Liposomal Irinotecan Plus Bevacizumab in Irinotecan-refractory Metastatic Colorectal Cancer

The standard treatment regimen based on irinotecan with or without bevacizumab is commonly used in metastatic colorectal cancer. With administration of traditional irinotecan, the parent drug and active metabolite SN-38 exist in the form of active lactone and carboxylate, and the lactone ring structure is unstable in neutral and alkaline solutions. In physiological pH conditions, the active lactone rapidly hydrolyzes to the inactive carboxylate, thereby reducing the efficacy, so there is certain limitation in clinical application. Liposomes Irinotecan load the active substance irinotecan into liposomes, so that it can be slowly released in the body and achieve the effect of reducing toxicity and increasing efficacy.After being rationally designed, irinotecan liposomes can also take advantage of the high permeability and retention effect (EPR) to specifically target the tumor area, increase the amount of drug taken up by cancer cells, reduce the dosage, improve efficacy, and reduce side effects. We are currently conducting an Phase I/II study in mCRC patients who have previously received irinotecan. After determining the maximum tolerable dose (MTD) of irinotecan liposomes in the combined regimen of irinotecan liposomes and bevacizumab, we will further explore the safety and initial efficacy of irinotecan liposomes combined with bevacizumab.