• To demonstrate the efficacy in terms of the Formoterol fumarate component of SKP FlutiForm HFA pMDI (250/10ug) compared to SKP Fluticasone HFA pMDI (250ug), on the change in FEV1 from morning pre-dose at Baseline (Week 0) to 2 hours post-dose at Week 12. [ Time Frame: Week 0 and 12 visits ] [ Designated as safety issue: No ]
  

• Demonstrate the efficacy of SKP FLUTIFORM HFA pMDI (250/10ug) compared to FLOVENT® Fluticasone pMDI (250ug) on the change in FEV1 from morning pre-dose at Baseline (Week 0) to 2 hours post-dose at Week 12. [ Time Frame: Week 0 and 12 visits ] [ Designated as safety issue: No ]
  
• Demonstrate the efficacy of SKP FLUTIFORM HFA pMDI (250/10ug) using other pulmonary function tests (PFTs), and clinical endpoints. [ Time Frame: Whole duration of study ] [ Designated as safety issue: No ]
  
• Assess the safety profile of SKP FLUTIFORM HFA pMDI (250/10ug twice daily) using incidence of adverse events, and changes in electrocardiograms, clinical laboratory tests and vital signs. [ Time Frame: Whole duration of study ] [ Designated as safety issue: Yes ]
  
• To assess the 12-hour serial FEV1 area under the curve (AUC) in a subset population (in a minimum of 66 patients). [ Time Frame: Week 0; 2 and 12 visits ] [ Designated as safety issue: No ]
  

This Phase 3 randomized, double-blind, active-controlled, parallel group, stratified, multi-center study will evaluate the safety and efficacy of FlutiForm (250/10ug) after twice daily dosing over 12 weeks delivered by SKP HFA pMDI compared with Fluticasone propionate (250ug of twice daily) delivered by SKP HFA pMDI and Flovent® Fluticasone 250ug HFA pMDI in adolescent and adult patients with moderate to severe asthma. Only steroid-requiring patients (inhaled steroid regimen stable for at least 4 weeks prior to the Screening Visit at a dose not greater than 500ug/day Fluticasone propionate or equivalent) will be eligible. All patients will undergo a Run-In Period of 14 ± 3 days during which they will receive asthma maintenance therapy using Fluticasone HFA pMDI (Flovent® HFA 50 ug/actuation: 100µg/day (one inhalation twice daily) if they were using less than or equal to 250mg/day Fluticasone propionate or equivalent inhaled steroid, or 200ug/day (two inhalations twice daily) if they were using greater than 250ug/day Fluticasone propionate or equivalent inhaled steroid prior to the Screening Visit.). The use of rescue Salbutamol (Albuterol) pMDI will be permitted for all patients as needed for the control of worsening asthma symptoms during the Run-In Period. At the Baseline Visit (Week 0) following the Run-In period, eligible patients will be randomized to the treatment groups. Treatment assignment will be stratified according to their Baseline FEV1 % predicted (40-60% or >60-80%).Study drug will be administered twice daily over a 12-week period. Patient visits will occur at Weeks 2, 4, 8, and 12 during which assessments (including serial PFTs up to 4 hours) will be made. In a subset of at least 66 patients (22 patients per treatment group) from selected centers, post-dose 12-hour serial PFTs will be performed at Baseline, Weeks 2 and 12. During the Treatment Period, patients may only take their blinded study medication; all other asthma medications will be withheld for the duration of the Treatment Period. However, the use of rescue Salbutamol (Albuterol) pMDI will be permitted in all patients as needed during the Treatment Period for the control of worsening asthma symptoms.