Phytocannabinoids for the Treatment of Chronic Chemotherapy-Induced Peripheral Neuropathy in Breast and Colon Cancer Survivors

Inclusion Criteria:

Documented informed consent of the participant and/or legally authorized representative

Assent, when appropriate, will be obtained per institutional guidelines

Agreement to allow the use of archival tissue from diagnostic tumor biopsies

If unavailable, exceptions may be granted with study principal investigator (PI) approval
Willingness to comply with all study interventions including the use of medical cannabis and follow-up assessments
Age: >= 18 years
Eastern Cooperative Oncology Group (ECOG) =< 2
Ability to read and understand English for questionnaires
Patients must have either neuropathy >= 1 according to Common Terminology Criteria for Adverse Events (CTCAE) version (v) 5.0 scale or a neuropathy score of > 3 on a 0-10 scale plus a FACT/GOG-Ntx score of > 10
The patient's previous chemotherapy treatment must have included a taxane (paclitaxel, nab-paclitaxel, or docetaxel) or platinum (cisplatin, oxaliplatin, or carboplatin) and considered the primary cause of the neuropathy by the medical team
Total bilirubin =< 1.5 x upper limit of normal (ULN) (unless has Gilbert's disease)
Aspartate aminotransferase (AST) =< 3 x ULN
Alanine aminotransferase (ALT) =< 3 x ULN
Women of childbearing potential (WOCBP): negative urine or serum pregnancy test. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required

Agreement by females and males of childbearing potential to use an effective method of birth control or abstain from heterosexual activity for the course of the study through at least 1 months after the last dose of protocol therapy

Childbearing potential defined as not being surgically sterilized (men and women) or have not been free from menses for > 1 year (women only)
Current active treatment with chemotherapy, radiation or surgery in the past 3 months or planned treatment during this study protocol period. Note: Hormonal therapy is allowed

Exclusion Criteria:

Concurrent use of other alternative medicines such as medical cannabis, herbal agents and high dose vitamins and minerals
Liver cirrhosis Child-Pugh B or C
Mental incapacitation or significant emotional or psychological disorder that, in the opinion of the investigators, precludes study entry (These patients may not be able to cooperate with this slightly invasive procedure or with the data collection process)
History of diabetic neuropathy, neuropathy related to human immunodeficiency virus (HIV), or other medical causes of chronic neuropathy in the baseline assessment including past medical history, any history of diabetes, alcoholism, and vitamin B deficiency
Previous medical cannabis use for any indication within 30 days of enrollment

Planned or actual changes in type of medications that could affect symptoms related to CIPN. New medications for the treatment of CIPN are not allowed during the study.

Note: Subjects need to be on stable doses of CIPN medications for 4 weeks
Strong inhibitors or inducers of CYP3A4
History of allergic reactions attributed to compounds of similar chemical or biologic composition to study agent
Clinically significant uncontrolled illness
Diagnosis of Gilbert's disease
Females only: Pregnant or breastfeeding
Any other condition that would, in the Investigator's judgment, contraindicate the patient's participation in the clinical study due to safety concerns with clinical study procedures
Prospective participants who, in the opinion of the investigator, may not be able to comply with all study procedures (including compliance issues related to feasibility/logistics)