ASCO spokespersons at the press briefing lauded the results with larotrectinib and called for broader testing for tropomyosin receptor kinase fusions.
The data for larotrectinib “bring us into a new era where treatment is truly based on mutation, not location,” said Sumanta Kumar Pal, MD, a medical oncologist at City of Hope, Duarte, California. “When I was in training … it would have been a pipe dream to think that we could have treated cancers independent of their site of origin.… With the data presented by Dr. Hyman for larotrectinib, we may now be poised to treat many cancers in a manner that is agnostic of their site of origin and that is instead based on molecular criteria.”
He added, “The real challenge moving ahead is for oncologists to determine whether larotrectinib would sit within existing treatment algorithms. For rare cancers where there is no established standard of care, such as salivary gland tumors, for instance, there may be a call to screen for relevant mutations right away. In other diseases, such as colon cancer and prostate cancer, we’ll have to sit down and determine how larotrectinib sits against existing standards such as chemotherapy or hormone -therapy, respectively. These elements will all play into establishing at what juncture molecular testing is offered to determine candidacy for larotrectinib.”
Expanding the Search for Mutations
John V. Heymach, MD, PhD, Professor of Medicine and Chair of Thoracic/Head and Neck Medical Oncology at The University of Texas MD Anderson Cancer Center, Houston, said it is important to find these alterations. “You only find what you look for, and to date, we look for things we know are there, such as certain mutations in lung cancer. Tropomyosin receptor kinase fusions have not been commonly captured by most assays currently being done, so it’s easy to underestimate how common they may be,” he said.
“This study shows it’s important to look for tropomyosin receptor kinase fusions because we have a treatment that can work for these patients. Patients with this alteration who get this drug have dramatic benefits. This argues to the importance of expanding what we are looking for,” he said. ■
DISCLOSURE: Drs. Pal and Heymach reported no conflicts of interest.
Larotrectinib, an oral inhibitor of tropomyosin receptor kinase, showed “striking” activity in adult and pediatric patients with the genetic aberrations known as tropomyosin receptor kinase (TRK) fusion, researchers reported at the 2017 ASCO Annual Meeting.1 Of 55 patients treated with...