Phase II Study of Erdafitinib in Patients With Tumors With Fibroblast Growth Factor Receptor Mutations or Fusions: Results From the NCI-MATCH ECOG-ACRIN Trial (EAY131) Subprotocol K2

PURPOSE

Subprotocol K2 (EAY131-K2) of the NCI-MATCH platform trial was an open-label, single-arm, phase II study designed to evaluate the antitumor efficacy of the oral FGFR1-4 inhibitor, erdafitinib, in patients with tumors harboring FGFR1-4 mutations or fusions.

METHODS

Central confirmation of tumor FGFR1-4 mutations or fusions was required for outcome analysis. Patients with urothelial carcinoma were excluded. Enrolled subjects received oral erdafitinib at a starting dose of 8 mg daily continuously until intolerable toxicity or disease progression. The primary end point was objective response rate (ORR) with key secondary end points of safety, progression-free survival (PFS), and overall survival (OS).

RESULTS

Thirty-five patients were enrolled, and 25 patients were included in the primary efficacy analysis as prespecified in the protocol. The median age was 61 years, and 52% of subjects had received ≥3 previous lines of therapy. The confirmed ORR was 16% (4 of 25 [90% CI, 5.7 to 33.0], P = .034 against the null rate of 5%). An additional seven patients experienced stable disease as best-confirmed response. Four patients had a prolonged PFS including two with recurrent WHO grade IV, IDH1-/2-wildtype glioblastoma. The median PFS and OS were 3.6 months and 11.0 months, respectively. Erdafitinib was manageable with no new safety signals.

CONCLUSION

This study met its primary end point in patients with several pretreated solid tumor types harboring FGFR1-3 mutations or fusions. These findings support advancement of erdafitinib for patients with fibroblast growth factor receptor-altered tumors outside of currently approved indications in a potentially tumor-agnostic manner.

Phase II Study of Erdafitinib in Patients With Tumors With FGFR Amplifications: Results From the NCI-MATCH ECOG-ACRIN Trial (EAY131) Subprotocol K1

PURPOSE

Despite fibroblast growth factor receptor (FGFR) inhibitors being approved in tumor types with select FGFR rearrangements or gene mutations, amplifications of FGFR represent the most common FGFR alteration across malignancies. Subprotocol K1 (EAY131-K1) of the National Cancer Institute-MATCH platform trial was designed to evaluate the antitumor efficacy of the oral FGFR1-4 inhibitor, erdafitinib, in patients with tumors harboring FGFR1-4 amplification.

METHODS

EAY131-K1 was an open-label, single-arm, phase II study with central confirmation of presence of FGFR1-4 amplification in tumors. Patients with urothelial carcinoma were excluded. Enrolled patients received oral erdafitinib at a starting dose of 8 mg once daily continuously with escalation to 9 mg once daily continuously, on the basis of predefined time point assessments of phosphate levels, until disease progression or intolerable toxicity. The primary end point was centrally assessed objective response rate (ORR), with key secondary end points being 6-month progression-free survival (PFS6), PFS, overall survival (OS), and safety.

RESULTS

Thirty-five patients were enrolled into this study with 18 included in the prespecified primary efficacy analysis. The median age of the 18 patients was 60 years, and 78% had received ≥3 previous lines of therapy. There were no confirmed responses to erdafitinib; however, five patients experienced stable disease (SD) as best response. One patient with an FGFR1-amplified breast cancer had a prolonged PFS >168 days (5.5 months). The median PFS was 1.7 months (90% CI, 1.1 to 1.8 months) and the median OS was 4.2 months (90% CI, 2.3 to 9.3 months). The estimated PFS6 rate was 13.8% (90% CI, 3.3 to 31.6). The majority of toxicities were grade 1 to 2 in nature, although there was one grade 5 treatment-related adverse event.

CONCLUSION

Erdafitinib did not meet its primary end point of efficacy as determined by ORR in treatment-refractory solid tumors harboring FGFR1-4 amplifications. Our findings support that rearrangements and gene mutations, but not amplifications, of FGFR remain the established FGFR alterations with approved indications for FGFR inhibition.

Impact of the 2021 CKD-EPI equation on anticancer pharmacotherapy in black and non-black cancer patients

Cancer and kidney disease disproportionately impact Black patients. The CKD-EPI2021 equation was developed to estimate glomerular filtration rate (eGFR) without using race. We assessed the impact of using CKD-EPI2021 instead of CKD-EPI2009 or Cockcroft-Gault (CG) on dosing and eligibility of anticancer drugs in Black and non-Black patients. Utilizing the National Cancer Institute Theradex database, deindexed eGFR (mL/min) was calculated for 3931 patients (8.6 % Black) using CKD-EPI2021, CKD-EPI2009, and CG. Dosing simulations based on each eGFR were performed for ten anticancer drugs with kidney function-based eligibility or dosing cutoffs. eGFR differences using CKD-EPI2021 versus CKD-EPI2009 varied between Black and non-Black patients (p < 0.001); on average, Black patients had 10.3 mL/min lower eGFR and non-Black patients had 4.2 mL/min higher eGFR using CKD-EPI2021. This corresponded to a difference in relative odds of cisplatin ineligibility using CKD-EPI2021 versus CKD-EPI2009; Black patients had 48 % higher odds of ineligibility and non-Black patients had 27 % lower odds of ineligibility using CKD-EPI2021 (p < 0.001). When using CKD-EPI2021 versus CG, eGFR differences were similar between Black and non-Black patients (p = 0.679) and relative difference in odds of cisplatin ineligibility did not vary. Using CKD-EPI2021 versus CKD-EPI2009 differentially impacts Black versus non-Black cancer patients; Black patients have lower calculated eGFR and are less likely to receive full doses of drug using CKD-EPI2021. From the historical default of CG, adopting CKD-EPI2021 would not disparately impact patients based on race, but would result in Black patients being less likely to receive full doses of drug than if CKD-EPI2009 were used.

Circulating Tumor DNA Dynamics Fail to Predict Efficacy of Poly(ADP-ribose) Polymerase/VEGFR Inhibition in Patients With Heavily Pretreated Advanced Solid Tumors

PURPOSE

Cell-free circulating tumor DNA (ctDNA) has shown its potential as a quantitative biomarker for longitudinal monitoring of response to anticancer therapies. However, ctDNA dynamics have not been studied in patients with heavily pretreated, advanced solid tumors, for whom therapeutic responses can be weak. We investigated whether changes in ctDNA could predict clinical outcomes in such a cohort treated with combined poly(ADP-ribose) polymerase/vascular endothelial growth factor receptor inhibitor therapy.

MATERIALS AND METHODS

Patients with metastatic pancreatic ductal adenocarcinoma (PDAC), triple-negative breast cancer (TNBC), small-cell lung cancer (SCLC), or non-small-cell lung cancer (NSCLC) received up to 7 days of cediranib 30 mg orally once daily monotherapy lead-in followed by addition of olaparib 200 mg orally twice daily. Patients had progressed on a median of three previous lines of therapy. Plasma samples were collected before and after cediranib monotherapy lead-in and on combination therapy at 7 days, 28 days, and every 28 days thereafter. ctDNA was quantified from plasma samples using a multigene mutation-based assay. Radiographic assessment was performed every 8 weeks.

RESULTS

ctDNA measurements were evaluable in 63 patients. The median baseline ctDNA variant allele fractions (VAFs) were 20%, 28%, 27%, and 34% for PDAC, TNBC, SCLC, and NSCLC, respectively. No association was observed between baseline VAF and radiographic response, progression-free survival, or overall survival (OS). Similarly, no association was found between ctDNA decline and radiographic response or survival. However, an increase in ctDNA at 56 days of combination therapy was associated with disease progression and inferior OS in a landmark analysis.

CONCLUSION

ctDNA levels or dynamics did not correlate with radiographic response or survival outcomes in patients with advanced metastatic malignancies treated with olaparib and cediranib.

The New NCI Precision Medicine Trials

Basket, umbrella, and platform trial designs (master protocols) have emerged over the last decade to study precision medicine approaches in oncology. First-generation trials like NCI-MATCH (Molecular Analysis for Therapy Choice) have proven the principle that studying targeted therapies on a large scale is feasible both from the laboratory and clinical perspectives. However, single-agent targeted therapies have shown limited ability to control metastatic disease, despite careful matching of drug to target. As such, newer approaches employing combinations of targeted therapy, or targeted therapy with standard therapies, need to be considered. The NCI has recently embarked on three second-generation precision medicine trials to address this need: ComboMATCH, iMATCH, and myeloMATCH. The design of these trials and necessary infrastructure are discussed in the following perspective.

Phase II Study of Olaparib and Temozolomide for Advanced Uterine Leiomyosarcoma (NCI Protocol 10250)

PURPOSE

Uterine leiomyosarcoma (uLMS) is an aggressive subtype of soft-tissue sarcoma with frequent metastatic relapse after curative surgery. Chemotherapy provides limited benefit for advanced disease. Multiomics profiling studies have identified homologous recombination deficiency in uLMS. In preclinical studies where olaparib and temozolomide provided modest activity, the combination was highly effective for inhibiting uLMS tumor growth.

PATIENTS AND METHODS

NCI Protocol 10250 is a single-arm, open-label, multicenter, phase II study evaluating olaparib and temozolomide in advanced uLMS. Patients with progression on ≥1 prior line received temozolomide 75 mg/m2 orally once daily with olaparib 200 mg orally twice a day both on days 1-7 in 21-day cycles. The primary end point was the best objective response rate (ORR) within 6 months. A one-stage binomial design was used. If ≥5 of 22 responded, the treatment would be considered promising (93% power; α = .06). All patients underwent paired biopsies that were evaluated with whole-exome sequencing (WES)/RNAseq and a RAD51 foci formation assay.

RESULTS

Twenty-two patients were evaluable. The median age was 55 years, and 59% had received three or more prior lines. Best ORR within 6 months was 23% (5 of 22). The overall ORR was 27% (6 of 22). The median progression-free survival (mPFS) was 6.9 months (95% CI, 5.4 months to not estimable). Hematologic toxicity was common (grade 3/4 neutropenia: 75%; thrombocytopenia: 32%) but manageable with dose modification. Five of 16 (31%) of tumors contained a deleterious homologous recombination gene alteration by WES, and 9 of 18 (50%) were homologous recombination-deficient by the RAD51 assay. In an exploratory analysis, mPFS was prolonged for patients with homologous recombination-deficient versus homologous recombination-proficient tumors (11.2 v 5.4 months, P = .05) by RAD51.

CONCLUSION

Olaparib and temozolomide met the prespecified primary end point and provided meaningful clinical benefit in patients with advanced, pretreated uLMS.

Randomized Phase II Trial of Sunitinib or Cediranib in Alveolar Soft Part Sarcoma

PURPOSE

Alveolar soft part sarcoma (ASPS) is a rare, highly vascular tumor with few treatment options. We designed a phase II randomized trial to determine the activity and tolerability of single-agent cediranib or sunitinib in patients with advanced metastatic ASPS.

PATIENTS AND METHODS

Patients 16 years of age and older were randomized to receive cediranib (30 mg) or sunitinib (37.5 mg) in 28-day cycles. Patients could cross over to the other treatment arm at disease progression. The primary endpoint was to measure the objective response rate (ORR) for each agent. Median progression-free survival (mPFS) for the two arms was also determined.

