NEW YORK (TheStreet) -- CytRx Corp. (CYTR) extended its gains, parlaying an announcement Wednesday into a two-day rally. Shares closed 52.2% higher to $6.12 during Thursday's trading session, adding to an overall 152.1% gain since Wednesday's open.

CYTR Chart
CYTR data by YCharts

A rally was sparked after the oncological specialist announced the success of a mid-stage clinical trial of its cancer treatment before the bell Wednesday. The aldoxorubicin study, an experimental treatment targeting soft-tissue sarcomas, was found to have an 80% to 100% success rate in progression-free survival over using chemotherapeutic agent doxorubicin in isolation.

The success of CytRx is in stark contrast to ImmunoCellular Therapeutics (IMUC) which more than halved its value on Thursday. The cancer immunotherapy researcher closed 59.9% lower to $1.09, after a phase II study of its cell-based vaccine treating aggressive brain tumors failed to reap statistical significance in overall survival among patients.

--Written by Keris Alison Lahiff