Nobel-Winning Pill Hunting Down Kidney Cancer’s Invisible Sleeper Cells
For many kidney cancer survivors, the most frightening part begins when the surgeon declares, "We got it all." The scans are clear, and the stitches have healed, but the dread remains that invisible cancer cells may still be hidden in the body. A new international study reveals that this nervous waiting period no longer has to be passive. 

A large global study conducted by Dana-Farber Cancer Institute researchers found that an aggressive combo treatment administered after surgery can greatly lower the probability of kidney cancer returning in individuals at high risk. The findings were presented at the American Society of Clinical Oncology Genitourinary Cancers Symposium, which took place in San Francisco recently. 

The study focused on clear cell renal cell carcinoma (ccRCC), the most frequent kind of kidney cancer. Surgery can remove the apparent tumour, but doctors know that microscopic "sleeper cells" are frequently left behind. These cells are too small to detect, yet they can reactivate the disease months or even years later. Until now, the typical post-surgery treatment has been pembrolizumab, an immunotherapy medicine that increases the body's natural defensive system. While effective, it nevertheless fails approximately one in every five patients. 

"That gap is not acceptable anymore," said Dr Toni Choueiri, head of Dana-Farber's Lank Center for Genitourinary Cancer and main investigator of the phase 3 LITESPARK-022 trial. "Because microscopic cancer cells might go unnoticed, a large percentage of patients with high-risk kidney cancer relapse within five years of surgery. " We need new therapies that can work together to better prevent cancer from returning." 

The new strategy employs what doctors refer to as a scientific "one-two punch". The first medication, pembrolizumab, acts like removing blindfolds from the immune system, allowing immune cells to detect and destroy cancer. The second medicine, belzutifan, is a daily pill that targets the cancer's internal fuel source. Belzutifan inhibits HIF-2α, a protein found in excess in kidney cancer cells that promotes their growth and survival. In 2019, Dr William G. Kaelin Jr, a Dana-Farber scientist, received the Nobel Prize in Medicine for his work on this pathway. 

LITESPARK-022 included 1,841 patients from several countries. All had undergone surgery and had no visible cancer but were at high risk of relapse. Patients were randomly allocated to receive either pembrolizumab with belzutifan or a placebo. 

After a median follow-up of slightly over 28 months, the findings were stunning. The combo treatment decreased the risk of cancer recurrence by 28%. The two-drug regimen resulted in around 81% of patients remaining cancer-free, compared to 74% with the current standard treatment. Side effects were consistent with what physicians already knew about the two medications. 

"People at high risk of ccRCC coming back after surgery may have a new option to reduce that risk," Dr Choueiri added. "Belzutifan, in combination with pembrolizumab, reduces the chance of recurrence compared with pembrolizumab alone." 

While researchers are still determining if the treatment improves overall survival, experts believe the message is clear. Post-surgery cancer care has progressed beyond waiting and observing. The age of deliberately seeking out hidden cancer cells has begun.