The trial failed to meet its main goal of improving all scleroderma patients’ hand function. Subgroup analyses indicated that those with diffuse scleroderma benefitted while those with limited scleroderma did not.
Cytori plans to meeting with U.S. Food and Drug Administration officials to decide how to move forward with the therapy.
“The STAR trial suggests that Habeo may provide clinically meaningful improvements in the hand function and functional disability to patients with the diffuse form of the disease who have no other treatment options,” Dr. Dinesh Khanna, director of the University of Michigan School of Medicine’s Scleroderma Program, said in a press release.
“The diffuse subset has a more severe disease burden, with significant hand dysfunction and internal organ involvement as well as the highest mortality rate among all rheumatic diseases,” he said. “It is important for these patients that this innovative technology moves forward in the clinical and regulatory process.”
The STAR trial (NCT02396238) covered 88 scleroderma patients with hand problems and Raynaud’s phenomenon, a disease that reduces blood flow in arteries, including in fingers. They were randomly assigned to receive Habeo Cell therapy or a placebo.
Habeo is a treatment composed of cells found in fat tissue. Cytori calls them adipose-derived regenerative cells, or ADRCs. It gathers them by suctioning a patient’s own fat tissue from under the skin.
After increasing the concentration of the ADRCs, doctors inject the cells into patients’ fingers. ADRCs are known to contribute to healing processes.
Trial participants received a single treatment, which researchers evaluated after 24 and 48 weeks.
Cytori completed patient follow-up in May 2017, and has now analyzed many of the trial results.
The main goal was for the treatment to improve patients’ Cochin Hand Function Scores. But hand function in those receiving Habeo Cell Therapy was the same as those receiving a placebo after 24 or 48 weeks.
Secondary measures, including one covering patients’ functional disability, also did not indicate that the treatment had benefitted the patients.
When researchers looked at patients with diffuse and limited scleroderma separately, they realized that those with tbe diffuse version had improved.
“We are disappointed that the study missed the primary and secondary endpoints [goals],” said Dr. Marc H. Hedrick, Cytori’s president and CEO. “However, we are very encouraged by the trends toward improved hand function and scleroderma-related health status in patients with diffuse cutaneous scleroderma.”
After 48 weeks, the Hand Function Scores of Habeo-treated diffuse patients were twice as high as diffuse patients who received a placebo. While the difference did not reach statistical significance, it did meet standards indicating that it had generated a minimal difference in hand function. Functional disability measures in the diffuse patients improved in a similar way.
The diffuse group was small. Thirty-two received the cell therapy, and 19 the placebo.
“The safety and efficacy results from this trial in the diffuse subset of patients with scleroderma are impressive and represent important new information for the field,” Khanna said.
The side effects of the treatment were mostly mild or moderate, and researchers did not detect any significant safety issues, including for the fat-suction and finger-injection procedures.
“We are pleased with both the efficacy trends as well as the safety profile of Habeo,” said Dr. Mark Marino, senior vice president of Cytori.
Researchers are further analyzing results, which they will present at the American College of Rheumatology Annual Meeting in November 2017.
Cytori has not decided how to move forward with Habeo therapy. Once it completes its full analysis, it plans to work with trial investigators, patient advocates, and regulatory agencies to identify the best way to advance the treatment.
“We thank the STAR investigators and patients for participating in this trial, which has yielded new insights into scleroderma and shows yet again that discrete patient populations may respond differently to investigational therapies – an important consideration for individuals currently lacking treatment options for rare diseases,” Hedrick said.
In February, Cytori received Small Business Status from the FDA, which will allow it to pay reduced fees for regulatory filings.