Li, Shuli

6026 Background: We examined a large patient dataset based on E1305, a completed phase III randomized trial of platinum-based chemotherapy with or without bevacizumab (Argiris et al. JCO 2019), to evaluate prognostic factors in the first-line treatment of patients with recurrent or metastatic squamous cell carcinoma of the head and neck (RM SCCHN) and expand on our previous observations in cooperative group trials (Argiris et al. Cancer 2004). Methods: All 403 patients enrolled in E1305 were analyzed. Overall survival (OS) was the outcome of interest. Clinical and tumor characteristics were examined using Cox proportional hazards models. Variables which were significant in the univariate setting at a level of ≤ 0.10 were included in a multivariable model, and backwards selection was performed (threshold of p ≤ 0.05). The final multivariable model was then applied to the two treatment arms, separately. Variables for which the hazards ratio (HR) within an arm was more than 10% different than that for the whole cohort, were removed from the final cohort model. Results: The median OS in the whole study cohort was 11.8 months. A prognostic score model for OS was built, using the 4 independent prognostic factors identified in the multivariable model: ECOG performance status (1 vs 0), prior radiation, primary region (non-oropharynx vs oropharynx), and metastatic disease bone or liver (vs other sites/no metastases). Prognostic score was dichotomized (0-2 and > 2). Patients with 0-2 risk factors (n = 249) had a median OS of 15.2 months (90% CI: 13.8, 18.1), while patients with > 2 risk factors (n = 154) had a median OS of 7.6 months (90% CI: 6.5, 9.3); HR of 2.14 (95% CI: 1.73, 2.66), p < 0.0001. Compared to our previous 5-factor model from analysis of older trials in a similar setting, the variable “bone/liver metastasis” is new, but “tumor cell differentiation” and “weight loss” were not significant and not included in the new model for OS. Conclusions: The new proposed model includes 4 prognostic factors for OS (performance status, primary site, prior radiation, presence of bone/liver metastasis) in the first-line treatment of RM SCCHN.

6010 Background: Definitive or postoperative chemoradiation (CRT) is highly curative for human papillomavirus-associated (HPV+) oropharynx cancer (OPC) but induces significant toxicity. As a potential deintensification strategy, we studied primary transoral surgery (TOS) and, in intermediate pathologic risk patients, reduced dose postoperative RT (PORT). Methods: E3311 is a phase II trial with randomization to reduced- or standard-dose PORT for resected stage III-IVa (AJCC7) intermediate pathologic risk HPV+ OPC, stratified by smoking history. Primary endpoints have been reported; we now present updated 3-year PFS and patient-reported outcomes (PRO), including head and neck-cancer specific quality of life (FACT-H&N) and swallowing perception and performance (MDADI). Results: Of 519 enrolled patients, 495 underwent TOS. The primary oncologic endpoint was 2-year PFS for 50 Gy (Arm B) or 60Gy (Arm C). Among 360 eligible and treated patients (ETP), Arm A (observation, N = 38) enrolled 11%, Arms B (N = 100) or C (N = 109) randomized 58%, and Arm D (66Gy + weekly cisplatin, N = 113) enrolled 31%. With 35.1 months median follow-up, 3-year PFS Kaplan-Meier estimate is 96.9% (90% CI [91.9%, 100%]) for Arm A; 94.9% (90% CI [91.3%, 98.6%]) for Arm B; 93.5% (90% CI [89.4%, 97.9%]) for Arm C; and 90.7% (90% CI [86.2%, 95.4%]) for Arm D. Recurrences and death without recurrence were 4 and 1 in Arm B, and 5 and one in Arm C. Smokers ( > 10 pack-years) did not have worse 3-year PFS in Arms B or C. Treatment arm distribution and outcome for ineligible patients who started adjuvant therapy mirrored the 360 ETP. A comparison combining arms B/C versus arm D in the proportion of patients stable/improved in FACT-H&N total score, from baseline to 6 months post-treatment as a pre-specified endpoint, was 56% vs. 38% (p value = 0.011, one-sided Fisher’s exact test); however, underlying differences in treatment and risk may be confounding. An exploratory comparison between Arms B and C revealed improvement in FACT H&N (63% in Arm B vs. 49% in Arm C had a stable/improved score, p-value = 0.056). Conclusions: Primary TOS and reduced PORT retained outstanding oncologic outcome at 35 months follow up, with favorable QOL and functional outcomes, in intermediate risk HPV+ OPC. Clinical trial information: NCT 01898494.

