An open invitation to join the Pediatric Proton/Photon Consortium Registry to standardize data collection in pediatric radiation oncology

OBJECTIVE

The Pediatric Proton/Photon Consortium Registry (PPCR) is a comprehensive data registry composed of pediatric patients treated with radiation. It was established to expedite outcomes-based research. The attributes which allow the PPCR to be a successful collaboration are reviewed.

METHODS AND MATERIALS

Current eligibility criteria are radiotherapy patients < 22 years treated at one of the 15 US participating institutions. Detailed health and treatment data are collected about the disease presentation and treatment exposures, and annually thereafter, in REDCap (Research Electronic Data Capture). DICOM (Digital Imaging and Communications in Medicine) imaging and radiation plans are collected through MIM/MIMcloud. An optional patient-reported quality-of-life (PedsQL) study is administered at 10 sites.

RESULTS

Accrual started October 2012 with 2,775 participants enrolled as of 25 July 2019. Most patients, 62.0%, were treated for central nervous system (CNS) tumors, the most common of which are medulloblastoma (n = 349), ependymoma (n = 309), and glial/astrocytoma tumors (n = 279). The most common non-CNS diagnoses are rhabdomyosarcoma (n = 284), Ewing's sarcoma (n = 153), and neuroblastoma (n = 130). While the majority of participants are US residents, 18.7% come from 36 other countries. Over 685 patients participate in the PedsQL study.

CONCLUSIONS

The PPCR is a valuable research platform capable of answering countless research questions that will ultimately improve patient care. Centers outside of the USA are invited to participate directly or may engage with the PPCR to align data collection strategies to facilitate large-scale international research.

ADVANCES IN KNOWLEDGE

For investigators looking to carry out research in a large pediatric oncology cohort or interested in registry work, this paper provides an updated overview of the PPCR.

Efficacy of Platinum/Pemetrexed Combination Chemotherapy in ALK-Positive NSCLC Refractory to Second-Generation ALK Inhibitors

INTRODUCTION

The current standard initial therapy for advanced ALK receptor tyrosine kinase (ALK)-positive NSCLC is a second-generation ALK tyrosine kinase inhibitor (TKI) such as alectinib. The optimal next-line therapy after failure of a second-generation ALK TKI remains to be established; however, standard options include the third-generation ALK TKI lorlatinib or platinum/pemetrexed-based chemotherapy. The efficacy of platinum/pemetrexed-based chemotherapy has not been evaluated in cases that are refractory to second-generation TKIs.

METHODS

This was a retrospective study performed at three institutions. Patients were eligible if they had advanced ALK-positive NSCLC refractory to one or more second-generation ALK TKI(s) and had received platinum/pemetrexed-based chemotherapy.

RESULTS

Among 58 patients eligible for this study, 37 had scans evaluable for response with measurable disease at baseline. The confirmed objective response rate to platinum/pemetrexed-based chemotherapy was 29.7% (11 of 37 patients; 95% confidence interval [CI]: 15.9% - 47.0%), with median duration of response of 6.4 months (95% CI: 1.6 months - not reached). The median progression-free survival for the entire cohort was 4.3 months (95% CI: 2.9 - 5.8 months). Progression-free survival was longer in patients who received platinum/pemetrexed in combination with an ALK TKI compared to those who received platinum/pemetrexed alone (6.8 months vs. 3.2 months, respectively; hazard ratio = 0.33; p = 0.025).

CONCLUSIONS

Platinum/pemetrexed-based chemotherapy shows modest efficacy in ALK-positive NSCLC after failure of second-generation ALK TKIs. The activity may be higher if administered with an ALK TKI, suggesting a potential role for continued ALK inhibition.

Phase II Study of Proton Beam Radiation Therapy for Patients With Breast Cancer Requiring Regional Nodal Irradiation

PURPOSE

To evaluate the safety and efficacy of proton beam radiation therapy (RT) for patients with breast cancer who require regional nodal irradiation.

METHODS

Patients with nonmetastatic breast cancer who required postoperative RT to the breast/chest wall and regional lymphatics and who were considered suboptimal candidates for conventional RT were eligible. The primary end point was the incidence of grade 3 or higher radiation pneumonitis (RP) or any grade 4 toxicity within 3 months of RT. Secondary end points were 5-year locoregional failure, overall survival, and acute and late toxicities per Common Terminology Criteria for Adverse Events (version 4.0). Strain echocardiography and cardiac biomarkers were obtained before and after RT to assess early cardiac changes.

RESULTS

Seventy patients completed RT between 2011 and 2016. Median follow-up was 55 months (range, 17 to 82 months). Of 69 evaluable patients, median age was 45 years (range, 24 to 70 years). Sixty-three patients (91%) had left-sided breast cancer, two had bilateral breast cancer, and five had right-sided breast cancer. Sixty-five (94%) had stage II to III breast cancer. Sixty-eight (99%) received systemic chemotherapy. Fifty (72%) underwent immediate reconstruction. Median dose to the chest wall/breast was 49.7 Gy (relative biological effectiveness) and to the internal mammary nodes, 48.8 Gy (relative biological effectiveness), which indicates comprehensive coverage. Among 62 surviving patients, the 5-year rates for locoregional failure and overall survival were 1.5% and 91%, respectively. One patient developed grade 2 RP, and none developed grade 3 RP. No grade 4 toxicities occurred. The unplanned surgical re-intervention rate at 5 years was 33%. No significant changes in echocardiography or cardiac biomarkers after RT were found.

CONCLUSION

Proton beam RT for breast cancer has low toxicity rates and similar rates of disease control compared with historical data of conventional RT. No early cardiac changes were observed, which paves the way for randomized studies to compare proton beam RT with standard RT.

