IDEAYA Biosciences Announces Successful FDA Type C Meeting for IDE849, DLL3 TOP1 ADC, on Phase 3 Registrational Trial Design for Potential Accelerated and Full Approval in Extensive Stage Small Cell Lung Cancer
Rhea-AI Summary
IDEAYA Biosciences (NASDAQ: IDYA) reported a successful FDA Type C meeting that informed the planned design of a global randomized Phase 3 registrational trial of IDE849, a DLL3-targeting TOP1 antibody-drug conjugate, in extensive stage small cell lung cancer (ES‑SCLC) with prior tarlatamab treatment.
IDEAYA is targeting Phase 3 initiation by year-end 2026, enrolling ~400 ES‑SCLC patients randomized 1:1 to IDE849 monotherapy versus investigator’s choice (topotecan or amrubicin). The primary endpoint for potential accelerated approval will be ORR by blinded independent central review; median overall survival will serve as the primary endpoint for potential full approval.
Ongoing Phase 1 work is evaluating 2.4 mg/kg and 3.5 mg/kg IV Q3W to select the recommended Phase 3 dose. IDE849 is also being studied in combinations with AstraZeneca’s Imfinzi and IDEAYA’s PARG inhibitor IDE161 to inform a potential first‑line SCLC Phase 3 trial design.
Positive
- Successful FDA Type C meeting supports IDE849 Phase 3 trial design in ES-SCLC
- Planned global Phase 3 trial to enroll ~400 ES-SCLC patients randomized 1:1
- Clear registrational endpoints: ORR by BICR for accelerated and median OS for full approval
- Ongoing dose evaluation at 2.4 mg/kg and 3.5 mg/kg IV Q3W to define RP3D
- Combination studies with Imfinzi and IDE161 exploring potential first-line SCLC strategy
Negative
- None.
Key Figures
Previous Clinical trial Reports
| Date | Event | Sentiment | 24h Move | Catalyst |
|---|---|---|---|---|
| Jul 27 | Phase 1/2 expansion | Positive | +3.9% | Initiated Part 2 monotherapy expansion in the IDE892 Phase 1/2 study. |
| Jun 15 | Phase 1/2 combination | Positive | +4.3% | Enrolled the first patient in an IDE892 combination trial. |
| Jun 01 | Phase 2/3 data | Positive | -1.8% | Reported complete OptimUM-02 data showing improved clinical outcomes versus investigator's choice. |
| Apr 30 | NDA submission | Positive | +3.7% | Initiated the planned FDA real-time oncology review submission process. |
| Apr 21 | ASCO presentation | Neutral | -5.3% | Announced a late-breaking oral presentation of complete Phase 2/3 data. |
24h Move is the share-price change in the day after each event; other market factors may also have contributed.
Tag-specific clinical-trial announcements produced three positive and two negative 24-hour reactions, indicating mixed historical follow-through.
Key Terms
overall response rate medical
blinded independent central review medical
recommended phase 3 dose medical
antibody drug conjugate medical
AI-generated analysis. How Rhea-AI works. Not financial advice.
- Based on FDA Type C meeting, targeting to initiate a randomized Phase 3 registrational trial for IDE849 monotherapy by year-end 2026 in ES-SCLC, with ORR by BICR as the primary endpoint for potential accelerated approval and median OS as the primary endpoint for potential full approval
- Dose evaluation ongoing of 2.4mg/kg and 3.5 mg/kg IV Q3W to determine the RP3D
- Target enrollment for the Phase 3 study will be ~400 ES-SCLC patients, randomized 1:1 treatment vs. investigator's choice
- Clinical data updates for IDE849 in 100 ES-SCLC and NEC patients by partner Hengrui at ESMO 2026 and the IDEAYA sponsored Phase 1/2 clinical trial in ES-SCLC and NEC in Q4 2026 to support a potential best-in-class profile
- IDE849 is being evaluated in clinical combinations with PDL1 and IDEAYA's PARG inhibitor IDE161 to determine a potential 1L SCLC Phase 3 registrational trial design
"Based on the FDA Type C meeting, we are targeting to initiate a randomized Phase 3 registrational study for IDE849 monotherapy in extensive stage small cell lung cancer to enable a potential accelerated approval and full approval in one seamless study design," said Yujiro S. Hata, President and Chief Executive Officer, IDEAYA Biosciences. "We also look forward to the clinical data updates at ESMO 2026 and later this year from our company sponsored clinical trial in ES-SCLC and NEC to support a potential best-in-class profile."
The anticipated enrollment target for the IDEAYA-sponsored global Phase 3 registrational study is approximately 400 ES-SCLC patients with prior tarlatamab treatment. The study will be randomized 1:1 between the treatment and an investigator's choice control arm that will include topotecan and ambrucin. The primary endpoint for accelerated approval will be overall response rate (ORR) by blinded independent central review (BICR) and the primary endpoint for full approval will be median overall survival. The secondary endpoints will include median duration of response by BICR, progression free survival, safety, among others.
