Oxamic acid is an inhibitor of LDH-A and exhibits antitumor activity. It demonstrates antiproliferative effects on cancer cells and can induce apoptosis.

Oxamic acid effectively inhibits the proliferation, migration, and invasion of A2780 and SKOV3 cells. At a concentration of 10 μM and over periods ranging from 24 to 72 hours, it reduces cell growth in NPC cancer cells in both a dose- and time-dependent manner. Furthermore, Oxamic acid induces cell cycle arrest in the G2/M phase within 24 hours at concentrations between 0 and 100 mM in CNE-1 and CNE-2 cells. It also triggers apoptosis in NPC cells after 48 hours at similar concentrations through caspase-3 activation and the mitochondrial pathway, in addition to escalating ROS levels after 24 hours. Assays conducted confirm these effects, with IC 50 values ranging from 74.6 to 17.8 mM in CNE-1 cells and 62.3 to 31.6 mM in CNE-2 cells based on various durations. The Apoptosis Analysis across the same cell lines demonstrates an increase in early and late apoptotic cells, elevation in pro-apoptotic Bax and cleaved-caspase-3 levels, alongside a decrease in anti-apoptotic Bcl-2 and pro-caspase-3 markers, all in a dose-dependent fashion. Similarly, the Cell Cycle Analysis showed an increase in the proportion of CNE-1 and CNE-2 cells in the G2/M phase, also dependent on the dose.

Oxamic acid administered via intraperitoneal injection at a dosage of 750 mg/kg daily for three weeks enhances the effectiveness of tumor suppression in vivo when used in conjunction with radiation therapy.