Combination Olaparib and Temozolomide in Relapsed Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive malignancy in which inhibitors of PARP have modest single-agent activity. We performed a phase I/II trial of combination olaparib tablets and temozolomide (OT) in patients with previously treated SCLC. We established a recommended phase II dose of olaparib 200 mg orally twice daily with temozolomide 75 mg/m² daily, both on days 1 to 7 of a 21-day cycle, and expanded to a total of 50 patients. The confirmed overall response rate was 41.7% (20/48 evaluable); median progression-free survival was 4.2 months [95% confidence interval (CI), 2.8-5.7]; and median overall survival was 8.5 months (95% CI, 5.1-11.3). Patient-derived xenografts (PDX) from trial patients recapitulated clinical OT responses, enabling a 32-PDX coclinical trial. This revealed a correlation between low basal expression of inflammatory-response genes and cross-resistance to both OT and standard first-line chemotherapy (etoposide/platinum). These results demonstrate a promising new therapeutic strategy in SCLC and uncover a molecular signature of those tumors most likely to respond. SIGNIFICANCE: We demonstrate substantial clinical activity of combination olaparib/temozolomide in relapsed SCLC, revealing a promising new therapeutic strategy for this highly recalcitrant malignancy. Through an integrated coclinical trial in PDXs, we then identify a molecular signature predictive of response to OT, and describe the common molecular features of cross-resistant SCLC.See related commentary by Pacheco and Byers, p. 1340.This article is highlighted in the In This Issue feature, p. 1325.

Total Neoadjuvant Therapy With FOLFIRINOX Followed by Individualized Chemoradiotherapy for Borderline Resectable Pancreatic Adenocarcinoma: A Phase 2 Clinical Trial

Importance

Patients with borderline-resectable pancreatic ductal adenocarcinoma have historically poor outcomes with surgery followed by adjuvant chemotherapy. Evaluation of a total neoadjuvant approach with highly active therapy is warranted.

Objective

To evaluate the margin-negative (R0) resection rate in borderline-resectable pancreatic ductal adenocarcinoma after neoadjuvant FOLFIRINOX (fluorouracil, irinotecan, and oxaliplatin) therapy and individualized chemoradiotherapy.

Design, Setting, and Participants

A single-arm, phase 2 clinical trial was conducted at a large academic hospital with expertise in pancreatic surgery from August 3, 2012, through August 31, 2016, among 48 patients with newly diagnosed, previously untreated, localized pancreatic cancer determined to be borderline resectable by multidisciplinary review, who had Eastern Cooperative Oncology Group performance status 0 or 1 and adequate hematologic, renal, and hepatic function. Median follow-up for the analysis was 18.0 months among the 30 patients still alive at study completion.

Interventions

Patients received FOLFIRINOX for 8 cycles. Upon restaging, patients with resolution of vascular involvement received short-course chemoradiotherapy (5 Gy × 5 with protons) with capecitabine. Patients with persistent vascular involvement received long-course chemoradiotherapy with fluorouracil or capecitabine.

Main Outcomes and Measures

The primary outcome was R0 resection rate; secondary outcomes were median progression-free survival (PFS) and median overall survival (OS).

Results

Of the 48 eligible patients, 27 were men and 21 were women, with a median age of 62 years (range, 46-74 years). Of the 43 patients who planned to receive 8 preoperative cycles of chemotherapy, 34 (79%) were able to complete all cycles. Twenty-seven patients (56%) had short-course chemoradiotherapy, while 17 patients (35%) had long-course chemoradiotherapy. R0 resection was achieved in 31 of the 48 eligible patients (65%; 95% CI, 49%-78%). Among the 32 patients who underwent resection, the R0 resection rate was 97% (n = 31). Median PFS among all eligible patients was 14.7 months (95% CI, 10.5 to not reached), with 2-year PFS of 43%; median OS was 37.7 months (95% CI, 19.4 to not reached), with 2-year OS of 56%. Among patients who underwent resection, median PFS was 48.6 months (95% CI, 14.4 to not reached) and median OS has not been reached, with a 2-year PFS of 55% and a 2-year OS of 72%.

Conclusions and Relevance

Preoperative FOLFIRINOX followed by individualized chemoradiotherapy in borderline resectable pancreatic cancer results in high rates of R0 resection and prolonged median PFS and median OS, supporting ongoing phase 3 trials.

Trial Registration

ClinicalTrials.gov Identifier: NCT01591733.

Treatment with Next-Generation ALK Inhibitors Fuels Plasma ALK Mutation Diversity

PURPOSE

Acquired resistance to next-generation ALK tyrosine kinase inhibitors (TKIs) is often driven by secondary ALK mutations. Here, we investigated utility of plasma genotyping for identifying ALK resistance mutations at relapse on next-generation ALK TKIs.

EXPERIMENTAL DESIGN

We analyzed 106 plasma specimens from 84 patients with advanced ALK-positive lung cancer treated with second- and third-generation ALK TKIs using a commercially available next-generation sequencing (NGS) platform (Guardant360). Tumor biopsies from TKI-resistant lesions underwent targeted NGS to identify ALK mutations.

RESULTS

By genotyping plasma, we detected an ALK mutation in 46 (66%) of 70 patients relapsing on a second-generation ALK TKI. When post-alectinib plasma and tumor specimens were compared, there was no difference in frequency of ALK mutations (67% vs. 63%), but plasma specimens were more likely to harbor ≥2 ALK mutations (24% vs. 2%, P = 0.004). Among 29 patients relapsing on lorlatinib, plasma genotyping detected an ALK mutation in 22 (76%), including 14 (48%) with ≥2 ALK mutations. The most frequent combinations of ALK mutations were G1202R/L1196M and D1203N/1171N. Detection of ≥2 ALK mutations was significantly more common in patients relapsing on lorlatinib compared with second-generation ALK TKIs (48% vs. 23%, P = 0.017). Among 15 patients who received lorlatinib after a second-generation TKI, serial plasma analysis demonstrated that eight (53%) acquired ≥1 new ALK mutations on lorlatinib.

