CHICAGO (TheStreet) -- Four clinical trials involving the checkpoint inhibitors from Merck MRK and Bristol-Myers Squibb (BMY) are showing promising signs of efficacy in a wide range of solid tumors, according to results unveiled for the first time Friday at the start of the American Society of Clinical Oncology (ASCO) annual meeting.
The class of cancer immunotherapy drugs which target the protein PD-1 has already dramatically improved treatment options, including prolonged survival, for patients with skin cancer. Now, the same drugs are proving to be effective against advanced liver, head and neck, lung and colon cancers.
In some cases, doctors are able to look at the genetic signature of the tumors to determine in advance which patients may benefit most from treatment with checkpoint inhibitors.
The ASCO annual meeting doesn't usually get rolling until Saturday morning. This year is different. ASCO scheduled a media briefing Friday afternoon so researchers could discuss data on four studies involving checkpoint inhibitors. The highlights:
- Merck's Keytruda demonstrated a 62% tumor shrinkage in patients with advanced colon cancer containing a newly discovered genetic biomarker.
- The tumor response rate to Bristol's Opdivo in patients with advanced liver cancer was 19%. The overall survival rate at 12 months was 62%. While early, the results suggest Opdivo may have a role to play in the treatment of the disease where only a single targeted drug has proven effective.
- In a study of patients with head and neck cancer, Merck's Keytruda demonstrated a tumor response rate of 25%, or more than double the response typically seen with Eli Lilly's Erbitux.
- In the only randomized study discussed Friday enrolling patients with advanced, non-squamous, non-small cell lung cancer (the most common form of lung cancer) treatment with Bristol's Opdivo led to a 27% reduction in the risk of death compared to a placebo. Patients with tumors expressing high levels of the protein PD-1 lived even longer.
Roche's (RHHBY) Avastin is currently the most broadly used targeted cancer treatment, with approvals in six different solid tumors. Avastin kills tumors by shutting down their blood supply. Cancer immunotherapies work differently by stimulating the patient's own immune system to identify and kill cancer. More specifically, the checkpoint inhibitors work by blocking a protein used by cancer cells to hide from the immune system.