Pusztai, Lajos

Abstract Background LIV-1, a transmembrane protein and downstream target of STAT3, is highly expressed in breast cancer cells. It is associated with lymph node involvement and metastatic progression. SGN-LIV1A is an anti-LIV-1 antibody conjugated via a protease-cleavable linker to monomethyl auristatin E (MMAE). Upon binding to cell-surface LIV-1, SGN-LIV1A is internalized and releases MMAE, which binds to tubulin and induces G2/M arrest and apoptosis. Methods This is an ongoing, phase 1 dose-escalation study evaluating safety, tolerability, pharmacokinetics, and antitumor activity of SGN-LIV1A (q3 wks IV) in women with LIV-1-positive, unresectable, locally advanced or metastatic breast cancer (LA/MBC) (NCT01969643). Patients (pts) with measurable disease and ≥2 prior cytotoxic regimens for LA/MBC were eligible. Pts with ≥Grade 2 neuropathy were excluded. Response was assessed per RECIST v1.1; pts with stable disease (SD) or better could continue treatment until disease progression or intolerable toxicity. At completion of dose escalation in hormone receptor-positive/HER2-negative (HR+/HER2–) and triple-negative (TN) pts, expansion cohorts were opened to further evaluate safety and antitumor activity of monotherapy in TN pts and combination therapy with trastuzumab (Tz) in HER2-positive (HER2+) pts. Pre- and post-treatment tumor biopsies were done to evaluate LIV-1 expression and other correlative endpoints. Results To date, 39 pts (18 HR+/HER2–, 21 TN) have received a median of 3 cycles (range, 1–10) of SGN-LIV1A monotherapy at doses of 0.5–2.8 mg/kg. Median age was 57 yrs (range, 33–79). At baseline, pts had a median of 4 prior cytotoxic regimens for LA/MBC (range, 2–8); 36 had visceral disease and 25 had bone involvement. No dose-limiting toxicities (DLT) occurred in 19 DLT-evaluable pts; maximum tolerated dose was not exceeded at 2.8 mg/kg. Treatment-emergent adverse events (AEs) reported in ≥30% of pts were: fatigue (64%), nausea (54%), alopecia (46%), decreased appetite (41%), constipation (39%), neutropenia (33%), and vomiting (31%). Peripheral neuropathy was reported in 9 pts (23%). Most AEs were Grade 1/2, except neutropenia (all ≥Grade 3). Four pts discontinued treatment due to AEs (acute respiratory distress syndrome, nausea, pneumonia, tachycardia). In dose escalation, modest activity was observed in 17 efficacy evaluable (EE) HR+/HER2- pts, with a disease control rate (DCR) of 59% (10 SD), including 1 pt with SD≥24 wks. Among the 17 EE TN pts (dose escalation plus cohort expansion), the overall response rate (ORR) was 41% (7 PR), DCR was 82% (7 PR, 7 SD) and clinical benefit rate (CBR=OR+SD≥24 wks) was 53% (9 pts). For TN pts, median PFS was 17.1 wks (95% CI: 6.0, 18.4); 6 pts remain on treatment. Of 281 MBC tumor samples evaluated for LIV-1, 93% were positive; 81% had moderate-to-high expression (H-score ≥100). Conclusions LIV-1 is expressed in almost all MBC tumors. SGN-LIV1A monotherapy has been generally well tolerated and shown encouraging antitumor activity in heavily pretreated TN MBC, with a PR rate of 41% and a CBR at ≥24 wks of 53%. Response duration data continue to evolve. Enrollment continues in the TN monotherapy expansion cohort and the HER2+ combination cohort with Tz. Citation Format: Forero-Torres A, Modi S, Specht J, Miller K, Weise A, Burris III H, Liu M, Krop I, Pusztai L, Kostic A, Li M, Mita M. Phase 1 study of the antibody-drug conjugate (ADC) SGN-LIV1A in patients with heavily pretreated metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-12-04.

