Ebenezer A. Kio

Randomized, Placebo-Controlled, Phase 2 Study of Veliparib in Combination with Carboplatin and Paclitaxel for Advanced/Metastatic Non-Small Cell Lung Cancer.

Purpose: PARP plays an important role in DNA repair. Veliparib, a PARP inhibitor, enhances the efficacy of platinum compounds and has been safely combined with carboplatin and paclitaxel. The primary endpoint of this phase II trial determined whether addition of veliparib to carboplatin and paclitaxel improved progression-free survival (PFS) in previously untreated patients with advanced/metastatic non–small cell lung cancer. Experimental Design: Patients were randomized 2:1 to carboplatin and paclitaxel with either veliparib or placebo. Veliparib (120 mg) or placebo was given on days 1 to 7 of each 3-week cycle, with carboplatin (AUC = 6 mg/mL/min) and paclitaxel (200 mg/m2) administered on day 3, for a maximum of 6 cycles. Results: Overall, 158 were included (median age, 63 years; male 68%, squamous histology 48%). Median PFS was 5.8 months in the veliparib group versus 4.2 months in the placebo group [HR, 0.72; 95% confidence interval (CI), 0.45–1.15; P = 0.17)]. Median overall survival (OS) was 11.7 and 9.1 months in the veliparib and placebo groups, respectively (HR, 0.80; 95% CI, 0.54–1.18; P = 0.27). In patients with squamous histology, median PFS (HR, 0.54; 95% CI, 0.26–1.12; P = 0.098) and OS (HR, 0.73; 95% CI, 0.43–1.24; P = 0.24) favored veliparib treatment. Objective response rate was similar between groups (veliparib: 32.4%; placebo: 32.1%), but duration of response favored veliparib treatment (HR, 0.47; 95% CI, 0.16–1.42; P = 0.18). Grade III/IV neutropenia, thrombocytopenia, and anemia were comparable between groups. Conclusions: Veliparib combination with carboplatin and paclitaxel was well-tolerated and demonstrated a favorable trend in PFS and OS versus chemotherapy alone. Patients with squamous histology had the best outcomes with veliparib combination. Clin Cancer Res; 23(8); 1937–44. ©2016 AACR.

Anti-CD22 90Y-epratuzumab tetraxetan combined with anti-CD20 veltuzumab: a phase I study in patients with relapsed/refractory, aggressive non-Hodgkin lymphoma

A lingering criticism of radioimmunotherapy in non-Hodgkin lymphoma is the use of cold anti-CD20 antibody along with the radiolabeled anti-CD20 antibody. We instead combined radioimmunotherapy with immunotherapy targeting different B-cell antigens. We evaluated the anti-CD22 90Y-epratuzumab tetraxetan with the anti-CD20 veltuzumab in patients with aggressive lymphoma in whom at least one prior standard treatment had failed, but who had not undergone stem cell transplantation. Eighteen patients (median age 73 years, median of 3 prior treatments) received 200 mg/m2 veltuzumab once-weekly for 4 weeks, with 90Y-epratuzumab tetraxetan at planned doses in weeks 3 and 4, and 111In-epratuzumab tetraxetan in week 2 for imaging and dosimetry. Veltuzumab effectively lowered levels of B cells in the blood prior to the radioimmunotherapy doses. No significant immunogenicity or change in pharmacokinetics of either agent occurred in combination. 111In imaging showed tumor targeting with acceptable radiation dosimetry to normal organs. For 90Y-epratuzumab tetraxetan, transient myelosuppression was dose-limiting with 6 mCi/m2 (222 MBq/m2) × 2 being the maximal tolerated dose. Of 17 assessable patients, nine (53%) had objective responses according to the 2007 revised treatment response criteria, including three (18%) complete responses (2 relapsing after 11 and 13 months, 1 continuing to be clinically disease-free at 19 months), and six (35%) partial responses (1 relapsing after 14 months, 5 at 3 – 7 months). Responses occurred in patients with different lymphoma histologies, treated at different 90Y dose levels, and with a predicted risk of poor outcome, most importantly including five of the six patients treated with the maximal tolerated dose (2 of whom achieved durable complete responses). In conclusion, the combination of 90Y-epratuzumab tetraxetan and veltuzumab was well-tolerated with encouraging therapeutic activity in this difficult-to-treat population.

