A startup has developed new technology that it claims can open a new front in the war on cancer.

Guardant Health has developed a non-invasive screening tool that relies on a blood sample rather than tissue. The test, dubbed the “Guardant 360,” is designed to help patients avoid risky and expensive biopsies. Biopsies can cost up to $10,000 for people not covered by insurance. Final pricing for Guardant’s test has not yet been disclosed.

The Redwood City, Calif.-based company announced this week that it will begin selling its genetic screening tool to some 100,000 patients in a handful of cancer clinics. Guardant also disclosed that it has raised $10 million in capital from Sequoia Capital, a venture firm that is increasingly investing in the personalized medicine trend. Sequoia’s health investor, Warren Hogarth, has joined the company’s board.

Guardant chief executive Helmy Eltoukhy has a long career in biotech. He joined Illumina in 2008 after the biotech giant acquired his company Avantome just a few short months after he started it. Last month, Illumina made the shocking announcement that its new machine could slash the cost of genome sequencing to $1,000.

“Sequencing costs are down a hundredfold at least, but we haven’t changed survival outcomes for diseases based on DNA sequencing. That’s where Guardant comes in,” said Eltoukhy in a phone interview.

‘Cancer treatment hasn’t improved much in 40 years’

Most cancer patients can only afford a biopsy once or twice during the course of their treatment. Biopsies are also risky and invasive, so physicians are reluctant to subject patients to repeat procedures. As a result, Eltoukhy estimates that 75 percent of cancer patients are taking ineffective drugs, usually based on biopsies that are several years old.

“Cancer is one of those areas where treatment hasn’t improved much in nearly 40 years,” Eltoukhy said. One of the challenges is that new drugs are being approved all of the time, but they aren’t being matched to the right patient. As a result, treatment costs are sky-high at about $100,000, but survival rates have remained fairly steady for decades.

Eltoukhy hopes that patients will elect to take a Guardant blood test far more frequently. An oncologist can then track how the cancer is progressing and identify the most effective treatment. “Even slight mutations can mean the difference between one drug working and one drug failing,” he said.

What’s new about Guardant?

Scientists have known since the 1990s that blood carries genetic fragments from dying cells of tumors. This is analogous to a discovery that a pregnant women’s blood carries genetic material from a fetus.

Fetal DNA is easier to analyze from a blood test, which has given rise to a slew of companies. Companies like Ariosa Diagnostics and Natera both offer non-invasive tests for pregnant women. With a high degree of accuracy, these tests can diagnose a fetus with Down’s Syndrome and other genetic conditions.

However, the fragments of a cancerous tumor are in such low concentrations (around one part in 200) that it’s been near-impossible to rely on this information. For this reason, other startups like Boston-based On-Q-ity have attempted — and failed — to treat individual cancer patients by counting and characterizing tumor DNA in the blood. On-Q-ity had also developed a proprietary technology, known as circulating tumor cell (CTC), and made similarly bold clams about the new era of personalized cancer treatment.

That said, On-Q-ity may have been ahead of its time. Early-stage biotech investor Camille Samuels told me she’s paying close attention to the new tools that monitor cancer as it progresses. And Guardant’s biomedical researchers are not the only ones developing an alternative to biopsies. According to a March report in Nature, a slew of labs hope to chart the course of cancer by monitoring cells that slough off of the tumor and enter the bloodstream.

Eltoukhy is confident that Guardant is a step ahead of its rivals. He said the Guardant360 tool can capture higher-resolution snapshots of the tumor fragments “well over a hundredfold.” He declined to disclose the specifics on the technology.

Instead, he pointed to promising results from recent clinical studies for patients with the top five cancers: breast, lung, colorectal, skin, and prostate. Combined, these five types account for half of all cancer patients.

Feedback from the medical community

The findings from these studies were presented earlier this week to 3,000 physicians at the Molecular Medicine Tri-Conference in San Francisco. Guardant adviser Dr. Dave Hoon is also a director of oncology at the John Wayne Cancer Institute in Santa Monica, Calif. Hoon said the test can detect cancer-specific genetic changes in nearly 90 percent of patients, regardless of the disease type or stage.

“We have long known about the potential to monitor patients for emergent tumor mutations through blood analysis and how critical this could be to improving outcomes for cancer patients,” said Hoon.

Richard Bambury, the chief medical officer of Portable Medical Technology and an oncologist, seemed optimistic about the cancer monitoring space. (Bambury has no financial relationship with Guardant.) Doctors are increasingly relying on genetic information to make treatment decisions, he pointed out. If Guardant can deliver on its promise, he expects that “the real-time information regarding tumor genetics will be of huge value to practicing physicians.”

Some biotech experts are less gung ho about the company’s prospects and point to significant hurdles along the way. For example, what’s to stop Guardant from jacking up its prices to the point where only wealthy or well-insured can afford it? Will insurance providers agree to reimburse patients for this test? Will the FDA get involved? (The agency recently cracked down on genetics firm 23andMe, raising concerns for many genetic-testing companies.)

Ted Driscoll, a health care and genetics investor at Claremont Creek Ventures, and who is not connected with Guardant, expressed a more fundamental concern about the technology. Driscoll believes we do need better diagnostic tests for cancer. However, he’s not convinced that a blood test is the best approach.

“Typically, cancer shows in the blood after it is already somewhat developed,” Driscoll wrote to me. “In my opinion, the most important problem in cancer is early detection, before it has become easily visible in blood.”

In other words, once fragments of the cancerous tumor can be detected in a patient’s blood, it may already be too late. It’s typically a metastatic cancer, meaning it has already spread from the primary site to other parts of the body.

Plans for the future

Guardant has been evaluating its test for about a year and a half in select cancer centers in the U.S. The Centers for Medicare and Medicaid Services recently certified the tool under federal rules governing laboratory diagnostics.

In the coming years, Guardant’s chief financial officer Michael Wiley will roll out plans to reimburse patients who take the cancer test. Wiley is pinning his hopes on a strong demand for the tool from oncologists.

“The physicians will drive reimbursement when they start demanding the test,” he said.

Eltoukhy will focus on gathering data from patients to prove that Guardant can significantly improve patient outcomes in the long-term. “The holy grail for us is to refine our test so that it works for the majority of cancers,” he said, but admitted that the team will need to conduct “rigorous studies” over time. Guardant executives expect that thousands of patients will pay for the test this year, up from several hundred.

According to Eltoukhy, the first patients are already showing strong signs of recovery. Before concluding our interview, he shared a story about a 62-year-old male patient with melanoma. This patient received three different forms of treatment, but nothing worked, and a handful of metastases formed around his liver. Guardant’s test found a mutation that the biopsy did not, and his physician prescribed a new course of treatment.

“His tumors have shrunk 90 percent,” said Eltoukhy. “It’s amazing. I believe the sky is the limit with this technology.”