CONCLUSIONS

ALK resistance mutations increase with each successive generation of ALK TKI and may be underestimated by tumor genotyping. Sequential treatment with increasingly potent ALK TKIs may promote acquisition of ALK resistance mutations leading to treatment-refractory compound ALK mutations.

Abstract 4736: Dose optimization of olaparib plus temozolomide in small cell lung cancer (SCLC) patient-derived xenograft (PDX) models for clinical translation

Introduction: SCLC is an aggressive high-grade neuroendocrine malignancy in which targeting DNA-damage repair pathways has shown efficacy in pre-clinical and clinical contexts. We previously conducted a phase I/II trial combining the PARP inhibitor olaparib (O) tablets with the alkylating agent temozolomide (T) in patients with relapsed SCLC, in which O and T were both given days (d) 1-7 of each 21 d cycle. The recommended phase 2 dose (RP2D) was O 200 mg PO BID and T 75 mg/m2 PO daily, and the response rate among the first 29 evaluable patients was 41.4%, with the primary toxicities being hematologic (Farago et al., ASCO 2018). Continuous PARP inhibition with O may improve efficacy, though it is unknown how best to incorporate T onto this backbone. Simultaneous clinical testing of multiple dosing schedules for concurrent OT would be impractical. Here we present an optimization of the OT regimen using PDX models generated from patients treated with OT. Methods: SCLC PDX models derived from two patients prior to their durable responses to OT, MGH1518-1B and MGH1528-1, were used for dose optimization. Based on a human-murine comparison of serum Cmax for OT, the estimated murine-equivalents for the RP2D doses were O 25 mg/kg BID and T 6.25 mg/kg/d. The RP2D regimen was then modulated in both dose intensity and duration in a 9-arm PDX trial. The arms included 3 schedule categories, with doses varied within each category: discontinuous regimens (OT d 1-7); continuous O regimens (O d1-21 + T d 1-7); and rapid- or slow-alternating regimens administering O and T on non-overlapping days. Tumor bearing mice were treated when subcutaneous tumors reached a volume of 400-800 cc, enabling measurement of tumor regression (PDX response) and time to volume doubling (PDX TTP). Findings: The RP2D regimen resulted in near-complete response in both models. This degree of regression was recapitulated with nearly all dosing schedules, and was not improved by increasing T to 2x-RP2D. However, the PDX TTP varied. In both models, the longest TTP was seen with continuous O at full- or half-RP2D and d 1-7 T at half-RP2D. This regimen prolonged TTP by 12% in MGH1518-1B and 20% in MGH1528-1, versus discontinuous OT at RP2D. Based on these results, we initiated clinical treatment in a new cohort of patients on OT, with a phase 1 dose escalation starting with O 50 mg BID d 1-21 and T 50 mg/m2 d 1-7 of each 21 d cycle (NCT02446704). At this first dose level, a partial response by RECIST 1.1 criteria was observed in a heavily pre-treated patient, indicating clinical activity of this combination with this new dosing strategy. Conclusions: In PDX models sensitive to OT at our previously determined RP2D, we find that continuous O with intermittent T permits dose reduction of both O and T without loss of efficacy. A clinical trial is ongoing to determine whether this strategy may enable longer-term dosing and improve efficacy in patients.

Citation Format: Benjamin J. Drapkin, Sarah Phat, David T. Myers, Jun Zhong, Beow Y. Yeap, Elisabetta Leo, Anna Stansiszewska, Aaron Smith, Elaine Cadogan, Maria C. Pietanza, Nicholas J. Dyson, Anna Farago. Dose optimization of olaparib plus temozolomide in small cell lung cancer (SCLC) patient-derived xenograft (PDX) models for clinical translation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4736.

Pencil Beam Scanning Proton Beam Chemoradiation Therapy With 5-Fluorouracil and Mitomycin-C for Definitive Treatment of Carcinoma of the Anal Canal: A Multi-institutional Pilot Feasibility Study

PURPOSE

Definitive chemoradiation with concurrent 5-fluorouracil (5-FU)/mitomycin C (MMC) is an effective treatment for localized anal cancer, but it is associated with significant acute long-term treatment-related toxicity. Pencil beam scanning proton beam (PBS-PT) radiation therapy may potentially reduce this toxicity. This is a multi-institutional pilot study evaluating the feasibility of definitive concurrent chemoradiation with PBS-PT in combination with 5-FU and MMC for carcinoma of the anal canal.

METHODS AND MATERIALS

Patients were enrolled on a National Cancer Institute-sponsored, prospective, multi-institutional, single-arm pilot study (NCT01858025). Key eligibility criteria included Eastern Cooperative Oncology Group 0 to 2, age ≥18 years, histologically confirmed invasive squamous cell carcinoma of the anal canal, and clinically staged T1-4, N0-3 disease. Patients were treated with PBS-PT per Radiation Therapy Oncology Group 0529 dose schema and concurrent 5-FU/MMC on day 1 and 29. The primary objective of this study was to determine feasibility of PBS-PT with concurrent 5-FU/MMC, defined as grade 3+ dermatologic toxicity less than 48% (reported grade 3+ dermatologic toxicity from Radiation Therapy Oncology Group 98-11). Secondary objectives were to determine the rates of overall grade 3+ toxicities, clinical complete response rate, and disease outcomes.

