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Syndax >> Syndax Announces Positive Interim Data Demonstrating Robust Clinical Activity in Phase 1 Portion of the AUGMENT - 101 Trial of SNDX - 5613 in Patients with Genetically - Defined Acute Leukemias April 20 , 2021 - - 48 % overall response rate in patients with MLLr or NPM1c ; 67 % of responders achieved minimal residual disease- negative status - - - Doses identified for advancement into Phase 2- - Company on track to initiate pivotal Phase 2 portion of trial in 2Q21- - Company to host conference call and webcast today at 8:00 a.m. ET - WALTHAM , Mass . , April 20 , 2021 / PRNewswire / -- Syndax Pharmaceuticals , Inc. ( " Syndax , " the " Company " or " we " ) ( Nasdaq : SNDX ) , a clinical stage biopharmaceutical company developing an innovative pipeline of cancer therapies , today announced updated positive data from the Phase 1 dose escalation portion of the ongoing Phase 1/2 AUGMENT - 101 trial of SNDX - 5613 in patients with mixed lineage leukemia rearranged ( MLLr ) and nucleophosmin ( NPM1c ) mutant relapsed / refractory ( R / R ) acute leukemias . SNDX - 5613 is the Company's highly selective , oral menin inhibitor . Information on how to access the live video webcast and accompanying slide presentation can be found below . " Data reported today further support the potential for SNDX - 5613 to induce clinically meaningful responses in patients with genetically - defined acute leukemias , " said Briggs W. Morrison , M.D. , Chief Executive Officer of Syndax . " Notably , robust clinical activity , including multiple complete responses with no evidence of minimal residual disease ( MRD- ) , were observed in heavily pretreated MLLr and NPM1c patients . We have identified a candidate recommended Phase 2 dose ( RP2D ) and expect to commence the pivotal Phase 2 portion of the trial by the end of the second quarter . " " Genetically - defined acute leukemias , including those harboring MLLr and NPM1c mutations , represent a disease area with a particularly poor prognosis and few effective treatment options , " said Eytan M. Stein , M.D. , Assistant Attending Physician and Director , Program for Drug Development in Leukemia , Department of Medicine at Memorial Sloan Kettering Cancer Center , and the trial's principal investigator . " With five - year survival rates in MLLr and NPM1c mutant acute leukemias of 50 % or less , novel treatments that can offer clinically - meaningful benefit are desperately needed . I am excited to present evidence that underscores previous observations that SNDX - 5613 has the potential to disrupt the treatment paradigm for this disease . " As of a March 12 , 2021 data cutoff date , 43 patients with a median of three prior therapies , such as prior stem cell transplant , venetoclax and chemotherapy , were dosed in the Phase 1 portion of the AUGMENT - 101 trial . A total of 31 patients were evaluable for efficacy at the time of the data cutoff date , with the remaining patients either not yet at their initial efficacy assessment ( n = 4 ) or not harboring either the MLLr or NPM1c mutation ( n = 8 ) . The overall response rate 1 ( ORR ) among evaluable patients was 48 % ( n = 15 ) , with 67 % ( n = 10 ) of these responders achieving MRD negative status , with four of these patients proceeding to receive stem cell transplant . The ORR in evaluable patients harboring an MLL - rearrangement ( n = 24 ) , was 54 % ( n = 13 ) , and in evaluable patients harboring an NPM1c mutation ( n = 7 ) , was 29 % ( n = 2 ) . A candidate RP2D of 226 mg every 12 hours was identified for patients who are not receiving a concomitant strong CYP3A4 inhibitor , and 113 mg every 12 hours for patients on a concomitant strong CYP3A4 inhibitor treatment . Eighteen patients treated at the RP2D were efficacy - evaluable and response results observed at the RP2D were consistent with the overall population . Across all patients enrolled in the trial as of the data cutoff date ( n = 43 ) , SNDX - 5613 was generally well - tolerated , with no discontinuations due to treatment - related adverse events observed in heavily pretreated patients . The only grade 3 or greater related adverse events occurring in at least 5 % of patients were QT prolongation , anemia , and differentiation syndrome . Among all patients treated at the candidate RP2D ( n = 22 ) as of the data cutoff date , 9 % of patients ( n = 2 ) experienced grade 3 QT prolongation . About AUGMENT - 101 AUGMENT - 101 is a Phase 1/2 open - label trial designed to evaluate the safety , tolerability , pharmacokinetics , and efficacy of orally administered SNDX - 5613 . The Phase 1 dose escalation portion of AUGMENT - 101 was separated into two cohorts based on concomitant treatment with a strong CYP3A4 inhibitor . Arm A enrolled patients not receiving a strong CYP3A4 inhibitor , while Arm B enrolled patients receiving a strong CYP3A4 inhibitor . The pivotal Phase 2 portion of the trial will evaluate efficacy , as defined by complete response rate ( per International Working Group response criteria ) , across three expansion cohorts : MLLr acute lymphoblastic leukemia ( ALL ) , MLLr acute myeloid leukemia ( AML ) , and NPM1c mutant AML . Conference Call and Webcast Details The Company will host a conference call and webcast today , Tuesday , April 20 , 2021 at 8:00 a.m. ET . The presentation will feature the trial's principal investigator , Eytan M. Stein , M.D. , Assistant Attending Physician and Director , Program for Drug Development in Leukemia , Department of Medicine at Memorial Sloan Kettering Cancer Center . The live video webcast and accompanying slides may be accessed through the Events & Presentations page in the Investors section of the Company's website at www.syndax.com . Alternatively , the conference call may be accessed through the following : Conference ID : 3129568 Domestic Dial - in Number : ( 877 ) 474-0326 International Dial - in Number : ( 918 ) 922-6881 Live webcast : https://onlinexperiences.com/Launch/QReg/ShowUUID=E0296F2E-256E-494B-A4F6-FD7220BACE26 For those unable to participate in the live event , a replay will be available on the Investors section of the Company's website , www.syndax.com . About SNDX - 5613