Safety and Tolerability of AIN457 in Adults (18-65 Years) With Moderate to Severe Ankylosing Spondylitis

Inclusion Criteria: * Patients who took part and completed in the core CAIN457A2209 study * Patients who discontinued the core study due to unsatisfactory therapeutic effect at their Visit 14 (Week 16) or later could enter the extension study within 3 weeks of completing the study discontinuation visit of the core study, provided that at their discontinuation visit they fulfilled either one of the criteria below. Patients who did not enter the extension study within 3 weeks of completing the study discontinuation visit of the core study, were required to come for an additional baseline visit (Visit 17) and were required to fulfill either one of the criteria below: * No improvement (compared with the core study baseline) in two out of the following four domains: patient global assessment, pain, BASFI and the mean of the two morning stiffness questions from the BASDAI. OR * Deterioration (compared with the core study baseline) in one of the four domains (deterioration defined as \>=20% worsening and an absolute worsening of \>=1 unit) Exclusion Criteria: * Patients for whom continued treatment with AIN457 is not considered appropriate by the treating physician. * Patients who were non-compliant or who demonstrated a major protocol deviation in the core CAIN457A2209 study. * Patients who discontinued from the core CAIN457A2209 study before Visit 14 (Week 16), and patients who completed the core study * Pregnant or lactating women * Presence of active infection * Positive PPD or HIV test in patients where repeated testing was deemed appropriate due to their risk profile Other protocol-defined inclusion/exclusion criteria may apply