RESULTS

Between February 2014 and April 2017, we enrolled 25 patients into our study, all of whom were analyzed. Twenty-three patients (92%) completed treatment per protocol, and 2 patients died on treatment. Median time to completion of treatment was 42 days (range, 38-49). The grade 3+ radiation dermatitis rate was 24%. Median follow-up is 27 months (range, 21-50) among the 21 patients still alive. The overall rate of clinical complete response was 88%. The 2-year local failure, colostomy-free survival, progression-free survival, and overall survival are 12%, 72%, 80%, and 84%, respectively.

CONCLUSIONS

In our prospective, multi-institutional pilot study of PBS-PT with concurrent 5-FU/MMC, PBS-PT was found to be feasible. A phase 2 study of proton beam radiation therapy is currently underway.

Efficacy of platinum-pemetrexed combination chemotherapy in ALK+ non-small cell lung cancer refractory to second-generation ALK TKIs

9067

Background: Second-generation (gen) ALK tyrosine kinase inhibitors (TKIs) are standard first- and second-line therapies in patients (pts) with advanced ALK+ non-small cell lung cancer (NSCLC). After progression on second-gen TKI(s), standard options include platinum (PT)-based chemotherapy (chemo) or the third-gen ALK TKI lorlatinib. The efficacy of PT-based chemo is established in treatment-naive pts but is undefined in pts who have failed prior ALK TKIs. Here we evaluate the efficacy of PT/pemetrexed (pem)-based chemo in pts with ALK+ NSCLC refractory to second-gen TKIs. Methods: A retrospective study was performed at three institutions. Pts were eligible if they had advanced ALK+ NSCLC refractory to ≥1 second-gen TKI, and received PT-pem-based chemo. Medical records and imaging were reviewed to determine outcomes. Results: Among 55 eligible pts, chemo regimens included: PT/pem (31/55, 56%), PT/pem/bevacizumab (bev) (6/55, 11%), PT/pem/PD-1 inhibitor (3/55, 5%), PT/pem with ALK TKI (8/55, 15%), PT/pem/bev with TKI (6/55, 11%), and PT/pem/PD-1 inhibitor with TKI (1/55, 2%). Pts had received one (6/55, 11%), two (38/55, 69%), or more (11/55, 20%) prior TKIs. Six pts (11%) previously received adjuvant or neoadjuvant chemo. Radiographic data for response evaluation was available for 39 pts. Among 36 pts with measurable baseline disease, confirmed ORR was 31% (11/36; 95% CI, 16-48%); 13 (36%) had stable disease. The median duration of response was 5.4 months (95% CI, 1.5-7.1 months). The median progression-free survival (PFS) for the entire cohort was 4.0 months (95% CI, 2.8-4.6 months). Chemo (PT/pem +/- bev or PD-1 inhibitor) plus ALK TKI (n = 15) was associated with a significant increase in PFS compared to chemo without TKI (n = 40) (median PFS 6.8 vs 3.2 months; HR 0.306; p = 0.002). Similarly, PT/pem plus ALK TKI (n = 8) was associated with increased PFS compared to PT/pem without TKI (n = 31) (median PFS 6.8 vs 2.9 months; HR 0.358; p = 0.036). Conclusions: The efficacy of PT-pem-based chemo is limited after failure of second-gen ALK TKIs but may be higher in pts who receive chemo plus ALK TKI, suggesting a potential role for ongoing ALK inhibition. The modest benefit of PT-pem-based chemo highlights the need for other therapeutic strategies for pts refractory to second-gen TKIs.

A pilot study of neoadjuvant FOLFIRINOX followed by chemoradiation for gastric and gastroesophageal cancer: Preliminary results

4057

Background: We performed a single-arm pilot study of total neoadjuvant approach including FOLFIRINOX and chemoradiation (CRT) with concurrent carboplatin/taxol (C/T) followed by surgery in patients with locally advanced gastric or gastroesophageal junction (GEJ) cancer. Methods: Patients were enrolled on a NCI sponsored, prospective, single arm study (NCT03279237). Key eligibility criteria included: histologically confirmed T3/4 or lymph node (LN) positive gastric or GEJ cancer, ECOG PS ≤1, age 18+, life expectancy > 3 months. Exclusion criteria included: visceral metastases, prior chemotherapy or RT, or prior targeted therapy. Extensive LN disease beyond the surgical field (supraclavicular or para-aortic) was permitted if deemed feasible to be encompassed within a RT field. Laparoscopy was not required. Pts were treated with neoadjuvant FOLFIRINOX x 8, restaging, CRT (45 Gy for gastric, 50.4 Gy for GEJ) with concurrent C/T, restaging, followed by surgical resection. Dose reductions were at discretion of the treating physician. The primary objective was to determine the rate of completion of FOLFIRINOX x 8 followed by CRT delivered in the preoperative setting. Secondary endpoints included: 1) acute toxicity and 2) pathologic complete response (pCR). Results: From Oct 2017 to June 2018, 25 pts were enrolled. Median age was 60 (range:30-76), 17 pts were male (68%). All pts started FOLFIRINOX; 23 (92%) pts completed all 8 planned cycles. Two pts did not complete the planned 8 cycles due to metastatic progression. Rates of grade 3+ overall, gastrointestinal, and hematologic toxicities were 28%, 12%, and 28% respectively. Of the entire cohort, 23 (92%) pts started chemoRT and 22 (88%) pts completed chemoRT (1 pt died during CRT due to pulseless electrical activity arrest). All 22 pts (88%) who completed CRT went for surgical exploration, of whom 2 pts were found with intraoperative metastases. Therefore, 20 (80%) pts underwent surgical resection. At time of abstract, 1 pt’s pathology is in process; 7 pts had a pCR (37% in resected cohort, 28% in ITT cohort), all with R0 resection. Conclusions: Total neoadjuvant FOLFIRINOX followed by CRT is feasible with acceptable rates of treatment completion and grade 3+ toxicity. In our small series, the rate of pCR is promising and a follow-up study is currently planned. Clinical trial information: NCT03279237.