Abstract Background:Anti-HER2 agents are associated with an increased risk of cardiotoxicity, occurring mostly during treatment and being generally reversible. To date, no cardiac biomarkers have been validated as predictive markers of cardiotoxicity in patients (pts) receiving anti-HER2 therapies. We evaluated high sensitivity (HS) troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in pts treated with neoadjuvant anti-HER2 therapies to evaluate if early elevation of cardiac biomarkers predicts early or late cardiac events. Material and Methods: 455 pts were randomized to receive either lapatinib (154 pts), trastuzumab weekly (149 pts), or lapatinib with trastuzumab for a total of 6 weeks (152 pts). After this biological window, pts continued on the same targeted therapy plus 12-weekly paclitaxel until definitive surgery. After surgery, patients received adjuvant FEC (3x) followed by the same HER2 therapy as in the neoadjuvant phase for further 34 weeks (to complete 52 weeks in total). Eligible pts had an LVEF ≥50%. Cardiac biomarkers were centrally tested in plasma samples collected at baseline, week 2 (W2) and at surgery. Elevated biomarker was defined as either TNT >0.015 μg/L or NT-proBNP >125 pg/mL. The small number of pts and rarity of marker elevations allowed only descriptive analyses. Results: At a median follow-up of 3.8 years, 280 pts had cardiac biomarkers tested at baseline (61.5%) and NT-proBNP was elevated in 39 pts (13.9%) while TNT was elevated in only 1 pt (0.35%). From those 39 pts with NT-proBNP elevated at baseline, only 1 pt experienced a cardiac event. Also, hypertension was presented in 14 pts (24.5%) with elevated NT-proBNP. Serial measurements were available in 173 pts (61.7%) and NT-proBNP was elevated in 25, 10 and 21 pts at baseline, W2 and at surgery, respectively, while among 171 pts (61%) TNT was elevated in 1, 1 and 5 pts, respectively. There were 13 cardiac events in 11 pts in the entire trial. Five of these pts had a measurement of cardiac biomarkers at baseline (non-elevated NT-prBNP and TNT were observed in 4 and 5 pts), 9 of them had a measurement at week 2 (non-elevated NT-prBNP and TNT were observed in 8 and 9 pts) and 3 of them at surgery (non-elevated NT-prBNP and TNT were observed in 3 and 3 pts), respectively. The following table show the low specificity of the cardiac biomarkers. Patients without cardiac event (N)Patients with cardiac event (N)Patients with elevated markerElevated NT-proBNP Baseline38139Week 229130Surgery40040Elevated TNT Baseline101Week 2101Surgery606 During adjuvant phase, 13 pts experienced LVEF drop to <50% and none had either NT-proBNP elevated or TNT at surgery. Conclusions: Despite the small sample size, we demonstrated that cardiac biomarkers are rarely elevated in pts receiving anti-HER2 therapies, which is probably due to the absence of myocyte necrosis with respect to TNT, and the lack of chamber dilation in the case of NT-proBNP after exposure to these drugs. In addition, few cardiac events were present in this population not previously exposed to anthracycline-based chemotherapy; therefore the use of cardiac biomarkers in this population may be unnecessary. Citation Format: de Azambuja E, Bradbury I, Ewer M, Campbell C, Zardavas D, Ameels H, Baselga J, Huober J, Izquierdo M, Bozovic-Spasojevic I, Maetens M, Harbeck N, Pusztai L, Piccart M, Rodeheffer R, Sutter T. Cardiac biomarkers for early detection and prediction of trastuzumab and/or lapatinib-induced cardiotoxicity in patients with HER2 positive early breast cancer (BIG 1-06) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-09.

