No patients dosed

This randomized, double-blind, placebo-controlled study will evaluate the efficacy, safety and tolerability of RO5036505 in patients with inadequately controlled moderate to severe asthma. Patients will be randomized to receive either RO5036505 (380mg iv infusion once weekly) or placebo for 8 weeks. Patients will be on a standardized inhaled corticosteroid/long-acting beta-agonist regimen during study treatment. Target sample size is 50-100 individuals.

Inclusion Criteria:

• adult patients, 18-70 years of age
• moderate to severe asthma for >/=2 years
• ACQ score >/= 1.5
• ICS and LABA regimen at moderate to high dose
• non-smokers

Exclusion Criteria:

• oral corticosteroid use within 4 weeks prior to screening
• current escalating immunotherapy
• acute infection/antibiotic therapy within 4 weeks prior to screening, or chronic infection
• pulmonary disease other than asthma
• therapy with any approved monoclonal antibody or biologic agent within 12 months prior to screening
• previous exposure to investigational monoclonal antibodies or biologics