A phase II study of ipilimumab and nivolumab with radiation in microsatellite stable (MSS) metastatic colorectal adenocarcinoma (mCRC)

3514

Background: mCRC remains a lethal cancer and immunotherapy in MSS mCRC has yet to show significant activity. In preclinical models, radiation induced cellular damage may increase responsiveness to immunotherapy via the abscopal effect, with evidence for synergy between radiation therapy (RT) and dual checkpoint blockade. In this study, we assessed dual blockade of CTLA-4 and PD-1 combined with RT as a strategy to stimulate an immune response for patients with MSS mCRC. Methods: In this open-label, single arm phase-2 study, we enrolled 40 MSS mCRC patients (pts). Eligible pts had histologically-confirmed MSS mCRC, ECOG PS 0-1, and progression on at least two lines of therapy. Treatment (Tx) consisted of ipilimumab (1mg/kg q6 weeks), nivolumab (240 mg q2 weeks) and 3 fractions of 8 Gy of RT at cycle 2 every other day. Tx continued until progression, discontinuation or withdrawal. The primary endpoint was Disease Control Rate (DCR), with radiological evaluations every 3 months. Exploratory endpoints included ORR, PFS, OS and safety. Response was defined as disease control outside the radiation field. We obtained serial tumor biopsies pre-tx, during checkpoint blockade alone (cycle 1) and 2 weeks after initiation of radiation. Intention-to-treat analysis (ITT) includes all pts receiving at least one dose of study agent. Results: 40 pts (median age 59 years (26-83), 58% male) enrolled and started treatment from 7/2017 to 12/2018. DCR was 17.5% (7/40) with a 7.5% (3/40) ORR by ITT. Median duration of disease control was 77 days in the ITT; 252 days for those with disease control (n=7) based on the first re-staging scans at 3 months or censored (n=3) and 70.5 days for pts with PD (n=17) or who did not receive RT due to clinical progression (n=13). In the modified ITT (all pts receiving RT and restaged), N=24 pts, excluding 1 pt pending 1st scans post-RT, DCR was 29.2% (7/24) and ORR 12.5% (3/24). Median duration of disease control in mITT was 77.5 days: 252 days for those with disease control and 77 days for those with PD. TRAEs were reported in 22/40 (55%). 20/40 (50%) with grade ≥3 toxicities, with fatigue, nausea, vomiting, diarrhea, infusion-related reaction and dyspnea being the most common. 1(2%) pt died of respiratory failure possibly related to tx. Conclusions: Dual blockade of CTLA-4 and PD-1 with RT is feasible and demonstrates durable activity in pts with MSS mCRC. There are 3 pts who have not completed RT or had their post-RT re-staging. We will report updated efficacy data and outcomes from correlative serial tumor biopsies upon trial completion. Clinical trial information: NCT03104439.

Quantitative Clinical Staging for Patients With Malignant Pleural Mesothelioma

Background

Analysis of the International Association for the Study of Lung Cancer (IASLC) Malignant Pleural Mesothelioma (MPM) database revealed that clinical (cTNM) staging minimally stratified survival and was discrepant with pathological (pTNM) staging. To improve prognostic classification of MPM, alternative staging models based on quantitative parameters were explored.

Methods

An institutional review board–approved MPM registry was queried to identify patients with available pathological and preoperative imaging data. Qualifying patients were randomly assigned to training and test sets in a 1:2 ratio. Computed cTNM and pTNM staging (AJCC Cancer Staging Manual, 7th ed.) were compared. Quantitative image analysis included tumor volume assessed from three-dimensional reconstruction of computed tomography scans (VolCT) and maximal fissural thickness (Fmax). Survival was estimated using the Kaplan-Meier method, and the relationship with VolCT was examined by Cox regression analysis to identify optimized cut-points. Performance of cTNM and quantitative models derived was compared in the test set using Harrell’s C index.

Results

A total of 472 patients met inclusion criteria. TNM staging was concordant with pathological TNM staging in 171 of 472 (36.2%), understaged in 209 (44.2%), and overstaged in 92 (19.4%) patients. The most concordant feature was involvement of interlobar fissures. A quantitative clinical staging model comprising VolCT and Fmax (c-index = 0.638, 95% confidence interval [CI] = 0.603 to 0.673) performed statistically significantly better as a prognostic classifier when compared in the test set with cTNM (c-index = 0.562, 95% CI = 0.525 to 0.599, P = .001).

Conclusions

Improved prognostic performance may be achievable by quantitative clinical staging combining VolCT and Fmax, providing a cost-effective and clinically relevant surrogate for clinical TNM stage.

