Metabolic effects of ketohexokinase inhibition in individuals with non-alcoholic fatty liver disease

The liver is an important organ in our body and plays an important role in our
fat and sugar metabolism. A disturbance of fat and sugar metabolism in the
liver can lead to fat accumulation, which is called non-alcoholic fatty liver
disease. A fatty liver can cause the inability to switch between fat and sugar
metabolism and decreases hepatic insulin sensitivity. This together can lead
to, among other things, cardiovascular disease, type 2 diabetes and liver
cirrhosis.

From previous it is known that the amount of fat and sugar in the diet
influences the amount of hepatic fat. Fructose is a sugar that is highly
frequent in the western diet and seems to play an important role in the
development of a fatty liver. In a recent study in individuals with
non-alcoholic fatty liver disease with PF-06835919, a ketohexokinase inhibitor,
a decrease in hepatic fat was observed. Ketohexokinase is the first binding
step in fructose metabolism and is predominantly expresses in the liver, gut
and kidneys. Inhibiting ketohexokinase consequently prevents conversion of
fructose to glucose or fat and facilitates urinary excretion of fructose.

In this recent study using PF-06835919 an increase in adiponectin was also
observed, which has more widespread favorable metabolic effects like inhibiting
gluconeogenesis, de novo lipogenesis and stimulation of fatty acid oxidation.
Additionally in this study they observed that after ketohexokinase inhibition
still 'only' 10% of the consumed fructose was excreted via urine (compared to
only a fraction in the physiological state).

In this study we want to investigate different (favorable) metabolic effects,
besides a decrease in hepatic fat, of inhibiting ketohexokinase by PF-06835919
in individuals with non-alcoholic fatty liver disease. Since the amount of
hepatic fat influences hepatic insulin sensitivity, we want to see if a
decrease in hepatic fat content is accompanied by an improvement in hepatic
insulin sensitivity. Additionally we want to investigate if an increase in
adiponectin will result in associated positive metabolic changes, like a
favorable change in fat distribution and adipose tissue function. Furthermore,
the aforementioned study indicated that not all consumed fructose was excreted
via the urine after ketohexokinase inhibition, although there was a significant
increase compared to the physiological state. Therefore, in this study, we want
to explore alternative pathways in the body for fructose metabolism or
excretion, like fructose uptake by other organs, incomplete inhibition of
ketohexokinase, and fructose metabolism by the gut microbiota.

Primary objective: determining the effect of the ketohexokinase inhibitor,
PF-06835919, on hepatic insulin sensitivity in individuals with non-alcoholic
fatty liver disease.

Secondary objective: determining the effect of the ketohexokinase inhibitor,
PF-06835919, on fat distribution and adipose tissue function

Exploratory objectives: determining the in vivo activity of ketohexokinase, gut
microbiota composition and alternative metabolic pathways of fructose after
treatment with PF-06835919.

This is a randomized, double blind, placebo controlled cross-over trial. In
this study metabolic effects of PF-06835919 will be investigated in people with
non-alcoholic fatty liver disease

Participants of this study will visit the university 10 times and several
measurements will be done.

-Screening 1: During the first part of the eligibility assessment, weight,
height and blood pressure will be measured and a 12-lead ecg will be performed.
Additionally a fasted blood sample and urine sample will be taken to determine
markers of overall health (i.e. kidney and liver function, and sugar values)
and a medical history questionnaire will be filled in,

-Screening 2: If all results of screening 1 comply with eligibility, the second
part of the eligibility assessment will follow. During this visit the amount of
hepatic fat will be measured using H-MRS.

-Baseline: The participants will fill in a 3-day food diary en collect 24-hour
urine. The baseline measurements will consist of two short visits to pick up
the food diary and urine container en hand them in. If, based on the 3-day food
diary, participants do not consume enough fructose (<60 grams/day) in their
habitual diet, they will be asked to compensate this during the intervention
period by drinking sugar sweetened beverages provided by the researcher.

-Run-in period: Participant will undergo a 7-day run-in period before the start
of the intervention. During this run-in period participants will start
consuming the sugar sweetened beverages. If participant already consumed enough
fructose, no additional sugar sweetened beverages will be given and the
habitual diet will be continued.

-Intervention period 1: On the first day of the first intervention period
participants will visit the university, where they will receive instruction
about the use of the medication and consume the product for the first time.
Hereafter participants will receive the medication/placebo for the whole first
intervention period, a urine container, feces collecting material and the 3-day
food diary. During the following 6 weeks, two telephonic interviews will be
scheduled and in week three the participants will visit the university for
bloodpressure measurement, 12-lead ecg and a fasted blood sample and urine
sample will be taken, to check. At the end of the intervention period
participants will visit the university, and hand in the collected urine and
feces and the food diary. Bloodpressure measurement, 12-lead ecg and taking of
a fasted blood sample and urine sample will be performed.The further
measurements will consist of MRI/MRS scans, a physical activity questionnaire,
overnight stay in a respiration chamber, a Bod Pod measurement, a muscle biopsy
and a hyperinsulinemic euglycemic clamp.

-Follow-up: One week after ending the first intervention period, a follow-up
phone call will be scheduled to check

-Wash-out period: After ending the first intervention period, participants will
enter a wash-out period of minimally 5 weeks during which no medication/placebo
or sugar sweetened beverages are taken.

-Intervention period 2: After the wash-out period, participants will start with
the second intervention period, identical to intervention period 1 (including
run-in period and follow-up).

During the first intervention period, participants will take once daily for 6
weeks a 300 mg tablet PF-06835919 or a an indistinguishable placebo. During the
second intervention period, the participants will take the other study product,
depending on what they received during the first intervention period. The order
(PF-06835919-placebo/placebo-PF-06835919) will be unknown for both the
researchers and the participant, and will be randomized so half of the
participants will start the first intervention period with PF-06835919 and half
will start with the placebo.

The main burden of this study is the large time investment. The risks and
discomforts of the measurements will be minimized by strictly applying the
exclusion criteria and contra-indications and performance of measurements by
experienced researchers. In previous research in a similar population
PF-06835919 was well tolerated, and a dose of 300 mg/day is reported to be
safe. During the 6-week intervention period and after both muscle biopsy
telephonic checks will be scheduled to check for side effects, general health
and check in on the recovery of the biopsy site. Additionally in week 3 of each
interventionperiod, there will be a fysical visit, during which measurements
regarding overall health will be performed (i.e. bloodpressure, 12-lead ecg,
blood and urine analysis), which will also be performed at the end of each
intervention period.