Therapy of Small Cell Lung Cancer (SCLC) with a Topoisomerase-I–inhibiting Antibody–Drug Conjugate (ADC) Targeting Trop-2, Sacituzumab Govitecan

Purpose: We evaluated a Trop-2–targeting antibody conjugated with SN-38 in metastatic small cell lung cancer (mSCLC) patients. Experimental Design: Sacituzumab govitecan was studied in patients with pretreated (median, 2; range, 1–7) mSCLC who received either 8 or 10 mg/kg i.v. on days 1 and 8 of 21-day cycles. The primary endpoints were safety and objective response rate (ORR); duration of response, progression-free survival (PFS), and overall survival (OS) were secondary endpoints. Results: Sixty percent of patients showed tumor shrinkage from baseline CTs. On an intention-to-treat basis (N = 50), the ORR was 14% (17% for the 10-mg/kg group); the median response duration, 5.7 months; the clinical benefit rate (CBR ≥4 months), 34%; median PFS, 3.7 months; and median OS, 7.5 months. There was a suggested improvement in PR, CBR, and PFS with sacituzumab govitecan in second-line patients who were sensitive to first-line therapy, but no difference between first-line chemosensitive versus chemoresistant patients in the overall population. There was a statistically significant higher OS in those patients who received prior topotecan versus no topotecan therapy in a small subgroup. Grade ≥3 adverse events included neutropenia (34%), fatigue (13%), diarrhea (9%), and anemia (6%). Trop-2 tumor staining was not required for patient selection. No antibodies to the drug conjugate or its components were detected on serial blood collections. Conclusions: Sacituzumab govitecan appears to have a safe and effective therapeutic profile in heavily pretreated mSCLC patients, including those who are chemosensitive or chemoresistant to first-line chemotherapy. Additional studies as a monotherapy or combination therapy are warranted. Clin Cancer Res; 23(19); 5711–9. ©2017 AACR.

Smoking History Predicts Sensitivity to PARP Inhibitor Veliparib in Patients with Advanced Non–Small Cell Lung Cancer

Introduction: Tobacco‐related NSCLC is associated with reduced survival and greater genomic instability. Veliparib, a potent poly(adenosine diphosphate–ribose) polymerase inhibitor, augments platinum‐induced DNA damage. A phase 2 trial of untreated advanced NSCLC showed a trend for improved outcomes (hazard ratio [HR] = 0.80, 95% confidence interval: 0.54–1.18, p = 0.27 for overall survival and HR = 0.72, 95% CI: 0.45–1.15, p = 0.17 for progression‐free survival) when veliparib was added to carboplatin/paclitaxel. Here we report an exploratory analysis by smoking history. Methods: Patients were randomized 2:1 to receive carboplatin/paclitaxel with veliparib, 120 mg (n = 105), or placebo (n = 53). Patients were stratified by histologic subtype and smoking history (recent smokers [n = 95], former smokers [n = 42], and never‐smokers [n = 21]). Plasma cotinine level was measured as a chemical index of smoking. Mutation status was assessed by whole exome sequencing (n = 38). Results: Smoking history, histologic subtype, age, Eastern Cooperative Oncology Group performance status, sex, and geographic region predicted veliparib benefit in univariate analyses. In multivariate analysis, history of recent smoking was most predictive for veliparib benefit. Recent smokers treated with veliparib derived significantly greater progression‐free survival and overall survival benefits (HR = 0.38 [p < 0.01] and HR = 0.43 [p < 0.01]) than former smokers (HR = 2.098 [p = 0 0208] and HR = 1.62 [p = 0.236]) and never‐smokers (HR = 1.025 [p = 0.971] and HR = 1.33 [p = 0.638]). Sequencing data revealed that mutational burden was not associated with veliparib benefit. The rate of grade 3 or 4 adverse events was higher in recent smokers with veliparib treatment; all‐grade and serious adverse events were similar in both treatment arms. Conclusions: Smoking history predicted for efficacy with a veliparib‐chemotherapy combination; toxicity was acceptable regardless of smoking history. A prespecified analysis of recent smokers is planned for ongoing phase 3 studies of veliparib in NSCLC.

Abstract CT155: Phase 2 study of sacituzumab govitecan (IMMU-132), an anti-Trop-2/SN-38 antibody-drug conjugate (ADC), in patients with pretreated metastatic small-cell lung cancer (mSCLC)

