In the final article on the lung cancer mini series this week, it’s time to discuss one of my least favourite topics – chemotherapy.
Regular readers will remember the guest post from Dr Al Lalani just prior to ASCO on the acronymania that pervaded the abstract book this year for various clinical trials. I was therefore much amused to play ‘buzzword bingo’ at the meeting and see how many of his list I came across 😉
One trial in particular stood out in a session on lung cancer called PARAMOUNT. Three years ago, I wrote about the FDA approval of pemetrexed (Alimta) in front line treatment of NSCLC in non squamous histology.
The new phase III data looked at whether it was safe and effective to continue pemetrexed as maintenance therapy after initial induction treatment with the pemetrexed plus cisplatin doublet for four cycles. A total of 939 patients with advanced nonsquamous NSCLC were enrolled in the study.
Patients whose disease had not progressed during the induction, and had a good performance status of 0-1 (n=439), were randomized to receive either:
- Pemetrexed maintenance (500 mg/m2 on day one of a 21-day cycle) plus best supportive care (n=359) OR
- Placebo plus best supportive care (n=180) until disease progression.
All patients received vitamin B12, folic acid and dexamethasone. The main goal of the trial was to determine if progression-free survival (PFS) was improved by maintenance therapy with pemetrexed.
The final analysis demonstrated that the primary endpoint was met:
- Median PFS of 3.9 months (95% CI: 3.0-4.2) in the pemetrexed arm versus 2.6 months (95% CI: 2.2-2.9) in the placebo arm.
- In addition, disease control rate (% patients with response/stable disease) was 71.8% in the pemetrexed group and 59.6% in the placebo arm (P=0.009).
Toxicities were in line with those expected for pemetrexed based on previous studies, ie anemia, fatigue and neutropenia were all greater than placebo. Discontinuations due to AEs were 5.3% with ALIMTA and 3.3% with placebo.
Overall, when considering the question of whether pemetrexed improves PFS as maintenance therapy for non-squamous NSCLC patients, it looks to be a safe and viable option, albeit with a small additional increase of 1.3 months in survival.