Maintenance therapy does not impair subsequent treatment with pemetrexed in metastatic lung cancer

The authors aimed to determine whether previous maintenance therapy with gemcitabine or erlotinib impaired pemetrexed treatment. 

Maintenance therapy is the ongoing use of chemotherapy  or another treatment given to help the primary treatment succeed and prevent cancer recurrence. Two drugs have been approved as maintenance therapies for use in advanced non-small cell lung cancer (NSCLC); pemetrexed (Alimta) and erlotinib (Tarceva) – these block cells involved in cancer growth. Gemcitabine (Gemzar) is another drug used as maintenance therapy in NSCLC that prevents cell growth and causes cell death.

However, there is concern that maintenance therapy may cause resistance to future therapy in the case of cancer progression or return. 

The aim of this study was to determine whethermaintenance treatment with erlotinib or gemcitabine impaired pemetrexed treatment in advanced NSCLC patients. 

464 patients were used in this study. Patients were separated into three treatment groups – an observation group (155 patients – patients remained treatment-free until cancer progression), a gemcitabine group (154 patients) and an erlotinib group (155 patients). From this, 360 patients received pemetrexed as a second-line treatment (treatment following cancer progression or return);  83% from the observation group, 74% from the gemcitabine group and 75% from the erlotinib group.

Progression-free survival (time from treatment that the cancer remains stable or does not return) was similar throughout all 3 groups with an average time until cancer progression following pemetrexed treatment of  4.2 months in both the gemcitabine and erlotinib groups compared to 3.9 months in the observation group.

Overall survival (patients who did not die from NSCLC following treatment) was not significantly better following pemetrexed treatment for either gemcitabine (8.3 months) or erlotinib (9.1 months) showing only a slight improvement when compared to the observation group (7.5 months).

Adverse events (side-effects occurring as a result of treatment) were comparable across all 3 groups with 76.2% in the observation group, 74.6% in the gemcitabine group and 73.3% in the erlotinib group experiencing side-effects such as fatigue, infection and pain. 30% of patients who received pemetrexed experienced side-effects where low white blood cell (immune cells) count, low blood platelet count and low red blood cell count were the most common.

The authors concluded that gemcitabine or erlotinib maintenance treatment does not impair second-line treatment with pemetrexed compared to a treatment-free interval. 

The results were analysed by researchers and have not been reviewed independently.

If you are considering maintenance therapy or second-line treatment with pemetrexed and have concerns about the benefits and risks please consult your doctor.