This helped me.
Delete a word - Send Hex Codes - 0x1b 0x08 or 0x17
0x1b 0x08
0x17
Delete a line - Send Hex Codes - 0x15
0x15
Go to your iTerm preferences select "profiles" then "key" and change your presets in "Natural Text Editing"
It should work immediately after.
It works with iTerm version 3.3.12
ctrl + w in iTerm,
ctrl + w
BTW, in text editorsalt + delete to delete whole previous wordfn + delete to delete next word
alt + delete
fn + delete