PURPOSE NCI-MATCH is a nationwide, histology-agnostic, signal-finding, molecular profile–driven trial for patients with refractory cancers, lymphomas, or myelomas. Patients with tumors harboring actionable aberration(s) in fibroblast growth factor receptor ( FGFR) 1-3 were treated with AZD4547, an oral FGFR1-3 inhibitor. METHODS Patients’ tumors were screened by next-generation sequencing for predefined FGFR amplification, activating mutations, or fusions. Patients were treated with AZD4547, 80 mg orally twice daily until progression of disease or drug intolerance. A response rate of 16% was considered promising. RESULTS Between July 2016 and June 2017, 70 patients were assigned and 48 received protocol therapy and are eligible for analysis. Patients’ tumors harbored FGFR1 or FGFR2 amplification (n = 20), FGFR2 or FGFR3 single-nucleotide variants (n = 19), or FGFR1 or FGFR3 fusions (n = 9). The most common primary tumors were breast (33.3%), urothelial (12.5%), and cervical cancer (10.4%).Grade 3 adverse events were consistent with those described in previous clinical trials. Confirmed partial responses were seen in 8% (90% CI, 3% to 18%) and were observed only in patients whose tumors harbored FGFR1-3 point mutations or fusions. Stable disease was observed in 37.5% (90% CI, 25.8% to 50.4%). The median progression-free survival (PFS) was 3.4 months, and the 6-month PFS rate was 15% (90% CI, 8% to 31%). For patients with tumors harboring FGFR fusions, the response rate was 22% (90% CI, 4.1% to 55%), and 6-month PFS rate was 56% (90% CI, 31% to 100%). CONCLUSION Preliminary signals of activity appeared to be limited to cancers harboring FGFR activating mutations and fusions, although AZD4547 did not meet the primary end point. Different FGFR somatic alterations may confer different levels of signaling potency and/or oncogene dependence.

6500 Background: ECOG-ACRIN 3311 examines reduced postoperative therapy in patients with “intermediate risk” p16+ oropharynx cancer (OPC) undergoing primary transoral surgical management. We report the primary endpoint of 2-year progression free survival (PFS) for patients randomized to 50Gy vs 60Gy without chemotherapy. Methods: Between December 2013 and July 2017, 82 credentialed surgeons performed transoral resection (TOS) for 519 OPC patients (cT1-2 stage III/IV AJCC7 without matted neck nodes); post-operative management was determined by pathologically assessed risk. Among 353 eligible and treated patients, Arm A enrolled 10% (N=37) for clear margins, 0-1 nodes, no extranodal extension (ENE)), Arms B (50Gy, N=102) or C (60Gy, N=104) randomized 58%, for clear/close margins, 2-4 + nodes, or ENE ≤1mm, while Arm D (N=110, 60-66Gy plus weekly cisplatin, 40 mg/m2, positive margin with any T stage, >4 + nodes, or >1mm ENE) enrolled 31%. Arm D assignment was based on >1mm ENE (76%), > 4 nodes (27%), and/or positive margins (11%). Intermediate-risk patients were stratified by smoking history (>10 pk-yr). Of the 80 pts (15%) deemed ineligible, 28 had scans/labs not done per protocol, however treatment arm distribution for all patients mirrored that for the 353 pts eligible and treated. Results: Median follow-up was 31.8 months. 2 yr PFS for Arms A, B and C were 93.9% (90% CI=87.3%, 100%), 95.0% (90% CI=91.4%, 98.6%) and 95.9% (90% CI=92.6%, 99.3%) respectively, while Arm D was 90.5% (90% CI=85.9%, 95.3%). The regimen of TOS + low-dose radiation is considered worthy of further study, since the primary endpoint of the upper bound of the 90% CI (in the intermediate risk group) exceeding 85% was met. Of 17 progression events, 7 were locoregional. There were 10 distant recurrences: Arm A=1, Arm B=2, Arm C=4, Arm D=3. Grade III/IV treatment-related AE rates were 15%/2% during surgery, 13%/2% for Arm B and 25%/0% for Arm C. There were 2 treatment-related deaths (one surgical and one Arm D). Conclusions: Transoral resection of p16+ OPC is safe and results in good oncologic outcome, presenting a promising deintensification approach. For patients with low-risk disease, 2-yr PFS is favorable without post-operative therapy. For those with uninvolved surgical margins, <5 involved nodes, and minimal (<1mm) ENE, reduced dose postoperative RT without chemotherapy appears sufficient. Transoral surgery plus 50Gy should be compared to optimal non-surgical therapy in a phase III trial. Clinical trial information: NCT01898494 .

