NCT04392622 · Stanford University
d-Limonene +Radiation +PlatinumBasedChemo for Xerostomia Prevention in LocallyAdvanced HNSCC
What this study is about
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.
View original scientific description
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.
Interventions
DRUG
D-Limonene Gelcaps
Administered orally at 2 to 8 grams daily
RADIATION
Intensity modulated radiotherapy (IMRT)
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.
DRUG
Cisplatin
Standard of Care -Cisplatin as 100 mg/m2 IV
OTHER
Xerostomia questionnaire
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
Primary outcome measures
Dose limiting Toxicity
Time frame: 9 weeks
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).
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- 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
Exclusion criteria
- History of allergic reactions attributed to citrus fruits
- Pregnant or lactating
Where
- Stanford, California
Collaborators
National Institutes of Health (NIH), National Cancer Institute (NCI)
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Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jul 20, 2025 · Source of record for eligibility and locations