Celldex Therapeutics, Inc. (NASDAQ:CLDX) has announced positive results of the Phase 2 clinical trials that the firm has been carrying out in patients suffering from malignant melanoma.

The phase 2 trials evaluated the immune responses in patients after they were treated with a cocktail of the CDX‑301 and CDX‑1401 drugs. The trials were conducted by the Cancer Immunotherapy Trials Network (CITN) which was sanctioned by Cooperative Research and Development Agreement (CRADA)between the National Cancer Institute and the Cancer Therapy Evaluation Program.

CDX‑301 is a powerful hematopoietic cytokine that is also known as recombinant human Flt3 ligand. It increases the hematopoietic stem cells and the dendritic cells in a unique manner. CDX‑1401 on the other hand is an antibody fusion protein that is designed for immunotherapy. Celldex presented the results of the clinical trials at the 2016 American Society of Clinical Oncology (ASCO) held in Chicago. The Society holds the event every year.

The trials involved 60 patients that were between stages two and stage four of the cancer, and they were divided into two groups. The patients were grouped to determine whether the response of the patients treated with CDX-1401 could be amplified by first treating the subjects with CDX-301 to increase the number of dendritic cells. The latter are vital towards provoking immune responses. The primary objective of the study was to analyze the immune end points as well as safety and patients were therefore not selected for NY‑ESO‑1 manifestation.

The trials lasted four months for both groups where they received poly-ICLC (Hiltonol®) and CDX‑1401. One group was treated with CDX‑301 during the first two cycles while the other group of patients did not receive the regiment for the initial two cycles. The trial subjects responded well to the drug cocktail and no side effects requiring discontinuation were reported during the trial period.

Researchers reported that the NY-ESO-1 cells manifested earlier and were significantly more in the first group compare to the second group. Cellex vice president and Chief Medical Officer stated that the trials confirmed that a combination of the treatments was effective towards enhancing immune responses to malignant melanoma.