Abstract Background The proportion of tumors of various histologies that may respond to drugs targeted to molecular alterations is unknown. NCI-MATCH, a collaboration between ECOG-ACRIN Cancer Research Group and the National Cancer Institute, was initiated to find efficacy signals by matching patients with refractory malignancies to treatment targeted to potential tumor molecular drivers regardless of cancer histology. Methods Trial development required assumptions about molecular target prevalence, accrual rates, treatment eligibility, and enrollment rates as well as consideration of logistical requirements. Central tumor profiling was performed with an investigational next-generation DNA–targeted sequencing assay of alterations in 143 genes, and protein expression of protein expression of phosphatase and tensin homolog, mutL homolog 1, mutS homolog 2, and RB transcriptional corepressor 1. Treatments were allocated with a validated computational platform (MATCHBOX). A preplanned interim analysis evaluated assumptions and feasibility in this novel trial. Results At interim analysis, accrual was robust, tumor biopsies were safe (&lt;1% severe events), and profiling success was 87.3%. Actionable molecular alteration frequency met expectations, but assignment and enrollment lagged due to histology exclusions and mismatch of resources to demand. To address this lag, we revised estimates of mutation frequencies, increased screening sample size, added treatments, and improved assay throughput and efficiency (93.9% completion and 14-day turnaround). Conclusions The experiences in the design and implementation of the NCI-MATCH trial suggest that profiling from fresh tumor biopsies and assigning treatment can be performed efficiently in a large national network trial. The success of such trials necessitates a broad screening approach and many treatment options easily accessible to patients.

Abstract Oncology has undergone major changes in systemic treatment options, from chemotherapy to antiangiogenic agents to tyrosine-kinase inhibitors to immunotherapy. Historically, a therapeutic agent is tested in separate trials as monotherapy or combined with investigational or approved agents/modalities, to determine antitumor activity in each histology based on the premise that each histology responds differently to the same treatment. This paradigm is time consuming and may or may not make use of molecular characterization to test each agent in each histology. However, with the expansion of biologic understanding and development of various biomarkers, e.g., estrogen receptor and Her 2 amplification, we move beyond the basic paradigm of general histology to one in which treatment is based upon molecular characteristics of the tumor. Examples of recent discoveries from this more modern paradigm are (1) multiple histologies sharing a common molecular profile and (2) a subset within a single histology having a given molecular characteristic. Various agents have been tested singularly in terms of molecular aberrations and histology, e.g., ALK inhibitors and NSCLC. However, with the rapid increase in the number of targeted agents in development, more facile and efficient clinical trial designs are needed. The National Cancer Institute (NCI) and ECOG-ACRIN Cancer Research Group (ECOG-ACRIN) collaborated in designing the Molecular Analysis for Therapy Choice trial (NCI-MATCH or EAY131), the first large-scale signal-finding precision medicine oncology trial in the United States to incorporate centralized NGS testing to direct patients to parallel (nonrandomized) phase II treatment arms under a master protocol. The trial is being conducted by the NCI National Clinical Trials Network (NCTN), with ECOG-ACRIN leading the trial. More than 100 investigators from across the NCTN adult cancer-oriented member groups (Alliance for Clinical Trials in Oncology, ECOG-ACRIN, NRG Oncology, and SWOG) have worked collaboratively to design and lead what is currently 30 treatment arms (subprotocols), with more arms in development. Wide-scale NCTN investigator involvement ensures use of the latest knowledge to define the actionable mutations required for eligibility and to make evidence-based selections of experimental agents. In NCI-MATCH, patients are assigned treatment based on the genomic alterations found in their tumors through genomic sequencing and other tests at the time of initial enrollment for screening. Unlike other phase II trials, each arm is open to advanced solid tumors, lymphomas, or myeloma that share a set of molecular aberrations, not restricted to a single histology. This strategy accommodates and encourages enrollment of rare tumors for which there are often no standard treatments and limited clinical trial options. NCI-MATCH has 10-30 concurrent treatment arms available to patients at any given time, testing both investigational agents and FDA-approved drugs for new indications. Most treatment arms have an enrollment goal of 35 patients, with some arms that address tumor gene variants of higher prevalence expanded to 70 patients. Together, the NCTN and NCI Community Oncology Research Program provide infrastructure for many clinical sites (&gt;1100) to participate, providing ready access to physicians and patients; screening enrollment has occurred in all 50 states in the U.S, the District of Columbia, and Puerto Rico. A specific assay was developed for the trial (the MATCH assay), and a laboratory network was organized to rapidly process the tissue and efficiently interrogate for mutations. NCI and ECOG-ACRIN statisticians developed the analysis plan and are currently maintaining data that are closely monitored by safety experts for any adverse event signals. Lastly, a bioinformatics system (MATCHbox) was developed to coordinate molecular data collection and support rule-based decision-making based on those data. Because genomics in oncology is rapidly expanding and evolving, NCI-MATCH required flexibility to accommodate brisker screening accrual than anticipated, and adaptation to constantly emerging information about new drugs and new molecular alterations. The goal to sequence the tumors of 6,000 patients with NCI funding was achieved two years ahead of schedule, but that cohort was not sufficient to fill all the arms—in particular, those aimed at the most rarely occurring tumor gene aberrations. Currently, the goal for the trial is to complete the open treatment arms by allowing for designated commercial and academic laboratories to notify ordering physicians when genomic tests they ordered to guide clinical care indicate a potential eligibility to a NCI-MATCH arm with a rare variant and allow for enrollment to the relevant treatment subprotocol if the patient meets all subprotocol eligibility criteria. The tissue confirmation of the molecular abnormality on the MATCH assay by the central laboratories will be accomplished after subprotocol enrollment so that patient treatment will not be delayed for confirmation. A demonstration project is now under way to test the applicability of this approach and potentially develop common standards for future use. With tumor sequencing becoming a more and more common practice in oncology, this may allow patients with mutations of low prevalence to have investigational treatment options. NCI-MATCH is expanding its panel and definition of actionable mutations to allow greater flexibility to incorporate in real time new mutations supported with adequate levels of evidence. The valuable genomic and clinical outcome data collected in the trial will permit evaluation of efficacy of targeting certain actionable mutations with a specific agent. In addition, biospecimens are being collected to build a rich resource for conducting auxiliary biology studies that may answer questions about prevalence of mutations in the metastatic setting, prevalence of mutations in rare histologies, and resistance mechanisms of various targeted therapy. At this meeting, two abstracts will provide an overall trial update and present information about the prevalence of mismatch repair deficiency (dMMR) in the centrally screened population. Citation Format: Alice P. Chen, Peter J. O'Dwyer, Lyndsay Harris, Barbara A. Conley, Stanley R. Hamilton, Mickey Williams, Robert J. Gray, Shuli Li, Lisa M. McShane, Lawrence V. Rubinstein, Susanna I. Lee, Shaji Kumar, Edith P. Mitchell, James A. Zwiebel, Constantine A. Gatsonis, Lalitha K. Shankar, Paolo F. Caimi, Carlos L. Arteaga, A John Iafrate, Jeffrey Sklar, Richard F. Little, Keith T. Flaherty. NCI-MATCH: A new paradigm in the era of genomic oncology [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr PL03-01.

