Drug Combo May Boost Survival for Tough-to-Treat Liver Cancers
A new drug combination for advanced liver cancer can extend people's lives substantially more than the long-standing drug of choice, new study findings confirm.
The treatment involves two drugs approved to fight various cancers: bevacizumab (Avastin) and atezolizumab (Tecentriq). Avastin, an intravenous (IV) drug, starves tumors by preventing new blood vessel growth.
Tecentriq, also given by IV, is an immune checkpoint inhibitor. Those newer, "immunotherapy" drugs help the immune system seek and destroy tumors.
In a trial published last year, researchers found that for patients with advanced liver cancer, the combination worked better than a drug that had been the standard of care for 13 years.
It lengthened patients' lives to a greater degree and bought them more time before their cancer progressed.
At the time, experts hailed the trial as a "landmark," and an approval by the U.S. Food and Drug Administration quickly followed.
The new findings offer a longer-term look at the study patients, showing what the "true" median survival is, said lead researcher Dr. Richard Finn.
Median survival refers to the point where half of patients given a treatment are still alive.
Finn's team found that median survival among Avastin/Tecentriq patients was just over 19 months, compared with 13 months among patients given a drug called sorafenib (Nexavar).
Nexavar, which was approved for liver cancer in 2007, had been the standard first choice for patients like those in the study. All had hepatocellular carcinoma (HCC) -- the most common type of cancer originating in the liver -- and in all cases, the disease had either spread or could not be treated with surgery.
Until this trial, "we'd never been able to improve upon sorafenib in these patients," said Finn, a professor at the University of California, Los Angeles Geffen School of Medicine.
Since the FDA approval, Avastin/Tecentriq has become the new standard of care, said Dr. Augusto Villanueva, a liver cancer specialist who was not involved in the trial.
So the updated results do not change care, Villanueva said, but they give doctors and patients new information.
"This is a breakthrough in the management of HCC," said Villanueva, an assistant professor at Mount Sinai's Icahn School of Medicine, in New York City.
He chaired the session where the data were reported Saturday, at an online meeting of the European Association for the Study of the Liver.
Beyond lengthening patients' lives, Villanueva said, the drug combo can also help them live better, versus sorafenib: Trial patients on the new regimen gave higher ratings to their quality of life.
Villanueva said that's likely because the side effects are less debilitating than sorafenib's, which include appetite loss, diarrhea and nausea.
Avastin/Tecentriq can cause fatigue or high blood pressure. But the main concern, Finn said, is that Avastin carries a bleeding risk.
Patients with varices -- swollen veins in the throat or stomach -- were excluded from the trial because they face an increased bleeding risk, Villanueva pointed out. For them, sorafenib might be a better option.
Finn said patients should get an upper endoscopy to find any varices before starting the combination therapy.
There's also the issue of cost, as the drugs carry a hefty price tag. Patients with insurance can generally get it covered, Finn said, since it's FDA-approved for HCC.
The trial, funded by the drugs' maker Genentech/Roche, included 500 patients with advanced, inoperable HCC. They were randomly assigned to either sorafenib, taken by mouth, or Avastin/Tecentriq, given by IV every three weeks.
After 18 months, 52% of patients on the combination were still alive, versus 40% of sorafenib patients. In addition, Finn said, 30% of combination patients were showing a response -- meaning their tumors shrank -- while in 8%, the tumors were no longer detectable.
It's not clear yet how long those responses could last. Also, the data have not yet been peer-reviewed for publication in a medical journal.
Both Finn and Villanueva said it's an encouraging time in liver cancer treatment, with additional drug combinations currently in trials.
Unfortunately, HCC is most often diagnosed at an advanced stage, Villanueva said.
It typically develops after long-standing cirrhosis, or scarring of the liver. Cirrhosis patients, Villanueva said, can be screened for the cancer with ultrasound every six months -- but many people with the condition don't know it.
The American Cancer Society has more on liver cancer.
SOURCES: Richard Finn, MD, professor, medicine, Geffen School of Medicine, University of California, Los Angeles; Augusto Villanueva, MD, PhD, assistant professor, medicine, Icahn School of Medicine at Mount Sinai, New York City; Feb. 6, 2021 presentation, Digital Liver Cancer Summit, European Association for the Study of the Liver