These entries are queried from radb.net using whois, you can try my project getting these.
:AS53900 route: 38.121.137.0/24 descr: OrbiMed origin: AS53900 mnt-by: MAINT-AS27506 changed: probillard [at] lightower.com 20141209 source: RADB last-modified: 2023-11-13T15:47:01Z rpki-ov-state: not_found # No ROAs found, or RPKI validation not enabled for source