NCT04392622

Brief Summary

This study explores the safety of d-limonene, a commercially-available dietary supplement (food) as a potential therapeutic for the severe dry mouth (xerostomia) experienced by patients with head and neck cancer as a side effect of their anti-cancer treatment.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
40

participants targeted

Target at P50-P75 for phase_1

Timeline
24mo left

Started Feb 2021

Longer than P75 for phase_1

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress72%
Feb 2021May 2028

First Submitted

Initial submission to the registry

May 11, 2020

Completed
8 days until next milestone

First Posted

Study publicly available on registry

May 19, 2020

Completed
9 months until next milestone

Study Start

First participant enrolled

February 15, 2021

Completed
6.5 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 15, 2027

Expected
9 months until next milestone

Study Completion

Last participant's last visit for all outcomes

May 15, 2028

Last Updated

July 20, 2025

Status Verified

July 1, 2025

Enrollment Period

6.5 years

First QC Date

May 11, 2020

Last Update Submit

July 16, 2025

Conditions

Outcome Measures

Primary Outcomes (1)

  • Dose limiting Toxicity

    Dose limiting toxicity is defined as d-limonene related toxicity causing: * Greater than 1 week delay in completing the radiation course. * Inability to receive ≥ 66 Gy of radiotherapy. * Inability to receive at least 200 mg/m2 of total cisplatin equivalent dose or a total area under the curve (AUC) of 10 for carboplatin equivalent dose due to toxicity related to d-limonene Grade 3 or higher diarrhea that is attributable to the study drug. * Grade 3 abdominal pain that is attributable to the study drug. The outcome will be reported as the number of participants per dose level who experience any DLT (a number without dispersion / variance).

    9 weeks

Secondary Outcomes (2)

  • Feasibility of adjuvant d-limonene administration

    4 months

  • Xerostomia toxicity

    12 months post completion of chemoradiation

Study Arms (7)

d-limonene -2gram

EXPERIMENTAL

2 gram d-limonene orally, once daily delivered during chemoradiation

Drug: D-Limonene GelcapsRadiation: Intensity modulated radiotherapy (IMRT)Drug: CisplatinOther: Xerostomia questionnaire

d-limonene -4gram

EXPERIMENTAL

4 gram d-limonene orally, as 2 grams 2 times daily delivered during chemoradiation

Drug: D-Limonene GelcapsRadiation: Intensity modulated radiotherapy (IMRT)Drug: CisplatinOther: Xerostomia questionnaire

d-limonene -6gram

EXPERIMENTAL

6 gram d-limonene orally, as 3 grams 2 times daily delivered during chemoradiation

Drug: D-Limonene GelcapsRadiation: Intensity modulated radiotherapy (IMRT)Drug: CisplatinOther: Xerostomia questionnaire

d-limonene -8gram

EXPERIMENTAL

8 gram d-limonene orally, as 4 grams 2 times daily delivered during chemoradiation

Drug: D-Limonene GelcapsRadiation: Intensity modulated radiotherapy (IMRT)Drug: CisplatinOther: Xerostomia questionnaire

de-escalation dose d-limonene -6gram

EXPERIMENTAL

6 gram d-limonene orally, as 3 grams 2 times daily delivered during chemoradiation

Drug: D-Limonene GelcapsRadiation: Intensity modulated radiotherapy (IMRT)Drug: CisplatinOther: Xerostomia questionnaire

de-escalation dose d-limonene -4gram

EXPERIMENTAL

4 gram d-limonene orally, as 2 grams 2 times daily delivered during chemoradiation

Drug: D-Limonene GelcapsRadiation: Intensity modulated radiotherapy (IMRT)Drug: CisplatinOther: Xerostomia questionnaire

de-escalation dose d-limonene -2gram

EXPERIMENTAL

2 gram d-limonene orally, once daily delivered during chemoradiation

Drug: D-Limonene GelcapsRadiation: Intensity modulated radiotherapy (IMRT)Drug: CisplatinOther: Xerostomia questionnaire

Interventions

Administered orally at 2 to 8 grams daily

d-limonene -2gramd-limonene -4gramd-limonene -6gramd-limonene -8gramde-escalation dose d-limonene -2gramde-escalation dose d-limonene -4gramde-escalation dose d-limonene -6gram

