Is Crizotinib Effective in Treating Cancer?

Is Crizotinib Effective in Treating Cancer?

In a clinical study of patients with ALK-positive metastatic NSCLC, 172 received crizotinib and 171 received standard chemotherapy. Results showed that the median time without cancer progression (i.e., no tumor growth or spread) for patients taking crizotinib was 10.9 months. This means that half of the patients in this group had disease stability for more than 10.9 months, while the other half had a shorter duration. In comparison, the median progression-free survival for patients receiving chemotherapy was only 7.0 months. These data indicate that crizotinib has a significant advantage over traditional chemotherapy in delaying disease progression.

Objective Response Rate of Tumors to Crizotinib

Objective response rate is an important measure of a tumor's response to treatment, including tumor shrinkage. Study results showed that the objective response rate for patients taking crizotinib reached 74%, meaning 74% of patients had significant tumor shrinkage or disappearance; while the objective response rate for patients receiving chemotherapy was only 45%. In the crizotinib group, 3 patients achieved "complete response" where all signs of cancer disappeared (though this does not mean the cancer was cured); in the chemotherapy group, 2 patients achieved complete response. Additionally, 125 patients in the crizotinib group achieved partial response (reduction in cancer spread or tumor shrinkage), compared to 75 patients in the chemotherapy group.

Duration of Response and Overall Survival

For patients who achieved partial or complete response, the median time before the tumor resumed growth or spread was 11.3 months in the crizotinib group, compared to only 5.3 months in the chemotherapy group. This means that crizotinib not only more effectively shrinks tumors but also maintains this response for a longer period. The study also measured overall survival time from the start of treatment; data collection is ongoing. To date, no significant difference in overall survival has been observed between patients treated with crizotinib and those receiving chemotherapy. It is important to note that participants in these studies had not previously received systemic therapy for metastatic NSCLC.