vetting IP claims (although he wouldn’t comment on specifics concerning Solstice.) But vetting potential security risks isn’t something he’s had to do in the past. Asking around for advice, he said he’s gotten a “few jokes about bodyguards,” but he says he’s not concerned about his personal safety.
There are also risks involved in Solstice that biotech people are more accustomed to: The risk of putting time, money, and energy into an unproven technology. When Solstice launched in January 2013, its lead investor, VenBio’s Goodman, described to me the prospects of turning Dowdy’s RNA idea into new drugs as a “big if, with a capital I and capital F.” VenBio and Aeris Capital, a Swiss investment firm, were behind Solstice’s $18 million Series A. [CORRECTION: The name of Aeris was spelled incorrectly in a previous version.]
At launch time, Dowdy said the technology—which he calls RNNs, or ribonucleic neutrals—might move medicine forward in two ways. First, it would deliver the promise of RNA interference therapy into tissues beyond the liver and the eye, where many first-generation programs have focused because those cells are easier to reach with such fragile molecules. Second, Dowdy spoke of the potential for adjusting RNNs quickly as their targeted disease mutates—for example, as a pandemic flu virus spreads or a patient’s tumor genetics evolve. When asked last week if that ability to fine-tune a patient’s therapy is still the vision, Dowdy wrote that it was “more of a broader statement from me as a Professor than any suggestion of what Solstice may [or] may not do.”
Indeed, the company hasn’t yet named a disease it wants to tackle. Tartaglia says as CEO he’ll be asking potential licensing partners which tissues they’d like to see as therapeutic targets. Both Tartaglia and VenBio’s Goodman were careful to note that the RNN work has evolved since Solstice gained access to it in 2012. The main idea behind RNNs is to add extra chemical parts to the core RNA that change its electrical charge from negative to neutral and help it slip more easily into cells. There are other modifications, too, all of which are removed by enzymes within the cell, leaving the RNA to do its therapeutic work.
Others have tried a similar “prodrug” approach for RNA delivery—using modifications that acted as a sort of invisibility cloak to help the drug itself get to where it needs to be—but failed. When asked what makes Solstice different, Tartaglia said it’s confidential. “We’ve held it close to the chest… but it goes way beyond the ‘charged neutralization’ strategy.”
Joining Tartaglia is new CFO John Borgeson, a Pfizer veteran who worked with VenBio’s Goodman when both were at Pfizer’s short-lived biotech center in San Francisco. More recently he has worked with Goodman on VenBio startups.
Tartaglia leaves Third Rock as the Boston-based firm ramps up investment from its third fund and expands its San Francisco presence.
Like many Third Rock partners, he served interim executive roles at several startups that emerged from the venture firm, including Ember Therapeutics and Editas Medicine. (Third Rock is not an investor in Solstice.)
Tartaglia will continue to serve on the scientific advisory board of Ember and the board of directors of Ablexis. In an emailed statement, Third Rock spokeswoman Naomi Aoki said, “We will miss him, but we wish him well and fully support him as he enters this next chapter of his career.”