RESULTS

Twenty-nine of 34 enrolled patients were evaluable for response. One patient on each of the initial two treatment arms had a partial response (ORR: 6.7% and 7.1% for cediranib and sunitinib, respectively). Twenty-four patients had a best response of stable disease (86.7% and 78.6% for cediranib and sunitinib, respectively). There were no significant differences in mPFS for the two treatment arms. Clinical benefit (i.e., objective response or stable disease for a minimum of four or six cycles of therapy) on the first-line tyrosine kinase inhibitor (TKI) therapy did not predict benefit on the second-line TKI. Both drugs were well tolerated. As of August 2021, 1 patient (unevaluable for ORR) remains on study.

CONCLUSIONS

The study did not meet its endpoints for ORR. Although both TKIs provided clinical benefit, the outcomes may have been attenuated in patients who had progressed ≤6 months before enrollment, potentially accounting for the low response rates. See related commentary by Wilky and Maleddu, p. 1163.

A Phase I Study of Combination Olaparib and Radium-223 in Men with Metastatic Castration-Resistant Prostate Cancer (mCRPC) with Bone Metastases (COMRADE)

Given that radium-223 is a radiopharmaceutical that induces DNA damage, and olaparib is a PARP inhibitor that interferes with DNA repair mechanisms, we hypothesized their synergy in metastatic castration-resistant prostate cancer (mCRPC). We sought to demonstrate the safety and efficacy of olaparib + radium-223. We conducted a multicenter phase I 3+3 dose escalation study of olaparib with fixed dose radium-223 in patients with mCRPC with bone metastases. The primary objective was to establish the RP2D of olaparib, with secondary objectives of safety, PSA response, alkaline phosphatase response, radiographic progression-free survival (rPFS), overall survival, and efficacy by homologous recombination repair (HRR) gene status. Twelve patients were enrolled; all patients received a prior androgen receptor signaling inhibitor (ARSI; 100%) and 3 patients (25%) prior docetaxel. Dose-limiting toxicities (DLT) included cytopenias, fatigue, and nausea. No DLTs were seen in the observation period however delayed toxicities guided the RP2D. The RP2D of olaparib was 200 mg orally twice daily with radium-223. The most common treatment-related adverse events were fatigue (92%) and anemia (58%). The rPFS at 6 months was 58% (95% confidence interval, 27%-80%). Nine patients were evaluable for HRR gene status; 1 had a BRCA2 alteration (rPFS 11.8 months) and 1 had a CDK12 alteration (rPFS 3.1 months). Olaparib can be safely combined with radium-223 at the RP2D 200 mg orally twice daily with fixed dose radium-223. Early clinical benefit was observed and will be investigated in a phase II study.

A phase 1 study of veliparib (ABT-888) plus weekly carboplatin and paclitaxel in advanced solid malignancies, with an expansion cohort in triple negative breast cancer (TNBC) (ETCTN 8620)

BACKGROUND

Veliparib is a poly-ADP-ribose polymerase (PARP) inhibitor, and it has clinical activity with every 3 weeks carboplatin and paclitaxel. In breast cancer, weekly paclitaxel is associated with improved overall survival. We aimed to determine the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of veliparib with weekly carboplatin and paclitaxel as well as safety, pharmacokinetics, and preliminary clinical activity in triple negative breast cancer (TNBC).

METHODS

Patients with locally advanced/metastatic solid tumors and adequate organ function were eligible. A standard 3 + 3 dose-escalation design was followed by a TNBC expansion cohort. Veliparib doses ranging from 50 to 200 mg orally bid were tested with carboplatin (AUC 2) and paclitaxel (80 mg/m2) given weekly in a 21-day cycle. Adverse events (AE) were evaluated by CTCAE v4.0, and objective response rate (ORR) was determined by RECIST 1.1.

RESULTS

Thirty patients were enrolled, of whom 22 had TNBC. Two dose-limiting toxicities were observed. The RP2D was determined to be 150 mg PO bid veliparib with weekly carboplatin and paclitaxel 2 weeks on, 1 week off, based on hematologic toxicity requiring dose reduction in the first 5 cycles of treatment. The most common grade 3/4 AEs included neutropenia, anemia, and thrombocytopenia. PK parameters of veliparib were comparable to single-agent veliparib. In 23 patients with evaluable disease, the ORR was 65%. In 19 patients with TNBC with evaluable disease, the ORR was 63%.

CONCLUSION

Veliparib can be safely combined with weekly paclitaxel and carboplatin, and this triplet combination has promising clinical activity.

Multicenter Phase II Trial of the PARP Inhibitor Olaparib in Recurrent IDH1- and IDH2-mutant Glioma

Purpose

Isocitrate dehydrogenase (IDH) 1 and IDH2 mutations (IDH1/2mt) are frequent in glioma. Preclinical studies suggest IDH1/2mts confer "BRCAness" phenotype, a vulnerability that can be targeted through PARP inhibition. To test this hypothesis, we conducted a multicenter study of olaparib monotherapy in patients with IDH1/2mt gliomas.

Methods

Patients with recurrent, contrast-enhancing IDH1/2mt gliomas were enrolled in a two-step phase II trial; the primary endpoint was overall response rate per Response Assessment in Neuro-Oncology (RANO) criteria. Olaparib 300 mg orally twice daily was given.

Results

A total of 15 evaluable patients were enrolled. Histology was astrocytoma (N = 12) and oligodendroglioma (N = 3). Most toxicities were grade 1 or 2. Best response was stable disease (SD) in 9 (60%) patients. Median progression-free survival (PFS) was 3.63 months and median overall survival was 20.7 months. For patients with SD, median PFS was 5.53 months; 4 patients had SD for >6 months. Among patients with best response progressive disease (N = 6), 5 had grade 4 tumor and 4 had known CDKN2A alteration. PFS was 5.23 months for grades 2 or 3 tumors (N = 10) versus 1.8 months for grade 4 (N = 5; P = 0.0013).

Conclusion

The study did not meet the prespecified response-based activity threshold for moving to step 2. However, prolonged SD was observed in patients with grades 2 and 3 histologies, suggesting olaparib monotherapy could be of clinical benefit in select populations. Grade 4 tumors per 2021 World Health Organization classification defined by histology or CDKN2A alteration derived no benefit from this drug, highlighting the usefulness of this classification for future patient stratification and trial design.

Significance

A single-arm phase II trial of olaparib in IDH-mutant glioma demonstrated clinically significant prolonged SD for select patients with grade 2/3 disease, suggesting potential benefit of olaparib in IDH-mutant gliomas.

Randomized Trial of Olaparib With or Without Cediranib for Metastatic Castration-Resistant Prostate Cancer: The Results From National Cancer Institute 9984

PURPOSE

Cediranib, a pan-vascular endothelial growth factor receptor inhibitor, suppresses expression of homologous recombination repair (HRR) genes and increases sensitivity to poly-(ADP-ribose) polymerase inhibition in preclinical models. We investigated whether cediranib combined with olaparib improves the clinical outcomes of patients with prostate cancer.

METHODS

Patients with progressive metastatic castration-resistant prostate cancer (mCRPC) were randomly assigned 1:1 to arm A: cediranib 30 mg once daily plus olaparib 200 mg twice daily or arm B: olaparib 300 mg twice daily alone. The primary end point was radiographic progression-free survival (rPFS) in the intention-to-treat patients. The secondary end points were rPFS in patients with HRR-deficient and HRR-proficient mCRPC.

RESULTS

In the intention-to-treat set of 90 patients, median rPFS was 8.5 (95% CI, 5.4 to 12.0) and 4.0 (95% CI, 3.2 to 8.5) months in arms A and B, respectively. Cediranib/olaparib significantly improved rPFS versus olaparib alone (hazard ratio [HR], 0.617; 95% CI, 0.392 to 0.969; P = .0359). Descriptive analyses showed a median rPFS of 10.6 (95% CI, 5.9 to not assessed [NA]) and 3.8 (95% CI, 2.33 to NA) months (HR, 0.64; 95% CI, 0.272 to 1.504) among patients with HRR-deficient mCRPC, and 13.8 (95% CI, 3.3 to NA) and 11.3 (95% CI, 3.8 to NA) months (HR, 0.98; 95% CI, 0.321 to 2.988) among patients with BRCA2-mutated mCRPC in arms A and B, respectively. The incidence of grades 3-4 adverse events was 61% and 18% in arms A and B, respectively.

CONCLUSION

Cediranib combined with olaparib improved rPFS compared with olaparib alone in men with mCRPC. This combination was associated with an increased incidence of grades 3-4 adverse events. BRCA2-mutated subgroups treated with olaparib with or without cediranib were associated with a numerically longer median rPFS.

Implementing Modernized Eligibility Criteria in US National Cancer Institute Clinical Trials

In 2018, the Cancer Therapy Evaluation Program (CTEP) at the US National Cancer Institute published new protocol template language that focused on organ function and prior and concurrent cancers in an effort to modernize eligibility criteria for cancer treatment trials. We conducted an analysis of CTEP-supported trials to evaluate the uptake and incorporation of the new language. The analysis included evaluation of 122 protocols approved in the years 2018-2020 for inclusion of the modernized eligibility criteria and consistency with new protocol template language related to 7 major eligibility criteria. These were cardiac function, liver function, kidney function, HIV status, prior and/or concurrent malignancies, treated and/or stable brain metastasis, and new and/or progressive brain metastases. Overall, CTEP trials evaluated in this period demonstrated that eligibility criteria were implemented to a relatively high degree ranging from a low of 54.1% for prior and/or concurrent malignancies to a high of 93.4% for eligibility criteria related to HIV infection. The findings demonstrate that modernized eligibility criteria can be successfully implemented but that consistent implementation requires sustained focused effort. As a result of these findings, CTEP began a new initiative in January 2022 that incorporates a specific review of eligibility criteria for new protocols to promote and improve consistency with the modernization effort.

Early drug development in solid tumours: analysis of National Cancer Institute-sponsored phase 1 trials

BACKGROUND

The low expectation of clinical benefit from phase 1 cancer therapeutics trials might negatively affect patient and physician participation, study reimbursement, and slow the progress of oncology research. Advances in cancer drug development, meanwhile, might have favourably improved treatment responses; however, little comprehensive data exist describing the response and toxicity associated with phase 1 trials across solid tumours. The aim of the study is to evaluate the trend of toxicity and response in phase 1 trials for solid tumours over time.

METHODS

We analysed patient-level data from the Cancer Therapy Evaluation Program of the National Cancer Institute-sponsored investigator-initiated phase 1 trials for solid tumours, from Jan 1, 2000, to May 31, 2019. We assessed risks of treatment-related death (grade 5 toxicity ratings possibly, probably, or definitely attributable to treatment), all on-treatment deaths (deaths during protocol treatment regardless of attribution), grade 3-4 toxicity, and proportion of overall response (complete response and partial response) and complete response rate in the study periods of 2000-05, 2006-12, and 2013-2019, and evaluated their trends over time. We also analysed cancer type-specific and investigational agent-specific response, and analysed the trend of response in each cancer type over time. Univariate associations of overall response rates with patients' baseline characteristics (age, sex, performance status, BMI, albumin concentration, and haemoglobin concentration), enrolment period, investigational agents, and trial design were assessed using risk ratio based on the modified Poisson regression model.

