As of Dec 2021, there are no R packages released either as closed source collaborations between companies, or our gold standard of open sourced. If you are considering developing a package with a similar scope to any of the below, we encourage you first make contact with the lead developer to discuss whether a collaboration may be possible.
According to CDISC: SDTM provides a standard for organizing and formatting data to streamline processes in collection, management, analysis and reporting. Implementing SDTM supports data aggregation and warehousing; fosters mining and reuse; facilitates sharing; helps perform due diligence and other important data review activities; and improves the regulatory review and approval process.
SDTM is one of the required standards for data submission to FDA (U.S.) and PMDA (Japan).

Contains data check functions to identify SDTM issues that are generalizable, actionable, and meaningful for analysis
Upcoming packages

SDTM mapping algorithms via R functions OPEN SOURCE RELEASE EXPECTED ~MID-2023 Contact Ram Ganapathy (ganapar1@gene.com)

Applying a datacut to SDTM
In addition, a collaboration of 7 companies is being formed to tackle “Open Source test data generation” for SDTM mapping via an R package. it would be focused on test data from EDC systems that is needed to test SDTM mapping.