Study shows: Vaccine combination offers little progress in melanoma

Study shows: Vaccine combination offers little progress in melanoma

Today at the ESMO Annual Meeting 2025, the IOB-013 study was presented, looking at the combination of the vaccine IO102-IO103 and pembrolizumab (Keytruda) in untreated advanced melanoma. The results show that the combination does not provide a significant increase in median progression-free survival (PFS) compared to pembrolizumab alone, although some positive aspects were observed. The median PFS was 19.4 months for the combination compared to 11.0 months for pembrolizumab alone, yielding a hazard ratio (HR) of 0.77 (P = 0.0558), just below the significance threshold of 0.045, as Medscape reported.

The study included 407 patients enrolled at approximately 100 sites worldwide. The median age of the patients was 71 years in the combination group and 69 years in the pembrolizumab group. Subgroup analysis revealed significant improvements in BRAF V600-mutated patients (HR 0.60), as well as in PD-L1-negative patients (HR 0.54) and those with elevated LDH levels (HR 0.60). Specifically, the median PFS for PD-L1-negative tumors was 16.6 months in the combination vs. 3.0 months in the pembrolizumab group. These results were additionally confirmed by Cancer Network highlighted.

Objective response rate and reactions

The objective response rate was 44.8% in the combination group and 41.2% in the pembrolizumab group. The duration of the response was also longer in patients who received the vaccine, with a hazard ratio of 0.44 for the duration of the confirmed objective response. The most common adverse events included itching (21.0%), fatigue (20.0%), injection site swelling (15.5%), and diarrhea (14.5%).

The study was funded by IO Biotech ApS and Merck Sharp & Dohme LLC, and Jessica C. Hassel, MD, and Ines Pires da Silva, MD, PhD, were instrumental in its implementation. The primary endpoints included PFS, assessed by a blinded independent central review, and additional secondary endpoints such as overall survival and response rate, assessed by both Medscape as well as from Cancer Network were highlighted.

Treatment with pembrolizumab

Pembrolizumab is a new anti-PD-1 antibody that plays an important role in the immunotherapy of metastatic malignant melanoma. According to reports from the medical journal Pembrolizumab shows high response rates and long duration of response in various studies. A few years ago, the choice of systemic treatment options for metastatic melanoma was very limited, with a median overall survival of only six to nine months.

Advances in cancer research, including the development of kinase inhibitors and novel immunotherapies, have already significantly improved treatment outcomes. Pembrolizumab has been shown to be well tolerated and less toxic compared to other immune checkpoint inhibitors. Ongoing research and combination therapies provide hope for improved treatment for patients with advanced melanoma.