Cyclisation of open structures or the creation of an additional ring in a structure is one of the most useful methods in the search for biologically active conformations. The ultimate goal is to obtain a more constrained molecule, with a particular conformation as a consequence of increased conformational restriction. Based on this approach, they have concentrated their synthetic efforts on structures with the aim of achieving greater biological selectivity and, therefore, a concomitant reduction in potential toxicity as antitumour drugs.

To evaluate the effect of bozepinib on tumour growth, heterotopic tumour xenografts were established using the breast cancer cell line MDA-MB 468. Nine days later, tumours reached a size greater than 100 mm3 and mice received an intraperitoneal injection of 25 mg bozenipib/kg body weight. Bozepinib treatment significantly inhibited breast tumour growth compared to the control group. From day 18 and after bozenipib injection, the average tumour volume was significantly smaller compared to the control group.

FOLFOX is the acronym for the chemotherapy combination consisting of the following antineoplastic drugs: folinic acid, 5-fluoroacyl and oxaliplatin. This combination is mainly administered as first-line treatment for advanced or metastatic stages in humans. Also, when the tumour is resectable, it can be administered as an adjuvant after surgery.
Two of its compounds have shown remarkable anti-tumour activities in mice with xenografts after the use of the human colon carcinoma cell line HCT-116, with doses of 100 mg/kg for alternating days over 26 days. These compounds reduce tumour weight to a greater extent than the FOLFOX combination.

Racemic mixtures of 7- or 9-(1,2,3,5-(1,2,3,5- tetrahydro-4,1-benzoxazepin3-yl)-7H- or 9H-purines are available in general as a preclinical development based on compounds selectively active against tumour cells by inhibiting tyrosine kinases overexpressed in most cancers and related to tumour proliferation, migration and angiogenesis. These compounds exert a non-toxic anti-tumour effect, with no acute or chronic toxicity in vivo.