This study (A7881006) is the first multiple dose study in moderate asthmatic subjects and aims to determine the safety and efficacy of PF-00610355 when subjects take PF-00610355 on a daily basis for 4 weeks in subjects maintained on inhaled corticosteroid.

Inclusion Criteria:

• Subjects with a physician documented history or diagnosis of persistent asthma for at least 6 months prior to Screening Visit 1.

Trough FEV1 must be 50-100% of predicted at Screening Visit 1.

Subjects who have been maintained on a stable dose of ICS over the previous month prior to screening.

Exclusion Criteria:

• Subjects who have had a severe asthma exacerbation in the 2 months prior to screening.

Subjects meeting any of the criteria of 'very poorly controlled' according to the NIH EPR 3 guidelines.

Subjects with evidence or history of cardiovascular disease including angina, myocardial, infarction, clinically significant cardiac arrhythmia (eg, atrial fibrillation, atrial flutter,supraventricular tachycardia, ventricular tachycardia), systemic hypertension (SBP > 160 mmHg or DBP >100mmHg), pulmonary hypertension or cerebrovascular disease (including transient ischaemic attacks).

Information relating to our policy on data sharing and the process for requesting data can be found at the following link: http://www.pfizer.com/research/clinical\_trials/trial\_data\_and\_results/data\_requests