Iterable allows you to clone blast and triggered campaigns. To clone a campaign:
Navigate to Messaging > Campaigns.
Hover over a campaign and click Clone.
If you have campaign folders enabled, right-click on a campaign and click Clone.
For blast campaigns, this will create a clone of the campaign but will not schedule the campaign. The cloned campaign will use the same list and template as the original campaign.
If the original campaign had an unfinished A/B experiment associated with it (if there is still an option to End Experiment), then that experiment will also be cloned for the new campaign. If the original campaign's experiment completed with a winning variant (denoted by a Winner icon) then that variant will be used for the cloned campaign. If there was no winner selected, then the control will be used for the cloned campaign.
You will be able to make template design changed before you schedule the new campaign for send.
You can also clone triggered campaigns. The cloned campaign will have a new campaign ID and will not be sent until the appropriate target API is called: