Current article provides empirical evidence on the process of structural transformations of an international cluster. The research is held under the case study approach of the biopharmaceutical cluster Medicon Valley. According to the research results, an organized international cluster has three distinguishing stages of structural transformation during the process of its successful development. The initial stage of the cross-border cluster, being the result of trans-regionalization activities of the neighboring countries can subsequently transform into transnational cluster, involving actors of the remote regions. The prevailing importance of organizational proximity of an international cluster is observed in the scattered localization of its members. Innovation activity holding the predominant role in establishing bonds between the stakeholders is the cause of establishment of the sustainable network between the cluster and the external actors, forming the international cluster-network structure. Similar to the corporate alliances, successful international clusters tend to establish unions or associations, while seeking for new sources of knowledge and competences. This form of co-opetition is defined as international cluster network.