Dose intensity of neoadjuvant FOLFIRINOX (FFX) in borderline and locally advanced pancreatic cancer (LAPC): A comparison to the adjuvant benchmark

392

Background: Optimal timing and duration of FFX for resectable, borderline resectable, and LAPC has not been established. The PRODIGE 24/CCTG PA.6 study used 12 cycles of adjuvant modified FFX (eliminating bolus 5FU, irinotecan at 150mg/m2) demonstrating superior DFS (21.6 mo) over gemcitabine (12.8 mo). However, only 48% of patients (pts) received 70% of intended chemo dosing, and 66.4% of pts completed all doses due to postoperative tolerability. We conducted total neoadjuvant therapy (TNT) studies in borderline and LAPC. (LAPC study included Losartan experimentally.) Dose intensity of TNT with FFX is compared to the benchmark adjuvant data. Methods: In this retrospective analysis, chemotherapy data were analyzed from NCT01821729 (LAPC) and NCT01591733 (Borderline). Both studies included 8 cycles of neoadjuvant FFX: b5FU 400mg/m2, CI 5U 1200mg/m2/d x 2d, oxaliplatin 85mg/m2, and irinotecan 180mg/m2. Results: 92 pts were studied: Borderline n = 43, LAPC n = 49. Sixteen of 92 (17.3%) patients discontinued chemotherapy prior to 8 cycles due to: withdrawal of consent (2), chemotherapy toxicity (6), progression (4), and disease-related complications (4). 82.6% of patients completed 8 doses. 61.4% of all bFU was given at the intended dose of 400 mg/m2. The mean relative dose intensity of b5FU (the actual cumulative dose relative to the planned cumulative dose over 8 cycles) was 72%. 65.5% of patients required a reduction in b5FU over eight cycles. Data for all chemotherapy are presented in Table 1. Overall, 71 of 92 patients (77.2%) had > 70% dose of FFX, with mean relative dose intensity of 81.2%. Among surgically resected patients, mPFS was 21.3 months in LAPC (n = 34) and 48.6 months in Borderline (n = 33). Conclusions: Compared to adjuvant therapy, dose intensity was achieved in a higher proportion of participants with TNT, utilizing a FFX regimen that included b5FU and irinotecan at 180mg/m2. PFS among resected patients reflects this highly active treatment. [Table: see text]

Protons versus Photons for Unresectable Hepatocellular Carcinoma: Liver Decompensation and Overall Survival

PURPOSE

Ablative radiation therapy is increasingly being used for hepatocellular carcinoma (HCC) resulting in excellent local control rates; however, patients without evidence of disease progression often die from liver failure. The clinical benefit of proton- over photon-based radiation therapy is unclear. We therefore sought to compare clinical outcomes of proton versus photon ablative radiation therapy in patients with unresectable HCC.

METHODS AND MATERIALS

This is a single-institution retrospective study of patients treated during 2008 to 2017 with nonmetastatic, unresectable HCC not previously treated with liver-directed radiation therapy and who did not receive further liver-directed radiation therapy within 12 months after completion of index treatment. The primary outcome, overall survival (OS), was assessed using Cox regression. Secondary endpoints included incidence of non-classic radiation-induced liver disease (defined as increase in baseline Child-Pugh score by ≥2 points at 3 months posttreatment), assessed using logistic regression, and locoregional recurrence, assessed using Fine-Gray regression for competing risks. All outcomes were measured from radiation start date.

RESULTS

The median follow-up was 14 months. Of 133 patients with median age 68 years and 75% male, 49 (37%) were treated with proton radiation therapy. Proton radiation therapy was associated with improved OS (adjusted hazard ratio, 0.47; P = .008; 95% confidence interval [CI], 0.27-0.82). The median OS for proton and photon patients was 31 and 14 months, respectively, and the 24-month OS for proton and photon patients was 59.1% and 28.6%, respectively. Proton radiation therapy was also associated with a decreased risk of non-classic radiation-induced liver disease (odds ratio, 0.26; P = .03; 95% CI, 0.08-0.86). Development of nonclassic RILD at 3 months was associated with worse OS (adjusted hazard ratio, 3.83; P < .001; 95% CI, 2.12-6.92). There was no difference in locoregional recurrence, including local failure, between protons and photons.

CONCLUSIONS

Proton radiation therapy was associated with improved survival, which may be driven by decreased incidence of posttreatment liver decompensation. Our findings support prospective investigations comparing proton versus photon ablative radiation therapy for HCC.

Efficacy of Alectinib in Patients with ALK-Positive NSCLC and Symptomatic or Large CNS Metastases

BACKGROUND

Central nervous system (CNS) metastases represent a significant source of morbidity and mortality for patients with ALK tyrosine kinase gene (ALK)-positive NSCLC. Alectinib has demonstrated robust CNS activity in both crizotinib-naive and crizotinib-resistant settings. However, the CNS efficacy of alectinib has not been established in patients with untreated symptomatic, large CNS metastases.

METHODS

In this retrospective study, patients were eligible if they had advanced ALK-positive NSCLC with large (defined as ≥1 cm) or symptomatic CNS metastases and received alectinib. Medical records and radiographic imaging were reviewed to determine treatment outcomes. CNS efficacy was assessed per the modified Response Evaluation Criteria in Solid Tumors version 1.1.

RESULTS

Of the 19 patients, 15 (79%) had measurable CNS disease at baseline and were evaluable for response. The CNS objective response rate in these patients was 73.3% (95% confidence interval [CI]: 44.9%-92.2%), the CNS disease control rate was 100.0% (95% CI: 78.2%-100.0%), and the median CNS duration of response was 19.3 months (95% CI: 14.3 months-not evaluable). In 18 evaluable patients with measurable and/or nonmeasurable baseline CNS disease, the CNS objective response rate was 72.2% (95% CI: 46.5%-90.3%), the CNS disease control rate was 100.0% (95% CI: 81.5%-100.0%), and the median CNS duration of response was 17.1 months (95% CI: 14.3 months-not evaluable). All eight patients with symptoms attributable to CNS metastases had clinical improvement upon starting alectinib therapy. Six patients (32%) eventually required salvage brain radiotherapy.