Introduction: Sacituzumab govitecan (IMMU-132) is an antibody-drug conjugate (ADC) delivering SN-38, a topoisomerase-1 inhibitor, to mSCLC cells expressing Trop-2. We are studying the safety/tolerability and efficacy of IMMU-132 in patients with relapsed/refractory mSCLC who had received a platinum-containing first-line regimen. Experimental Procedure: Patients received 8 or 10 mg/kg IV IMMU-132 on days 1 and 8 of repeated 21-day cycles. Objective tumor response (ORR) was determined by RECISTv1.1 in patients receiving at least one treatment cycle, and progression-free survival (PFS) and overall survival (OS) in all patients by Kaplan-Meier methods. (ClinicalTrials.gov, NCT01631552) Summary of New Unpublished Data: A total of 53 patients (23/30 M/F, median 63 years old) with 1-7 (median 2) prior lines of therapy were enrolled between November, 2013 and June, 2016. Immunohistochemistry of evaluable archival tumor specimens for Trop-2 expression (N=26) showed 92% positivity (61% moderately to strongly positive). They received up to 32 treatment cycles (median 5); the most frequent Grade >3 adverse events were neutropenia (34%), fatigue (13%) and diarrhea (9%). Four patients did not complete one cycle of treatment. In the other 49 patients (14 at 8 mg/kg, 35 at 10 mg/kg), there were 7 confirmed PRs and 21 SDs as best response. The resulting ORR rate was 14% (7/49), with a median duration and time-to-progression of a response of 4.0 and 7.6 mos, respectively, and the clinical benefit rate (PR+SD >4 mos) was 35% (17/49). The ORR rate was similar in pts who were sensitive (>3 mos response) or resistant ( Conclusion: These interim results demonstrate encouraging activity in patients with late-stage mSCLC having a high expression of Trop-2. Even after failing 1st-line platinum chemotherapy or 2nd-line topotecan therapy, IMMU-132 showed promising activity, and has a manageable toxicity profile. IMMU-132 given at 10 mg/kg on day 1 and 8 of a 3-week cycle was selected for further clinical evaluation in this population. Citation Format: Jhanelle E. Gray, Rebecca S. Heist, Alexander N. Starodub, D. Ross Camidge, Ebenezer Kio, Gregory Masters, W. Thomas Purcell, Michael J. Guarino, Jamal Misleh, Charles J. Schneider, Bryan J. Schneider, Allyson J. Ocean, Tirrell Johnson, Leena Gandhi, Kevin Kalinsky, Serengulam V. Govindan, Pius Maliakal, Boyd Mudenda, William A. Wegener, Robert M. Sharkey, David M. Goldenberg. Phase 2 study of sacituzumab govitecan (IMMU-132), an anti-Trop-2/SN-38 antibody-drug conjugate (ADC), in patients with pretreated metastatic small-cell lung cancer (mSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT155. doi:10.1158/1538-7445.AM2017-CT155

Abstract B77: Phase I study of TH-302, an investigational hypoxia-targeted drug, in combination with sunitinib.

Background: Tumors often consist of highly hypoxic subregions known to be resistant to chemotherapy and radiotherapy. TH-302 is an investigational hypoxia-targeted drug that selectively releases the DNA cross-linker bromo-isophosphoramide mustard under hypoxic conditions. Preclinical models demonstrate that treatment with antiangiogenic receptor tyrosine kinase inhibitor sunitinib increased the tumor hypoxic fraction, the therapeutic target of TH-302, in a dose dependent manner. Treatment with TH-302 following sunitinib significantly increased antitumor activity in these models. In this Phase I dose-escalation study, TH-302 was combined with standard dose sunitinib. Methods: Eligible patients (pts) for the study ([NCT01381822][1]) had advanced renal cell carcinoma (RCC), gastrointestinal stromal tumors (GIST) or pancreatic neuroendocrine tumors (PNET), evaluable disease by RECIST, ECOG ≤2 and acceptable hematologic, hepatic and renal function. Pts received TH-302 in combination with standard full doses of 50 mg PO sunitinib daily from Day 1 to Day 28 of a 6 week cycle. TH-302 was administered IV on Days 8, 15 and 22. TH-302 starting dose was 240 mg/m2. The study objectives were to determine the maximum tolerated dose (MTD), dose limiting toxicities (DLTs) and the recommended Phase II dose (RP2D), and to evaluate the safety and preliminary efficacy of TH-302 when used in combination with sunitinib. Results: Twelve pts were enrolled. Median age: 51 (range 27-72); Female (4)/ Male (8); ECOG 0 (6); ECOG 1 (6); Primary tumor: RCC (8), GIST (4). Median prior systemic therapies: 2 (range: 0-6) including prior sunitinib in 8 pts. No DLTs were observed in the 3 pts at the 240 mg/m2 cohort and 1 pt of 6 DLT evaluable in the 340 mg/m2cohort had a DLT of stomatitis. Eleven pts discontinued [progressive disease (9), pursued other treatment options (1), adverse event unrelated to study drugs (1)]. Three pts had a study drug related SAE (neutropenic sepsis, anemia, hyperthyroidism). Common TH-302 related AEs were nausea and mucosal toxicity and were mostly grade 1 or 2. Grade 3/4 thrombocytopenia and neutropenia were reported in 3 pts and 5 pts, respectively. One of 4 (25%) pts with GIST had a confirmed PR and 3 of 6 (50%) pts with RCC had PRs including 2 with confirmed PRs. All 4 pts with PRs had received prior sunitinib. Conclusions: TH-302 can be administered in combination with full dose sunitinib. Stomatitis was dose limiting. These preliminary data suggest activity of TH-302 in combination with sunitinib in patients with RCC who had progressed on prior sunitinib. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B77. Citation Format: Alexander Starodub, Daniel Vaena, Kenneth L. Pennington, Ebenezer A. Kio, Daniel Bruetman, Tracy Thorne, Stewart Kroll, Mohammed M. Milhem. Phase I study of TH-302, an investigational hypoxia-targeted drug, in combination with sunitinib. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B77. [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01381822&atom=%2Fmolcanther%2F12%2F11_Supplement%2FB77.atom