The development and expedited approval of targeted therapies, particularly in oncology, is increasing exponentially. Many of these therapies require a companion diagnostic (CDx) to support the drug. When a sponsor is developing a drug that satisfies the requirements for expedited regulatory pathways, development of the CDx can be the rate limiting factor for ensuring the drug reaches patients as quickly as possible. Current industry practices exist for managing these challenges, and regulators have exhibited flexibility in approaches. However, examples of phase-appropriate practices to expedite CDx co-development would be helpful in streamlining co-development. The goal of this panel is to discuss methods to accelerate CDx co-development to enable earlier patient access to novel, innovative therapies.