On Wednesday December 10th, 2014 Merck (MRK) reported that it achieved early positive results using KEYTRUDA against patients that had triple-negative breast cancer. Triple-negative breast cancer is an advanced form of breast cancer that is more difficult to treat compared to other forms of breast cancer. This is because Triple-negative breast cancer doesn't express genes known as: HER2/neu, estrogen receptor — ER — and progestrone receptor –PR. Since Triple-negative breast cancer doesn't contain these genes there are no treatment options other than combining known chemotherapies to treat it like paclitaxel and docetaxel. This combination of therapies makes treatment options for these patients very toxic for their bodies. Even then, the efficacy of these combination drugs are far from ideal.
Merck on the other hand has developed an immunotherapy drug known as KEYTRUDA which is a monoclonal antibody. This monoclonal antibody binds to and activates PD-1 in the cells of the body. This means that once the monoclonal antibody binds to the targeted cancer cell it unleashes the body's own immune system — T-cells — to target and destroy breast cancer cells. PD-1 is becoming a huge deal in the biotech space being combined with other immunotherapy drugs in hope of improving survival outcomes in cancerous patients with less side effects.
The Results of the phase 1 trial showed that 5 of the 27 patients had a response when taking 10 mg/kg of KEYTRUDA every 2 weeks. Specifically, these patients achieved an 18.5% overall response rate. In other words, these patients had some type of tumor reduction over the course of treatment with KEYTRUDA. With these great initial results, Merck is planning to start a phase 2 trial using KEYTRUDA against Triple-negative breast cancer in the first half of 2015. Merck has been doing quite well with its PD-1 therapy and with these type of results the company can go on to advance KEYTRUDA in other forms of cancers. We believe that Merck is well positioned to achieve long term success using KEYTRUDA and will appreciate in share price over the coming months.
