Participants who received omarigliptin during the base study, received omarigliptin 25 mg once weekly and placebo to metformin once daily for 66 weeks (Extension).

Participants who received matching placebo to omarigliptin during the base period, received pioglitazone administered once daily and matching placebo to omarigliptin once weekly for 66 weeks (extension period). Note: A protocol amendment removed pioglitazone during the extension period. Participants discontinued pioglitazone and switched to blinded metformin. Participants who were previously rescued with open-label metformin during the base period continued in the extension period on open-label metformin.

Matching placebo to omarigliptin 0.25, 1, 1.5, 10 or 25 mg oral capsule administered once weekly. For matching placebo to omarigliptin 3 mg, participants received two matching placebo to omarigliptin 1.5 mg capsules.

Pioglitazone 15 mg oral tablet or capsule administered once daily

Metformin 500 mg oral tablet administered once or twice daily

Matching placebo to metformin oral tablet administered once daily

An adverse event is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the Sponsor's product, whether or not considered related to the use of the product. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a preexisting condition which is temporally associated with the use of the Sponsor's product, is also an adverse event. Data presented below excludes data after the initiation of glycemic rescue.

A1C levels were measured as a percent at baseline (Week 0) for participants who entered the extension period.

A1C levels were measured as a percent. Change from baseline was calculated by subtracting the baseline level from the Week 78 level.

Plasma 2h-PMG levels were measured at baseline (Week 0) for participants who entered the extension period.

Change from baseline was calculated by subtracting the baseline level from the Week 78 level.

Plasma FPG levels were measured at baseline (Week 0) for particiapnts who entered the extension period.

Change from baseline was calculated by subtracting the baseline level from the Week 78 level.

Omarigliptin 3 mg administered once weekly for 12 weeks (base period)

Omarigliptin 10 mg administered once weekly for 12 weeks (base period)

Omarigliptin 25 mg administered once weekly for 12 weeks (base period)

Matching placebo to omarigliptin administered once weekly for 12 weeks (base period)

Total of all reporting groups

Participants with data: Omariglptin 0.25 mg, n=113; Omariglptin 1 mg, n=115; Omariglptin 3 mg, n=114; Omariglptin 10 mg, n=115; Omariglptin 25 mg, n=113; Placebo, n=113; Total, n=683

Participants with data: Omariglptin 0.25 mg, n=111; Omariglptin 1 mg, n=113; Omariglptin 3 mg, n=113; Omariglptin 10 mg, n=112; Omariglptin 25 mg, n=111; Placebo, n=110; Total, n=670

Participants with data: Omariglptin 0.25 mg, n=113; Omariglptin 1 mg, n=115; Omariglptin 3 mg, n=114; Omariglptin 10 mg, n=115; Omariglptin 25 mg, n=114; Placebo, n=113; Total, n=684

Omarigliptin 3 mg administered once weekly for 12 weeks (base period)

Omarigliptin 10 mg administered once weekly for 12 weeks (base period)

Omarigliptin 25 mg administered once weekly for 12 weeks (base period)

Matching placebo to omarigliptin administered once weekly for 12 weeks (base period)

An adverse event is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the Sponsor's product, whether or not considered related to the use of the product. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a pre-existing condition which is temporally associated with the use of the Sponsor's product, is also an adverse event. Data presented below excludes data after the initiation of glycemic rescue.

The all participants as treated population defined as all randomized participants who received at least one dose of study treatment. Participants were included in the treatment group corresponding to the study treatment they actually received during the study.

An adverse event is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the Sponsor's product, whether or not considered related to the use of the product. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a pre-existing condition which is temporally associated with the use of the Sponsor's product, is also an adverse event. Data presented below excludes data after the initiation of glycemic rescue.

The all participants as treated population defined as all randomized participants who received at least one dose of study treatment. Participants were included in the treatment group corresponding to the study treatment they actually received during the study.

An adverse event is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the Sponsor's product, whether or not considered related to the use of the product. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a preexisting condition which is temporally associated with the use of the Sponsor's product, is also an adverse event. Data presented below excludes data after the initiation of glycemic rescue.

Analysis population defined as all randomized participamts who received at least one dose of extension study treatment. Participants were included in the treatment group corresponding to the study treatment they actually received. Participants who received glycemic rescue during the base period were excluded from this analysis population.

An adverse event is defined as any unfavorable and unintended change in the structure, function, or chemistry of the body temporally associated with the use of the Sponsor's product, whether or not considered related to the use of the product. Any worsening (i.e., any clinically significant adverse change in frequency and/or intensity) of a preexisting condition which is temporally associated with the use of the Sponsor's product, is also an adverse event. Data presented below excludes data after the initiation of glycemic rescue.

Analysis population defined as all randomized participants who received at least one dose of extension study treatment. Participants were included in the treatment group corresponding to the study treatment they actually received. Participants who received glycemic rescue during the base period were excluded from this analysis population.

Change from baseline was calculated by subtracting the baseline level from the Week 12 level.

Full analysis set defined as all randomized participants who received at least one dose of study treatment and had a baseline measurement or a post-randomization measurement for the analysis endpoint subsequent to at least one dose of study treatment.

Change from baseline was calculated by subtracting the baseline level from the Week 12 level.

Full analysis set defined as all randomized participants who received at least one dose of study treatment and had a baseline measurement or a post-randomization measurement for the analysis endpoint subsequent to at least one dose of study treatment.

A1C levels were measured as a percent at baseline (Week 0) for participants who entered the extension period.

All participants who entered the extension period of the study with available A1C baseline data.

A1C levels were measured as a percent. Change from baseline was calculated by subtracting the baseline level from the Week 78 level.

Extension full analysis set population defined as all randomized participants who received at least one dose of extension study treatment, have baseline and at least one post-randomization observation for the analysis endpoint subsequent to at least one dose of extension study treatment.

Plasma 2h-PMG levels were measured at baseline (Week 0) for participants who entered the extension period.

All participants who entered the extension period of the study with available 2h-PMG baseline data.

Change from baseline was calculated by subtracting the baseline level from the Week 78 level.

Extension full analysis set population defined as all randomized participants who received at least one dose of extension study treatment, have baseline and at least one post-randomization observation for the analysis endpoint subsequent to at least one dose of extension study treatment.

Plasma FPG levels were measured at baseline (Week 0) for particiapnts who entered the extension period.

All participants who entered the extension period of the study with available FPG baseline data.

Change from baseline was calculated by subtracting the baseline level from the Week 78 level.

Extension full analysis set population defined as all randomized participants who received at least one dose of extension study treatment, have baseline and at least one post-randomization observation for the analysis endpoint subsequent to at least one dose of extension study treatment.

Omarigliptin 1 mg administered once weekly for 12 weeks (base period)

Omarigliptin 3 mg administered once weekly for 12 weeks (base period)

Omarigliptin 10 mg administered once weekly for 12 weeks (base period)

Omarigliptin 25 mg administered once weekly for 12 weeks (base period)

Matching placebo to omarigliptin administered once weekly for 12 weeks (base period)

Participants received omarigliptin 25 mg once weekly for 66 weeks (extension period)

Participants who received matching placebo to omarigliptin during the base study, received pioglitazone 30 mg once daily and matching placebo to omarigliptin once weekly for 66 weeks (Extension period). Participants were switched from pioglitazone to metformin starting at 500 mg once daily and titrated up to 1000 mg twice a day