The days may be numbered for the use of duvelisib, a very effective but potentially toxic oral medication used in CLL/SLL.
Duvelisib was approved in 2018, but the FDA now says that after about five years of follow-up in the Phase III trial that led to its approval, the final overall survival (OS) showed a possible increased risk of death for those taking it, with a hazard ratio (HR) of 1.09 (95% confidence interval [CI] 0.79, 1.51). An HR above 1 suggests a higher risk of dying. Please note this is not a statistically significant difference and maybe just a random finding.
However, 80/160 of those enrolled in the trial randomized to duvelisib died, compared with 70/159 of those on ofatumumab, according to the FDA.
As a result, the FDA plans to hold a public meeting to discuss the findings from the clinical trial and whether duvelisib should continue to be prescribed for patients. That is looking less and less likely.
CLL Society has written to the FDA with the signatures of 40 of the top CLL/SLL doctors in the country, thanking the FDA for their watching out for us while reminding them that CLL/SLL is not a solved problem and that there are few choices outside of clinical trials for patients after they become relapsed/refractory to both a BTK and BCL2 inhibitor (also called double refractory). The prognosis for those with double refractory disease is not good. We believe these drugs have a limited but important role to play for admittedly a small select group of CLL/SLL patients. We would like them to remain available but with enhanced monitoring and precautions.
Duvelisib has already been voluntarily withdrawn from the US market for relapsed/refractory follicular lymphoma. The same is true for umbralisib in CLL, which is a different PI3K inhibitor, as we outlined in TG Therapeutics Announces Voluntary Withdrawal of the BLA/sNDA (biologics license application/supplemental new drug application) for U2 to Treat Patients with CLL and SLL: The End of the Road for Any New PI3Ki for CLL/SLL?
Here is the FDA’s statement: FDA warns about possible increased risk of death and serious side effects with cancer drug Copiktra (duvelisib).