A Study to Investigate the Safety, Tolerability and Preliminary Efficacy of NGI226 Microparticles in Patients With Achilles Tendinopathy

Inclusion Criteria: * Written informed consent must be obtained prior to all study specific screening procedures, as close to the start of the screening period as possible. * Presence of clinically (local Achilles tendon pain on tendon-loading activities, pain on palpation at the level 2-6 cm proximal to the calcaneal insertion) and ultrasound (local tendon thickening with hypoechogenicities and irregular fibre orientation) or MRI diagnosed mid-portion Achilles tendinopathy with symptoms present ≥8 weeks but \<12 months at screening. * The Achilles tendinopathy must have been refractory to at least 6 weeks of conservative treatment (physiotherapy, NSAIDS, RICE), but participants do not need to be in physiotherapy at the time of study entry. Exclusion Criteria: * Medical condition that would affect safety of peritendon injection (e.g., peripheral vascular disease, use of anticoagulant medication) * History of recurrent, acute, symptomatic infections, including outbreaks of oral or genital herpes (\> 2 symptomatic infections or \>2 courses of anti-infective treatments required in the last 6 months; active systemic infection during last 2 weeks; known active infections (e.g. chronic or active Hepatis B or C, HIV) - simple cold excluded * History or evidence of clinically significant cardiac or cardiovascular disease * History of deep vein thrombosis, pulmonary embolism or evidence of primary or secondary hypercoagulable states * History of surgical intervention for the treatment of tendinopathy, history of ankle surgery, ankle arthritis, traumatic, inflammation or deformity of ankle * History of full-thickness tear or complete rupture of the Achilles tendon