Post-approval indications and clinical trials for cardiovascular drugs: some implications of the US Inflation...

To describe the historical baseline landscape of cardiovascular drug post-approval activity, including the number and timing of post-approval clinical trials and approved indications. The US Inflation Reduction Act of 2022 (IRA) Drug Price Negotiation Program (DPNP) and its Maximum Fair Prices (MFPs) will affect incentives for investment in post-approval activity such as clinical trials for new indications. While three of the first ten drugs selected for the DPNP and MFP-setting are cardiovascular or antithrombotic drugs, limited attention has been paid to potential cardiovascular drug impacts, and to post-approval innovation.

For the 65 drugs originally approved by the FDA from 1995 through 2021 for a cardiovascular or antithrombotic indication (60 small molecules and 5 biologics), we develop a novel dataset of industry-sponsored, post-approval clinical trials and FDA-approved label changes for new indications. We analyze their number and timing relative to DPNP drug selection and MFP implementation dates, by drug approval-year cohort.

We find 49% of indications were awarded and 76% of industry-funded clinical trials were completed post-approval, reaching 98% of trials for drugs in the earliest 1995-99 cohort. For the 60 small molecules, 76% of post-approval trials ended five years or more after original drug approval, 65% ended seven or more years after original drug approval (i.e. after potential DPNP selection), and 53% nine or more years after original drug approval (i.e. after potential MFP implementation).

Post-approval FDA indication approvals and clinical trial starts and primary completion dates often occurred after or near new DPNP selection and MFP implementation dates. This has economic consequences for future investment incentives. Post-approval trials for small molecules, longer-duration trials, and larger-enrollment trials, and post-approval indications focused on limited patient populations and older patients could face particular economic challenges.