Evaluating a new drug combination with pertuzumab and subcutaneous trastuzumab

This study investigated if a combination including pertuzumab (Perjeta) and subcutaneous trastuzumab (Herceptin Hylecta) is safe in breast cancer (BC). 

They found that this combination was well tolerated in patients with HER2-positive BC.

Breast cancer (BC) is the most common cancer in women. Some BC tumors are classified based on certain genes or proteins. One common type of BC is human epidermal growth receptor 2-positive (HER2+). HER2+ BC can be difficult to treat. 

One of the most effective treatments for HER2+ BC is trastuzumab (Herceptin). Pertuzumab (P) is another drug that targets HER2+ cells. It targets a different location on the cancer cell. Using pertuzumab and trastuzumab improves the overall response (OR) to treatment. These drugs are usually administered intravenously. They can also be combined with a taxane drug (TD). TDs are a chemotherapy used to treat many cancers. A new formulation of trastuzumab (T) has been developed for subcutaneous (sc; into the deep layer of skin) administration. It is unclear if combining sc trastuzumab (scT) and P is safe in patients with HER2+ BC.

This study included 50 patients with advanced HER2+ BC. All patients were treated with a combination of P, scT and a taxane drug. TDs included docetaxel (Taxotere), paclitaxel (Taxol), and nab-paclitaxel (Abraxane). Safety was the primary outcome measure. Side effects were recorded. OR and progression-free survival (PFS; survival without cancer growing or spreading) were also determined.

The most common side effects included diarrhea, fatigue, rash, and nausea. Peripheral neuropathy (wasting of nerves in the body) was also reported. 6 patients withdrew from the trial due to serious side effects. Severe side effects were due to heart complications including heart failure and hypertension.

The OR was 73.3%. The average PFS was 17 months.

The authors concluded that pertuzumab and subcutaneous trastuzumab were well tolerated in patients with HER2-positive BC.

Many of the side effects reported are common with most cancer treatments. The number of patients in this trial was small. More investigation is needed. 

This study was sponsored by Roche, the manufacturer of subcutaneous trastuzumab.