FINDINGS

We analysed 465 protocols that enrolled 13 847 patients using 261 agents. 144 (31%) trials used a monotherapy and 321 (69%) used combination therapies. The overall treatment-related death rate was 0·7% (95% CI 0·5-0·8) across all periods. Risks of treatment-related deaths did not change over time (p=0·52). All on-treatment death risk during the study period was 8·0% (95% CI 7·6-8·5). The most common grade 3-4 adverse events were haematological; grade 3-4 neutropenia occurred in 2336 (16·9%) of 13 847 patients, lymphopenia in 1230 (8·9%), anaemia in 894 (6·5%), and thrombocytopenia in 979 (7·1%). The overall response rate for all trials during the study period was 12·2% (95% CI 11·5-12·8; 1133 of 9325 patients) and complete response rate was 2·7% (2·4-3·0; 249 of 9325). Overall response increased from 9·6% (95% CI 8·7-10·6) in 2000-05 to 18·0% (15·7-20·5) in 2013-19, and complete response rates from 2·5% (2·0-3·0) to 4·3% (3·2-5·7). Overall response rates for combination therapy were substantially higher than for monotherapy (15·8% [15·0-16·8] vs 3·5% [2·8-4·2]). The overall response by class of agents differed across diseases. Anti-angiogenesis agents were associated with higher overall response rate for bladder, colon, kidney and ovarian cancer. DNA repair inhibitors were associated with higher overall response rate in ovarian and pancreatic cancer. The rates of overall response over time differed markedly by disease; there were notable improvements in bladder, breast, and kidney cancer and melanoma, but no change in the low response of pancreatic and colon cancer.

INTERPRETATION

During the past 20 years, the response rate in phase 1 trials nearly doubled without an increase in the treatment-related death rate. However, there is significant heterogeneity in overall response by various factors such as cancer type, investigational agent, and trial design. Therefore, informed decision making is crucial for patients before participating in phase 1 trials. This study provides updated encouraging outcomes of modern phase 1 trials in solid tumours.

FUNDING

National Cancer Institute.

Survey of Lifestyle, Past Medical History and Complementary and Alternative Medicine Use Among Adult Patients Participating in the National Cancer Institute's Exceptional Responders Initiative

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Fifty percent of exceptional responders changed diet after cancer diagnosis.

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Forty percent of exceptional responders changed level of physical activity after cancer diagnosis

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Sixty percent of subjects reported using complementary and alternative approaches during exceptional response period

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Complementary and alternative medicine users generally used multiple interventions

Introduction

The Exceptional Responders Initiative (ERI) at the National Cancer Institute attempts to correlate unusually good outcomes in patients with cancer with genetic targets in tumors and the therapies the patients received. It is not known if other factors might contribute to exceptional responses or outcomes. We explored aspects of the medical history, lifestyle changes, complementary and alternative medicine (CAM) use and communication between health care practitioners and patients who experienced an exceptional response following cancer treatment.

Methods

All subjects whose case was submitted to the ERI were eligible to participate in the survey. A 121-question survey questionnaire was developed to assess aspects of the subject's past medical history, lifestyle (e.g., diet, exercise, spirituality) and use of CAM.

Results

Thirty subjects completed and returned the questionnaire from approximately 88 patients invited to participate (approximate response rate = 34%). Approximately 68% were female and 32% were male. Fifty percent of subjects changed their diet after their cancer diagnosis. Eighteen patients (60%) reported using a CAM therapy (not including oral vitamins/minerals or spiritual practices) during their Exceptional Response (ER).

Conclusion

Multiple factors, including features of the tumor itself, the patient, or the environment, could affect tumor response or patient survival, either solely or in combination with the treatments received. Many patients use other medications, change their diet or physical activity or use CAM interventions after their cancer diagnosis. Investigators attempting to understand the exceptional response phenomenon should acquire rich data sets of their subjects that include information about these factors.

Abstract CT168: Randomized phase 2 trial of sunitinib or cediranib in alveolar soft part sarcoma

Background: Alveolar soft part sarcoma (ASPS) is a rare, highly vascular tumor with few effective treatment options. Cediranib (C) and sunitinib (S) are potent oral inhibitors of all 3 VEGF receptors. Cediranib showed substantial single-agent activity (objective response rate [ORR] = 35%) in our previous trial in patients (pts) with metastatic ASPS (NCT00942877). Here we report a phase 2 randomized multicenter trial of single agent C or S in pts with ASPS (NCT01391962).

Methods: We conducted a multicenter phase 2 trial with an optimal 2-stage design targeting an ORR of 40%. Enrolled pts were &gt;16 years with metastatic ASPS, previously not treated (N) and unresectable, or previously treated (T), who have progressed per RECIST 1 within the 6-month period preceding enrollment. Pts were randomized to receive C (30 mg) or S (37.5 mg) orally, once a day, in 28-day cycles and could crossover to the other treatment arm at disease progression. ORR (primary endpoint), median progression-free survival (mPFS), and PFS rate at 24 weeks for the 2 arms (C and S) were evaluated; T and N cohorts were assessed separately in each arm. Arm accrual closed if ≤ 1 of the first 10 enrolled pts responded to the first treatment.

Results: Thirty-four pts (47% white, 29.4% black, 17.6% Asian, 5.8% Pacific Islander) were enrolled; 29 pts were evaluable for response. One pt on each of the initial treatment arms had a confirmed partial response (PR), rates of 6.7% (1/154) and 7.1% (1/14) for C and S tx or tx-naive, respectively. Among pts who crossed over, there was 1 PR in a pt receiving C after initially responding (PR) on S (1/9; ORR 11.1%). Twenty-four pts had a best response of stable disease (86.7% and 78.6%) for C and S, respectively. The mPFS was 7.6 months (mo) (95% CI: 3.7-9.9 mo) and 5.5 mo (95% CI: 1.8-14.5 mo) for C and S, respectively administered as first therapy (p=0.92). PFS rate at 24 weeks was 62.5% (95% CI: 29.5-76.2%) and 50% (95% CI: 25.9-70.1%) for pts receiving C and S respectively, as initial therapy. There was no difference in mPFS between T or N pts in the C (6.7 mo [95% CI: 1.4-9.9 mo] vs 8.3 mo [95% CI: 2.7 - 16.6 mo]; P=0.35) arm, but some evidence of a potential difference in the S (4.8 mo [95% CI: 0.9-7.9 mo] vs 14.7 mo 95% CI: 1.8 - 21.6 mo]; P=0.058) arm. Overall, 43.7% (C) and 77.8% (S) of pts experienced grade ≥3 adverse events (AEs) at least possibly related to the study drug. Common grade ≥3 AEs included: diarrhea (C), neutropenia (S), hypertension (C and S). AEs were in line with the known safety profiles of each agent. As of August 2021, 1 pt (unevaluable for ORR) remains on study.

Conclusions: The study did not meet its endpoints for ORR. There were no differences in mPFS for the 2 treatment arms. The selection of pts with more aggressive disease, who had progressed in the 6 months prior to enrollment, may account for the low patient response rates compared to our previous study of cediranib in ASPS.

Funded by NCI Contract No. HHSN261200800001E. The study was a collaboration between NCI and Pfizer.

Citation Format: Naoko Takebe, James Nguyen, Shivaani Kummar, Albiruni Abdul Razak, Sant P. Chawla, Suzanne George, Shreyaskumar R. Patel, Mary Louise Keohan, Sujana Movva, Geraldine O’Sullivan, Khanh Do, Larry Anderson, Lamin Juwara, Brooke Augustine, Seth Steinberg, Laura Kuhlmann, S. Percy Ivy, James H. Doroshow, Alice P. Chen. Randomized phase 2 trial of sunitinib or cediranib in alveolar soft part sarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT168.

Bringing experimental therapeutics clinical trials network (ETCTN) to underrepresented population

6542

Background: Access to health care including clinical trials (CT) leading to paradigm-changing cancer treatments are critical for high quality cancer care and equity in society. In this report, we highlight methods in accruing to ETCTN wherein underrepresented rural, low-income, and racial minorities comprise >50% of enrollment. Methods: University of Kansas Cancer Center (KUCC) is one of eight National Cancer Institute (NCI) designated cancer centers awarded CATCH-UP.2020 (CATCH-UP), a congressionally mandated P30 supplement to enhance access for minority/underserved populations to ETCTN precision medicine CT. KUCC catchment area is 23% rural by Rural Urban Continuum Codes (RUCC); almost 90 % of counties are designated primary care HPSA’s (Health Professional Shortage Areas). KUCC Early Phase and Masonic Cancer Alliance (rural outreach network) partnered to operationalize CATCH-UP. We engaged disease-focused champion investigators in disease working groups and MCA physicians who selected scientifically sound CT that fit catchment area needs. Patient and Investigator Voices Organizing Together, a patient research advocacy group provided practical feedback. MCA navigator coordinated recruitment. Telehealth was used for rural patients that would have a significant distance to travel just to be screened. Results: CATCH-UP was initiated in September 2020. Twenty-eight CT were activated, many in community sites. Average activation time was 81 days. Delays were mainly from CT amendments. KUCC enrolled the first patient in the CATCH-UP program. In 6 months, we met accrual requirements (24/year, 50% minorities). During first year, we enrolled 47 (>50% minorities), an increase of 680% from our average accrual of 6/year (>50% minorities) in ETCTN through Early Drug Development Opportunity Program (2016-2020). To date, we have enrolled 61, 54% from rural, HPSA, race and other minorities. Although the proportion of minorities did not change but remained high, this funding allowed us to substantially increase the number of patients from a catchment area with high proportion of geographically and socioeconomically underserved minorities given access to early phase CT through ETCTN. Conclusions: Amid COVID-19 pandemic, the NCI CATCH-UP program and methods we used allowed access to novel therapies for rural, medically underserved, and other minority groups. Funded by NIH: 3P30CA168524-09S2.

Multicenter phase 2 trial of the PARP inhibitor (PARPi) olaparib in recurrent IDH1 and IDH2-mutant contrast-enhancing glioma

2035

Background: Isocitrate dehydrogenase ( IDH) 1 and IDH2 mutations ( IDH1/2mt) are the most common mutations in gliomas, occurring in over 70% of low grade and 20% of higher grade gliomas. IDH1/2mts are associated with improved prognosis, although tumors typically recur and progress to a higher grade despite first lines of treatment. Recent preclinical studies have suggested IDHmt and accumulation of 2-HG confer a “BRCAness” phenotype, a vulnerability that can be targeted through PARPi. To test this hypothesis, we conducted a multicenter study of olaparib monotherapy in patients (pts) with IDH1/2mt gliomas that had progressed despite standard therapy. Methods: Eligible pts had contrast enhancing and biopsy confirmed IDH1/2mt glioma that progressed despite standard therapy. Pts with prior treatment with PARPi or IDHmt inhibitors were excluded. The primary endpoint was overall response rate (ORR). Secondary objectives were progression free survival (PFS), overall survival (OS) and duration of response (DR). Olaparib 300 mg orally twice daily was given. A standard Simon 2 stage design was used. Stage 1 included 15 pts. If 2/15 pts responded stage 2 would expand by 30 pts. Responses were assessed with RANO criteria and reviewed centrally. Results: 15 evaluable pts were enrolled. Most recent histology as per 2021 WHO classification was 12 astrocytoma (4 grade 2, 3 grade 3, 5 grade 4) and 3 oligodendroglioma (2 grade 2, 1 grade 3). A total of 13 pts’ tumors had IDH1 R132H mutations; 2 pts had IDH2mt (R172G, R172K). All pts had >1 and 10 pts had >2 prior lines of systemic therapy (median 2, range 1-4). Most toxicities were grade 1 or 2. Nausea (67%) and fatigue (47%) were most frequent. Grade 3 lymphopenia, thrombocytopenia, and hypertension were seen in 1 patient each. Best response was stable disease (SD) in 9 pts and 6 pts had disease progression (PD). The median PFS was 3.6 months, 6-month PFS rate 26.7%, median OS 13.2 months. For pts with SD, median PFS was 5.5 months; 4 pts had SD for > 6 months. 2/6 pts with PD had confirmed WHO grade 4 by histology; 4 had CDKN2A deletion. CDKN2A deletion was unknown for 2 pts. Conclusions: Olaparib was well tolerated in this pt population. The study did not meet the pre-specified response-based threshold for moving to step 2, but prolonged SD was observed in pts with grades 2 and 3 histologies, suggesting olaparib monotherapy could be of clinical benefit in select pts. Grade 4 tumors per the 2021 WHO classification defined by histology or CDKN2A mutation derived minimal to no benefit from this drug highlighting the usefulness of this new classification for future patient stratification and trial design and suggesting investigation of this treatment earlier in the disease course might be of interest. Further studies are needed to identify other molecular or clinical predictive markers of benefit from PARPi as well as novel drug combinations for improved efficacy in this population. Clinical trial information: NCT03212274.