BACKGROUND13‐Cis retinoic acid (13‐CRA) is a synthetic vitamin A derivative. High‐dose 13‐CRA in patients with squamous cell cancers of the head and neck (SCCHNs) reduces the incidence of second primary tumors (SPTs). The authors report long‐term results from a phase 3 randomized trial that compared treatment with low‐dose 13‐CRA versus placebo for patients who had early stage SCCHN, with a focus on the development of SPTs and overall survival (OS).METHODSIn total, 176 patients who received treatment for stage I/II SCCHN were randomized to receive either low‐dose 13‐CRA (weight‐based dose of 7.5 mg or 10 mg) or placebo for 2 years. A competing‐risk approach and the log‐rank test were used to compare the time to SPT and OS, respectively, between groups.RESULTS13‐CRA neither significantly reduced the cumulative incidence of SPT (P = .61) nor improved the time to SPT (hazard ratio [HR] for 13‐CRA/placebo; 0.86; P = .61). Despite limited power, there was a trend toward improved OS for the 13‐CRA arm (HR, 0.75; P = .14), particularly among patients whose index tumor was surgically excised (N = 26; HR, 0.50; P = .057) and among women (N = 39; HR, 0.44; P = .065) and never/former smokers (N = 129; HR, 0.61; P = .055), with a median follow‐up of 16 years. The main 13‐CRA related toxicities were dry skin and cheilitis.CONCLUSIONSTreatment with low‐dose 13‐CRA for 2 years did not decrease the incidence of SPT; subset analysis indicates a potential survival advantage among patients who are women and never/former smokers. More targeted interventions based on clinical risk factors and molecular characterization of tumors may yield greater success in future prevention trials. Cancer 2017;123:4653‐4662. © 2017 American Cancer Society.