there are already a number of antibodies against specific tumors in commercial use and in development; piggybacking on that technology could potentially provide new treatments for a host of cancers.
The pair were able to raise about $8 million from angel investors and a variety of grants (from the National Cancer Institute, the Massachusetts Technology Transfer Center, the Massachusetts Life Science Center and others) to back the idea, forming ImmuneXcite in December 2011 around the technology, which it calls “mAbXcite.” Bejerano is the president and CEO; Rubin-Bejerano, who left academia to pursue the idea full-time, is the CSO. Whitehead founding member Gerard Fink chairs the company’s scientific advisory board, which also includes oncology specialists from Johns Hopkins University (Charles Drake, Drew Pardoll), former Genzyme CSO Alan Smith, and immunology expert K. Frank Austen.
ImmuneXcite is starting out by strapping the fungal sugar to two different well-known cancer antibody drugs: cetuximab (Erbitux), and trastuzumab (Herceptin). That makes for a tricky business model, however: ImmuneXcite doesn’t have any rights to these drugs, so it would have to either wait for them to go off patent, cut deals to license their use, or find other antibodies to work with. (The startup doesn’t intend to make its own antibodies). Bejerano says the company is discussing “several approaches” to addressing that problem, like in-licensing antibodies that have shown they can get to their targets, but which haven’t been that effective as stand-alone molecules in clinical testing.
The big opportunity for ImmuneXcite may be to get in on the evolving mix and match game going on with cancer immunotherapy drugs. There’s currently much excitement around the new wave of so-called checkpoint inhibitors—drugs like nivolumab (Opdivo, from Bristol-Myers) and pembrolizumab (Keytruda, from Merck) that release a brake that otherwise stops T cells from attacking tumors. But these drugs don’t work for everyone, and so companies are testing them in combination with a variety of other molecules, searching for ones that boost the checkpoint inhibitors’ effectiveness.
That could be a perfect niche for ImmuneXcite’s drugs. “We already know that [checkpoint inhibitors] aren’t effective in large numbers of cancer patients—but we might be able to make those drugs effective by virtue of getting the immune storm to begin with this approach,” says Keith Flaherty, the director of developmental therapeutics at Massachusetts General Hospital’s Cancer Center, who isn’t affiliated with ImmuneXcite but is familiar with the company’s technology.
“That’s why we’re seeing a lot of interest from pharma,” Rubin-Bejerano says. “You can bring T cells to new tumors, release brakes if needed, and get responses in more people in more indications.”
That’s yet to be seen, of course. ImmuneXcite has some key challenges ahead of it as it moves into human testing. Flaherty points to a few in particular. On the efficacy side: sure, cetuximab and trastuzumab are known to be able to get to tumors, but when those molecules are linked to a sugar will they have the same success, or will they get cleared out by the body first? And on the safety side, will these conjugates create too powerful of an immune storm?
The answers to those questions, and others—like which antibody ImmuneXcite will ultimately use first—are coming soon. Bejerano says ImmuneXcite aims to raise a funding round this year, which would get the company to its first clinical trials. By then, we’ll see if ImmuneXcite has been able make some noise in the fast-growing immuno-oncology field.
“Every time I’m speaking with a company I’m surprised how many approaches people can come up with to use [these] sugars,” Rubin-Bejerano says. “It’s very exciting.”