Abstract Background LIV-1, a multispan transmembrane protein and downstream target of STAT3, is highly expressed in breast cancer cells (Sussman 2014). It has been associated with lymph node involvement and linked with malignant progression to metastasis (Manning 1994). SGN-LIV1A is an anti-LIV-1 antibody conjugated via a protease-cleavable linker to monomethyl auristatin E (MMAE). Upon binding to cell-surface LIV-1, SGN-LIV1A is internalized and releases MMAE, which binds to tubulin and induces G2/M arrest and apoptosis. Methods A phase 1, open-label, dose-escalation study is ongoing to evaluate the safety, tolerability, antitumor activity, pharmacokinetics (PK), and the maximum tolerated dose (MTD) of SGN-LIV1A monotherapy (q3 wks IV) in women with LIV-1-positive, metastatic breast cancer (MBC) (NCT01969643). Patients (pts) with either hormone receptor-positive/HER2-negative (HR+/HER2–) or triple-negative (TN) disease were eligible if they had measurable disease and received ≥2 prior cytotoxic regimens in the metastatic setting. Pts with ≥ Grade 2 neuropathy were excluded. Response was assessed per RECIST v1.1, and pts with stable disease (SD) or better were eligible to continue treatment until disease progression or intolerable toxicity. Fresh tumor biopsies were obtained pre- and post-treatment to evaluate the LIV-1 expression-response relationship, mechanism of action, and tumor sensitivity to SGN-LIV1A. Results To date, 21 pts (17 HR+/HER2–, 4 TN) have received a median of 3 cycles (range, 1–7) of SGN-LIV1A at doses of 0.5–2.8 mg/kg. Median age was 58 yrs (range, 34–73), and pts had a median of 8 prior systemic metastatic therapies (range, 2–15). At baseline, 19 pts had visceral disease and 15 had bone involvement. No dose-limiting toxicities (DLTs) in Cycle 1 were observed in the 18 DLT-evaluable pts; MTD has not yet been identified. Treatment-emergent adverse events (AEs) reported in ≥30% of pts were primarily Grade 1/2 in severity and were: nausea (57%), fatigue and peripheral neuropathy (43% each), alopecia (38%), and vomiting (33%). Two pts discontinued treatment due to AEs (1 nausea, 1 tachycardia). Preliminary PK data suggest a linear increase in antibody-drug conjugate (ADC) exposure with increasing dose. In the 19 efficacy-evaluable pts, the overall response rate (ORR) was 11% (2 partial responses [PRs]) with clinical benefit of SD or better achieved in 63% (2 PR, 10 SD) of pts. Of note, all 4 pts with TN MBC achieved clinical benefit: 2 PR and 2 SD. Currently, the median duration of clinical benefit is 12.7 wks (range, 6.1–26.3). Four pts remain on treatment. To date, of the 179 MBC tumor specimens evaluated for LIV-1, 156 (87%) were LIV-1-positive; moderate-to-high LIV-1 expression (H-score ≥100) was present in 91% (94 of 103) of HR+/HER2– and 81% (47 of 58) of TN samples. Conclusions LIV-1 is expressed in the majority of metastatic breast cancer tissue samples, with moderate-to-high expression in both HR+/HER2- and TN disease. To date, SGN-LIV1A monotherapy has been generally well tolerated and resulted in a clinical benefit of SD or better in 63% of these heavily pre-treated pts, including 2 PRs in the 4 TN MBC pts. Response duration data continue to evolve. Clinical subtype-specific expansion cohorts are planned. Citation Format: Forero A, Burris III H, Mita M, Specht J, Weise A, Liu MC, Modi S, Pusztai L, Kostic A, Yang J, Li M, Hengel S, Miller K. Interim analysis of a phase 1 study of the antibody-drug conjugate SGN-LIV1A in patients with metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-14-05.

