8-K: Kura Oncology's Ziftomenib NDA Accepted by FDA with Priority Review for Relapsed/Refractory AML, Pivotal Phase 2 Data Shows Promising Efficacy and Safety

Kura Oncology announced that the FDA has accepted its New Drug Application for ziftomenib for relapsed/refractory acute myeloid leukemia with an NPM1 mutation, granting it Priority Review with a target action date of November 30, 2025, following positive pivotal Phase 2 KOMET-001 trial results.

Summary

• The U.S. Food and Drug Administration (FDA) has accepted Kura Oncology's New Drug Application (NDA) seeking full approval for ziftomenib as a treatment for adult patients with relapsed or refractory (R/R) acute myeloid leukemia (AML) with a nucleophosmin 1 (NPM1) mutation.
• The application has been granted Priority Review and assigned a Prescription Drug User Fee Act (PDUFA) target action date of November 30, 2025.
• The NDA is based on positive results from the Phase 2 KOMET-001 registrational trial in R/R NPM1-mutant (NPM1-m) AML, which included 92 adult patients with a median age of 69.
• Ziftomenib is the only investigational therapy to receive Breakthrough Therapy Designation (BTD) from the FDA for R/R NPM1-mutant AML, and also holds Fast Track and Orphan Drug Designations.
• A complete remission (CR) plus CR with partial hematological recovery (CRh) rate of 23% (21/92) was observed among patients in the Phase 2 portion of the KOMET-001 trial, meeting the primary endpoint against a 12% historical control rate.
• Among those 21 patients who achieved CR/CRh, 13 had a CR and eight had a CRh, with a median duration of CR/CRh responses of 3.7 months (95% CI: 1.9, not estimable).
• Minimal residual disease (MRD) negativity was achieved in 63% (12/19) of CR/CRh patients assessed.
• Comparable CR/CRh rates were observed across pre-specified subgroups, regardless of prior hematopoietic stem cell transplantation, prior venetoclax, or FLT3/IDH co-mutations.
• A median overall survival (OS) of 16.4 months (95% CI, 9.6-20.4) was observed for responders (patients who achieved CR, CRh, CRi/CRp, morphologic leukemia-free state or partial response), compared to 3.5 months (95% CI, 2.5-4.0) for non-responders.
• The safety profile of ziftomenib was consistent with previously reported data, with treatment-related adverse events (TRAEs) leading to treatment discontinuations in 3% of patients.
• Grade 3 differentiation syndrome occurred in 13% of patients but was well managed by protocol-specified mitigation strategies, with no Grade 4/5 treatment-related differentiation syndrome observed.
• QTc prolongation (1 Gr2; 2 Gr3) was reported in three patients (3%) per investigator assessment, but all were on concomitant medications associated with QTc prolongation, two had electrolyte abnormalities, and one had a prior diagnosis of atrial fibrillation, indicating no clinically significant QTc prolongation attributed solely to ziftomenib.

Sentiment

Score: 9

Explanation: The document conveys highly positive news, including FDA Priority Review, a clear PDUFA date, and strong pivotal Phase 2 clinical trial results that met the primary endpoint and showed a favorable safety profile. The financial position is also strong, supporting future development.

