What happened

This morning Syndax Pharmaceuticals (SNDX -1.14%) updated investors with initial data from a phase 1/2 trial evaluating its leukemia drug, and shares are soaring 55% at 12:05 pm EST on Tuesday.

So what

Syndax is a clincial-stage healthcare company developing cancer drugs, including SNDX-5613, a therapy for the treatment of leukemia caused by specific genetic abnormalities, including rearrangements of the MLL gene (MLL-r) and NPM1 mutation.

A doctor speaks through a megaphone.


On Monday, Syndax unveiled initial results of SNDX-5613 efficacy in a small handful of patients with MLL-r. So far six patients have been treated at increasing dose levels in its phase 1 trial. After 28 days, a clinical response was seen in two of three patients harboring MLL-r, including one complete response and one partial response. No dose-limiting toxicities were reported, suggesting the treatment may be safe. 

The initial results are particularly intriguing because patients with MLL-r and NPM1 mutations have a poor prognosis; thus new treatment options are needed. MLL-r is seen in between 5% to 10% of acute myeloid leukemia (AML) and acute lymphocytic leukemia cases, while NPM1 mutations are observed in 30% of adult AML cases. Sadly, the five-year survival rate for MLL-r acute leukemia patients is less than 55%.

Now what

Syndax is presenting SNDX-5613's early trial data at 4:50 pm EST today at the 2020 American Association for Cancer Research (AACR) virtual annual meeting. The trials are ongoing, with additional results to be announced in Q4 2020.  

SNDX-5613 isn't Syndax's most advanced drug currently in clinical trials, though. The company is also conducting a phase 3 study of entinostat plus Pfizer's Aromasin in HR+, HR2- breast cancer. Overall survival data from this trial is anticipated this quarter, and if the results are positive, a Food and Drug Administration filing for approval will soon follow. While there's no telling what survival data will show, phase 2 data showed a entinostat/exemestane combination produced clinically meaningful overall survival benefits versus Aromasin monotherapy.