- In a notable failure, Celldex on Monday halted its gliobastoma phase 3 study after its cancer vaccine Rintega appeared unlikely to reach the study's primary endpoint.
- Although Rintega performed consistent with prior studies, the control group "significantly outperformed" expectations of overall survival rates. Celldex will continue to provide the drug on a compassionate use basis, but will be discontinuing the study.
- Celldex's stock's value promptly halved in early Monday trading as investors soured on the biotech.
Rintega was designed to stimulate an immune response against a particular tumor mutation known as EGFRvIII. By boosting the body's response to the brain cancer, Rintega could act as a "vaccine" and teach the immune system to target and kill the cancer.
However, interim analysis by an independent data board found patients on Rintega performed worse as measured by overall survival times. Patients treated with the drug showed an overall survival of 20.4 months, comparing unfavorably to the control group's 21.1 months.
"We are extremely disappointed for patients that the ACT IV study was not successful...While this is certainly not the desired outcome, we remain steadfast believers in the power of immunotherapy to transform the future of cancer treatment," said co-founder and Celledex CEO Anthony Marucci.
Gliobastoma is particularly difficult to treat, with its more aggressive form typically leading to death within about 15 months, according to the American Brain Tumor Association.
Rintega was Celldex's primary drug in development, although it has seven clinical trials currently ongoing across five different products. The Hampton, NJ-based company ended 2015 with roughly $290 million in cash on hand but registered a net loss of $127 million on the year.