Correlative results from NCI protocol 10250: A phase II study of temozolomide and olaparib for the treatment of advanced uterine leiomyosarcoma

11509

Background: uLMS is an aggressive sarcoma subtype of smooth muscle origin. Chemotherapy provides limited benefit for advanced disease. 18-25% of uLMS harbor deleterious alterations in homologous recombination (HR) DNA repair genes. uLMS exhibits high levels of replicative stress. These findings prompted a phase 2 study of O+T in pretreated uLMS where O+T demonstrated activity: ORR 27%, mPFS 6.9 mos (Ingham M. et. al. ASCO 2021: #11506) Methods: NCI protocol #10250 is a single-arm, multicenter, phase 2 trial evaluating O+T in advanced uLMS pts with progression on ≥1 prior line. Pre-treatment (Pre) and on-treatment (On) biopsies were collected from 22 pts. In prespecified analysis, we evaluated for a relationship between clinical outcomes and HR gene alterations by whole exome sequencing (WES), SLFN11/MGMT expression by RNAseq, and RAD51 foci formation (functional assay). HRD scores were calculated from WES using scarHRD. Gene expression was evaluated using a Spearman rank-order correlation analysis to identify genes associated with PFS (p < 0.01) and overexpressed in sensitive (S: PFS > 240d) or resistant (R: PFS < 240d) pts. Gene set enrichment analysis (GSEA) was performed (q = FDR-adjusted p value). Pts with available results: WES/RNAseq (16), Pre HRD score (13), Pre RAD51 foci (12). Results: 31% (5/16) pts had a mutation (Mut) or homozygous deletion (Hd) in the HR panel: ATRX Mut (2), ATR Mut, PALB2 Hd, RAD51B Hd. Pts with PALB2 and RAD51B Hd had longest PFS on study. Recurrent alterations also occurred in TP53 (56%) and RB1 (19%). Median HRD score in Pre samples was 51 (range 36-66) and 10/13 had HRD scores ≥ 42. Pre and On SLFN11 and MGMT RNA expression were not correlated with ORR/PFS. 6/13 Pre samples were HR-deficient by the RAD51 foci assay. Of pts with PFS ≥ 200d, 4/6 were HR-deficient. In Pre samples, 81 genes were overexpressed in S pts and 73 in R pts. In On samples, 146 genes were overexpressed in S pts and 127 in R pts. In On samples, GSEA identified the epithelial-mesenchymal transition enriched in S pts (q = 3.38e-7) and cell cycle pathways (E2F targets, G2M checkpoint) in R pts (q = 7.43e-4). Only 2 genes, CXCL10 and PCDH15, were differentially expressed between paired Pre and On samples (both increased in On). Gene expression signatures for replicative stress showed borderline association with worse PFS. Conclusions: Most uLMS tumors exhibit HR defects as measured by HRD scores. A subset of pts with greater benefit from O+T were identified by WES for HR genes and the RAD51 assay. There was no correlation between SLFN11 and MGMT expression and outcomes. GSEA identified pathways differentially expressed in S and R pts in On samples. O+T induced CXCL10 which has been associated with T-cell trafficking to tumors. A randomized phase 3 trial of O+T versus investigator’s choice is planned. These results provide insight into which pts may benefit most from this novel drug combination. Clinical trial information: NCT03880019.

A phase 1 and pharmacodynamic study of chronically-dosed, single-agent veliparib (ABT-888) in patients with BRCA1- or BRCA2-mutated cancer or platinum-refractory ovarian or triple-negative breast cancer

PURPOSE

BRCA1 or BRCA2 mutated cancers (BRCAmut) have intrinsic sensitivity to PARP inhibitors due to deficiency in homologous recombination-mediated DNA repair. There are similarities between BRCAmut and BRCAwt ovarian and basal-like breast cancers. This phase I study determined the recommended phase II dose (RP2D) and preliminary efficacy of the PARP inhibitor, veliparib (ABT-888), in these patients.

PATIENTS AND METHODS

Patients (n = 98) were dosed with veliparib 50-500 mg twice daily (BID). The BRCAmut cohort (n = 70) contained predominantly ovarian (53%) and breast (23%) cancers; the BRCAwt cohort (n = 28) consisted primarily of breast cancer (86%). The MTD, DLT, adverse events, PK, PD, and clinical response were assessed.

RESULTS

DLTs were grade 3 nausea/vomiting at 400 mg BID in a BRCAmut carrier, grade 2 seizure at 400 mg BID in a patient with BRCAwt cancer, and grade 2 seizure at 500 mg BID in a BRCAmut carrier. Common toxicities included nausea (65%), fatigue (45%), and lymphopenia (38%). Grade 3/4 toxicities were rare (highest lymphopenia at 15%). Overall response rate (ORR) was 23% (95% CI 13-35%) in BRCAmut overall, and 37% (95% CI 21-55%) at 400 mg BID and above. In BRCAwt, ORR was 8% (95% CI 1-26%), and clinical benefit rate was 16% (95% CI 4-36%), reflecting prolonged stable disease in some patients. PK was linear with dose and was correlated with response and nausea.

CONCLUSIONS

Continuous veliparib is safe and tolerable. The RP2D was 400 mg BID. There is evidence of clinical activity of veliparib in patients with BRCAmut and BRCAwt cancers.

Reaching beyond maximum grade: progress and future directions for modernising the assessment and reporting of adverse events in haematological malignancies

Remarkable improvements in outcomes for many haematological malignancies have been driven primarily by a proliferation of novel therapeutics over the past two decades. Targeted agents, immune and cellular therapies, and combination regimens have adverse event profiles distinct from conventional finite cytotoxic chemotherapies. In 2018, a Commission comprising patient advocates, clinicians, clinical investigators, regulators, biostatisticians, and pharmacists representing a broad range of academic and clinical cancer expertise examined issues of adverse event evaluation in the context of both newer and existing therapies for haematological cancers. The Commission proposed immediate actions and long-term solutions in the current processes in adverse event assessment, patient-reported outcomes in haematological malignancies, toxicities in cellular therapies, long-term toxicity and survivorship in haematological malignancies, issues in regulatory approval from an international perspective, and toxicity reporting in haematological malignancies and the real-world setting. In this follow-up report, the Commission describes progress that has been made in these areas since the initial report.

Combined PARP and HSP90 inhibition: preclinical and Phase 1 evaluation in patients with advanced solid tumours

PURPOSE

PARP inhibitor resistance may be overcome by combinatorial strategies with agents that disrupt homologous recombination repair (HRR). Multiple HRR pathway components are HSP90 clients, so that HSP90 inhibition leads to abrogation of HRR and sensitisation to PARP inhibition. We performed in vivo preclinical studies of the HSP90 inhibitor onalespib with olaparib and conducted a Phase 1 combination study.

PATIENTS AND METHODS

Tolerability and efficacy studies were performed in patient-derived xenograft(PDX) models of ovarian cancer. Clinical safety, tolerability, steady-state pharmacokinetics and preliminary efficacy of olaparib and onalespib were evaluated using a standard 3 + 3 dose-escalation design.

RESULTS

Olaparib/onalespib exhibited anti-tumour activity against BRCA1-mutated PDX models with acquired PARPi resistance and PDX models with RB-pathway alterations(CDKN2A loss and CCNE1 overexpression). Phase 1 evaluation revealed that dose levels up to olaparib 300 mg/onalespib 40 mg and olaparib 200 mg/onalespib 80 mg were safe without dose-limiting toxicities. Coadministration of olaparib and onalespib did not appear to affect the steady-state pharmacokinetics of either agent. There were no objective responses, but disease stabilisation ≥24 weeks was observed in 7/22 (32%) evaluable patients including patients with BRCA-mutated ovarian cancers and acquired PARPi resistance and patients with tumours harbouring RB-pathway alterations.

CONCLUSIONS

Combining onalespib and olaparib was feasible and demonstrated preliminary evidence of anti-tumour activity.

Trends in Grade 5 Toxicity and Response in Phase I Trials in Hematologic Malignancy: 20-Year Experience From the Cancer Therapy Evaluation Program at the National Cancer Institute

PURPOSE

Cancer drug development has largely shifted from cytotoxic chemotherapy to targeted treatment in the past two decades. Although previous studies have highlighted improvement in response rates in recent phase I trials, disease-focused reporting is limited.

METHODS

We integrated patient-level data for patients with hematologic malignancies who participated in phase I trials sponsored by the National Cancer Institute Cancer Therapy Evaluation Program between January 2000 and May 2019 and estimated the trend of grade 5 toxicity and response by disease subtype over time.

RESULTS

We analyzed 161 trials involving 3,308 patients, all of whom were assessed for toxicity and 2,404 of whom were evaluable for response to therapy. The overall rate of grade 5 toxicities was 1.81% (95% CI, 1.36 to 2.27), with no significant change in the rate over time. Baseline characteristics associated with higher risk of grade 5 toxicity were age and performance status ≥ 2 at enrollment. Overall response rate (ORR) and complete response (CR) rate for all trials during the study period were 25.1% and 14.7%, respectively. A significant increase in both ORR and CR rate was observed over time (ORR: 18.5% in 2000-2005, 25.9% in 2006-2012, and 50.6% in 2013-2019, P < .001). ORR in phase I trials varied across disease subtypes: 20.2% in acute myeloid leukemia, 9.1% in myelodysplastic syndrome, 43.2% in lymphoma, 42.9% in chronic lymphocytic leukemia, 15.1% in acute lymphoblastic leukemia, and 16.5% in myeloma.

CONCLUSION

Over time, the ORR and CR rates in phase I trials for hematologic malignancy have improved meaningfully, whereas the rate of toxicity-related death remains stable. This study provides broad experience that physicians can use when discussing the potential outcomes for patients with hematologic malignancy considering participation in phase I trials.