Abstract Background: Abnormalities of the PI3kinase/AKT/mTOR signaling network are common in BC. This pathway is associated with resistance to endocrine therapies among HR+ tumors. Everolimus, an mTOR-inhibitor, increases the biological activity of endocrine therapy. S1207 evaluates the role of everolimus in combination with endocrine therapy in the adjuvant setting. Methods: Specific aims/ design: Randomized phase III double-blinded, placebo-controlled trial. Primary objective is to assess whether the addition of everolimus to standard adjuvant endocrine therapy improves invasive disease-free survival (DFS) among patients with high risk, HR+ BC. Secondary objectives include overall survival, distant recurrence-free survival, safety, adherence and QoL. Patients are randomized to receive standard adjuvant endocrine therapy in combination with one year of everolimus (10 mg PO daily) or placebo. Submission of tissue specimens/blood samples is required for translational studies Eligibility criteria: Patients with histologically confirmed HER2-negative and HR+ invasive BC treated with surgery, adjuvant chemotherapy and radiation therapy (if indicated) are eligible if they have: node-negative disease and tumors >2cm and a recurrence score (RS) >25; 1-3 positive nodes and RS >25 or grade 3 in the absence of RS; >4 positive lymph nodes regardless of RS. Patients >1 positive lymph node after completing neoadjuvant chemotherapy are eligible. Statistics/Target accrual:Parallel randomization design with equal allocation to the two treatment groups, the study will randomize 3,500 patients. All analyses are intent-to-treat with the primary analysis conducted 3 years after the last patient is randomized. The study has 90% power (with 2-sided α=0.05) to detect an effective hazard ratio of 0.75 for everolimus versus placebo, corresponding to a gain in DFS of approximately 4.3% at 5 years. All patients will be followed for 10 years. Support: NIH/NCI NCTN Grants CA180888, 180819, 180868, 180821,180822 189867, and in part by Novartis Clinical trial information: NCT01674140. Citation Format: Chavez-MacGregor M, Barlow WE, Pusztai L, Goetz MP, Rastogi P, Ganz PA, Mamounas EP, Paik S, Bandos H, Gralow J, Lew DL, Hortobagyi GN. Phase III randomized, placebo-controlled clinical trial evaluating the use of adjuvant endocrine therapy +/- one year of everolimus in patients with high-risk, hormone receptor (HR) positive and HER2-negative breast cancer (BC): SWOG/NRG/Alliance S1207 (NCT01674140). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT1-03-11.

Abstract Background. Locally advanced breast cancer (LABC) and inflammatory breast cancer (IBC) remain difficult challenges despite progress in multimodality treatment. The SWOG trial S0800 (clinicaltrial.gov NCT00856492) compared bevacizumab in combination with weekly nab-paclitaxel followed by dose-dense AC to nab-paclitaxel followed or preceded by AC as neoadjuvant treatment for HER2-negative IBC/LABC. The rationale was based on the proposed role of angiogenesis, potential role of improved flow and oxygenation in enhancing the delivery of chemotherapy agents, and the proapoptotic effect with certain chemotherapeutic agents, particularly taxanes. Methods. This was a randomized open-label Phase II trial with an accrual goal of 200 patients equally allocated to either bevacizumab (Arm 1) or no bevacizumab.Two patients were ineligible and five withdrew consent leaving 208 for analysis. The no bevacizumab group was further randomized to two sequences (Arm 2: nab-paclitaxel - AC+PEG-G versus Arm 3: AC+PEG-G- nab-paclitaxel) with 50 patients expected in each sequence. The primary endpoint of this study was pathologic complete response (pCR) defined as no evidence of invasive tumor at the primary site and axillary lymph nodes in the surgical specimen. The power for the primary comparison of bevacizumab (bev) versus no bevacizumab (no bev) ignoring sequence was 80% with a 1-sided α = 0.10. Randomization was stratified by hormone receptor status and type of disease (IBC or LABC). Results 215 patients were accrued May 2010 - September 2012. Most had LABC (88%) versus IBC (12%) and most tumors were hormone-receptor (HR) positive (67%). Fourteen (7%) patients had no definitive surgery (included as no pCR); 135 (65%) had residual disease (no pCR) and 59 (28%) had pCR. The bevacizumab pCR rate was higher (35/96; 38%) than that in the non-bevacizumab arms (24/112; 21%) (exact p=0.021; stratified p=0.015). In HR-positive disease there was slight improvement that was not statistically significant (bev 25% vs. non-bev 18%; p=0.41) while the difference was larger in HR-negative disease (bev 59% vs. non-bev 28%; p=0.014). In LABC the overall pCR rate was 29% with