REGiMMUNE’s lead candidate to prevent graft-versus-host disease after stem cell transplants has passed its phase 2 trial, setting the Taiwan-based biotech up for a late-stage test.
The therapy, dubbed RGI-2001, is designed to activate regulatory T cells through a novel mechanism that the company claimed could also have applications for the treatment of other autoimmune and chronic inflammatory diseases.
The study assessed 47 patients across the U.S. who received six weekly doses of RGI-2001—as well as standard immunosuppression in the form of Prograf and methotrexate—following allogeneic hematopoietic cell transplantation. Between 20% and 40% of patients who undergo this form of transplant develop clinically significant acute graft-versus-host disease (aGvHD). The disease is a reaction of donor immune cells against host tissues that is associated with significant morbidity and death.
The results, which the company presented at the American Society of Hematology annual meeting earlier in the month, showed that there were no cases of engraftment failure and no serious adverse events attributed to RGI-2001.
In the first 100 days, 20% of patients experienced aGvHD of grades II to IV, although only two of these cases were grade III or IV severity, the company noted. By Day 180, almost 94% of participants had survived, with 75% having avoided aGvHD of grades II to IV and just 4% experiencing disease relapse.
RGI-2001 contains the active moiety α-GalCer encapsulated in a liposomal glycolipid. This is designed to bind to the CD1d receptor of antigen-presenting cells resulting in activation of invariant natural killer cells, ultimately modulating the GVHD pathogenic cascade.
Earlier studies have shown that a single dose of RGI-2001 given on the day of transplant was safe and potentially contributed to preventing aGVHD. The company touted the latest results as “compelling,” adding that the biotech is “strongly considering moving forward with a phase 3 study.”
“We are definitely encouraged by the positive results from this study; it also provides a strong foundation to confidently advance our plans for phase 3 study,” REGiMMUNE CEO Kenzo Kosuda said in a statement Dec. 20.
There are already a few drugs on the market for various severities of GvHD disease. Last year, Kadmon—since acquired by Sanofi —nabbed an FDA approval for its first-in-class ROCK2 inhibitor Rezurock for a chronic form of GVHD. It joined Johnson & Johnson and AbbVie’s BTK inhibitor Imbruvica as well as Incyte’s Jakafi.
The most recent regulatory development was almost exactly a year ago, when Bristol Myers Squibb's long-standing rheumatoid arthritis drug Orencia was granted another lease on life after an FDA approval for aGVHD.