Tripathy, Debashish

e12641 Background: Many promising agents or combinations regimens relevant to breast cancer lack sufficient clinical information for use in the neoadjuvant setting. To enable acceleration of drug development by reducing time and cost of clinical trial planning and conduct, the Phase I initiative PRE-ISPY Program was created. Methods: The PRE-ISPY Program is built within the I-SPY network, with the overall aim to streamline the regulatory pathway and the processes of trial design, contracting, activation, enrollment, execution, data gathering and analysis, as well as reporting of new therapeutic agents or combinations of relevance to breast cancer. Results: The PRE-ISPY trial is an open-label platform phase IB study designed to evaluate compelling single agent or combination regimens with the overall goal of moving promising drug regimens into I-SPY2 Trial and/or into other oncology-based trials in a timely manner. Graduation of a PRE-ISPY regimen to I-SPY2 is not mandatory. The primary objectives in each study Arm are to determine safety and to obtain preliminary efficacy data of the new regimen in patients with metastatic cancer, including a cohort of breast cancer patients. Each Arm may contain a Part 1 (dose finding) and a Part 2 (dose expansion). The new treatment can be tested also in patients with other solid malignancies than breast cancer, in which the treatment may be applicable, as specified in the design of the Arm. A breast cancer specific cohort is required in Part 2. Candidate treatment regimens are selected with advice from the I-SPY2 Agent Selection Working Group. The PRE-ISPY/Phase IB trial has multiple ongoing drug regimen Arms subsequently added as new protocol appendices through amendments to a Master protocol. There is no randomization; participants are enrolled, and treatment selected according to the relevance of therapy to their disease. Prospective companion biomarkers are evaluated. The current arms under study are PRE1: ALX-148 combined with trastuzumab deruxtecan; PRE2: tucatinib combined with zanidatamab; and PRE3: vidutolimod combined with cemiplimab. Selected agents or therapeutic combinations are tested through this protocol in the I-SPY Network Centers that participate in the PRE-ISPY Program. Toxicities are graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE). Clinical responses are evaluated based on RECIST v1.1 criteria. Conclusions: Once safety is established, promising regimens can be rapidly transitioned to I-SPY 2.2 or other phase 2/3 trials. The first patient was enrolled on 2/1/2023. Clinical trial information: NCT05868226 .

505 Background: SWOG S1007 was a phase 3 randomized trial to evaluate the benefit of endocrine therapy alone (ET) or with chemotherapy (CET) in pts with HR+/HER2- invasive breast cancer with recurrence score (RS) ≤ 25. There was no invasive disease-free survival (IDFS) benefit for CET compared to ET in postmenopausal women However, in premenopausal women CET had an IDFS improvement compared to ET (HR=0.60; 95% 0.43-0.83). The objective was to further refine patient subgroups who benefit from CET, we measured baseline hormone levels in S1007 pts to quantify their menstrual status by serum hormone levels and associated clinical outcomes. Methods: Serum estradiol (E), progesterone (P), follicular stimulating hormone (FSH), luteinizing hormone (LH), anti-Müllerian hormone (AMH), and inhibin B (IB) were assessed on baseline serum samples from 1,015 pts who self-reported being premenopausal and age < 55. Magnetic fluorescent bead-based immunoassays ( i.e., Luminex assays) or colorimetric ELISAs were performed at the Biomarker Discovery Laboratory at the University of Kansas Medical Center to measure hormone levels. Associations of the markers (both continuous and dichotomized) with IDFS and distant relapse-free survival (DRFS) were tested for prognosis and prediction of CET benefit using Cox regression. Results: Single baseline measurement of IB, P, E, LH, FSH, or combination of E/LH/FSH, was not prognostic for IDFS or predictive for chemotherapy benefit. However, AMH levels (≥10 pg/mL) showed significant interaction with chemotherapy benefit (p=0.019), and risk increased with continuous AMH with ET alone, but not CET (p=0.03). Compared to ET alone, CET was beneficial in the 79% of premenopausal patients with AMH levels ≥10 pg/mL, a standard cutoff to define normal ovarian reserve (HR=0.48; 95% 0.33-0.69, adjusting for RS). CET was not beneficial in the 21% with AMH < 10 (HR=1.21; 95% 0.60-2.43). Absolute 5-year IDFS benefit of CET for RS ≤ 25 was 7.8% (95.2%-87.4%) for AMH ≥ 10 vs. -1.7% (89.1%-90.8%) for AMH < 10. DRFS showed a similar pattern with CET benefit in AMH ≥10 pg/mL (5-year DRFS benefit: 4.4%; HR=0.41; 95% 0.25-0.68, adjusting for RS) and no benefit in AMH < 10 (5-year DRFS benefit: -0.9%, HR=1.50; 95% 0.62-3.63). Conclusions: Among self-reported premenopausal patients < age 55, pts with baseline serum AMH levels ≥10 pg/mL showed significant benefit from CET compared to patients with AMH levels <10 pg/mL. AMH levels were a better indicator of CET benefit than self-reported menopause status, age, or E/LH/FSH levels. Use of AMH-based selection of patients may inform who most benefits from the addition of adjuvant chemotherapy to ET. Clinical trial information: NCT01272037 .