a higher rate in the bevacizumab patients (37% vs. 22%; p=0.035). For IBC there was improvement (30% vs. 14%), but not statistically significant (p=0.61) in a small sample. Overall, Grade 3 and 4 events were common in both (bev 67%; non-bev 65%), but did not differ by treatment. There were 21 deaths with 3-year overall survival (OS) of 87% and 83% for bevacizumab and non-bevacizumab, respectively (log-rank p=0.57). Conclusion Compared with combination anthracycline-taxane neoadjuvant chemotherapy, the Bev-Nab-paclitaxel-AC regimen significantly improved pCR rate overall, primarily for triple negative (TNBC) patients. This neoadjuvant regimen could be a good choice for TNBC/IBC . The observed pCR rate in ER negative disease (59%) suggests that the addition of bevacizumab to a standard chemotherapy backbone may improve outcome in this subset, and justifies further testing of such an approach. Correlative science studies to further delineate the biology of TNBC and the effects of bevacizumab are ongoing. Citation Format: Zeina A Nahleh, William E Barlow, Daniel F Hayes, Anne F Schott, Julie R Gralow, Edith A Perez, William M Sikov, Sudhathi Chennuru, Hamid Mirshahidi, Sarah Vidito, Danika L Lew, Lajos Pusztai, Robert B Livingston, Gabriel N Hortobagyi. S0800: Nab-paclitaxel, doxorubicin, cyclophosphamide, and pegfilgrastim with or without bevacizumab in treating women with inflammatory or locally advanced breast cancer (NCI CDR0000636131) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-11-16.

Abstract Background First identified as an estrogen-inducible gene in a breast cancer cell line, LIV-1 is a multispan transmembrane protein of the solute-carrier family 39 with putative zinc transporter and metalloproteinase activity. As a downstream target of STAT3, it promotes the epithelial-to-mesenchymal transition that is important in the malignant progression to metastasis. LIV-1 is expressed in a number of cancers with the highest prevalence and level of expression in breast, prostate, and melanoma. Additionally, LIV-1 has been linked with malignant progression to metastasis and associated with lymph node involvement in breast cancer. Normal tissue expression is predominantly limited to hormonally regulated tissues, including breast and prostate. In metastatic breast cancer tissue samples, the current validated immunohistochemistry assay for LIV-1 has detected moderate to high expression in 82% of samples tested, with 88% positivity in hormone receptor-positive tumors and 73% in triple-negative tumors. SGN-LIV1A is an antibody-drug conjugate (ADC) composed of a humanized anti-LIV-1 monoclonal antibody conjugated to the microtubule-disrupting agent monomethyl auristatin E (MMAE) via a protease-cleavable linker. In vitro, SGN-LIV1A shows target-specific internalization and cytotoxic activity against LIV-1-positive neoplastic cell lines. Significant dose-dependent tumor regression was demonstrated in mouse xenograft models. Methods The primary objective of this first-in-human phase 1, open label, multicenter study is to evaluate the safety and tolerability, and to identify the maximum tolerated dose of SGN-LIV1A using a 3+3 dose-escalation study design. Pharmacokinetics, immunogenicity, and antitumor activity will also be evaluated (ClinicalTrials.gov #NCT01969643). Enrollment to this US-based trial began in late 2013. Eligible patients are adult females who have hormone receptor-positive/HER2-negative or triple-negative metastatic breast cancer. Tumor tissue must be positive for expression of LIV-1 per central assessment. Patients must have received at least 2 prior cytotoxic regimens in the metastatic setting and have measurable disease per RECIST v1.1. Pre-existing neuropathy ≥ Grade 2 is not permitted. SGN-LIV1A is administered intravenously every 3 weeks at protocol-defined doses starting at 0.5 mg/kg. Patients who achieve an objective response or stable disease per RECIST v1.1 are eligible to continue treatment until disease progression. At the completion of dose escalation, expansion cohorts may be opened to enroll patients with specific breast cancer subtypes to further define safety and antitumor activity. Tumor biopsies are being obtained at baseline and after one cycle of treatment to evaluate the role of LIV-1 expression, target saturation, and other tumor-specific measurements in the antitumor activity of SGN-LIV1A. Citation Format: Andres Forero, Howard Burris III, Patricia LoRusso, Jennifer Specht, Kathy Miller, Monica Mita, Minetta C Liu, Shanu Modi, Lajos Pusztai, Django Sussman, Ana Kostic. SGN-LIV1A: A phase 1 trial evaluating a novel antibody-drug conjugate in patients with LIV-1-positive breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT2-3-01.