Updated biomarker results from a phase 1/2 study of olaparib and radium-223 in men with metastatic castration-resistant prostate cancer (mCRPC) with bone metastases (COMRADE)

119

Background: Radium-223 is an α-emitting radioisotope that induces DNA double-strand breaks leading to cell death. In preclinical models, PARP inhibitors have shown efficacy as radiosensitizing agents. We designed a phase 1/2 trial to test the safety and efficacy of radium-223 + olaparib. Tissue based studies investigated homologous recombination repair (HRR) gene status. Methods: This was an open-label, multi-center, phase 1/2 study (NCT03317392) evaluating the dosing, safety and efficacy of radium-223 + olaparib. Eligible patients (pts) had mCRPC with ≥2 bone metastases without visceral metastases or lymphadenopathy > 4 cm. There was no limit on prior therapy. All pts had a baseline biopsy and archival tissue was collected when available. The phase 1 used a 3+3 dose escalation design with fixed dose radium-223 (55 kBq/kg IV every 4 weeks x 6). Dose level 1 (DL1) was olaparib 200 mg PO BID; DL2 was olaparib 300 mg PO BID. The primary objective was to determine the recommended phase 2 dose (RP2D). Secondary objectives included radiographic progression-free survival (rPFS) (PCWG3 criteria), PSA response (50% decline from baseline), and alkaline phosphatase response (30% decline from baseline). HRR gene status was determined using Oncopanel tissue profiling. Results: 12 pts were enrolled on the phase 1. Median age was 68 (range 59-81) years. Median prior lines of CRPC therapies was 2 (1-5), including 3 (25%) who had received prior chemotherapy and 12 (100%) a prior novel hormone therapy. The RP2D of olaparib was 200 mg BID when combined with radium-223. Overall, PSA response and alkaline phosphatase response were 16.7% (n=2) and 67% (n=8), respectively. Median follow-up was 6.5 (range 2.8, 11.8) months, and 6-month rPFS was 57% (95% CI: 25%, 80%). 9 patients had available tissue for Oncopanel testing (7 from baseline metastasis biopsy; 2 from archival prostate tissue). Two patients were identified to have pathogenic HRR gene alterations: 1 patient with a BRCA2 mutation with rPFS of 11.63 months, 1 patient with CDK12 mutation with rPFS 2.60 months (Table). Conclusions: We demonstrate that olaparib can be safety combined with radium-223 with RP2D of 200 mg BID. Though limited by sample size, we demonstrate prolonged disease control in a pt with a BRCA2 mutation receiving radium-223 + olaparib. Additional profiling from the currently accruing phase 2 study of radium-223 +/- olaparib will further elucidate biomarkers of response. Clinical trial information: NCT03317392. [Table: see text]

Phase I pharmacokinetic study of single agent trametinib in patients with advanced cancer and hepatic dysfunction

BACKGROUND

Trametinib is an oral MEK 1/2 inhibitor, with a single agent recommended phase 2 dose (RP2D) of 2 mg daily (QD). This study was designed to evaluate RP2D, maximum tolerated dose (MTD), and pharmacokinetic (PK) profile of trametinib in patients with advanced solid tumors who had various degrees of hepatic dysfunction (HD).

METHODS

Advanced cancer patients were stratified into 4 HD groups based on Organ Dysfunction Working Group hepatic function stratification criteria: normal (Norm), mild (Mild), moderate (Mod), severe (Sev). Dose escalation was based on "3 + 3" design within each HD group. PK samples were collected at cycle 1 days 15-16.

RESULTS

Forty-six patients were enrolled with 44 evaluable for safety [Norm=17, Mild=7, Mod (1.5 mg)=4, Mod (2 mg)=5, Sev (1 mg)=9, Sev (1.5 mg)=2] and 22 for PK analysis. Treatment related adverse events were consistent with prior trametinib studies. No treatment related deaths occurred. Dose limiting toxicities (DLTs) were evaluable in 15 patients (Mild=6, Mod (1.5 mg)=3, Mod (2 mg)=2, Sev (1 mg)=3 and Sev (1.5 mg)=1). One DLT (grade 3 acneiform rash) was observed in a Sev patient (1.5 mg). Dose interruptions or reductions due to treatment related adverse events occurred in 15 patients (34%) [Norm=9, 53%; Mild=2, 29%; Mod (1.5 mg)=1, 33%; Mod (2 mg)=2, 33%; Sev (1 mg)=1, 11%; Sev (1.5 mg)=1; 50%]. There were no significant differences across HD groups for all PK parameters when trametinib was normalized to 2 mg. However, only limited PK data were available for the Mod (n = 3) and Sev (n = 3) groups compared to Norm (n = 10) and Mild (n = 6) groups. Trametinib is heavily protein bound, with no correlation between serum albumin level and unbound trametinib fraction (p = 0.26).

CONCLUSIONS

RP2D for trametinib in Mild HD patients is 2 mg QD. There are insufficient number of evaluable patients due to difficulty of patient accrual to declare RP2D and MTD for Mod and Sev HD groups. DLTs were not observed in the highest dose cohorts that reached three evaluable patients - 1.5 mg QD in Mod group, and 1 mg QD in Sev group.

TRIAL REGISTRATION

This study was registered in the ClinicalTrials.gov website ( NCT02070549 ) on February 25, 2014. .

Outcomes of pregnancy during immunotherapy treatment for cancer: Analysis of clinical trials sponsored by the National Cancer Institute

Despite expanding indications for immunotherapeutic agents, there is limited understanding about their clinical effects on pregnancy outcomes. Generally, pregnant cancer patients are excluded from clinical trials, and inadvertent pregnancies on trial result in patients being taken off due to concerns for fetal toxicity. To answer this question of pregnancy outcomes on immunotherapy-based trials, we performed a retrospective analysis of the National Cancer Institute's (NCI) Cancer Therapy Evaluation Program-Adverse Event Reporting System (CTEP-AERS) for unexpected pregnancies during NCI-CTEP sponsored immunotherapy clinical trials between 2011 and 2020. We identified 9 female patients who had unexpected pregnancies, of whom 7 chose to take their pregnancies to term. All 7 pregnancies resulted in vaginal births of apparently normal infants. This is the first report of pregnancy outcomes in multiple female patients exposed to immunotherapy. Our data suggest the need for further research to better evaluate and define contraception recommendations during immunotherapy treatment for cancer.

Effect of removing race from glomerular filtration rate-estimating equations on anticancer drug dosing and eligibility: a retrospective analysis of National Cancer Institute phase 1 clinical trial participants

BACKGROUND

Kidney function assessment by estimated glomerular filtration rate (eGFR) equations, such as the Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation, is important to determine dosing and eligibility for anticancer drugs. Inclusion of race in eGFR equations calculates a higher eGFR at a given serum creatinine concentration for Black patients versus non-Black patients. We aimed to characterise the effect of removing race from the CKD-EPI equation on dosing and eligibility of anticancer drugs with kidney function cutoffs.

METHODS

We did a retrospective analysis of patients enrolled in phase 1 studies sponsored by the Cancer Therapy Evaluation Program between January, 1995, and October, 2010. eGFR based on creatinine (eGFR_Cr) was calculated by the CKD-EPI equation and a version of the CKD-EPI equation without the race term (CKD-EPI_{without race}). Estimated creatinine clearance (eCl_Cr) was calculated by the Cockcroft-Gault equation. Dosing simulations based on each assessment of kidney function were done for ten anticancer drugs with kidney function cutoffs for dosing (oxaliplatin, capecitabine, etoposide, topotecan, fludarabine, and bleomycin) or eligibility (cisplatin, pemetrexed, bendamustine, and mitomycin) based on labelling approved by the US Food and Drug Administration or consensus guidelines. The absolute proportion of patients eligible or in each renal dosing range was calculated for each drug. Eligibility and dosing discordance rates were also calculated.

FINDINGS

Demographics and laboratory values from 340 Black patients (172 men and 168 women) were used. Median age was 57 years (IQR 47-64), median bodyweight was 78·1 kg (67·0-89·8), median body surface area was 1·91 m² (1·77-2·09), and median serum creatinine concentration was 0·9 mg/dL (0·8-1·1). Median eGFR_Cr or eCl_Cr was 103 mL/min (85-122) calculated by CKD-EPI, 89 mL/min (73-105) by CKD-EPI_{without race}, and 90 mL/min (72-120) by Cockcroft-Gault. Black patients were recommended to receive dose reductions or were rendered ineligible to receive drug more frequently when using CKD-EPI_{without race} than when using CKD-EPI, but at a similar rate as when using Cockcroft-Gault. The number of patients ineligible for therapy or recommended to receive any renal dose adjustment when CKD-EPI_{without race} versus CKD-EPI was used increased by 72% (from 25 of 340 to 43 of 340 patients) for cisplatin, by 120% (from five to 11) for pemetrexed, by 67% (from three to five) for bendamustine, by 150% (from ten to 25) for capecitabine, by 150% (from ten to 25) for etoposide, by 67% (from three to five) for topotecan, by 61% (from 74 to 119) for fludarabine, and by 163% (from eight to 21) for bleomycin. Up to 18% of patients had discordant recommendations using CKD-EPI_{without race} versus CKD-EPI.

INTERPRETATION

Removing race from the CKD-EPI equation will calculate a lower eGFR for Black patients and exclude more patients from receiving anticancer therapy, which could lead to undertreatment of Black patients with cancer and adversely affect their outcomes.

FUNDING

National Institutes of Health.

A phase 1/2 study of olaparib and radium-223 in men with metastatic castration-resistant prostate cancer (mCRPC) with bone metastases (COMRADE): Results of the phase 1 study

e17020

Background: Radium-223 is an α-emitting radioisotope that induces DNA double-stranded breaks leading to cell death and has improved survival in mCRPC. In preclinical models, PARP inhibitors have shown efficacy as radiosensitizing agents. We designed a phase 1/2 trial to test the hypothesis that radium-223 + olaparib will demonstrate anti-tumor activity in mCRPC irrespective of homologous recombination repair deficiency (HRD) status. Methods: This is an open label, multi-center, phase 1/2 study (NCT03317392) evaluating the dosing, safety and efficacy of radium-223 + olaparib. Eligible patients (pts) had mCRPC with ≥2 bone metastases without visceral metastases or lymphadenopathy > 4 cm. There was no limit on prior therapy. All pts had a baseline biopsy. The phase 1 used a 3+3 dose escalation design with fixed dose radium-223 (55 kBq/kg IV every 4 weeks x 6). Dose level 1 (DL1) was olaparib 200 mg PO BID; DL2 was olaparib 300 mg PO BID. The primary objective was to determine the recommended phase 2 dose (RP2D) and safety. The dose limiting toxicities (DLT) evaluation period was 2 cycles (1 cycle=28 days). Secondary endpoints included radiographic progression-free survival (rPFS) defined by PCWG3 criteria, PSA response (50% decline from baseline), and alkaline phosphatase response (30% decline from baseline). Results: 12 pts were enrolled on the phase 1. Median age was 68 (range 59-81) years. Median prior lines of CRPC therapies was 2 (1-5), including 3 (25%) who had received prior chemotherapy and 100% a prior novel hormone therapy. 6 pts were enrolled at DL1. 1 patient experienced a DLT outside the DLT evaluation period. 3 pts had grade (G) 3-4 treatment-related adverse events (TrAE) including G3 anemia (n=2) and G3 thrombocytopenia (n=1). No patient underwent dose reductions at DL1. 6 pts were enrolled at DL2. 1 patient experienced a DLT outside the DLT evaluation period. 2 pts had G3-4 TrAE including G3 anemia and G4 lymphocytopenia (n=1) and G3 stroke (n=1). 5 underwent dose reductions at DL2. There were no G5 events. Reason for treatment discontinuation is in the table below. After review of safety data, the safety monitoring committee deemed the RP2D of olaparib at 200 mg BID when combined with radium-223. Overall, PSA response and alkaline phosphatase response were 16.7% (n=2, 1 at DL1, 1 at DL2) and 67% (n=8, 3 at DL1, 5 at DL2), respectively. Median follow-up was 6.5 (range 2.8, 11.8) months, and 6-month rPFS was 57% (95% CI: 25%, 80%). Conclusions: We demonstrate that olaparib can be safety combined with radium-223 with RP2 dose of 200 mg BID. The phase 2 study of radium-223 +/- olaparib is accruing (target 120 pts). Outcomes by HRD status will be presented. Clinical trial information: NCT03317392. [Table: see text]

Dynamics of circulating tumor DNA in patients with advanced solid tumors treated with cediranib and olaparib