Positives

• FDA acceptance of the New Drug Application (NDA) for ziftomenib, signaling significant progress towards market approval.
• Granting of Priority Review by the FDA, which shortens the review period and indicates the potential for a significant improvement over existing therapies.
• A clear PDUFA target action date of November 30, 2025, provides a defined timeline for potential regulatory approval.
• Ziftomenib holds Breakthrough Therapy Designation (BTD), Fast Track, and Orphan Drug Designations, underscoring its potential to address a high unmet medical need.
• The pivotal Phase 2 KOMET-001 study met its primary endpoint, demonstrating a clinically meaningful complete remission (CR) plus CR with partial hematological recovery (CRh) rate of 23% in heavily pretreated R/R NPM1-m AML patients, significantly exceeding the 12% historical control rate.
• A high rate of minimal residual disease (MRD) negativity (63%) among responders suggests deep and durable responses, which is a strong indicator of treatment efficacy.
• Efficacy was consistent across various challenging subgroups, including patients with prior hematopoietic stem cell transplantation, prior venetoclax treatment, or FLT3/IDH co-mutations.
• Responders achieved a median overall survival (OS) of 16.4 months, which is considered a strong outcome in this difficult-to-treat relapsed/refractory setting.
• The safety profile is favorable, with low rates of ziftomenib-related myelosuppression and no clinically significant QTc prolongation, enhancing its potential as a well-tolerated therapy.
• Only 3% of patients discontinued treatment due to ziftomenib-related adverse events, indicating good tolerability.
• Differentiation syndrome, a known adverse event, was manageable with protocol-specified mitigation strategies, with no Grade 4/5 events.
• The collaboration with Kyowa Kirin Co., Ltd. provides significant funding for the expansive AML development program, including U.S. commercialization for frontline indications.
• The company's pro forma cash, cash equivalents, and short-term investments of $703.2 million as of March 31, 2025, combined with collaboration funding, are anticipated to fund the AML program through potential commercialization in frontline combinations.

Negatives

• The median duration of CR/CRh responses was 3.7 months, indicating that while responses are achieved, they may not be extremely prolonged without further intervention or combination therapies.
• The median overall survival for non-responders was 3.5 months, highlighting the aggressive nature of relapsed/refractory AML and the continued challenge for patients who do not respond to ziftomenib monotherapy.
• Differentiation syndrome, a Grade 3 adverse event, occurred in 13% of patients, requiring active management, although it was well-controlled.

Risks

• The risk that compounds appearing promising in early research or clinical trials may not demonstrate safety and/or efficacy in later preclinical studies or clinical trials.
• The risk that the Company may not obtain approval to market its product candidates.
• Uncertainties associated with performing clinical trials, regulatory filings, and other interactions with regulatory bodies.
• Risks associated with reliance on third parties to successfully conduct clinical trials.
• The risks associated with reliance on outside financing to meet capital requirements.
• The risk that the collaboration with Kyowa Kirin is unsuccessful.
• Risks associated with the process of discovering, developing, and commercializing drugs that are safe and effective for use as human therapeutics, and in the endeavor of building a business around such drugs.
• Unexpected adverse side effects or inadequate therapeutic efficacy of product candidates could delay or prevent regulatory approval or commercialization.
• Delays may be experienced in the commencement, enrollment, completion, or analysis of clinical testing for product candidates, or in the reporting of data from such clinical testing.
• Significant issues regarding the adequacy of clinical trial designs or the execution of clinical trials may arise, which could result in increased costs and delays, or limit the ability to obtain regulatory approval.

Future Outlook

Kura Oncology anticipates FDA approval for ziftomenib by November 30, 2025, for R/R NPM1-m AML. The company plans to initiate Phase 3 registration-enabling trials (KOMET-017) in frontline NPM1-m and KMT2A-r intensive and non-intensive AML in 2H 2025. Further clinical data from combination studies (KOMET-007, KOMET-008) and other programs (KO-2806, tipifarnib, next-gen menin inhibitors for diabetes, ziftomenib in GIST) are expected in 2H 2025. The collaboration with Kyowa Kirin is expected to fund the AML program through potential commercialization in frontline combinations.

Management Comments

• "The Company and its partners at Kyowa Kirin look forward to supporting FDA with its review of the ziftomenib NDA."
• "You don't have to think about dose based on being on an azole. You can take it once a day instead of twice a day, and you don't have to come for weekly EKGs. That ends up being quite a bit more convenient." (Hematologist/Oncologist)
• "The [lack of] myelosuppression is definitely a high advantage." (Hematologist/Oncologist)
• "So the minute that this drug hits the market, everyone's going to want to know about using it in triplet." (Hematologist/Oncologist)
• "The thing that makes me excited about it is that of those responders, the majority are MRD-negative..." (Hematologist/Oncologist)
• "...once a day, safer, you don't have to worry about QT prolongation." (Hematologist/Oncologist)
• "A 16.4-month median survival for the people [in the R/R setting] who respond, that is actually really good and longer than I would have expected." (Hematologist/Oncologist)
• "Our goal is to develop transformative therapies to extend and improve the lives of patients with cancer." (Kura Oncology)

