At Highlight Therapeutics, we continue taking firm steps to transform research into real therapeutic solutions. On this occasion, we are sharing the positive preliminary results from the phase IIb clinical study of BO-112, presented at the 36th Annual Meeting of the Society for Immunotherapy of Cancer (SITC), held in Washington, D.C.
The study evaluates the combination of BO-112, our double-stranded RNA agonist, with pembrolizumab, one of the most widely used PD-1 inhibitors in immuno-oncology, in patients with advanced melanoma whose disease had progressed after first-line treatment with anti-PD-1 therapies.
A challenge in the treatment of advanced melanoma
Advanced melanoma remains one of the major challenges in oncology.
Although immunotherapies based on PD-1 inhibitors have transformed the prognosis of many patients, only a fraction respond initially to treatment, and many eventually develop resistance over time.
This leaves an important unmet medical need: finding therapies capable of reactivating the immune system so it can once again recognize and attack the tumor.
Results that open a new therapeutic pathway
The results presented at SITC suggest that BO-112 could offer a second therapeutic opportunity for these resistant patients.
With a median follow-up of three months, the study achieved its primary objective, showing:
- an objective response rate (ORR) of 27%
- 8% complete responses
- a disease control rate (DCR) of 65%, significantly higher than the current second-line standard (around 8–13%)
In patients with mucosal melanoma, a particularly difficult-to-treat form of the disease, an ORR of 66% and a DCR of 100% were observed. In addition, the treatment showed a favorable and manageable safety profile, with no discontinuations due to adverse events.
BO-112: resensitizing tumors to anti-PD-1 therapy
BO-112 acts as a potent activator of the immune system. By simulating a viral infection, it stimulates the immune response and “resensitizes” tumors to anti-PD-1 therapy, improving antigen presentation and promoting T-cell infiltration within the tumor.
In this way, the body regains its ability to recognize and eliminate cancer cells, even in cases where tumors had previously stopped responding to immunotherapy.
As explained by our Executive Chairman, Dr. Carlos Paya: “These are potentially transformative results showing that BO-112 can rescue melanoma patients who had failed first-line immunotherapy. Anti-PD-1 immunotherapy has revolutionized cancer treatment, but only a fraction of patients initially respond and many ultimately progress. These early results demonstrate that BO-112, combined with a PD-1 inhibitor, may restore responses in approximately two-thirds of resistant patients.”
Our CEO, Marisol Quintero, added: “The preliminary objective response rate of 27%, including 8% complete responses, already exceeds the current standard. In addition, the excellent safety profile and signals of efficacy encourage us to continue moving forward. Our next step will be to advance toward a pivotal phase III study in melanoma and to explore new combinations in other tumor types.”
Another step toward new therapeutic options
The study, conducted together with Merck (MSD outside the United States and Canada), included 42 patients with cutaneous, mucosal, and acral melanoma at centers in France and Spain.
Among them were patients with elevated LDH levels, a group often excluded from other trials and typically associated with poorer therapeutic responses.
These early and highly encouraging results lay the foundation for the development of new studies in multiple solid tumors resistant to immunotherapy, both as monotherapy and in combination with PD-1 inhibitors.
Looking ahead
Following the presentation of these preliminary results at SITC, Highlight Therapeutics continues planning a pivotal phase III trial in second-line melanoma, while also evaluating new strategic partnerships to expand the potential of BO-112 across other cancer types.
In this way, we continue moving forward in the direction that has guided us from the beginning: leveraging science and collaboration to offer new and meaningful treatment options for patients who currently have none.