3035

Background: Circulating tumor DNA (ctDNA) has emerged as a potential biomarker to monitor treatment response in solid tumors. Our group previously showed that changes in ctDNA levels were predictive of radiographic response and survival in NSCLC patients receiving immunotherapy. Here we evaluated whether ctDNA dynamics could similarly be used to assess response in a PARP inhibitor-based therapy. Methods: A total of 122 patients with NSCLC, TNBC, PDAC or SCLC received cediranib (C) 30mg daily and Olaparib (O) 200mg twice daily in a phase II study NCI9881. Using a multigene NGS assay, ctDNA was measured longitudinally at baseline (T0), after 3 to 7 days of C monotherapy (T1), after 1 week of C+O combination (T2), after 4 weeks of C+O (T3), and every 4 weeks (T4+) thereafter. The first radiographic assessment was done after 8 weeks of C+O and every 8-12 weeks thereafter. CtDNA was quantified by determining the allele fraction of cancer-associated somatic mutations in plasma. We defined an early ctDNA response (e-ctDNA-R) as a >10% decrease in mutant allele fraction from T0 to T2, and an early ctDNA progression (e-ctDNA-P) as a > 10% increase; otherwise, it was stable ctDNA (e-ctDNA-S). Results: In total, 493 samples were analyzed from 94 patients, and 40 unique patients had both T0 and T2 ctDNA measurements, as well as corresponding radiographic assessments. These included 10 NSCLC, 17 TNBC, 3 SCLC and 10 PDAC. Of these patients, 4, 21, and 15 patients had PR, SD, and PD as best overall radiographic response respectively. Twenty-three (57.5%) patients had either e-ctDNA-R (17, 42.5%) or e-ctDNA-S (6, 15.0%), 18 (78.3%) of whom subsequently had either radiographic partial response (PR) or stable disease (SD). Seventeen (42.5%) patients had e-ctDNA-P, 10 (58.8%) of whom then had PD. A fair agreement was observed between e-ctDNA-R/S or e-ctDNA-P and radiographic PR/SD or PD with Cohen’s k 0.38 (70% agreement). The correlation between early ctDNA changes and PFS/OS are summarized in the table. All 25 patients with PR/SD eventually progressed. Of these, 17 (68%) had >10% increase in ctDNA from the nadir prior to disease progression (median 94.6%, 95%CI 38.2%-389.1%). The time between ctDNA progression and ctDNA nadir was significantly shorter (median 21 days, 95%CI 21-28) than the time between radiographic/clinical progression and initial PR/SD (median 107 days, 95%CI 56-204, P=0.0015). Conclusions: Longitudinal ctDNA measurements could enable early assessment of treatment response, resistance, and disease progression in patients treated with PARP inhibitor-based therapy. However, in this study, tumor responses and ctDNA changes were generally not as robust as have been observed with other classes of therapy.[Table: see text]

National Cancer Institute (NCI) implementation of the American Society of Clinical Oncology (ASCO) and Friends of Cancer Research (Friends) broadening clinical trials eligibility criteria

6518

Background: The 2017 ASCO/Friends eligibility criteria guidelines recommend inclusiveness to promote generalizable trial results and clear rationale for necessary exclusion. These guidelines focused on brain metastases, minimum age for enrollment, HIV infection, and organ dysfunction and prior and concurrent malignancies. In September 2018, the NCI Cancer Therapy Evaluation Program (CTEP) implemented modernized protocol template language to operationalize these criteria. We evaluated utilization of the new language among CTEP-sponsored treatment trials. Methods: We evaluated protocols first approved by CTEP between 11/01/2018 and 4/30/2020. The most recent approved protocol version was evaluated for consistency with the new template language for brain metastases, HIV infection, prior or concurrent malignancies, minimum age, and cardiac, liver and kidney function. If a particular criterion was not relevant for a trial, it was not included in the analysis. We did not score age in pediatric or adult-specific trials (e.g. prostate). Results: 122 trials (71% early and 29% late phase) were identified and included in the analysis. Compliance with the new criteria language ranged from a high of 87.7% for liver function to a low of 11.5% for “new or progressive brain metastases” (table). Modernized criteria language was lacking in nearly 46% of trials in the use of concurrent or prior malignancy criteria and 31% of trials for the cardiac criteria. Of the 87 trials for non-localized disease or non-brain tumor trials, 64.4% did not address brain metastases, leaving it to investigator discretion. Thus, 75.9% of trials could theoretically enroll patients with brain metastases. Only 6 trials were considered relevant for patients < 18 years old; 50% were consistent with the age criterion (not shown in table). Conclusions: Implementing ASCO/Friends eligibility criteria requires focused reviews during protocol development to ensure compliance. CTEP is using these findings to continue to improve its protocol review processes to broaden eligibility in clinical trials. Maximizing opportunities for diverse populations to participate in trials is a priority for the National Cancer Institute and CTEP will continue efforts to achieve this goal.[Table: see text]

Analysis of homologous recombination DNA repair gene mutation status in patients with metastatic small cell lung cancer treated with cediranib and olaparib on NCI 9881 study

8563

Background: Cediranib, a pan-vascular endothelial growth factor receptor tyrosine kinase inhibitor, suppresses expression of homologous recombination DNA repair (HRR) genes and increases sensitivity of tumors to a poly-(ADP-ribose) polymerase (PARP) inhibitor in vitro and in vivo models of breast and ovarian cancer. Olaparib, a PARP inhibitor, demonstrated clinical efficacy in patients with advanced solid tumor with a deleterious mutation in HRR genes. We hypothesized that cediranib induces HRR deficient phenotype by suppressing expression of HRR genes and cediranib and olaparib combination (C+O) results in an objectives response in patients with HRR proficient (HRP) advanced solid tumors. Herein, we report the biomarker data from analyses of targeted sequencing of 84 DNA repair (DR) genes with BROCA-HR assay in patients with metastatic small cell lung cancer (mSCLC). Methods: This multi-institutional phase 2 trial enrolled patients with mSCLC previously treated with a platinum-based chemotherapy. Patients received cediranib 30mg orally (po) daily plus olaparib 200mg po twice daily until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by RECIST v1.1. A tumor biopsy was obtained from the patients with safely accessible metastatic tumor. HRR deficiency (HRD) was defined as presence of a deleterious mutation in any of the 10 key HRR-related genes per BROCA-HR assay including: ATM, BARD1, BRCA1, BRCA2, BRIP1, CDK12 (somatic mutations only), NBN, PALB2, RAD51C, or RAD51D. Otherwise, the tumors were defined as HRR proficiency (HRP). Results: A total of 25 patients with SCLC received the study treatment. Fourteen patients had available tumor biopsy samples and/or germline available for BROCA-HR. One patient (7%) was determined to have a HRD tumor by a presence of PALB2 mutation. This patient had stable disease as a best overall response but came off study due to unequivocal clinical progression. Thirteen patients (93%) had a HRP tumor. Six of these (46%) patients had PR. Median PFS in patients with HPR tumors was 122 days. The most common gene alterations detected by BROCA-HR assay was TP53 (93%) and RB1 (79%). Other DR gene alterations noted from our study samples were MRE11, CKD12 PALB2, ERCC4, FANCB, and BAP1. Conclusions: HRD was infrequent in our mSCLC samples. C+O resulted in objective responses in 46% of mSCLC patients with HRP tumors. Mutations in TP53 and RB1 were the most common gene alterations. Further investigation in warranted to confirm this observation. Clinical trial information: NCT02498613.

NCI protocol 10250: A phase II study of temozolomide and olaparib for the treatment of advanced uterine leiomyosarcoma

11506

Background: Uterine leiomyosarcoma (uLMS) is an aggressive sarcoma subtype with frequent metastatic relapse. After failure of front-line chemotherapy, remaining options provide limited benefit (trabectedin: ORR 11%, mPFS 4.0 mos; pazopanib: ORR 11%, median PFS 2.9 mos; dacarbazine: ORR 9%, mPFS 1.5 mos). Recent molecular studies suggest uLMS harbors characteristic defects in the homologous recombination (HR) DNA repair pathway, including somatic biallelic BRCA2 deletion in 10%, implicating potential sensitivity to PARP-inhibitor based treatment approaches. In preclinical uLMS models in which temozolomide (T, an oral equivalent to dacarbazine) or the PARP inhibitor olaparib (O) showed limited single agent activity, the combination of T + O was highly effective in inhibiting uLMS tumor growth and promoting apoptosis. Methods: NCI protocol #10250 is a single-arm, open-label, multi-center phase II study evaluating T + O in advanced uLMS. Pts had progression on ≥ 1 prior line and ECOG PS ≤ 2. Pts received T 75 mg/m2 PO daily + O 200 mg PO BID days 1-7 in 21-day cycles. Primary endpoint was ORR. A one-stage binomial design was used. If ≥ 5/22 responded, the treatment was considered promising (95% power; α = 0.06). All pts underwent paired tumor biopsies. Correlative assays to evaluate for HR deficiency (whole exome sequencing/RNAseq, RAD51 foci formation) and for intrinsic PARP inhibitor resistance (SLFN11 expression) will be correlated with response. Results: 22 patients were evaluable (median age 55, median prior treatment lines 3). Median follow-up was 10.8 mos. Primary endpoint, ORR within 6 mos of initiating treatment, was 23% (5/22). Overall ORR was 27% (6/22). Median PFS was 6.9 mos (95% CI: 5.4 mos – not estimable (NE)). Median duration of response (DOR) was 12.0 mos (95% CI: 9.5 mos – NE). Hematologic toxicity was common (grade 3/4 neutropenia, 77%; thrombocytopenia 32%) but manageable with dose modification. Correlative assays are ongoing with plans to present at the meeting. An immunohistochemical assay for RAD51 foci has been adapted for uLMS samples and clearly distinguishes BRCA2- deleted and wild-type tumors. Conclusions: NCI 10250 met the prespecified primary efficacy endpoint of ORR in a population of patients with heavily pre-treated uLMS. Responses are durable (median DOR 12 mos). Correlative assays are being completed to evaluate whether uLMS tumors with HR deficiency or with preserved SLFN11 expression are most sensitive to T + O and may underlie durable responses. A randomized study of the combination is planned. Clinical trial information: NCT03880019.

NCI’s national treatment trial networks: Experience and adaptations during COVID-19

1562

Background: The National Cancer Institute supports several national trial networks which responded rapidly to the COVID-19 pandemic to overcome operational barriers to clinical cancer research. The National Clinical Trials Network (NCTN) focuses on late phase treatment trials, while the Experimental Therapeutics Clinical Trials Network (ETCTN) conducts early phase treatment trials. We report findings on the experience and adaptations of these networks during COVID-19. Methods: Using 2019 and 2020 accrual data, we analyzed changes in accrual levels and demographics. We also evaluated changes in trial activation numbers and timelines. In July 2020, we surveyed 255 investigators from academic and community sites to assess changes in research practices and get feedback on modified processes implemented by NCI to address trial conduct during the pandemic. Results: Accrual across the NCTN and ETCTN fell significantly in mid-March 2020, dropping from a weekly average of 307 patients in February to 169 the week of March 23-29. Accrual began to recover in June and July but did not return to pre-pandemic levels until September. Accrual in November and December 2020 followed the patterns seen in 2019, with short-term drops around major holidays. Non-White participants were enrolled to NCTN and ETCTN trials at similar monthly rates throughout 2019 and 2020, with slightly higher overall enrollment in 2020 (23.7% vs. 22.7%). New trials continued to be developed and activated throughout 2020. Between 2017 and 2019, an average of 71 trials were activated per year (NCTN = 46, ETCTN = 25), compared to 84 activated in 2020 (NCTN = 58, ETCTN = 26). The average time to trial activation was similar or slightly longer in 2020 compared to 2019. The investigator survey yielded 111 responses (43.5% response rate). 43% of respondents’ sites paused enrollment to phase 1 trials during the pandemic, compared to 18% for phase 3 trials. Many sites temporarily stopped opening new trials and processing specimens. Sites were more likely to keep enrolling to trials offering clear potential benefit and pause complex trials that required more patient contact. Respondents attributed some of the decline in accrual to a reduction in overall patient volume, increased patient concerns, and reduced research staff on site. Respondents were asked to rate the usefulness of modified trial processes NCI put in place during the pandemic. Telehealth was rated most useful (avg. 4.6/5), followed by shipping oral IND agents to enrolled patients (4.5/5), remote informed consent (4.2/5), coordinating care with local providers (3.9/5), and remote auditing (3.7/5). Conclusions: The cancer trials community has an opportunity to learn from working through the challenges of COVID-19. NCI will seek to continue and expand on modifications to clinical trial processes that have the potential to improve operational efficiency, reduce cost, and help bring trials to more patients.

