With progression of cancer, patients and their caregivers experience challenging emotional distress, which can make them feel depressed and very anxious.

Patients with advanced cancer often do not have long to live. However, most antidepressants take a long time to act and cause unwanted side effects. There is hence a need for a fast acting antidepressant with fewer unwanted side effects.

Ketamine is an effective and fast acting antidepressant originating from pain treatment, which has few unwanted side effects. It can be taken by a patient as a nasal spray when it is needed.

The idea of treating depression and anxiety in cancer patients in palliative care with ketamine nasal spray is new. How effective ketamine will be at reducing depression and anxiety in patients is unknown . It is also unknown whether this kind of treatment will be safe and practical for palliative care patients.

This study aims to answer these questions. Patients will be treated with a low dose (5 mg) of ketamine nasal spray and then measure its effectiveness, practicality and safety. Questionnaires will be used to measure these outcomes.

If treating depression and anxiety with ketamine nasal spray proves to be effective, practical and safe, then it could help to improve the quality of life for palliative care patients and reduce the burden of their caregivers.

With progression of cancer, patients, but also their caregivers, are predisposed to experience challenging emotional distress due to their terminal illness, resulting in depression and anxiety. However, the overall limited survival time and often complex medication regimes complicate a timely and tolerable treatment of these symptoms, when time-consuming psychotherapeutic sessions or classic antidepressant medication with side effects are unfavorable.

Ketamine is an effective and fast acting antidepressant originating from pain treatment, which can be administered non-invasively as easy to handle nasal spray. The possibility of using ketamine as needed, and not necessarily daily as classical antidepressants, limits the occurrence of side effects and has the potential to ease symptom burden in patients as well as caregivers in this vulnerable cohort. Yet, the efficacy and feasibility of intranasal ketamine self-administration in palliative care cancer patients has not been investigated to date.

In the open-label feasibility study proposed here, we aim at assessing the safety, feasibility and efficacy for the treatment of depression and anxiety with low-dose (5 mg per stroke) intranasal ketamine in a population of early palliative care cancer patients in an out-patient setting.

If self-administered nasal ketamine proves efficient and safe in this study population of often neglected palliative care patients, an easy to handle, low-cost and fast-acting drug with lower risk for interactions would be available to ease burden and emotional symptom load, and eventually increase quality of life for patients and caregivers.

Inclusion Criteria (patients):

• Informed Consent as documented by signature;
• HADS total score of 6 or greater;
• Age 18 years or older;
• Progressive cancer diagnosis (estimated life expectancy 24 months or more)
• Able to attend study visits;
• Ability to speak and understand German;

Exclusion Criteria (patients):

• Clinician assessed cognitive impairment;
• Clinician assessed alcohol or drug abuse;
• Pregnancy or breast-feeding;
• Severe hypertension (greater than 200/120 mmHg);
• Anamnestic mood disorder (major depressive disorder, treatment resistant depression, etc.);
• Suicidality (C-SSRS total score of "low" or less);
• Weight less than 39 kg, greater than 170 kg;
• Angina pectoris or myocardial infarction in the last 6 months;
• Lifetime abuse or dependence on ketamine or phencyclidine;
• Substance abuse or dependence in the 6 months before screen;
• Nasal obstructions or history of nasal surgery.
• Serious health risk caused by increased blood pressure or intracranial pressure:
• Known aneurysmal vascular disease (including intracranial, thoracic or abdominal aortic or peripheral arterial vessels);
• Known history of intracerebral hemorrhage;
• Recent (within 6 weeks) cardiovascular event including myocardial infarction (MI).

Inclusion criteria (caregivers):

• Informed Consent as documented by signature;
• Age 18 years or older;
• Able to attend study visits;
• Ability to speak and understand German.

Exclusion criteria (caregivers):

- None.

We are not required to provide information about plans to share individual participant data (IPD).