CONCLUSIONS

Alectinib demonstrated meaningful CNS efficacy in patients with ALK-positive NSCLC with untreated symptomatic or large brain metastases.

Increased Hepatotoxicity Associated with Sequential Immune Checkpoint Inhibitor and Crizotinib Therapy in Patients with Non-Small Cell Lung Cancer

INTRODUCTION

Immune checkpoint inhibitors (ICIs) are standard therapies in advanced NSCLC. Although genotype-directed tyrosine kinase inhibitors represent the standard of care for subsets of oncogene-driven NSCLC, patients may receive ICIs during their disease course. The impact of sequential ICI and tyrosine kinase inhibitor therapy on the risk of hepatotoxicity has not been described.

METHODS

Patients with advanced ALK receptor tyrosine kinase (ALK)-driven, ROS1-driven, or MET proto-oncogene, receptor tyrosine kinase (MET)-driven NSCLC treated with crizotinib, with or without preceding ICI therapy, were identified. The cumulative incidences of crizotinib-associated grade 3 or higher increases in transaminase level (per the Common Terminology Criteria for Adverse Events, version 4.0) were compared.

RESULTS

We identified 453 patients who had NSCLC with an oncogenic alteration in ALK receptor tyrosine kinase gene (ALK), ROS1, or MET proto-oncogene, receptor tyrosine kinase gene (MET) and were treated with crizotinib (11 with and 442 without prior ICI therapy). Among the 11 patients treated with an ICI followed by crizotinib, five (cumulative incidence 45.5% [95% confidence interval (CI): 14.9-72.2]) experienced development of a grade 3 or 4 increase in alanine transaminase level and four (cumulative incidence 36.4% [95% CI: 10.0-64.2]) experienced development of a grade 3 or 4 increase in aspartate transaminase level. In comparison, among the 442 patients who received crizotinib only, a grade 3 or 4 increase in alanine transaminase level occurred in 34 patients (cumulative incidence 8.1% [95% CI: 5.7-11.0, p < 0.0001]) and a grade 3 or 4 increase in aspartate transaminase level occurred in 14 (cumulative incidence 3.4% [95% CI: 1.9-5.5, p < 0.0001]). There were no grade 5 transaminitis events. All cases of hepatotoxicity after sequential ICI and crizotinib use were reversible and nonfatal, and no case met the Hy's law criteria.

CONCLUSIONS

Sequential ICI and crizotinib treatment is associated with a significantly increased risk of hepatotoxicity. Careful consideration and monitoring for hepatotoxicity may be warranted in patients treated with crizotinib after ICI therapy.

Clinical outcomes of patients with resected, early-stage ALK-positive lung cancer

OBJECTIVES

Reports of the prognostic significance of ALK-rearrangement in resected non-small cell lung cancer (NSCLC) have been contradictory. We aimed to determine the prognosis of early-stage ALK-positive lung cancers relative to KRAS- and EGFR-mutant lung cancers.

MATERIAL AND METHODS

We reviewed medical records of patients with resected NSCLC harboring an ALK rearrangement (n = 29) or a driver mutation in EGFR (n = 255) or KRAS (n = 480). Recurrence-free survival (RFS) was estimated for each genotype with the differences reported as a hazard ratio (HR).

RESULTS

Among the 764 patients, 555 (73%), 101 (13%), and 108 (14%) had stage I, II, and III NSCLC, respectively. ALK-positive patients were distributed across all stages: 10 (34%) stage I, 6 (21%) stage II, and 13 (45%) stage III. Median RFS was not reached for EGFR-mutant patients, 24.3 months (95%CI 11.4-65.3) for ALK-positive patients, and 72.9 months (95%CI 59.7 to undefined) for KRAS-mutant patients. When adjusted for stage, ALK-positive NSCLC remained associated with worse RFS compared to EGFR-mutant (HR 1.8, 95%CI: 1.1-3.1), but not when compared to KRAS-mutant (HR 1.3, 95%CI: 0.8-2.1) NSCLC.

CONCLUSIONS

In this large series of resected NSCLC, ALK rearrangements were associated with a trend toward inferior disease outcomes compared to other clinically relevant genomic subsets. These data support the need for clinical trials evaluating use of ALK inhibitors among ALK-positive patients with localized or locally-advanced disease.

Abstract 2972: Co-clinical trial of olaparib and temozolomide in SCLC PDX models uncovers new biomarkers of sensitivity

Introduction: Small cell lung cancer (SCLC) is a common and rapidly fatal malignancy for which no biomarker-targeted therapies have been developed. Despite a critical need, progress suffers from (1) scarcity of cutting-edge laboratory models and (2) absence of promising targets. Patient-derived xenografts (PDX) may faithfully model the clinical disease, but because SCLC is rarely biopsied or resected, specimens for PDX generation are scarce. PARP inhibition has recently emerged as a compelling strategy for SCLC, and an ongoing phase 1/2 trial of combination olaparib tablets and temozolomide (O/T) has shown promising activity in patients. However, biomarkers for patient selection remain elusive.

Methods: We generated SCLC PDX models from circulating tumor cells (CTCs), biopsies and malignant effusions. CTCs were enriched with an automated microfluidic device, the CTC-iChip. To assess the genomic fidelity of the models, we performed comparative whole exome sequencing (WES) and RNA-seq on 6 sets of corresponding patient biopsies, founder (P0) PDX tumors, and early-passage PDXs. We then assessed the activity of combination O/T in a panel of PDX models, and compared PDX responses with molecular profiles to identify candidate biomarkers.

