Lenvatinib mesylate (crystalline form) vs. Lenvatinib (free base): SALT under Section 3(d)

Section 3(d) structural comparison for IN-236500 (Eisai R&D Management Co., Ltd.). Candidate 'Lenvatinib mesylate (crystalline form)' evaluated against known substance 'Lenvatinib (free base)'. Structural relationship classified as SALT: Same active molecule; new compound adds counterion fragment(s): ['CS(=O)(=O)O']. Falls under Section 3(d)'s 'salts' category. Flags derivative category under Section 3(d) of the Indian Patents Act for manual efficacy verification.