The most full-scale attack on breast cancer is currently underway. The tried and true treatment mechanisms, via hormone therapy, chemotherapy, and radiation are still valuable options for prolonging life. But these blunt-force attacks are often not enough to keep cancer at bay, and can also lead to the collateral damage of healthy cells. More targeted therapies have been the holy grail of innovators for decades. In the past few years, many other cancers have seen the benefits of these therapies, including leukemia, prostate, and ovarian cancers. 2018 marks the year that breast cancer - a disease that kills over 40,000 American women per year – gets its turn.
For breast cancer patients that are BRCA1 or BRCA2 positive, there is new hope for a targeted therapy that is already seeing success in the ovarian cancer market. While first-line cancer DNA-creating proteins are often dismantled by chemo, BRCA genes have a backup up plan to repair that DNA, carried out by poly-ADP-ribose polymerases (PARPs). In 2017, results from a Phase III clinical trials indicated breast cancer patients treated with a PARP inhibitor alone received 7 months of progression-free-survival as compared with 4 months for patients who received only chemotherapy. This difference, while limited thus far, is sparking the imaginations of researchers, companies, and oncologists to take PARP inhibitors to new levels.
HER2-positive breast cancer is named for an overabundant protein that promotes the growth of cancer cells. This overabundance, which impacts 20% of breast cancer patients, is often resistant to the traditional treatment methods. These targeted therapies, however, are demonstrating positive initial results, especially in combination with chemotherapy. One study showed long term remissions in a handful of patients who had undergone the combination therapy.
Patients with ER-Positive/HER2-negative breast cancer also have reason to be hopeful. In 2018, there will be three CDK4/6 inhibitors on the market which interfere with a cell’s process to synthesize DNA and prepare for its division. Experts believe the cumulative results from a variety of studies are pointing to an increasing survival rate, and perhaps the eventual end of chemotherapy for a significant population of breast cancer patients.
Where Are They Now
In January 2018, the first PARP inhibitor to treat breast cancer was FDA approved. The brain child of two large pharma companies, this PARP inhibitor won approval to treat BRCA-mutated disease based on impressive clinical trial data. In October of 2018, the FDA approved a second PARP inhibitor to treat breast cancer. These two large approvals significantly shape the targeted therapy market. CDK4/6 inhibitors, our other targeted therapy classification covered by this nomination, have also made great strides. To date, there are a handful of CDK4/6 inhibitors approved for use in breast cancer, with the most recent approval in July of 2018.