females of childbearing potential must have a negative serum b-human chorionicgonadotropin pregnancy test at Screening. Child-bearing potential is defined as anyfemale who has had their first period or is 12 years or older (or will be 12 duringthe study). Female of childbearing potential or that become child-bearing potentialduring the study must agree to use a highly effective, medically acceptable form ofbirth control for 30 days prior to Screening until at least 30 days after the lastdose of study drug. Alternatively, subject may remain abstinent until at least 30days after the last dose of study drug. Episodic abstinence is not reliable to avoidpregnancy, so is not considered a highly effective contraceptive method.Investigator discretion should use judgement and familiarity with the subject's "preferred and usual lifestyle" to assess if reporting of abstinence may be trustedto achieve required effectiveness. Male subjects with female partners must agree atScreening to remain abstinent or agree to use an effective and medically acceptableform of birth control from Screening to 90 days after the last dose of study drug.

5. Subject must be in general good health defined as absence of any clinicallysignificant abnormalities as determined by the Investigator based on physical andneurological examinations, vital signs, ECGs, medical history, and safety laboratorytests at screening. If any of the exams or tests are not within the laboratoryreference range, the Investigator must assess and determine if clinicallysignificant.

6. Subject's intellectual function is at an age-appropriate level, as deemed by theInvestigator.

7. Subjects need to be able to perform at least the basic level of problems on thePERMP pre-test with at least 5.5 questions answered correctly per minute performedat Visit 2.

8. Subject must meet Diagnostic and Statistical Manual of Mental Disorders - FifthEdition (DSM-5) criteria for the primary diagnosis of ADHD or any of the threepresentations (combined, inattentive, or hyperactive/impulsive presentation) uponclinical evaluation and confirmed by the MINI International NeuropsychiatricInterview of Children and Adolescents (MINI-KID). The MINI-KID should also be usedto evaluate any other psychotic disorders.

9. Subject must score 28 or higher on the ADHD-RS-5 scale at the screening visit (Visit

1. and Baseline visit (Visit 2). For subjects requiring washout of ADHD medications,adequate washout of stimulant ADHD medications will be defined as no medication forthe previous 5 days. Adequate washout of non-stimulant ADHD medications will bedefined as no medication for the previous 21 days.

10. Subject must have a score of 4 (moderately ill) or higher on theclinician-administrated Clinical Global Impressions-Severity (CGI-S) scale atscreening (Visit 1). For subjects requiring washout of ADHD medications, adequatewashout of stimulant ADHD medications will be defined as no medication for theprevious 5 days. Adequate washout of non-stimulant ADHD medications will be definedas no medication for the previous 21 days.

11. Subject must be able and willing to wash out of stimulant ADHD medications (exceptstudy drug as indicated per protocol), including herbal medication, from 5 daysprior to the start of the dose optimization phase (Visit 2) and for the duration ofthe entire study, defined as completion of the safety follow-up visit. Additionally,subject must be able and willing to wash out from non-stimulant ADHD medications 21days prior to the start of the dose optimization phase (Visit 2) and for theduration of the entire study, defined as completion of the safety follow-up visit.

12. Subject and parents/legal guardians, and/or caregiver (if applicable) must be ableto read, write, speak, and understand English and be able to communicate with theInvestigator and study coordinator in a satisfactory fashion and complete anystudy-related materials. Subject and parents/legal guardians, and/or caregivers (ifapplicable) must plan to be available for the entire duration of the study.

13. One or more of the parents/legal guardians, or caregivers of the subject mustvoluntarily give written permission for him/her to participate in the study.

14. Subject must provide written assent prior to study participation

15. Subject, subject's parents/legal guardians, and/or caregivers (if applicable) mustunderstand and be willing and able to comply with study procedures as well as thevisit schedule. If the subject is cared for by a caregiver for relevant portions ofthe day, the caregiver may be more suitable for certain assessments, and thecaregiver will need to agree to the applicable procedures and visits. The mostappropriate assessor should be determined prior to the double-blind, randomized,efficacy portion. The assessor for each individual subject should be the sameassessor throughout the double-blind, randomized, efficacy portion of the study.

16. Subject must be able to swallow the CTx-1301 tablet as evidenced by ability toswallow a similar size tablet (placebo) at screening.

Exclusion Criteria:

1. If female and of child-bearing potential, the subject must not be pregnant orbreastfeeding at any time during the study or for 30 days following the completionof the study. If of child-bearing potential, urine hCG tests will be administered atprotocol-specified time points. Any positive pregnancy test during the study willexclude them from further participation in the study.