Abstract Background: Patients achieving a pathologic complete response (pCR) following neoadjuvant therapy have significantly improved event-free survival relative to those who do not; and pCR is an FDA-accepted endpoint to support accelerated approval of novel agents/combinations in the neoadjuvant treatment of high risk early stage breast cancer. Previous studies have shown that recurrence risk increased with increasing burden of residual disease (as assessed by the RCB index). As well, these studies suggest that patients with minimum residual disease (RCB-I class) also have favorable outcomes (comparable to those achieving a pCR) within high risk tumor subtypes. In this study, we assess whether integrating RCB with MRI functional tumor volume (FTV), which in itself is prognostic, can improve prediction of distant recurrence free survival (DRFS); and identify a subset of patients with minimal residual disease with comparable DRFS as those who achieved a pCR. Imaging tools can then be used to identify the subset that will do well early and guide the timing of surgical therapy. Method: We performed a pooled analysis of 596 patients from the I-SPY2 TRIAL with RCB, pre-surgical MRI FTV data and known follow-up (median 2.5 years). We first assessed whether FTV predicts residual disease (pCR or pCR/RCB-I) using ROC analysis. We applied a power transformation to normalize the pre-surgical FTV distribution; and assessed its association with DRFS using a bi-variate Cox proportional hazard model adjusting for HR/HER2 subtype. We also fitted a bivariate Cox model of RCB index adjusting for subtype; and assessed whether adding pre-surgical FTV to this model further improves association with DRFS using a likelihood ratio (LR) test. For the Cox modeling, penalized splines approximation of the transformed FTV and RCB index with 2 degrees of freedom was used to allow for non-linear effects of FTV and RCB on DRFS. Result: Pre-surgical MRI FTV is significantly associated with DRFS (Wald p&lt;0.00001), and more effective at predicting pCR/RCB-I than predicting pCR alone (AUC: 0.72 vs. 0.65). Larger pre-surgical FTV remains associated with worse DRFS adjusting for subtype (Wald p &lt;0.00001). The RCB index is also significantly associated with DRFS adjusting for subtype (Wald p&lt;0.00001). Adding FTV to a model containing RCB and subtype further improves association with DRFS (LR p=0.0007). RCB-I patients have excellent DRFS (94% at 3 years compared to 95% in the pCR group). Efforts are underway to identify an optimal threshold for dichotomizing pre-surgical FTV and FTV change measures for use in combination with pCR/RCB-I class to generate integrated RCB (iRCB) groups as a composite predictor of DRFS. Conclusion: Pre-surgical MRI FTV is effective at predicting minimal residual disease (RCB0/I) in the I-SPY 2 TRIAL. Despite the association between FTV and RCB, FTV appears to provide independent added prognostic value (to RCB and subtype), suggesting that integrating MRI volume measures and RCB into a composite predictor may improve DRFS prediction. Citation Format: Hylton NM, Symmans WF, Yau C, Li W, Hatzis C, Isaacs C, Albain KS, Chen Y-Y, Krings G, Wei S, Harada S, Datnow B, Fadare O, Klein M, Pambuccian S, Chen B, Adamson K, Sams S, Mhawech-Fauceglia P, Magliocco A, Feldman M, Rendi M, Sattar H, Zeck J, Ocal I, Tawfik O, Grasso LeBeau L, Sahoo S, Vinh T, Yang S, Adams A, Chien AJ, Ferero-Torres A, Stringer-Reasor E, Wallace A, Boughey JC, Ellis ED, Elias AD, Lang JE, Lu J, Han HS, Clark AS, Korde L, Nanda R, Northfelt DW, Khan QJ, Viscusi RK, Euhus DM, Edmiston KK, Chui SY, Kemmer K, Wood WC, Park JW, Liu MC, Olopade O, Tripathy D, Moulder SL, Rugo HS, Schwab R, Lo S, Helsten T, Beckwith H, Haugen PK, van't Veer LJ, Perlmutter J, Melisko ME, Wilson A, Peterson G, Asare AL, Buxton MB, Paoloni M, Clennell JL, Hirst GL, Singhrao R, Steeg K, Matthews JB, Sanil A, Berry SM, Abe H, Wolverton D, Crane EP, Ward KA, Nelson M, Niell BL, Oh K, Brandt KR, Bang DH, Ojeda-Fournier H, Eghtedari M, Sheth PA, Bernreuter WK, Umphrey H, Rosen MA, Dogan B, Yang W, Joe B, I-SPY 2 TRIAL Consortium, Yee D, Pusztai L, DeMichele A, Asare SM, Berry DA, Esserman LJ. Refining neoadjuvant predictors of three year distant metastasis free survival: Integrating volume change as measured by MRI with residual cancer burden [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-07-03.

