An AE was any untoward medical occurrence attributed to study drug in a participant who received study drug. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. Treatment-emergent are events between first dose of study drug and up to 30 days after last dose that were absent before treatment or that worsened relative to pretreatment state.

Safety population (SAF) included all participants who signed the informed consent, had exposure to open label study drug and had at least one safety assessment.

WPAI: 6-question participant rated questionnaire to determine the degree to which SHP affected work productivity while at work and affected activities outside of work. It assesses amount of absenteeism, presenteeism and daily activity impairment attributable to a Human Immunodeficiency Virus (HIV) neuropathy pain. Number of participants who responded "Yes/No" to Question 1: Are you currently employed (working for pay)? are reported.

Intent to Treat (ITT) population: all enrolled participants who had at least one dose of open label study drug. 'N' (number of participants analyzed) signifies participants evaluable for this measure. Here 'n' signifies participants evaluable at given time point for each arm group, respectively.

WPAI: 6-question participant rated questionnaire to determine the degree to which SHP affected work productivity while at work and affected activities outside of work. It assesses amount of absenteeism, presenteeism and daily activity impairment attributable to a HIV neuropathy pain. Question 2 and 3 assesses absenteeism as: Hours of work missed in past 7 days due to leg/foot pain or other reason, respectively. Question 4 assesses presenteeism as: Hours of work performed in past 7 days.

ITT population: all enrolled participants who had at least one dose of open label study drug. 'N' (number of participants analyzed) signifies those participants who were evaluable for this measure. Here 'n' signifies participants evaluable at given time point for specific question for each arm group, respectively.

WPAI: 6-question participant rated questionnaire to determine the degree to which SHP affected work productivity while at work and affected activities outside of work. It assesses amount of absenteeism, presenteeism and daily activity impairment attributable to a HIV neuropathy pain. Question 5 and 6 assesses: How much leg/foot pain affect productivity and daily activity, respectively in past 7 days? on 11-point scale, where 0 (not affected/no impairment) to 10 (completely affected/impaired).

ITT population: all enrolled participants who had at least one dose of open label study drug. 'N' (number of participants analyzed) signifies participants evaluable for this measure. Here 'n' signifies participants evaluable at given time point for specific question for each arm group, respectively.

SF-36 is a standardized survey evaluating 8 domains of functional health and well being: physical and social (So) functioning (Fn), physical and emotional role (role-physical [R-P], role-emotional [R-E]) limitations, bodily pain (BP), general health (GH), vitality (Vit), mental health (MnH). Two summary scores include Physical Component (Ph C) and Mental Component (Mn C). The score for a section is an average of the individual question scores. Score range for domain scores and summary scores: 0-100 (100=highest level of functioning).

ITT population included all enrolled participants who took at least one dose of open label study drug. 'N' (number of participants analyzed) signifies those participants who were evaluable for this measure. Here 'n' signifies participants evaluable at given time point for specific parameter for each arm group, respectively.

Participants rated the severity of HIV neuropathy pain on a 0 to 100 millimeter (mm) Visual Analog Scale (VAS), where 0 mm = no pain and 100 mm = most severe pain.

ITT population: all enrolled participants who had at least one dose of open label study drug. 'N' (number of participants analyzed) signifies those participants who were evaluable for this measure. Here 'n' signifies participants who were evaluable at specific time points for each arm group, respectively.

PGI-C: participant rated instrument to measure participant's change in overall status since the start of the study, on a 7-point scale; range from 1 (very much improved) to 7 (very much worse). Number of participants in each category are reported.

ITT population: all enrolled participants who had at least one dose of open label study drug. 'N' (number of participants analyzed) signifies those participants who were evaluable for this measure.

S-STS:8-item clinician/participant administered prospective rating scale to assess TE suicidal(Su) ideation(ID),behavior(BHV).Items 1a,2-6,7a,8 scored on 5-point Likert scale 0(not at all) to 4(extremely). Items 1,1b,7 require yes/no response. S-STS total score range 0-30. Lower score=reduced Su tendency. Responses on S-STS were mapped to Columbia Classification Algorithm of Suicide Assessment(C-CASA) as 1:Completed Su; 2: Su attempt; 3: Preparatory acts; 4: Su ID; 5: Self-injurious (SI) BHV, intent unknown; 6: Not enough information; 7: SI BHV, no Su intent; 8: Other, no deliberate self harm.

SAF included all participants who signed the informed consent, had exposure to open label study drug and had at least one safety assessment.

PHQ-8: 8-item self-administered validated subset of PHQ-9, which comprises first 8 items of measure. Participant rated "Over past 2 weeks, how often bothered by any of following problems?": little interest in doing things(1); feeling down(2); trouble falling or staying asleep/sleeping too much(3); feeling tired(4); poor appetite/overeating(5); feeling bad about self(6); trouble concentrating(7); moving or speaking slowly or being so fidgety/moving around more than usual(8). Each item scored on scale of 0(not at all)-3(nearly every day). Total score range: 0-24, higher score=greater severity.

SAF population included all participants who signed the informed consent, had exposure to open label study drug and had at least one safety assessment. 'N' (number of participants analyzed) signifies those participants who were evaluable for this measure.