Industry Context

Acute Myeloid Leukemia (AML) affects approximately 22,010 people annually in the U.S., with a 5-year survival rate of 33% (as low as 8.6% for patients aged 65+), indicating a significant unmet medical need. Up to 50% of AML patients may benefit from menin inhibitor therapy. Ziftomenib, as a targeted investigational menin inhibitor, addresses a critical pathway in AML, particularly for NPM1-mutant patients, who represent a substantial portion of the AML population. The market opportunity for menin inhibitors in AML is projected to exceed $7 billion per year in the U.S., highlighting the commercial potential for effective therapies in this space.

Comparison to Industry Standards

• Ziftomenib's 23% CR/CRh rate in R/R NPM1-m AML patients in KOMET-001 compares favorably to a 12% historical control rate for similar patient populations, indicating superior efficacy.
• The median OS of 16.4 months for responders in the R/R setting is considered 'really good and longer than I would have expected' by a Key Opinion Leader, suggesting it may exceed typical expectations for this heavily pretreated population.
• The safety profile, characterized by low rates of myelosuppression and no clinically significant QTc prolongation, differentiates ziftomenib from some other AML therapies that may require more intensive monitoring or have more challenging safety profiles.
• The once-daily oral dosing and lack of required dose modifications with CYP3A4 inhibitors offer a convenience advantage over some existing or investigational therapies, potentially improving patient adherence and quality of life.

Stakeholder Impact

• Shareholders: Highly positive impact due to significant progress towards regulatory approval, strong clinical data, and a clear path to potential commercialization, which could increase company valuation and stock price.
• Patients (R/R NPM1-m AML): Highly positive impact as ziftomenib offers a new, potentially effective, and well-tolerated oral treatment option for a patient population with high unmet medical need and poor prognosis.
• Healthcare Providers: Provides a new therapeutic tool with a favorable safety and convenience profile (once-daily oral, no frequent QTc monitoring, low myelosuppression) for managing R/R AML patients.
• Kyowa Kirin (Partner): Positive impact as the collaboration progresses successfully towards regulatory milestones and potential market entry, validating their investment and partnership.

Next Steps

• FDA review of the ziftomenib NDA for R/R NPM1-m AML, with a target action date of November 30, 2025.
• Initiate KOMET-017 Phase 3 registration-enabling trials in frontline NPM1-m and KMT2A-r intensive and non-intensive AML in 2H 2025.
• Present preliminary clinical data from KOMET-007 Phase 1b trial in frontline intensive AML at the EHA2025 Congress (June 12-15, 2025).
• Initiate KOMET-015 Phase 1 trial of ziftomenib in combination with imatinib in patients with advanced GIST in 2Q 2025.
• Present preliminary clinical data from Phase 1b expansion of KOMET-007 in frontline non-intensive AML in 2H 2025.
• Initiate one or more expansion cohorts for KO-2806 / tipifarnib in combination with cabozantinib in RCC in 2H 2025.
• Present preliminary clinical data from FIT-001 trial for KO-2806 as monotherapy and combo with cabozantinib in RCC in 2H 2025.
• Present clinical data from the KURRENT-HN trial of tipifarnib in combo with alpelisib in PIK3CA-dependent HNSCC in 2H 2025.
• Nominate a development candidate for next-generation menin inhibitor program for diabetes mid-2025.

Key Dates

Recommendation

Keywords

Kura Oncology, Ziftomenib, Acute Myeloid Leukemia, AML, NPM1 mutation, Relapsed/Refractory AML, Menin Inhibitor, FDA, New Drug Application, NDA, Priority Review, PDUFA, KOMET-001, Clinical Trial, Phase 2, Breakthrough Therapy Designation, Orphan Drug, Fast Track, Oncology, Hematology, Biotechnology, Pharmaceuticals, Drug Development, Regulatory Approval, Kyowa Kirin, Cancer Treatment