IDEAYA has an ongoing multi-site global Phase 1 clinical trial for IDE849 in DLL3 upregulated solid tumor indications, including SCLC, and neuroendocrine carcinomas (NEC) (NCT07174583). The study is enrolling patients globally, including in
In addition, IDE849 is being evaluated in clinical combination study with AstraZeneca's PDL1 inhibitor Imfinzi, and IDEAYA's potential first-in-class Phase 1 PARG inhibitor, IDE161, to determine a potential first-line (1L) SCLC Phase 3 registrational trial design. IDE161 prevents the removal of poly(ADP-ribose) chains generated by PARP during the DNA damage response, leading to persistent PARylation and impaired resolution of DNA repair complexes. Together with TOP1-payload ADCs, this unique mechanism-of-action results in sustained TOP1 cleavage complexes and the accumulation of DNA damage that delivers enhanced anti-tumor activity. We believe this potential first-in-class combination has the potential to enhance durability of IDEAYA's TOP1-payload based ADC pipeline, including IDE849 and IDE034 (Phase 1 B7H3/PTK7 Bispecific TOP1 ADC).
DLL3 has been reported to be upregulated in multiple solid tumor types, including in SCLC, NEC and melanoma, among others. IDEAYA estimates the annual incidence of SCLC and NEC in
About IDEAYA Biosciences
IDEAYA is a precision medicine oncology company committed to the discovery and development of targeted therapeutics for patient populations selected using molecular diagnostics. IDEAYA's approach integrates capabilities in identifying and validating translational biomarkers with drug discovery to select patient populations most likely to benefit from its targeted therapies. IDEAYA is applying its research and drug discovery capabilities to synthetic lethality – which represents an emerging class of precision medicine targets.
Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and other applicable securities laws. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including, but not limited to, statements regarding IDEAYA's interpretation of, and the anticipated regulatory implications arising from, feedback received during the FDA Type C meeting for IDE849; the potential design, initiation, timing, enrollment, conduct and completion of a randomized Phase 3 registrational trial evaluating IDE849 monotherapy in patients with extensive-stage small cell lung cancer previously treated with tarlatamab (Imdelltra); the potential for such trial to support accelerated approval based on overall response rate by blinded independent central review and subsequent full approval based on median overall survival; the anticipated size, randomization, treatment arms, control therapies and endpoints of the Phase 3 trial; the evaluation of doses and the timing and selection of a recommended Phase 3 dose; the timing, availability, content and significance of clinical data updates from Hengrui and IDEAYA-sponsored clinical trials, including anticipated presentations at ESMO 2026 and clinical data updates in the fourth quarter of 2026; the potential safety, efficacy, tolerability, durability, clinical activity and therapeutic benefits of IDE849, including its potential best-in-class profile; the development and evaluation of IDE849 in combination with Imfinzi and IDE161; the potential design and initiation of a Phase 3 registrational trial in first-line small cell lung cancer; the potential first-in-class profile and mechanism of action of IDE161; the potential for IDE161 to enhance the activity or durability of IDEAYA's TOP1-payload ADC pipeline, including IDE849 and IDE034; the prevalence and therapeutic relevance of DLL3 expression across solid tumors; and the potential clinical and regulatory development of IDE849, IDE161 and IDE034.
Such forward-looking statements are based on IDEAYA's management's current expectations, assumptions and beliefs and involve risks, uncertainties, and other factors that could cause actual results, including those related to IDEAYA's clinical programs, regulatory activities, commercial activities and performance or achievements, to differ significantly or materially from those expressed or implied by the forward-looking statements.
Such risks and uncertainties include, among others, risks relating to the FDA's feedback from regulatory meetings is preliminary and nonbinding, and the FDA may subsequently require modifications to the proposed Phase 3 trial design, endpoints, patient population, statistical analysis plan or regulatory strategy, or may require additional clinical or nonclinical data or one or more additional trials; the FDA may determine that overall response rate does not support accelerated approval or that the trial results do not verify clinical benefit or support full approval; IDEAYA may experience delays in selecting a recommended Phase 3 dose or initiating, enrolling, conducting or completing clinical trials; clinical trial results, including interim, preliminary or topline results, may not be reproduced in later trials or may not support further development or regulatory approval; IDE849, IDE161 or IDE034 may not demonstrate the safety, efficacy, tolerability, durability, clinical activity or differentiated profile anticipated; combination therapies may result in unexpected toxicities or may not demonstrate additive or synergistic clinical benefit; data may be delayed, incomplete, inconsistent or unfavorable; regulatory authorities may not accept IDEAYA's proposed development or approval strategies; and IDEAYA may encounter difficulties arising from patient enrollment, clinical-site activation, drug supply, manufacturing, competition, reliance on third parties and other factors. For a further description of risks and uncertainties that could cause actual results to differ from those expressed in or implied by these forward-looking statements, as well as risks relating to IDEAYA's business generally, is included in IDEAYA's filings with the Securities and Exchange Commission, including its most recent Annual Report on Form 10-K, filed on February 17, 2026, subsequent Quarterly Reports on Form 10-Q and Current Reports on Form 8-K.
Forward-looking statements speak only as of the date of this press release, and IDEAYA undertakes no obligation to update or revise any forward-looking statements contained herein to reflect any change in expectations, new information, subsequent events or circumstances, or otherwise, except as required by law.
Investor and Media Contact
IDEAYA Biosciences
Joshua Bleharski, Ph.D.
Chief Financial Officer
investor@ideayabio.com
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