Dive Brief:
- CytRx showed positive updated results from its Phase 3 clinical trial evaluating aldoxorubicin for patients with relapsed or refractory soft tissue sarcomas, the company said Nov. 29.
- Overall, 246 of 433 patients enrolled in the study showed a statistically significant improvement in progression-free survival between aldoxorubicin as compared to investigators' choice — FDA-approved and commonly used — therapies, CytRx said. These 246 patients had leiomyosarcoma and liposarcoma, the two most common types of soft tissue sarcomas.
- Based on results, Los Angeles-based CytRx said it expects to submit a New Drug Application (NDA) with the Food and Drug Administration in 2017 for aldoxorubicin as a treatment for patients with relapsed or refractory soft tissue sarcomas.
Dive Insight:
In July, CytRx's stock fell nearly 60% after the biopharmaceutical R&D company announced that its drug aldoxorubicin did not perform better than other therapies. CytRx attributed the Phase 3 trial's shortcomings to a clinical hold placed in November 2014, asserting that nearly two-thirds of patients who entered the trial after the hold was resolved and enrollment resumed failed to get sufficient follow up. At the time, the company cited the need for subsequent analysis; those results were reported Nov. 29.
While CytRx's stock rallied after the company released its latest Phase 3 data, some stock analysts questioned the validity of the results, claiming data were manipulated.
On Nov. 29, CytRx Chairman and CEO Steven Kriegsman told BioPharma Dive that previous data were preliminary. Newly released data are complete and will be the basis of the company's NDA filing with the FDA, he said. He stressed that the trial's vetting process was stringent and involved blinded, independent analyses. "I'm a CPA. There's not an item in there that I'm aware of that hasn't been vetted by two independent parties" – an independent lab and biostatisticians – along with the contract research organization (CRO), he said. He noted that "a lot of money, $75 million," was spent on the trial.
In an interview, Kriegsman said there is "nothing inaccurate or manipulative" in the late-stage clinical trial's data. "We're optimistic the FDA will want to see this drug come to market," he said.
Kriegsman pointed to statements by Sant Chawla, director of the Sarcoma Oncology Center in Santa Monica, California, and principal investigator for CytRx's Phase 3 trial, in the press release announcing results. Chawla said the data represent "a major step forward for STS, a rare, highly complex and very difficult-to-treat group of cancers."
"These results are important because they demonstrate that treatment with aldoxorubicin can extend the time to progression in a clinically meaningful way," Chawla said. He described the trial design as "more stringent than any prior clinical trial in STS as it compared aldoxorubicin to real world alternatives." The control arm allowed trial investigators to select any one of the five most widely used treatments best suited to their patients' specific type of soft tissue sarcomas.
"We didn't go against placebo...We went against everything and we were better than any of them," Kriegsman said. CytRx anticipates meeting with FDA in first quarter 2017, filing its NDA in fourth quarter 2017, and hitting the market in 2018, he said. "The market is very, very unsaturated and we think we'll be a significant company in sarcoma at the minimum."
Despite the reassuring sentiments from the company, investors are skeptical that the drug will be approved by the FDA and showed their disapproval by pushing down the stock further. Shares of CytRx sunk another 7% in morning trading on Nov. 30, keeping the stock well below a $1 a share.