Ann: COVID-19 Interim Trial Results Meet All Primary Objectives, page-142

All companies have some rights to announce buy backs of unmarketable shares I suppose - I read the announcement and there are two things that come out.

1) there was a time limit for individual shareholders to refuse to have there shares taken up in the buy back.
2) shareholders will have the value of those shares (at the market value at the time of sale) paid to them.

Guess the weird point is that the announcement indicates that shareholders will only get that cash when the shares are sold on to someone else.

There may be limited avenues for legal action given 1) and 2) above.