Sesen Bio Inc. said the initial three-month results from an ongoing phase 3 trial of its medicine Vicinium, to treat a certain type of bladder cancer, were "encouraging."
Cambridge, Mass.-based Sesen said it is evaluating Vicinium to treat patients with high-grade non-muscle-invasive bladder cancer who have been previously treated with the bacillus Calmette-Guérin, or BCG, vaccine.
The trial is being carried out in three groups of patients.
The first group consists of 87 patients with carcinoma in situ — cancer found on the inner lining of the bladder that has not spread into the muscle or other tissue — with or without papillary disease whose cancer recurred within six months of their last course of BCG treatment. Out of the 72 evaluable patients in the first group, 39% had no detectable cancer remaining after treatment.
Sesen said the second group consisted of six patients with carcinoma in situ with or without papillary disease whose cancer recurred after six months, but before 11 months, after their last course of BCG therapy. Out of the 5 evaluable patients in this group, 80% showed no detectable cancer remaining after treatment.
The third group comprised 40 patients, with 34 evaluable patients who had papillary disease without carcinoma in situ and whose cancer recurred within six months of their last course of BCG treatment. These patients were not included in the primary goal assessment, but treatment with Vicinium demonstrated a 68% recurrence-free rate at three months.