Atara Bio Grabs $38.5M to Help Kidney Patients, Fight Cancer

Xconomy San Francisco — 

Amgen (NASDAQ: AMGN) tends to scoop up entrepreneurial teams and plug their work into the mother ship, not spin out cool ideas and entrepreneurs. But a couple of experimental drugs from Amgen’s pipeline are getting new life at a startup called Atara Biotherapeutics.

Atara, which has headquarters in Brisbane, CA and operations in Thousand Oaks, CA, is announcing today it has raised $38.5 million in a Series B venture financing. New investors Amgen Ventures, Celgene (NASDAQ: CELG), and EcoR1 Capital joined the second round of financing, along with original backers Alexandria Venture Investments, DAG Ventures, Domain Associates, and Kleiner Perkins Caufield & Byers. Atara has now pulled in more than $58 million since its founding in October 2012.

Amgen didn’t invest in the original licensing deal to Atara a year ago, but it chose to invest like all the others in the Series B round, says Atara CEO Isaac Ciechanover. Amgen is getting no special product rights through its investment, he adds.

The idea for a company came from scouting work that Ciechanover, a former Celgene business development executive, did more than a year ago while he was a life sciences partner at Kleiner Perkins. As Amgen shuffled around its R&D portfolio under new CEO Robert Bradway, it left little budget room for an experimental “peptibody” drug for muscle wasting in patients on kidney dialysis. The same budget squeeze hit an internal Amgen drug candidate that seeks to inhibit a protein called activin, as a new way to fight ovarian cancer. So Ciechanover got a license to the molecules from Amgen, and rounded up a VC syndicate on the promise they wouldn’t have to wait a decade to find out if the drugs were any good. Now Atara has the loot to gather data to find out whether these drugs work in human beings.

“Our goal is to build a standalone comnpany, and data to give us great confidence in these programs,” says Ciechanover, pictured above. “With our investor base, we think we can define our destiny.”

Carol Gallagher, the executive chair of Atara, added: “The company is developing interesting assets that are clinical stage, so the company has a good probability of creating significant value over the near-term. I was also particularly intrigued with the increased understanding of activin as a therapeutic target in cancer, particularly in ovarian cancer.”

Part of what’s also unusual about Atara is its business model. The company has structured itself as a central holding company that oversees a handful of limited liability companies (LLCs). This way, Atara can license out a single asset or sell it off to an acquirer without having to sell the whole company, or try to interest an acquirer in a whole bunch of other assets or people it may not want.

Atara isn’t the only company that’s trying to let pharma or biotech acquirers shop “a la carte” from its menu of programs—San Diego-based Inception Sciences and Watertown, MA-based Forma Therapeutics have structured themselves to execute on a similar idea.

In an ideal world, such a structure would allow for Atara to reward its investors time again, while allowing a solid management team to keep the band together longer in hopes of releasing more than one hit. Atara has gone so far as to name its first three LLCs after the three fabled ships led by explorer Christopher Columbus—Nina, Pinta, and Santa Maria.

In modern bizspeak, Ciechanover and Atara board members say this strategy gives it “optionality.” That’s opposed to the more traditional investment exit options, which requires someone to buy the whole company, or for the executive team to pull off an IPO.

So what exactly is Atara starting with? The first drug candidate is called PINTA 745. It’s a targeted peptibody (a genetically engineered combination of a peptide and an antibody) that zeroes in to specifically inhibit myostatin.

Scientists have learned a lot in recent years this muscle protein, and many believe it might be possible to treat muscle-wasting disorders by inhibiting it. Pfizer and Eli Lilly, among others, have experimental antibodies designed to inhibit myostatin. The others, Ciechanover says, are aiming their myostatin inhibitors in different directions, going after muscle disorders like Duchenne Muscular Dystrophy (Pfizer) and cancer (Eli Lilly). Atara has sought to position the drug against protein energy wasting, which is just a term for the muscle atrophy that patients develop when they have end-stage renal disease and get kidney dialysis treatment.

Amgen ran three Phase I clinical trials with the drug, and found it to be well-tolerated in healthy volunteers and patients with prostate cancer. The drug candidate, however, has a short half-life, meaning it will need to be given through frequent injections. That’s no big deal for patients undergoing kidney dialysis, because they already come in for treatment three times a week, Ciechanover said. But that kind of injection frequency may be a dealbreaker for cancer patients, who tend to come in to see the doctor less often.

The second drug candidate at Atara is called STM 434, and it’s positioned as an inhibitor of activin. It’s a protein involved in hormone signaling. The bet at Atara is that this drug offers a new line of attack against ovarian cancer, which is often detected late in the game and is difficult to treat. That drug isn’t as far along as the first—Atara said it has data from animal tests that say it might work on its own or in combination with chemotherapy. The company plans to use some of its new money to file an application with the FDA to start clinical trials, and gather some preliminary data on its safety at a variety of doses.

Atara is still a quite lean operation with just six full-time employees, while it leans on a network of part-time consultants and vendors. The new financing should be enough to carry the company through 2015, and get it to the point where it has much more clarity on the product profile of its two lead assets, Ciechanover says.

There is a personal motivator at work in Atara, as well. Ciechanover says his mother was diagnosed with ovarian cancer around the time he was starting the company. That experience intensified his interest in what’s new for the disease, and led him to the work being done at Amgen. Like many women, Ciechanover’s mother died just nine months after her diagnosis. As a tribute, he named the company after her, and has a picture of her on his office wall.

“She had a bad form of cancer,” Ciechanover says. “I want to try to help other patients and their families.”