Impairment of Methotrexate Transport Is Common in Osteosarcoma Tumor Samples

Table 1

Displacement of methotrexate and trimexate by PT430 grouped by sample type.

		All samples	Biopsy	Definitive surgery	Metastatic disease or relapse
% PT430 Displacement by methotrexate	n	69	50	11	8
	Range	0%–50.97%	0%–19.28%	0%–50.97%	1.13%–14.71%
	Median	3.10%	2.29%	5.81%	7.62%
	Average	4.88%	3.60%	8.89%	7.36%
% PT430 Displacement by trimetrexate	Range	3.27%–86.69%	3.27%–59.01%	6.84%–86.69%	12.48%–83.13%
	Median	21.05%	18.24%	30.50%	27.23%
	Average	24.66%	20.63%	32.81%	38.69%
MTX : TMTX Differential displacement ratio^a	Range	0.00–3.60	0.00–3.60	0.00–0.95	0.04–0.64
	Median	0.15	0.12	0.22	0.13
	Average	0.25	0.24	0.27	0.25

^aThe MTX : TMTX differential displacement ratio represents the percentage of PT430 displaced by methotrexate in relation to the percentage of PT430 displaced by trimetrexate. For example, a sample with methotrexate displacement of 25% and trimetrexate displacement of 50% would have an MTX : TMTX differential displacement ratio of 0.50.