True North Therapeutics raises $45M in Series D toward rare drug trials

Rare disease focused and early-stage biotech True North Therapeutics (aka TNT) has raised $45 million in its latest funding round as it gears up for midstage tests for its lead candidate TNT009.

This med, which inhibits the complement system, is currently in Phase Ib studies for the condition cold agglutinin disease (CAD), a rare type of autoimmune hemolytic anemia in which the body’s immune system mistakenly attacks and destroys its own red blood cells.

Much of the cash, which came from new investors HBM Healthcare Investments and Redmile Group, as well as Franklin Templeton Investments and existing investors, will be used toward furthering this study up the development pathway. This comes after the South San Francisco-based biotech secured a $35 million funding round last April.

Nancy Stagliano, CEO of TNT, did not tell FierceBiotech what the exact timelines for a Phase II were, but said: “We are continuing to make progress in the Phase Ib study, and once that is completed, we will be in a position to outline the go-forward CAD clinical timelines.” The drug already has orphan tags from the FDA and the EMA.

She is however excited by the data they already have. “Let me emphasize that the responses with TNT009 that we have seen to date are very encouraging and showed that TNT009 rapidly resulted in benefit to CAD patients. 

“So far, four of these five CAD patients in the Phase Ib study responded to TNT009 within the first 24 hours, as presented at EHA [European Hematology Association] in June. We believe that this shows that TNT009 has a strong profile as a potential treatment for CAD, and we are moving ahead as quickly as possible with our clinical program.”

She added that with the cash, the biotech will also seek to “prioritize additional clinical programs from our pipeline … We can then see where the science leads us.”

Perhaps not surprising given how tough the last year has been for IPOs, there was no talk of the biotech seeking to go public, despite having so many funding rounds behind it.

Stagliano, one of 2013's Fierce Top Women in Biotech, said: “As we evolve our business, the more options, the better and this includes future financings, partnering and investment in other programs. With the capital we’ve raised, we have the flexibility to consider those opportunities in the fullness of time, without being preoccupied with the current market environment.”

And what about a partner? “One of the benefits of pursuing orphan diseases, like CAD, with TNT009 is that it is feasible for a biotech company to pursue the development and commercialization of a drug for a rare disease independently, without a big pharma partner,” she explains.

“That said, there is strong interest by larger biotech and pharma companies in novel drugs that target the complement system, and we are always open to talking to potential partners.”

In addition to CAD, Stagliano said her company was also exploring TNT009 in three additional classical complement-mediated diseases in its Phase Ib trial: warm autoimmune hemolytic anemia, antibody-mediated rejection (such as with kidney transplant), and bullous pemphigoid (a rare and debilitating skin disease).

There is also another, early-stage candidate in the biotech’s pipeline; although details are thin at the moment, Stagliano said: “We expect our second candidate to be a next-generation antibody that inhibits C1s and offers a potentially different therapeutic profile than TNT009 for specific diseases beyond CAD.”

This is not the first drug to go after the complement system, as Alexion ($ALXN) helped pioneer this approach when developing its ultrarare med Soliris (eculizumab) that works by inhibiting terminal complement, specifically the C5 in the complement system.

TNT is a little different in that it is targeting C1s in the classical complement pathway. One of this year’s Fierce 15 companies, Annexon Biosciences, is also looking at a similar target with its two lead candidates: ANX005 for serious CNS and autoimmune disorders and ANX007 for ophthalmic disorders.

They both inhibit a protein known as C1q, which is the initiating molecule of the classical pathway and blocks the complement activation involved in neurodegeneration.