Clinical trial versus real-world outcomes
Of note, improved outcomes were reported in clinical trials versus real-world data, with overall survival higher in clinical trials among patients receiving the ATRA/ATO chemo-free treatment (P = .025), as well as in those receiving the AIDA chemotherapy (P < .001).
Early death, an uncommon but key concern with APL, usually due to bleeding complications and defined as death occurring within 30 days from APL diagnosis, occurred among 56 patients, or 5.9%, overall, and was significantly higher in the age 50-69 and over 70 groups versus those under 50 (P < .001).
Early death was more common among those with a Sanz high-risk score (15.4%), compared with low or intermediate risk (3.9%; P < .001); however, the risk was no different between the chemo-free (3.4%) and chemotherapy (5.7%) groups, regardless of whether patients had a low or high risk.
The rates of early death were significantly higher in the real-world population (10.2%), compared with patients in clinical trials (2.8%; P < .001), which Dr. Voso noted may be expected, as early deaths in some cases can occur even before a diagnosis is made.
“These patients sometimes come to the ER and if a diagnosis is not made, they may die before even receiving treatment,” she said in a press briefing.
“Indeed, the median time to death among those who had early death in the study was only 10 days, and there were even some patients dying at day 0,” she explained.
“So, it’s very important that not only hematologists but emergency doctors recognize this disease and try to reduce the early death rate.”
Overall, the results all remained consistent after adjustment in a multivariate analysis, Dr. Voso said.
“The multivariate analysis confirmed that increasing age, high Sanz risk score, the real-life treatment scenario, and the chemotherapy-based approach are independently associated with decreased survival,” she said.
The findings underscore that “elderly age and high Sanz risk score significantly impact on the rate of early deaths, irrespective of treatment,” Dr. Voso said.
ATRA/ATO ‘gold standard’ for low/intermediate risk
Commenting on the study, Alessandro Isidori, MD, PhD, a hematologist at AORMN Hospital, in Pesaro, Italy, who moderated the session, noted that the study underscores the greater challenges with higher-risk patients.
“The study did not show a statistical benefit for high-risk patients receiving ATRA/ATO versus AIDA,” he told this news organization, noting that “currently, there are many countries where ATRA/ATO is not approved for use in high-risk APL.”
“In high-risk APL, the AIDA combination should still be preferred to ATRA/ATO,” he said.
Dr. Isidori recommended careful efforts to stratify higher-risk patients who still may benefit from ATRA/ATO.
“The analysis of high-risk patients with white blood cell count as a continuous variable instead of a fixed variable (more or less than 10,000/mmc) may help to discriminate some high-risk patients who could benefit from ATRA/ATO,” he noted.
Overall, however, “ATRA/ATO is the gold standard for low and intermediate risk APL,” he said.
“Although promising, more data are needed to confirm the efficacy of ATRA/ATO in high-risk APL.”
Dr. Voso disclosed ties with companies including Celgene/Bristol Myers Squibb, Astellas, Jazz Pharmaceuticals, Abbvie, Novartis, and AstraZeneca. Dr. Isidori reported no disclosures.