Abstract Background: I-SPY 2 is a multicenter, phase II neoadjuvant trial in women with high-risk stage II/III breast cancer using adaptive randomization within biomarker subtypes to evaluate novel agents added to standard chemotherapy. Primary endpoint is pathologic complete response (pCR). Goal is to identify regimens that meet a high Bayesian predictive probability of statistical significance in a neoadjuvant 300-patient phase III trial defined by hormone-receptor (HR), HER2 status, and MammaPrint (MP). Experimental regimens may “graduate” in 1 of 10 signatures, with a maximum of 120 patients. We report efficacy results for neratinib (N). Methods: Tumors ≥2.5cm by clinical exam & ≥2cm by imaging are eligible for screening. MP low risk/HR+/HER2- tumors are ineligible for randomization. Patients receive chemotherapy (paclitaxel qwk x 12, doxorubicin and cyclophosphamide q2-3 wk x 4, T-&gt;AC). HER2- pts were randomized to N+T-&gt;AC vs. T-&gt;AC and HER2+ pts to N+T-&gt;AC vs. trastuzumab+T-&gt;AC. Analysis is intent-to-treat with pts who switch to non-protocol therapy regarded as non-pCRs. We provide estimated pCR rates (95% Bayesian probability intervals), probabilities of superiority of neratinib over control, and Bayesian predictive probabilities of success in an equally randomized phase III trial. Results: Neratinib met the predictive probability criterion in HR-/HER2+, “graduated”, and accrual ceased [115 N patients (65 HER2+), 78 concurrently randomized controls (22 HER2+)]. The table shows results for all 10 signatures. Two patients (1 N and 1 control) withdrew consent and are not included. Conclusion: I-SPY 2's standing trial mechanism efficiently evaluates agents in biomarker-defined patient subsets. In a modest number of patients, adaptive randomization successfully identified a biomarker signature (HR-/HER2+) for neratinib's further development. All HER2+ and MP+ tumors may also benefit from this regimen, consistent with preclinical data. Evaluation in I-SPY 3, a phase III registration trial, is planned. SignatureEstimated pCR Rate (95% probability interval)Probability NeratinibIs Superior to ControlPredictive Probability of Success in Phase IIINeratinibControlALL32% (28-36%)23% (19%-28%)92%44%HR+23% (18%-28%)17% (11%-22%)81%40%HR-43% (37%-49%)31% (24%-38%)89%53%HER2+39% (33%-45%)23% (15%-30%)95%73%HER2-26% (21%-32%)24% (18%-29%)63%20%MP+*45% (38%-53%)29% (20%-39%)91%66%HR-/HER2-36% (29%-43%)30% (23%-38%)72%34%HR-/HER2+55% (46%-64%)32% (22%-43%)94%78%HR+/HER2+31% (24%-37%)17% (10%-24%)91%65%HR+/HER2-14% (8%-19%)16% (10%-21%)39%12%* MammaPrint 44K Array Low/High score was adjusted to MammaPrint High1 (MP-) or High2 (MP+), using a pre-defined median cut-point of I-SPY 1 participants, who fit the eligibility criteria of I-SPY 2. Citation Format: John W. Park, Minetta C. Liu, Douglas Yee, Angela DeMichele, Laura van 't Veer, Nola Hylton, Fraser Symmans, Meredith B. Buxton, A. Jo Chien, Amy Wallace, Michelle Melisko, Richard Schwab, Judy Boughey, Debashish Tripathy, Hank Kaplan, Rita Nanda, Stephen Chui, Kathy S. Albain, Stacy Moulder, Anthony Elias, Julie E. Lang, Kirsten Edminston, Donald Northfelt, David Euhus, Qamar Khan, Julia Lyandres, Sarah E. Davis, Christina Yau, Ashish Sanil, Laura J. Esserman, Donald A. Berry. Neratinib plus standard neoadjuvant therapy for high-risk breast cancer: Efficacy results from the I-SPY 2 TRIAL. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT227. doi:10.1158/1538-7445.AM2014-CT227