A Study to Investigate the Glucose Lowering Effects of Dextromethorphan Alone or in Combination With Sitagliptin in Subjects With Type 2 Diabetes Mellitus (T2DM) After an Oral Glucose Tolerance Test

A Phase IIa, Dose-finding, Double-blind, Placebo-controlled, Double-dummy, Randomized, Eightfold Cross-over Study to Investigate the Glucose Lowering Effects of Dextromethorphan Alone or in Combination With Sitagliptin in Subjects With Type 2 Diabetes Mellitus (T2DM) After an Oral Glucose Tolerance Test

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01936025

Acronym

DXM2

Enrollment

Registered

2013-09-05

Start date

2013-10-31

Completion date

2014-04-30

Last updated

2017-11-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Type 2 Diabetes Mellitus

Keywords

Diabetes mellitus

Brief summary

The study has a randomized, double-blind, placebo-controlled, double dummy and eight-way cross-over design. Males with T2DM on a stable metformin monotherapy will be screened for participation in the study. Eligible subjects will be randomized to receive DXM 30 mg, DXM 60 mg, DXM 90 mg alone or in combination with sitagliptin 100 mg, sitagliptin 100 mg alone, or placebo (for DXM and sitagliptin) on in total eight treatment days. An OGTT will be started 1 hour after study drug administration and blood glucose will be measured over the next 4 hours. There will be a 3 to 14-day washout period between doses.

Detailed description

This study is performed to determine the optimal dose of DXM that, compared to placebo, decreases glucose excursions following an OGTT. Doses of 30 mg, 60 mg and 90 mg DXM were chosen. Since DXM 60 mg was effective in the previous study in increasing insulin secretion, this dose will be kept. A lower dose (30 mg) will be given to see whether effects on insulin secretion are present also at lower doses and then translate into a BG lowering action. A higher dose (90 mg) will be added to see whether this way an effect on glucose excursion reduction occurs following an OGTT, (like previously demonstrated with 270 mg DXM) that can be related to an increase of insulin secretion.

Interventions

DRUGDextromethorphan

DRUGSitagliptin

DRUGPlacebo

Study design

Allocation

RANDOMIZED

Intervention model

CROSSOVER

Primary purpose

TREATMENT

Masking

DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender

MALE

Age

45 Years to 70 Years

Healthy volunteers

Inclusion criteria

1. Signed and dated written informed consent obtained before any study-related activities 2. Male subjects with a diagnosis of type 2 diabetes mellitus according to ADA criteria at least 4 months prior to screening 3. Medical history without major pathology (with the exception of type 2 diabetes) 4. On a stable regimen of metformin monotherapy for at least 3 months 5. Aged between 45 and 70 years of age, both inclusive 6. Body mass index (BMI) between 25 and 35kg/m2, both inclusive

Exclusion criteria

1. Subjects with type 1 diabetes, MODY or secondary forms of diabetes such as due to pancreatitis 2. History of pancreatitis 3. Current or previous treatment with insulin therapy 4. Treatment with any hypoglycemic medication other than metformin within the three months prior to screening 5. Mean QTc\> 450 msec

Design outcomes

Primary

Measure	Time frame	Description
lowest dose of DXM	up to 4 hours after study drug administration	To find the lowest dose of DXM that, compared to placebo, exerts BG lowering effects related to an OGTT

Secondary

Measure	Time frame	Description
additive BG lowering effects	up to 4 hours after study drug administration	To demonstrate whether the administration of DXM on top of sitagliptin exerts additive BG lowering effects related to an OGTT as compared to sitagliptin alone and DXM alone

Countries

Germany

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026