Results: 44 PDXs were generated from 32 patients, including 6 sets of serial models and 4 synchronous CTC- and biopsy-derived models. PDXs were derived with high efficiency from both CTCs (35% per blood draw) and biopsies/effusions (82% per implant). WES demonstrated that somatic alterations in tumor biopsies were stably maintained in both CTC and biopsy-derived models, without significant accumulation of new mutations, and transcriptional profiles remained consistent through early passages. Six models were derived from O/T trial patients, including two sets of serial models before and after durable responses. The serial models faithfully recapitulated patient responses to O/T: pre-trial models were highly sensitive and post-relapse were highly resistant. The co-clinical trial was expanded to 30 models, using the models derived from trial patients to delineate the margins of clinical sensitivity (6 models), intermediate sensitivity (6 models) and resistance (18 models). Among the molecular features evaluated, basal protein PARylation best distinguished the O/T-sensitive category from both intermediate (p &lt; 0.001) and resistant models (p &lt; 0.0001). In addition, PARylation decreased after relapse in serial models from O/T trial patients.

Conclusions: Both biopsy- and CTC-derived SCLC PDX models faithfully recapitulate the genomic and functional features of the donor patient tumor. O/T sensitivity in this panel correlated with basal PARylation. The value of the co-clinical trial is the potential to refine the clinical application of O/T in real time, to optimize follow-on clinical trials and to develop biomarker-directed therapy for SCLC.

Citation Format: Benjamin J. Drapkin, Julie George, Marcello Stanzione, Beow Y. Yeap, Mari Mino-Kenudson, Camilla L. Christensen, Ruben Dries, Sarah Phat, Jun Zhong, David T. Myers, Joseph A. Licausi, Tilak Sundaresan, Marina Kem, Nima Abedpour, Leica V. Sequist, Alice T. Shaw, Aaron N. Hata, Mehmet Toner, Shyamala Maheswaran, Daniel A. Haber, Martin Peifer, Roman K. Thomas, Anna F. Farago, Nicholas J. Dyson. Co-clinical trial of olaparib and temozolomide in SCLC PDX models uncovers new biomarkers of sensitivity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2972.

Brigatinib in Patients With Alectinib-Refractory ALK-Positive NSCLC

INTRODUCTION

The second-generation anaplastic lymphoma kinase (ALK) inhibitor alectinib recently showed superior efficacy compared to the first-generation ALK inhibitor crizotinib in advanced ALK-rearranged NSCLC, establishing alectinib as the new standard first-line therapy. Brigatinib, another second-generation ALK inhibitor, has shown substantial activity in patients with crizotinib-refractory ALK-positive NSCLC; however, its activity in the alectinib-refractory setting is unknown.

METHODS

A multicenter, retrospective study was performed at three institutions. Patients were eligible if they had advanced, alectinib-refractory ALK-positive NSCLC and were treated with brigatinib. Medical records were reviewed to determine clinical outcomes.

RESULTS

Twenty-two patients were eligible for this study. Confirmed objective responses to brigatinib were observed in 3 of 18 patients (17%) with measurable disease. Nine patients (50%) had stable disease on brigatinib. The median progression-free survival was 4.4 months (95% confidence interval [CI]: 1.8-5.6 months) with a median duration of treatment of 5.7 months (95% CI: 1.8-6.2 months). Among 9 patients in this study who underwent post-alectinib/pre-brigatinib biopsies, 5 had an ALK I1171X or V1180L resistance mutation; of these, 1 had a confirmed partial response and 3 had stable disease on brigatinib. One patient had an ALK G1202R mutation in a post-alectinib/pre-brigatinib biopsy, and had progressive disease as the best overall response to brigatinib.

CONCLUSIONS

Brigatinib has limited clinical activity in alectinib-refractory ALK-positive NSCLC. Additional studies are needed to establish biomarkers of response to brigatinib and to identify effective therapeutic options for alectinib-resistant ALK-positive NSCLC patients.

An Update From the Pediatric Proton Consortium Registry

Background/objectives

The Pediatric Proton Consortium Registry (PPCR) was established to expedite proton outcomes research in the pediatric population requiring radiotherapy. Here, we introduce the PPCR as a resource to the oncology community and provide an overview of the data available for further study and collaboration.

Design/methods

A multi-institutional registry of integrated clinical, dosimetric, radiographic, and patient-reported data for patients undergoing proton radiation therapy was conceived in May 2010. Massachusetts General Hospital began enrollment in July of 2012. Subsequently, 12 other institutions joined the PPCR and activated patient accrual, with the latest joining in 2017. An optional patient-reported quality of life (QoL) survey is currently implemented at six institutions. Baseline health status, symptoms, medications, neurocognitive status, audiogram findings, and neuroendocrine testing are collected. Treatment details of surgery, chemotherapy, and radiation therapy are documented and radiation plans are archived. Follow-up is collected annually. Data were analyzed 25 September, 2017.

Results

A total of 1,854 patients have consented and enrolled in the PPCR from October 2012 until September 2017. The cohort is 55% male, 70% Caucasian, and comprised of 79% United States residents. Central nervous system (CNS) tumors comprise 61% of the cohort. The most common CNS histologies are as follows: medulloblastoma (n = 276), ependymoma (n = 214), glioma/astrocytoma (n = 195), craniopharyngioma (n = 153), and germ cell tumors (n = 108). The most common non-CNS tumors diagnoses are as follows: rhabdomyosarcoma (n = 191), Ewing sarcoma (n = 105), Hodgkin lymphoma (n = 66), and neuroblastoma (n = 55). The median follow-up is 1.5 years with a range of 0.14 to 4.6 years.

Conclusion

A large prospective population of children irradiated with proton therapy has reached a critical milestone to facilitate long-awaited clinical outcomes research in the modern era. This is an important resource for investigators both in the consortium and for those who wish to access the data for academic research pursuits.