Targeting the IL-2 inducible kinase in melanoma; a phase 2 study of ibrutinib in systemic treatment-refractory distant metastatic cutaneous melanoma: preclinical rationale, biology, and clinical activity (NCI9922)

BACKGROUND

IL-2 inducible kinase (ITK) is highly expressed in metastatic melanomas and its inhibition suppresses melanoma cell proliferation. We hypothesize that ibrutinib has a direct antitumor effect in melanoma cell lines and that treatment of metastatic melanomas with ibrutinib induces antitumor responses.

METHODS

We assessed the ibrutinib effect on melanoma cell proliferation, apoptosis, and motility. Patients with metastatic melanoma refractory to PD-1 and MAPK inhibitors (if BRAFV600-mutant) were treated with ibrutinib, 840 mg PO QD, as part of a phase II clinical trial (clinicaltrials.gov NCT02581930).

RESULTS

Melanoma cell lines frequently express ITK, YES1, and EGFR. Ibrutinib suppressed cell motility and proliferation in most cell lines. Eighteen patients (13 male; median age 63.5 years, range 37-82; 12 with ipilimumab resistance) were enrolled. The most frequent side effects were fatigue (61%), anorexia (50%), hyponatremia (28%), nausea, and vomiting (22% each). No antitumor responses were seen. At a median follow-up of 6 months (0.3-35.8 months), the median progression-free survival was 1.3 months (range 0.2-5.5 months). Fifteen patients were discontinued from the study due to progression, and 14 patients had died from metastatic melanoma. All archived tumors expressed ITK, 41% had no expression of p16 and PTEN, and 61% had absent tumor-infiltrating lymphocytes (TILs). Ibrutinib significantly suppressed proliferating (Ki67+) CD19+ peripheral blood mononuclear cells and had no significant effect on other lymphocyte subsets.

CONCLUSION

Ibrutinib did not induce any meaningful clinical benefit. ITK expression may not be clinically relevant. Treatment-refractory metastatic melanomas have other fundamental defects (i.e. absent PTEN and p16 expression, absent TILs) that may contribute to an adverse prognosis.

Clinical Activity and Safety of Cediranib and Olaparib Combination in Patients with Metastatic Pancreatic Ductal Adenocarcinoma without BRCA Mutation

Lessons Learned

Cediranib and olaparib combination did not result in clinically meaningful activity in patients with metastatic pancreatic ductal adenocarcinoma without known BRCA mutation.

Background

Cediranib, a vascular endothelial growth factor receptor inhibitor, suppresses expression of BRCA1/2 and RAD51 inducing homologous recombination DNA repair deficiency (HRD) in several cancer cell lines and xenograft models [1]. Olaparib provides a clinical benefit in patients with metastatic pancreatic adenocarcinoma (mPDAC) with germline BRCA mutation (gBRCAmt) [2]. We hypothesized that cediranib induces HRD in the absence of gBRCAmt and synergizes with olaparib, resulting in an objective response in patients with mPDAC.

Methods

Patients with mPDAC with at least one prior systemic chemotherapy were enrolled. Patients with known gBRCAmt were excluded. Patients took cediranib 30 mg daily and olaparib 200 mg twice daily, orally. The primary endpoint was objective response (OR) rate.

Results

Nineteen patients received the study drugs. Seven patients came off treatment before the first restaging scan: six because of clinical progression and one because of an adverse event. No OR was observed. Six patients had stable disease (SD) as a best overall response. The median duration of SD was 3.1 months. The median overall survival was 3.4 months. Common treatment‐related adverse events were fatigue, hypertension, and diarrhea.

Conclusion

Cediranib and olaparib combination did not result in clinically meaningful activity in patients with mPDAC without gBRCAmt.

A phase I/II study of combination olaparib and radium-223 in men with metastatic castration-resistant prostate cancer with bone metastases (COMRADE): A trial in progress

TPS182

Background: Radium-223 is an α-emitting radioisotope that induces DNA double-stranded breaks leading to cell death and has demonstrated improvement in overall survival in men with metastatic castration-resistant prostate cancer (mCRPC) with bone metastases. PARP inhibitors, including olaparib and rucaparib, inhibit repair of DNA single-stranded beaks and have demonstrated clinical efficacy in mCRPC patients harboring alterations in the homologous recombination repair (HRR) pathway. In extensive preclinical cancer models, PARP inhibitors have shown efficacy as radiosensitizing agents. We designed a phase 1/2 trial to test the clinical hypothesis that the combination of radium-223 with olaparib will demonstrate anti-tumor activity in patients with mCRPC irrespective of underlying HRR deficiency status. Methods: This is an open label, multi-center, phase 1/2 study (NCT03317392) evaluating the dosing, safety and efficacy of olaparib in combination with radium-223 in men with mCRPC with bone metastases. Patient must have 2 or more bone metastases and at least 1 bone metastasis that has not been treated with prior radiation therapy. Key exclusion criteria include the presence of visceral metastases or malignant lymphadenopathy exceeding 4 cm and prior therapy with radium-223 and/or PARP inhibitors. The phase 1 component of the study uses a 3+3 dose escalation design to determine the recommended phase 2 dose of olaparib in combination with standard of care dosing of Radium-223. The primary endpoint of the phase 1 component is safety. The phase 2 component of the study is an open-label, randomized study evaluating the combination of olaparib and radium-223 compared to radium-223 alone. The primary endpoint of the phase 2 component is radiographic progression-free survival as defined by Prostate Cancer Working Group 3 guidelines for bone metastases and RECIST v1.1 for non-bone metastases. Secondary endpoints include time to PSA progression, PSA response, time to subsequent therapy, time to first skeletal event, overall survival, and safety. Exploratory endpoints include stratification of response based on HRR alterations, whole exome sequencing of plasma cell free DNA both at baseline, on treatment, and at progression, and evaluation of changes in the tumor immune microenvironment with therapy. As of October 1, 2020, the phase 1 component has completed accrual and we anticipate opening the phase 2 component by December 2020. Clinical trial information: NCT03317392.

Biomarker analysis from a randomized phase II study of olaparib with or without cediranib in men with metastatic castration-resistant prostate cancer (mCRPC)

7

Background: We previously reported that cediranib, a vascular endothelial growth factor receptor tyrosine kinase inhibitor, combined with olaparib, a poly (ADP-ribose) polymerase inhibitor, prolonged radiographic progression-free survival (rPFS) compared with olaparib alone in patients with mCRPC. Herein, we present updated clinical data in the overall population and in subgroups by homologous recombination (HR) gene status. Methods: Men with a minimum of one prior line of systemic therapy for mCRPC were randomized 1:1 to receive olaparib 200 mg by mouth twice daily with cediranib 30 mg by mouth daily (C+O) or olaparib 300 mg by mouth twice daily (O). Patients were required to undergo a baseline metastasis biopsy. Next generation sequencing of HR genes was performed on available samples using BROCA-HR assay. HR deficiency (HRD) was defined by presence of homozygous deletions or deleterious mutations in HR genes including BRCA1, BRCA2, ATM, and others. The primary endpoint was rPFS and secondary endpoint was overall survival (OS). Results: Eighty-four patients were included in the analysis of whom 26 patients (31.0%) had HRD mCRPC. The most common HR gene alterations included BRCA2 (n=17, 20%), CDK12 (n=9, 11%), and ATM (n=7, 8%). Consistent with our prior report, in the overall cohort, C+O compared to O resulted in a significant improvement in rPFS (Table). The benefit in rPFS was most pronounced in patients with HRD mCRPC; however, there was no difference between arms in HR proficient (HRP) cancers. Independent of arm allocation, rPFS and OS were numerically longer in patients with HRD mCRPC compared to HRP mCRPC (rPFS: 8.8 versus 4.3 months, p=0.14; OS: 18.6 vs. 12.3 months, p=0.24). Conclusions: C+O improved rPFS in patients with mCPRC compared with O alone. The biomarker analyses revealed that the rPFS benefit of C+O over O is likely driven by patients with HRD mCRPC. Our data warrant validation and support further investigation of the combination of C+O in patients with HRD mCRPC. Clinical trial information: NCT02893917. [Table: see text]

Modernizing Clinical Trial Eligibility Criteria: Recommendations of the ASCO-Friends of Cancer Research Washout Period and Concomitant Medication Work Group

PURPOSE

Washout periods and concomitant medication exclusions are common in cancer clinical trial protocols. These exclusion criteria are often applied inconsistently and without evidence to justify their use. The authors sought to determine how washout period and concomitant medication allowances can be broadened to speed trial enrollment and improve the generalizability of trial data to a larger oncology practice population without compromising the safety of trial participants.

EXPERIMENTAL DESIGN

A multistakeholder working group was convened to define problems associated with excessively long washout periods and exclusion of patients due to concomitant medications. The group performed a literature search and evaluated study data from the Pancreatic Cancer Action Network (PanCAN), Emory University School of Medicine (Atlanta, GA), and the FDA to understand recent approaches to these eligibility criteria. The group convened to develop consensus recommendations for broadened eligibility criteria.

RESULTS

The data analysis found that exclusion criteria based on washout periods and concomitant medications are frequently inconsistent and lack scientific rationale. Scientific rationale for appropriate eligibility criteria are presented in the article; for washout periods, rationale is presented by treatment type.

CONCLUSIONS

Arbitrary or blanket washout and concomitant medication exclusions should be eliminated. Where there is evidence to support them, clinically relevant washout periods and concomitant medication-related eligibility criteria may be included.See related commentary by Giantonio, p. 2369.

Molecular Features of Cancers Exhibiting Exceptional Responses to Treatment

A small fraction of cancer patients with advanced disease survive significantly longer than patients with clinically comparable tumors. Molecular mechanisms for exceptional responses to therapy have been identified by genomic analysis of tumor biopsies from individual patients. Here, we analyzed tumor biopsies from an unbiased cohort of 111 exceptional responder patients using multiple platforms to profile genetic and epigenetic aberrations as well as the tumor microenvironment. Integrative analysis uncovered plausible mechanisms for the therapeutic response in nearly a quarter of the patients. The mechanisms were assigned to four broad categories-DNA damage response, intracellular signaling, immune engagement, and genetic alterations characteristic of favorable prognosis-with many tumors falling into multiple categories. These analyses revealed synthetic lethal relationships that may be exploited therapeutically and rare genetic lesions that favor therapeutic success, while also providing a wealth of testable hypotheses regarding oncogenic mechanisms that may influence the response to cancer therapy.

The Exceptional Responders Initiative: Feasibility of a National Cancer Institute Pilot Study

BACKGROUND

Tumor molecular profiling from patients experiencing exceptional responses to systemic therapy may provide insights into cancer biology and improve treatment tailoring. This pilot study evaluates the feasibility of identifying exceptional responders retrospectively, obtaining pre-exceptional response treatment tumor tissues, and analyzing them with state-of-the-art molecular analysis tools to identify potential molecular explanations for responses.

