Maintenance therapy after bevacizumab and chemotherapy treatment in advanced non–small cell lung cancer patients

This phase III trial compared two maintenance therapy strategies in the treatment of advanced non–small cell lung cancer (NSCLC) patients. The effect of bevacizumab (Avastin) was compared to that of combined bevacizumab and pemetrexed (Alimta) treatment.

Chemotherapy is one of the main strategies applied in the treatment of advanced NSCLC. Chemotherapeutic drugs, such as pemetrexed or cisplatin, inhibit the division and growth of cancer cells, thus delaying the progression of the disease.

Bevacizumab is another commonly used treatment in lung cancer patients. Bevacizumab inhibits the formation of new blood vessels, which are necessary for cancer spread. Often, a combination of chemothetapy and bevacizumab is used.

Recent studies have shown that maintenance therapy (continuing drug treatment in low doses for an extended period after the initial treatment has finished) is associated with improved progression free survival (PFS; the amount of time until the disease worsens or progresses after treatment). However, few studies have compared different agents and combinations used in maintenance therapy.

This trial included 373 patients diagnosed with NSCLC. All patients received standard chemotherapy treatment (with pemetrexed and cisplatin). 253 of these patients (67%) responded to initial treatment and were randomized to receive maintenance therapy.

125 patients received low dose maintenance bevacizumab and 128 patients received combined maintenance therapy with low dose bevacizumab and pemetrexed. Maintenance treatments were received until the disease progressed, or until the trial ended. Patients were followed for disease progression for an average of 8.1 months.

PFS from the time of the initial chemotherapy was significantly improved in the combined maintenance (bevacizumab plus pemetrexed) group.  Patients receiving combined maintenance had a PFS of 10.2 months, compared to a PFS of 6.6 months in patients receiving bevacizumab alone. This benefit to PFS was showed to be true for all ages. However, patients receiving combined maintenance therapy experienced more adverse side effects than patients treated with bevacizumab alone.  These adverse effects included nausea and vomiting, hypertension (high blood pressure), weakness and fatigue.

This study concluded that bevacizumab plus pemetrexed maintenance significantly increases PFS compared to maintenance with bevacizumab alone.

This study included a very short follow up period, and as a result the effects of treatment on overall survival could not be properly investigated. In addition, the patients genotypes (the genetic composition of the cancer) were not accounted for in this trial, and it is known that some cancer genotypes vary widely in regards to prognosis and disease progression. Another analysis comparing maintenance therapy with no maintenance therapy is also warranted to help guide treatment decisions.

Consult with your physician regarding the benefits of maintenance therapy after initial chemotherapy treatment.