2. Subject has any psychiatric diagnosis of bipolar I or II disorder, major depressivedisorder, conduct disorder, disruptive mood dysregulation disorder (DMDD),intellectual disability, obsessive-compulsive disorder, eating disorder, anxietydisorder (including generalized anxiety disorder), any history of psychosis, autismspectrum disorder, a history of motor or vocal tics or Tourette's Syndrome,confirmed genetic disorder with cognitive and/or behavioral disturbances, or anyother diagnosis/significant medical history that at the discretion of theInvestigator excludes the subject from entry into the study.

3. Subject has evidence of any chronic disease of the central nervous system (CNS) suchas tumors, inflammation, seizure disorder (excluding febrile seizures), vasculardisorder, potential CNS-related disorders that might occur in childhood, or historyof persistent neurological symptoms related to a serious head injury.

4. Subject has any clinically significant and/or unstable/uncontrolled medicalabnormality, chronic medical condition, persistent neurological symptoms, history ofcardiovascular abnormality, abnormalities of respiratory, hepatic, gastrointestinal,renal, or any disorder or history of a condition that would impact or interfere withdrug absorption, distribution, metabolism, or excretion during the study or mayinterfere with the subject's ability to participate in the study.

5. Subject has family history of early cardiovascular disease or sudden death.

6. Subject has any history of attempted suicide, clinically significant suicidalideation based on the Columbia Suicide Severity Rating Scale (C-SSRS) assessment, oranswers "yes" to "Suicidal Ideation" item 4 or 5 of any lifetime history on theC-SSRS Children's Lifetime/Recent assessment at screening.

7. Subject has a known primary sleep disorder (e.g., sleep apnea, narcolepsy, etc.)

8. If the subject's blood pressure is < 90th percentile for their age, sex, and height,the single read is sufficient. If the subject's blood pressure is ≥ 90th percentile,two additional reads will be taken, and the three reads will be averaged. If theaverage of the three readings is ≥ 95th percentile at screening they will beexcluded.

9. Subject is considered treatment refractory by the Investigator or is intolerant tostimulant ADHD medication.

10. Any use of anticonvulsants currently or within the past 2 years.

11. Uncontrolled thyroid disorder indicated by thyroid stimulating hormone (TSH) ≤0.8 xthe lower limit of normal (LLN) or ≥ 1.25 x the upper limit of normal (ULN) from thereference laboratory.

12. Subject has first-degree relatives (biological parent or sibling) with a history ofschizophrenia, schizoaffective disorder, bipolar I disorder, or bipolar II disorder.

13. Subject has history of substance abuse or shows evidence of substance or has apositive urine drug screen at screening and/or baseline. Subjects with positive drugscreens may be allowed to continue in the study if the result of the positive drugscreen is from prescribed medications and the subject is willing to washout of themedication as required per protocol.

14. Previous treatment experience/exposure to CTx-1301.

15. Subject has a history of allergic reaction or sensitivity to methylphenidate,dexmethylphenidate, or any other substance contained in CTx-1301 or the placebodrug.

16. Subject has participated in a classroom study within 6 months prior to the start ofScreening or has participated in any other clinical study with an investigationaldrug/product within 30 days prior to Screening or is currently participating inanother clinical study.

17. Subject's family anticipates a move outside the geographic range of theinvestigative site during the duration of the study period or plans on travel thatwould not allow compliance to the protocol during the study period.

18. Subject is unsuitable in any other way, to participate in the study, as determinedby the Investigator.

19. Subject is a family member of an employee at the study center, of the investigator,or those with direct involvement in the proposed study under the direction of thatinvestigator or study center.

20. Subjects that are siblings are not allowed to be in the same cohort.

Eligibility Criteria (end of dose-optimization phase)

Subjects will be required to meet the following additional eligibility criteria at the end of the dose-optimization phase (Visit 10) to enter into the double-blind, randomized phase. These criteria are based on the efficacy and safety observed over the 8-week dose-optimization period.

1. A minimum of 2 weeks on optimal dose

2. A reduction of greater than or equal to 30% reduction of the ADHD-RS-5 from Visit 2to Visit 10 (plus or minus 3 days) during the dose-optimization phase.

3. A CGI-I score of 1 or 2 points ("Very much improved" or "Much improved") at the endof the dose optimization phase (Visit 10 (plus or minus 3 days)).

4. Acceptable tolerability of the optimized CTx-1301 dose during the optimization phase (Visit 2 - Visit 10 (plus or minus 3 days)).