SAN DIEGO: Nearly a third of patients with advanced liver cancer who received a personalized vaccine developed by Geneos Therapeutics along with an immunotherapy drug in a small, early trial saw their tumors shrink, US researchers reported.
According to researchers presenting their findings at the American Association for Cancer Research conference in San Diego and published in Nature Medicine, nearly one-third of patients who received the personalized vaccine alongside Merck’s immunotherapy drug Keytruda experienced tumor shrinkage. This response rate was approximately double the typical response seen with immunotherapy alone.
The study focused on the development of vaccines based on neoantigens, which are new mutations unique to an individual patient’s tumor. By training the immune system to recognize and target these specific mutations, the vaccine aims to enhance the body’s ability to combat hard-to-treat cancers while minimizing damage to healthy tissue.
Dr. Mark Yarchoan of Johns Hopkins Kimmel Cancer Center, the study’s lead researcher, explained that the vaccine educates the immune system to recognize antigens it may have previously ignored, particularly in cancers with fewer mutations like liver cancer.
The trial involved 36 patients with hepatocellular carcinoma, the most common form of liver cancer. Participants received custom-made vaccines alongside Keytruda, the standard immunotherapy treatment for liver cancer.
Results showed that nearly 30.1% of patients treated with the combination therapy experienced tumor shrinkage, with some achieving complete responses. This efficacy surpasses the typical response rate of 12% to 18% seen in patients treated with immunotherapy alone.
The Geneos treatment, unlike many mRNA-based vaccine candidates, utilizes a DNA vaccine approach, delivering the genetic code of mutated proteins into cells using a small electrical impulse. Each vaccine can target up to 40 mutated genes.
The study also reported mild injection site reactions as the most common adverse effect, with no serious adverse events reported.