Abstract Background: Epidermal Growth Factor Receptor (EGFR, HER1) is known to heterodimerize with HER2 and may modulate the effectiveness of trastuzumab or lapatinib. Historically, it has been difficult to measure, but recently we reported a new, standardized, quantitative immunofluorescence assay and a novel EGFR antibody which showed that high levels of EGFR were associated with decreased benefit in the concurrent arm of the North Central Cancer Treatment Group (NCCTG/Alliance) N9831 trial (Rimm et al, SABCS 2012). Here we assess its value in the neo-adjuvant setting in the NeoALTTO trial. Methods: NeoALTTO randomized 455 breast cancer patients to neoadjuvant trastuzumab, lapatinib or both and showed benefit in both single anti-HER2 therapy arms, and the combination therapy showing about twice as much benefit as either single drug arm. We used the previously described AQUA method of quantitative immunofluorescence to measure EGFR levels using the D38B1 antibody on between 4 and 140 fields of view per slide on 353 specimens. The averaged EGFR score was standardized to the absolute concentration using cell lines and western blots and the 13 ng/ug total protein established in the N9831 trial was tested to determine predictive value for pathological complete response (pCR) defined as ypT0/is. Results: In NeoALTTO, 19% of the patients had EGFR levels above 13 ng/ug, compared to 16% in NCCTG N9831. The pCR rate was 35.3% in the patients with low EGFR, compared with 29.8% for high EGFR but this difference was not statistically significant. However, when adjusted for treatment and hormone receptor (HR) status, high EGFR is statistically significantly associated with lower response rate(p = 0.038). Continuous analysis measures were not significant. The effect on overall response at 6 weeks was also weakly significant when adjusting for treatment and HR status (p = 0.06). Surprisingly, for HR negative patients in the lapatinib only arm, the pCR rate in the low EGFR group was 47.2% compared with 16.0% in the high group. While this difference is statistically significant (p = 0.014), it should be interpreted cautiously because of the small numbers of patients and the multiple tests performed. Conclusions: High expression of EGFR by the AQUA platform appears to be associated with decreased pCR rate from HER2 targeted therapy in the neoadjuvant setting. This observation is consistent with NCCTG N9831. Although underpowered, high EGFR levels predicted decreased pCR rate from lapatinib, the opposite of that anticipated for this small molecule dual EGFR/HER2 inhibitor. Further studies are required to determine the clinical utility of this assay and the biological mechanisms underlying these observations. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-09.

Abstract New approaches to drug development are critically needed to lessen the time, cost, and resources necessary to identify and optimize active agents. Strategies to accelerate drug development include testing drugs earlier in the disease process, such as the neoadjuvant setting. The U.S. Food and Drug Administration (FDA) has issued guidance designed to accelerate drug approval through the use of neoadjuvant studies in which the surrogate short-term endpoint, pathologic response, can be used to identify active agents and shorten the time to approval of both efficacious drugs and biomarkers identifying patients most likely to respond. However, this approach has unique challenges. In particular, issues of patient safety are paramount, given the exposure of potentially curable patients to investigational agents with limited safety experience. Key components to safe drug development in the neoadjuvant setting include defining a study population at sufficiently poor prognosis with standard therapy to justify exposure to investigational agents, defining the extent and adequacy of safety data from phase I, detecting potentially harmful interactions between investigational and standard therapies, improving study designs, such as adaptive strategies, that limit patient exposure to ineffective agents, and intensifying safety monitoring in the course of the trial. The I-SPY2 trial is an example of a phase II neoadjuvant trial of novel agents for breast cancer in which these issues have been addressed, both in the design and conduct of the trial. These adaptations of phase II design enable acceleration of drug development by reducing time and cost to screen novel therapies for activity without compromising safety. Clin Cancer Res; 19(11); 2817–23. ©2013 AACR.