Standard of Care -All patients will receive standard radiation treatment of 66 to 70 Gy given in 33 to 35 fractions (2 to 2.12 Gy/fractions) over 6.5 to 7 weeks.

d-limonene -2gramd-limonene -4gramd-limonene -6gramd-limonene -8gramde-escalation dose d-limonene -2gramde-escalation dose d-limonene -4gramde-escalation dose d-limonene -6gram

Standard of Care -Cisplatin as 100 mg/m2 IV

d-limonene -2gramd-limonene -4gramd-limonene -6gramd-limonene -8gramde-escalation dose d-limonene -2gramde-escalation dose d-limonene -4gramde-escalation dose d-limonene -6gram

Xerostomia questionnaire consists of 4 items on dryness while eating/speaking and 4 on dryness at rest. Patients rate each symptom on an 11 point ordinal Likert scale from 0 to 10, with higher scores indicating greater xerostomia

d-limonene -2gramd-limonene -4gramd-limonene -6gramd-limonene -8gramde-escalation dose d-limonene -2gramde-escalation dose d-limonene -4gramde-escalation dose d-limonene -6gram

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Histologically or cytologically confirmed diagnosis of advanced loco regional squamous cell carcinoma of the nasopharynx (AJCC v8 Stage II IV); oropharynx (AJCC v8 Stage I III for HPV+ cancer, excluding T1 2N0; AJCC v8 Stage III IV for Human papillomavirus (HPV) negative cancer); larynx (AJCC v8 Stage III to IV); or hypopharynx (AJCC v8 Stage III to IV), scheduled to undergo chemoradiation. Patients with squamous cell carcinoma of the head and neck from an unknown primary site with involved nodes (N1 to 3) also qualify.
  • Scheduled to received definitive RT with concurrent platinum based chemotherapy at Stanford
  • Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0 to 1
  • Must be able to swallow d limonene gelcaps at the time of enrollment.
  • Adequate hepatic function within 2 weeks prior to registration defined as follows: Bilirubin ≤ 2 mg/dL; aspartate aminotransferase (AST) or alanine aminotransferase (ALT) \< 3 times the upper limit of normal
  • Adequate hematologic function within 2 weeks prior to registration defined as follows:
  • Absolute neutrophil count (ANC): ≥ 1,500/mm3
  • Platelets: ≥ 100,000/mm3
  • Hemoglobin: ≥ 8.0 g/dL (Note: The use of transfusion or other intervention to achieve Hgb ≥ 8.0 g/dL is acceptable).
  • Adequate renal function defined as follows:
  • Serum creatinine ≤ 1.5 mg/dL within 2 weeks prior to registration or creatinine clearance (CC) ≥ 50 mL/min within 2 weeks prior to registration determined by 24 hour collection or estimated by Cockcroft Gault formula:
  • CCr male = \[(140 - age) x (wt in kg)\] \[(Serum Cr mg/dL) x (72)\] CCr female = 0.85 x (CrCl male)
  • Negative serum pregnancy test within 2 weeks prior to registration and agreement to use a birth control method during the entire duration of d limonene treatment for women of childbearing potential
  • Ability to understand and the willingness to sign a written informed consent document

You may not qualify if:

  • History of allergic reactions attributed to citrus fruits
  • Pregnant or lactating

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Stanford University

Stanford, California, 94305, United States

RECRUITING

MeSH Terms

Conditions

Xerostomia

Interventions

Radiotherapy, Intensity-ModulatedCisplatin

Condition Hierarchy (Ancestors)

Salivary Gland DiseasesMouth DiseasesStomatognathic Diseases

Intervention Hierarchy (Ancestors)

Radiotherapy, ConformalRadiotherapy, Computer-AssistedRadiotherapyTherapeuticsChlorine CompoundsInorganic ChemicalsNitrogen CompoundsPlatinum Compounds

Study Officials

  • Quynh-Thu Le

    Stanford Universiy

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Study Design

Study Type
interventional
Phase
phase 1
Allocation
NON RANDOMIZED
Masking
NONE
Purpose
SUPPORTIVE CARE
Intervention Model
SEQUENTIAL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

May 11, 2020

First Posted

May 19, 2020

Study Start

February 15, 2021

Primary Completion (Estimated)

August 15, 2027

Study Completion (Estimated)

May 15, 2028

Last Updated

July 20, 2025

Record last verified: 2025-07

Data Sharing

IPD Sharing
Will not share

Locations