Two cystic fibrosis drugs have gained the first breakthrough therapy designation from the US Food and Drug Administration (FDA). In January, the agency announced that Vertex's Kalydeco (ivacaftor) alone and in combination with the experimental compound VX-809 would be the first to benefit from an expedited review process designed for potentially lifesaving drugs. In March, FDA added two oncology drugs to this pathway: the experimental lymphoma drug ibrutinib from Pharmacyclics of Sunnyvale, CA, and the Novartis drug LDK378 for the treatment of lung cancer. All three companies appear delighted but cautious about what the FDA breakthrough designation will mean for their products. FDA is considering another initiative, the Generating Antibiotic Incentives Now (GAIN) pathway, as an alternative approval for unmet medical needs, which appears to be intended mainly for anti-microbial drugs.