Wednesday, June 21, 2017

A rare opportunity

I presented the Alliance's poster at AACR.
By Suzie Siegel
Someday all cancers will be rare.

So says Rick Pazdur, MD, director of the FDA's Oncology Center of Excellence. As physicians and scientists learn more about genetics, they are breaking down cancers into smaller and smaller categories that may respond to specific drugs.

Dr. Pazdur spoke this spring to a group of advocates who won scholarships to attend the annual meeting of the American Association for Cancer Research (AACR) in Washington, D.C. I was the only sarcoma advocate in the Scientist↔Survivor Program, but that’s not surprising, considering sarcoma represents only 1 percent of adult cancer cases.

Carcinomas – what most people call cancer – are named for where they occur in the body, such as breast cancer or colon cancer. Sarcomas are named for the cells in which they are thought to come from. But sarcoma subtypes are now being divided still further.

Histological classifications are now supplemented by molecular subclassifications, which strongly influence prognosis and guide treatment decisions. More than ever, sarcomas are regarded as a complex and fragmented collection of uncommon entities, altogether rare and often extremely rare,” Jean-Yves Blay, MD, PhD, director of the Centre Léon Bérard in Lyon, France, wrote in Future Medicine. An example is liposarcoma, which arises in fat cells. It has been separated into well-differentiated, dedifferentiated, myxoid and pleomorphic liposarcoma.

Results of the largest study of sarcoma genetics were published last year, with more data coming from the Garvan Institute in Sydney, Australia. It leads the International Sarcoma Kindred Study, which is looking at the genetics of more than 1,000 people.

We also await more results from The Cancer Genome Atlas, a project of the National Cancer Institute in Bethesda, Md. Anna Barker, PhD, chair of the AACR survivor program, helped conceive and develop TCGA when she was deputy director of the NCI.  She is now co-director of Complex Adaptive Systems and director of the National Biomarker Development Alliance at Arizona State University in Tempe.

At the recent American Society of Clinical Oncology (ASCO) meeting in Chicago, a study was presented on an experimental drug named larotrectinib that targets TRK gene fusions. Some sarcoma patients should benefit.
The clinical trial was done basket-style, enrolling patients with different types of cancer. Getting enough sarcoma patients for meaningful research takes time; I think we benefit from basket studies that include people with other cancers. In a sense, many clinical trials in sarcoma have been basket studies because they enrolled people with different sarcoma subtypes.

Dr. Rick Pazdur
Companies need clinical trials to get their drugs approved. But Dr. Pazdur believes: “Clinical trials are here to serve the patient. Patients are not here to serve clinical trials.”

The FDA used to require companies prove that their drugs would help patients live longer. This can be hard to measure, in part because some patients have very advanced cancer by the time they go on a clinical trial. The FDA now approves some drugs if patients can go longer without their cancer progressing than they could on a standard drug. This change allowed trabectedin (Yondelis) to be approved for liposarcoma and leiomyosarcoma, for example.

I hope the FDA will use similar criteria to approve aldoxorubicin, which I wrote about in 2014.

Dr. Pazdur wants to expand access to clinical trials for patients who might not qualify because of how advanced their cancer is. He has suggested other innovations here and here. But he said he can do only so much because drug companies pay for almost all clinical trials. They control eligibility requirements, except where safety and a few other issues are concerned.

His desire to expand access stops at the “Right to Try” laws, which allow people with terminal illnesses to take unapproved drugs outside of trials. He said these laws directly contradict the Food, Drug and Cosmetic Act, which requires the FDA to oversee drug safety.

Trials are much more likely to be done in North America, Europe and Asia than in South America or Africa. That needs to be rectified, Dr. Pazdur said, to see if different populations respond differently to new drugs.

The AACR meeting drew 22,850 people from 60 countries, said CEO Margaret Foti, MD, PhD. She has spent 35 years with the organization and sees a much greater emphasis on cancer prevention.

Sarcoma researchers have been active in the AACR since its founding 110 years ago. The founders included Dr. William Coley, considered the father of immunotherapy, and Dr. James Ewing,  AACR’s first president. Dr. Ewing discovered the bone sarcoma that bears his name.  

George Demetri, MD, director of the Center for Sarcoma and Bone Oncology at Dana-Farber Cancer Institute in Boston, is on AACR’s current board. He decries cuts in federal funding for cancer research. “I do not believe for one second this is what the public wants.” 

Dr. Drew Pardoll
Recent gains in immunotherapy show the importance of investing in science even when the payoff isn’t immediate, said Drew Pardoll, MD, PhD, director of the Bloomberg-Kimmel Institute for Cancer Immunotherapy at Johns Hopkins University in Baltimore. He has been working in the field more than 30 years.

“Cancer genetics has married immunotherapy,” said Dr. Pardoll, discussing how pembrolizumab (Keytruda) works in people with DNA mismatch-repair deficiency (MMR), which causes microsatellite instability (MSI).

After approving Keytruda last month for this genetic defect, the FDA noted: “This is the first time the agency has approved a cancer treatment based on a common biomarker.”

Stefanie Joho
The evidence for supporting immunotherapy stood by Dr. Pardoll’s side: Stefanie Joho of Philadelphia, whose colon cancer disappeared after she joined a clinical trial for Keytruda. She recalled when she was inoperable: “The doctors say there’s nothing they can do. There’s no more hope. I’m ready to give up. I basically feel dead.”

Then her sister found the study at Hopkins. “The public has a misconception of clinical trials. I did, too. I was under the impression they were the last resort. I’d just be a guinea pig. But right now, you could be getting the most precise treatment for your specific kind of cancer.

“How do you go through an experience like this and not want to advocate, not just for other patients, but for cancer research?”

Suzie Siegel, a 15-year survivor of leiomyosarcoma, is a former board member of the Sarcoma Alliance.