Embryonic stem cell pioneers receive offer for abandoned programme from former executives

Two former CEOs of US drug company Geron are bidding to revive
its stem cell assets. Dr Michael West and Dr Thomas Okarma, who now work for
BioTime, issued an open letter to Geron's shareholders putting forward an offer
for the company's stem cell research programme, which has been suspended since
2011.

Dr West founded Geron in 1990, where he was director and vice-president until 1998 when he moved to Advanced Cell Technology. He was appointed CEO of BioTime, a biotechnology company focusing on
regenerative medicine based in California, USA in 2007. Dr Okarma was CEO of Geron
between 1999 and 2011. However, following Geron's move away from stem cell
research, Dr Okarma joined Biotime in September 2012.

Both men have spent much of their careers trying to bring products
derived from embryonic stem cells to the clinic. The letter to Geron's shareholders states they see this bid as an
opportunity to 'put the now dormant Geron stem cell assets
back on track'.

The proposal outlines an arrangement in which certain stem
cell assets owned by BioTime would be combined with those of Geron and controlled
by a new publicly traded company called BioTime Acquisition (BAC), to be led
by Dr Okarma.

Under the proposal, Geron shareholders would receive a 21.4
percent stake in the new company and subscription rights to purchase further
stock in BAC, with the potential to increase their ownership up to 45 percent.
BioTime would contribute $40 million in BioTime common shares, together with
BioTime warrants valued at $13 million and shares in BioTimes subsidiaries.

Although the final decision rests with Geron's board of
directors, the letter urges shareholders to contact the board in a bid to
encourage them to accept the proposal. The letter reminds shareholders that 'nearly
a year has now passed, and Geron has not announced any transaction that would
provide value to either Geron or its shareholders from those stem cell assets'.

Geron is yet to respond. However, the company's share prices
rose following the announcement, leading to speculation that Geron's investors
are interested in negotiating a deal.

Geron is currently focussed on developing
anti-cancer drugs, but it was previously an important player in stem cell research
and had pioneered development into stem cell based treatment for spinal cord
injury. Dr West and Dr Okarma believe that acceptance of their bid would 'speed
the development and commercialisation of innovative new products to treat
degenerative diseases'.