Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT02635386 |
Other study ID # |
RP15-008 |
Secondary ID |
AZ ESR-14-10725 |
Status |
Completed |
Phase |
Phase 3
|
First received |
|
Last updated |
|
Start date |
March 22, 2016 |
Est. completion date |
October 9, 2020 |
Study information
Verified date |
January 2021 |
Source |
Woman's |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
This is a randomized, single-blind, parallel 5 treatment group 24-week trial designed to
directly compare the therapeutic effects of exenatide once weekly (EQW), dapagliflozin
(DAPA), EQW plus DAPA, combined DAPA/metformin extended release (XR) and the weight loss
medication, phentermine/topiramate extended release (PHEN/TPM ER) on metabolic and
endocrinological parameters in overweight/obese non-diabetic women with PCOS. In this study,
we will examine the efficacy of these therapies on metabolic parameters, body weight and body
composition, anthropometric measurements, and reproductive function in a well-defined group
of pre-menopausal overweight/obese, non-diabetic women with PCOS, focusing on their
relationship to insulin resistance and obesity. We hope to determine which treatment(s)
addressing the multifaceted disturbances of individual subgroups emerge as the preferable
therapy.
Description:
Polycystic ovary syndrome is a heterogeneous condition characterized by disordered
reproductive and metabolic function which accounts for the myriad of clinical features
including androgen excess, chronic anovulation, insulin resistance adiposity, and
dyslipidemia. This syndrome is highly prevalent, affecting between 8 and 18% of the female
population, depending on the diagnostic criteria used. Hyperandrogenism, ovarian dysfunction
and metabolic abnormalities - the main determinants of PCOS - all appear to be involved in a
synergistic way in the pathophysiology of PCOS. Women with PCOS are more likely to be obese:
between 38 and 88% of women with PCOS are overweight or obese, although PCOS can also
manifest in lean women. Obesity, particularly abdominal obesity, plays a central role in the
development of PCOS, and exacerbates the reproductive and metabolic dysfunction. Rather than
absolute body weight, it is the distribution of fat that is important with central (visceral)
adiposity being a risk factor. Visceral adipose tissue is more metabolically active than
subcutaneous fat and the amount of visceral fat correlates with insulin resistance and
hyperinsulinemia. Weight gain is also often an important pathogenic factor, with PCOS usually
becoming clinically manifest in women with a presumable genetic predisposition for PCOS who
subsequently gain weight. Therefore, environmental (particularly dietary) factors are
important. However, BMI is also influenced by genetic factors such as the fat mass and
obesity-associated protein, and obesity is a highly heritable condition. Therefore, the
weight gain responsible for the manifestation of PCOS in many women with this condition is
itself influenced by genetic factors. Ethnicity, genetic background, personal and family
history, degree of obesity must all be taken into account because they might aggravate or
even trigger metabolic disturbances women with PCOS. Moreover, the incidence of glucose
intolerance, dyslipidemia, gestational diabetes, and type 2 diabetes (DM2) is increased in
women with PCOS at all weight levels and at a young age. PCOS may be a more important risk
factor than ethnicity or race for glucose intolerance in young women. The exact factors
responsible for this excess risk in women with PCOS have not been identified; family history
of DM 2, obesity, insulin resistance, beta cell (ß-cell) secretory dysfunction, and
hyperandrogenism are possible candidates. With better understanding of its pathophysiology,
the metabolic consequences of the syndrome are now evident. Therefore, these patients need to
be followed up even after their presenting complaint has been adequately resolved.
Lifestyle modification is a key component for the improvement of reproductive function for
overweight, anovulatory women with PCOS. Even a modest weight loss 5% of total body weight
can restore ovulation in overweight women with PCOS. Features of PCOS (e.g., hirsutism,
testosterone levels, insulin resistance, menstrual cyclicity and ovulation) showed marked
improvements, and PCOS frequently resolved after substantial weight loss induced by bariatric
surgery. Recently a number of anti-diabetes medications have been approved which facilitate
weight loss and improve the underlying insulin resistance. We reported that treatment with
the glucagon like peptide -1 (GLP-1) agonist, exenatide for 24 weeks was superior to single
agent metformin treatment in improving insulin action and reducing body weight and
hyperandrogenism in obese women with PCOS. We further observed exenatide treatment
significantly improved first-phase insulin responses to oral glucose administration. Since
aberrant first-phase insulin secretion and impaired suppression of endogenous glucose
production are major contributors to postprandial hyperglycemia and development of type 2
diabetes, the effects of exenatide once weekly [EQW (2 mg)] to target these defects, and
normalize glucose excursions are likely to be clinically significant in obese patients with
PCOS. Sodium/glucose cotransporter 2 (SGLT-2) inhibitors are the newest class of medications
for diabetes management that have not been investigated for use in the women with PCOS. The
SGLT2 inhibitor, dapagliflozin [DAPA (10 mg/day)] has an insulin-independent action, promotes
weight loss, has a low incidence of hypoglycemia, and complements the action of other
antidiabetic agents. The loss of glucose with attendant caloric loss contributes to weight
loss; in addition, improvements in β cell function have been seen. Because the SGLT2
inhibitors have a distinct mechanism of action that is independent of insulin secretion, the
efficacy of this class of drugs is not anticipated to decline in the presence of severe
insulin resistance. The weight loss seen with SGLT2 inhibitors is similar to that seen with
glucagon-like peptide 1 agonists, and may be more acceptable because they are oral agents.
The resulting weight loss will further assist in decreasing insulin resistance, leading to
increased glucose disposal thus contributing to an increased insulin secretion-insulin
sensitivity (ISSI) index, the primary outcomes measure.
The non-diabetic female with PCOS offers a unique model to study the relationship between
insulin resistance and adiposity. Women with PCOS demonstrate abnormal body composition
characterized by a greater percent body fat, body fat mass, and increased ratio of fat to
lean mass (F/L ratio). Studies using dual-energy X-ray absorptiometry (DEXA) methodology
report a higher degree of metabolic dysfunction in patients with PCOS which appears be
directly associated with their higher F/L ratio. Given that monotherapy and combined therapy
with exenatide once weekly (EQW),and dapagliflozin (DAPA) along with DAPA/ metformin XR
therapy are associated with weight loss introduces a confounder to the current study since it
prevents distinguishing direct effects of the compounds on β-cell function vs. effects due to
reduced adiposity. To control for loss of body mass and provide appropriate intervention in
the remaining study arm we propose the use of a comparator weight loss drug alone,
combination phentermine (PHEN)/topiramate (TPM) extended release (ER). To avoid the
confounding relationship of body fat and insulin resistance, we will enroll only obese
non-diabetic women with PCOS. All patients will receive diet and lifestyle counselling,
including advice on exercise, according to usual clinical routine commencing during the
lead-in period and continuing throughout the study We propose a randomized, single-blind,
parallel 5 treatment group 24-week trial designed to directly compare the therapeutic effects
of exenatide once weekly (EQW), dapagliflozin (DAPA), EQW plus DAPA, combined DAPA/metformin
ER and the weight loss medication, phentermine/topiramate extended release (PHEN/TPM ER) on
metabolic and endocrinological parameters in obese non-diabetic women with PCOS.