Plus Therapeutics ( NASDAQ: PSTV ) reported data from two ongoing trials of its radiation therapy Rhenium-186 Nanoliposome ( 186 RNL), radion to treat recurrent glioblastoma (GBM) and leptomeningeal metastases ( LM ).
GBM is a type of cancer that affects the brain or spinal cord. While, LM occur when the cancer spreads to membranes surrounding the brain and spinal cord.
The company said that in the ongoing phase 1/2a trial, dubbed ReSPECT-LM, in patients with LM, showed that 186 RNL dose administered through an intraventricular catheter was well tolerated with no treatment-related adverse events of greater than grade 1.
In addition, all three patients in the group were seen to have prompt and complete 186 RNL distribution throughout the cerebrospinal fluid (CSF) subarachnoid space that was durable past one week and well tolerated, the company noted in an Aug. 13 press release.
Plus Therapeutics added that all patients showed a decreased CSF cell count after treatment, ranging from 65% to 92% which was also durable.
"While we can draw only limited conclusions from the first patient cohort, these findings suggest that the application of locally delivered and highly targeted 186RNL for the treatment of LM has the potential to be an effective and safe treatment for patients," said Norman LaFrance, chief medical officer and SVP at Plus Therapeutics.
Meanwhile, a separate ongoing phase 1 trial, dubbed ReSPECT-GBM, was evaluating a single administration of 186 RNL in 23 patients with recurrent GBM.
The study showed that significant overall survival benefits were seen in those achieving an average absorbed radiation dose greater than 100 Gy to the tumor compared to those with less absorption, according to the company.
Plus Therapeutics noted that the data suggests a correlation in increasing convected drug volume and radiation dose with improvement in overall survival of patients and to date, 80% of patients in cohorts 5-7 met the threshold of high levels of absorption greater than 100 Gy.
The company noted that the therapy was safe and well-tolerated, with no adverse events with outcome of death or discontinuations. Four patients remain alive, as of the presentation date.
Plus Therapeutics said cohort 7 of the trial, with an increased dose of 186 RNL is currently enrolling.
PSTV +59.19% to $0.83 premarket Aug. 15
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Plus Therapeutics stock soars 59% as 186RNL shows promise in brain cancer trials