Detailed results from a recent clinical trial appear to support earlier use of a Bristol Myers Squibb drug for a cancer-like disease of the bone marrow, potentially giving doctors a new treatment option to replace a decades-old standard.
The data, revealed in a trial abstract published Thursday ahead of the American Society of Clinical Oncology’s annual meeting, color in the specifics of an announcement by Bristol Myers last October that the trial succeeded.
The drug, luspatercept, is already approved in the U.S. to treat anemia resulting from the bone marrow disease called myelodysplastic syndrome, or MDS. But it’s only cleared for use after older treatments stop working, and is limited to certain patients whose disease has specific characteristics.
The most recent trial pitted luspatercept directly against one of those older medicines, Amgen’s Epogen, in just over 350 adults with low-risk MDS who hadn’t previously been treated. In October, Bristol Myers said its drug helped more patients stop needing blood transfusions for their anemia, and increased levels of the vital oxygen-carrying protein hemoglobin.
Data disclosed in Thursday’s abstract reveal that 59% of study participants treated with luspatercept achieved transfusion independence for at least three months, compared to 31% on Epogen. To meet the criteria for the study’s primary goal, participants also had to have an increase in hemoglobin levels.
“Luspatercept may be an effective first treatment option for anemia associated with lower-risk MDS,” said Olatoyosi Odenike, a professor of medicine at University of Chicago, in a statement put out by ASCO. Odenike has previously consulted with Bristol Myers, along with other drugmakers.
Guillermo Garcia-Manero, a professor of leukemia at the MD Anderson Cancer Center and the study’s primary investigator, also noted how participants on luspatercept went longer without eventually needing a transfusion than those on Epogen.
Drugs like Epogen tend to only work for a short time, he said. “But the duration from those patients that responded [in the study] is very clearly in favor of luspatercept, which is really meaningful in my opinion,” Garcia-Manero said in an interview.
MDS describes a group of diseases in which the bone marrow doesn’t produce enough healthy blood cells and instead churns out immature cells called blasts. This can result in low levels of red and white blood cells as well as platelets, and in a minority of cases progresses to acute myeloid leukemia.
Anemia, or a shortage of red blood cells, is the most common manifestation of MDS and therefore is often the main target of drugs being developed for the condition.
Bristol Myers’ study findings are the first time a new medicine has proven superior as an initial MDS treatment to drugs like Epogen, which are collectively known as erythropoietin stimulating agents, or ESAs, for how they boost red blood cell production.
“Luspatercept could potentially alter this treatment landscape such that patients could receive [it] first instead of ESAs,” Garcia-Manero said in ASCO’s statement. “Patients will need to visit the clinic less often and receive blood transfusions less frequently.”
Both luspatercept and Epogen were associated with side effects, although the share who reported treatment-related adverse events was higher in the luspatercept group. Four study participants on Bristol Myers’ drug had their disease progress to leukemia while in the trial, compared to five on Epogen. About 18% of participants in both groups died.
An expanded approval for luspatercept, which Bristol Myers sells in the U.S. as Reblozyl, could give a boost to the pharmaceutical company. The drugmaker reported $158 million in first quarter U.S. sales for the drug, which is also approved to treat anemia in adults with the blood disorder beta thalassemia. It expects peak global sales to top $4 billion a year by 2030.
Other companies are also working on new drugs for MDS. Geron, a California-based biotechnology firm, in January reported the success of a Phase 3 trial testing its medicine imetelstat in previously treated, lower-risk MDS. Full data from that study, which compared Geron’s drug to a placebo, will also be presented at ASCO.
Because luspatercept and imetelstat work differently than ESAs, Garcia-Manero sees an opportunity to test whether the drugs could be used together.
“I think the studies are going to open the door for potential multiple [drug] combinations,” Garcia-Manero said. “There may be some additive or even synergistic activity of these compounds.”