The 2019-20 season in Scottish club rugby "has been classified as null and void" due to the coronavirus pandemic.
Scottish Rugby's decision affects the Premiership and National Leagues and follows similar moves by the Irish, Welsh and Italian unions.
The SRU says "there will be no automatic promotion/relegation".
Biggar had won the National League 1 in the men's game while Broughton and Annan were in contention to reach the women's Premiership.
Broughton and Annan's play-off final had been rearranged for April after being postponed in December but it is now cancelled.
"Five possible scenarios were presented, with around half of clubs favouring the null and void option," said Scottish Rugby. "The second most favoured option - finishing the season based on the league positions at the time of shutdown - received the support of around a quarter of clubs."
- Champions and Challenge Cups postponed
- Melrose Sevens postponed
- Pro14 final cancelled due to coronavirus
SRU president Dee Bradbury added: "It was clear from the outset that, in terms of the consequential impact on the various leagues in terms of promotion/relegation there would be no 'right' solution, particularly once it was clear that our preferred option of completing the season would no longer be possible.
"Every solution we looked at was likely to be problematic in some way - none was likely to be supported by everyone.
"It was therefore considered essential that the full range of options were explored, each potential option was sense checked and that, as far as possible, a broad consensus was reached across the game as to the most appropriate outcome.
"We fully accept some clubs will be disappointed with this decision and share their frustration that, for wider societal reasons beyond our control, their hard work to push for success this season hasn't yielded the rewards they deserve."