METHODS

Exceptional response was defined as partial (PR) or complete (CR) response to a systemic treatment with population PR or CR rate less than 10% or an unusually long response (eg, duration >3 times published median). Cases proposed by patients' clinicians were reviewed by clinical and translational experts. Tumor and normal tissue (if possible) were profiled with whole exome sequencing and, if possible, targeted deep sequencing, RNA sequencing, methylation arrays, and immunohistochemistry. Potential germline mutations were tracked for relevance to disease.

RESULTS

Cases reflected a variety of tumors and standard and investigational treatments. Of 520 cases, 476 (91.5%) were accepted for further review, and 222 of 476 (46.6%) proposed cases met requirements as exceptional responders. Clinical data were obtained from 168 of 222 cases (75.7%). Tumor was provided from 130 of 168 cases (77.4%). Of 117 of the 130 (90.0%) cases with sufficient nucleic acids, 109 (93.2%) were successfully analyzed; 6 patients had potentially actionable germline mutations.

CONCLUSION

Exceptional responses occur with standard and investigational treatment. Retrospective identification of exceptional responders, accessioning, and sequencing of pretreatment archived tissue is feasible. Data from molecular analyses of tumors, particularly when combining results from patients who received similar treatments, may elucidate molecular bases for exceptional responses.

Phase I and Pharmacokinetic Study of Romidepsin in Patients with Cancer and Hepatic Dysfunction: A National Cancer Institute Organ Dysfunction Working Group Study

PURPOSE

Romidepsin dosing recommendations for patients with malignancy and varying degrees of hepatic dysfunction was lacking at the time of regulatory approval for T-cell lymphoma. We conducted a multicenter phase I clinical trial (ETCTN-9008) via the NCI Organ Dysfunction Working Group to investigate safety, first cycle MTD, and pharmacokinetic profile of romidepsin in this setting.

PATIENTS AND METHODS

Patients with select advanced solid tumors or hematologic malignancies were stratified according to hepatic function. Romidepsin was administered intravenously on days 1, 8, and 15 of a 28-day cycle and escalation followed a 3 + 3 design in moderate and severe impairment cohorts. Blood samples for detailed pharmacokinetic analyses were collected after the first dose.

RESULTS

Thirty-one patients received one dose of romidepsin and were evaluable for pharmacokinetic analyses in normal (n = 12), mild (n = 8), moderate (n = 5), and severe (n = 6) cohorts. Adverse events across cohorts were similar, and dose-limiting toxicity occurred in two patients (mild and severe impairment cohorts). The MTD was not determined because the geometric mean AUC values of romidepsin in moderate (7 mg/m²) and severe (5 mg/m²) impairment cohort were 114% and 116% of the normal cohort (14 mg/m²).

CONCLUSIONS

Data from the ETCTN-9008 trial led to changes in the romidepsin labeling to reflect starting dose adjustment for patients with cancer and moderate and severe hepatic impairment, with no adjustment for mild hepatic impairment.

Phase II Study of AZD4547 in Patients With Tumors Harboring Aberrations in the FGFR Pathway: Results From the NCI-MATCH Trial (EAY131) Subprotocol W

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.

CTEP 9557: A dose-escalation trial of combination dabrafenib, trametinib, and AT13387 in patients with BRAF mutant solid tumors

3609

Background: Combination BRAF and MEK inhibitor therapy is associated with response in patients (pts) with BRAF mutant (mut) solid tumors; however critical limitations for the durable activity of these agents remains. Preclinically, the addition of heat shock protein 90 (HSP90) inhibitors improves the efficacy of BRAF inhibitor (BRAFi) therapy in both BRAFi -sensitive and resistant mutant cell lines. Methods: CTEP study 9557 (NCT02097225) is a phase I study designed to determine the safety and efficacy of the small molecule HSP90inhibitor, AT13387, in combination with dabrafenib (dab) and trametinib (tram) in patients with BRAF V600E/K mut solid tumors. Prior chemotherapy, immunotherapy, BRAF and/or MEK exposure was permitted. The primary objective was to determine the maximum tolerated dose (MTD). Results: From July 2015 to June 2018, 22 patients with previously treated, metastatic BRAF V600E/K mut solid tumors were enrolled using a 3 + 3 design at four dose levels (DL) (Table). Pts were predominantly female (59%) with a median age of 57.5yrs (37 -75). The most common tumor type was BRAF V600Emut colon cancer (N=12). Dose limiting toxicities (DLTs) occurred in one patient in DL3 and one in DL4, specifically grade 3 myelosuppression and fatigue, respectively. The MTD was Dab 150mg [BID/PO], Tram 2mg [QD/PO] and AT1187 260mg/m2 [D1,8,15/IV]. Twenty-one of 22 pts were eligible for efficacy assessment. Best response, per RECIST 1.1, was partial response (PR) in 2 pts – one with colon ca (TKI-naïve), one with melanoma (TKI-resistant) - stable disease (SD) in 8 pts, and disease progression (PD) in 11 with a disease control rate (PR + SD) of 47.6% (90% CI: 29% - 67%). Median time to progression was significantly longer in DL3 (3.9 mths; 1.8-9.2) compared to DL1 (1.6mths; 0.9-1.7) or DL2 (1.5; 0.6-3.6). Median PFS and OS were 1.8mths (90% CI: 1.6 – 3.7mths) and 5.1 mths (90% CI: 2.5 -10.6mths), respectively. Median OS was not reached in DL3/4. Correlative data on the expression of the key signaling proteins relating to response will be presented at the meeting. Conclusions: HSP90 inhibition combined with BRAF/MEK inhibition was determined to be safe with evidence of disease control in a heavily pre-treated population of pts with BRAF V600E/K mut solid tumors. Clinical trial information: NCT02097225 . [Table: see text]

Preliminary efficacy data of triple-negative breast cancer cohort of NCI 9881 study: A phase II study of cediranib in combination with olaparib in advanced solid tumors

1077

Background: Cediranib, a pan-vascular endothelial growth factor receptor tyrosine kinase inhibitor, suppresses expression of BRCA1, BRCA2, and RAD51 and increases sensitivity of tumors to poly-(ADP-ribose) polymerase (PARP) inhibitors in vitro. Olaparib, a PARP inhibitor, demonstrates clinical efficacy in patients with germline BRCA1/2 mutations and HER2-negative metastatic breast cancer. We therefore tested the anti-tumor activity of the combination of cediranib and olaparib in patients (pts) with metastatic triple-negative breast cancer (TNBC). Methods: This multi-institutional, two-stage, phase II study enrolled patients with metastatic TNBC previously treated with a minimum of one prior line of systemic therapy in the advanced setting. Patients were treated with cediranib 30mg po daily plus olaparib 200mg po BID until disease progression or unacceptable toxicity. The primary endpoint was objective response rate by RECIST v1.1. Baseline tumor biopsies were obtained for biomarker analyses. Results: Baseline characteristics of the 37pts enrolled are summarized below. The overall objective response rate was 14% (95% CI: 0.025, 0.2453). Median duration of response was 2.0 months (mos) with a range of 1.8 to 6.3 mos. Disease control rate ((# of pts with CR, PR or SD)/(# of evaluable pts)) was 81% (95% CI: 0.6846, 0.937). Median PFS was 3.7 mos (95% CI: 2.1, 4.3). Grade 3/4 adverse events (G3/4 AEs), irrespective of attribution, occurred in 25 of 38 (66%).G3/4 AEs occurring in > 5% of pts were hypertension (24%) and dyspnea (11%), diarrhea (8%) vomiting (8%). Conclusions: The cediranib/olaparib combination resulted in promising objective responses in 14% of biomarker-unselected patients with heavily pre-treated, metastatic TNBC. The regimen required prompt initiation of antihypertensives, but AEs were overall manageable. Analyses of mutation status in homologous recombination DNA repair genes are ongoing and will be correlated with clinical outcome. Clinical trial information: NCT02498613 . [Table: see text]

Preliminary efficacy data of platinum-pretreated small cell lung cancer (SCLC) cohort of NCI 9881 study: A phase II study of cediranib in combination with olaparib in advanced solid tumors

9065

Background: Cediranib, a pan-vascular endothelial growth factor receptor tyrosine kinase inhibitor, suppresses expression of BRCA1, BRCA2, and RAD51 and increases sensitivity of tumors to poly-(ADP-ribose) polymerase (PARP) inhibitors in vitro. Olaparib, a PARP inhibitor, demonstrated clinical efficacy in patients with advanced solid tumors carrying a germline BRCA mutation. We therefore tested the anti-tumor activity of cediranib and olaparib combination in patients (pts) with advanced solid tumors. Here, we report the data from the SCLC cohort. Methods: This multi-institutional, two-stage, phase 2 study enrolled pts with metastatic SCLC previously treated with a minimum of one prior line of platinum-based chemotherapy in advanced setting. Patients were treated with cediranib 30mg po daily plus olaparib 200mg po BID until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by RECIST v1.1. Baseline tumor biopsies were obtained for biomarker analyses. Results: Baseline characteristics of the 25 pts enrolled are summarized below. The overall ORR rate was 28% (95% CI: 0.104,0.456). Median duration of response was 3.8 months (mos). Six of 8 pts had an objective response lasting longer than 3 mos up to 10.3 months. Disease control rate (# of pts with CR, PR or SD / # evaluable pts) was 88% (95% CI: 0.75,1.01). Median progression free survival was 4.1 mos (95% CI: 2.3, 6.2). Median OS was 5.5 mos (95% CI: 3.4, NA). Grade 3/4 adverse events (G3/4 AEs), irrespective of attribution, occurred in 14 of 25 (56%). G3/4 AEs occurring in > 10% of pts were hypertension (21%), fatigue (17%) and weight loss (13%). Conclusions: The cediranib/olaparib combination resulted in promising clinical activity with ORR of 28% in biomarker-unselected pts with platinum-pretreated SCLC. The regimen required prompt initiation of antihypertensives, but AEs were overall manageable. Analyses of mutation status in homologous recombination DNA repair genes are going and will be correlated with clinical activity. Clinical trial information: NCT02498613. [Table: see text]

Evaluation of toxicities related to novel therapy in clinical trials for women with gynecologic cancer

BACKGROUND

Women with gynecologic cancer may be at increased risk for adverse events (AEs) due to peritoneal disease burden and prior treatment (surgery, chemotherapy, and pelvic radiotherapy). This study compared the toxicity profiles of patients with and without gynecologic cancer enrolled in phase 1 trials.

METHODS

This was a retrospective analysis of the National Cancer Institute phase 1 database for all trials enrolling 1 or more patients with gynecologic cancer over 2 decades (1995-2015). Clinical parameters collected included demographics, cancer history, trial information, AEs, and responses. AEs (according to the Common Terminology Criteria for Adverse Events) were documented for each patient during treatment, and they were counted once and analyzed on the basis of the highest grade and drug attribution. Multiple regression models were used to compare AEs at the baseline and during treatment.

RESULTS

A total of 4269 patients enrolled in 150 trials were divided into 3 groups: 1) women with gynecologic cancer (n = 685), 2) women with nongynecologic cancer (n = 1698), and 3) men with cancer (n = 1886). The median age was 58 years. The mean number of total AEs reported during treatment was highest for women with gynecologic cancer (17.1 vs 14.7 vs 13.5; P < .001), even though they were similar at the baseline (7.0 vs 7.4 vs 7.0; P = .09). The mean number of drug-related AEs was also highest for women with gynecologic cancer (8.3 vs 6.9 vs 6.2; P < .001). Grade 3 to 5 AEs were similar (2.3 vs 2.3 vs 2.1); however, grade 2 AEs were more frequent in women with gynecologic cancer (4.6 vs 3.9 vs 3.5). Treatment discontinuations due to AEs were similar (9% vs 9% vs 10%).

CONCLUSIONS

Women with gynecologic cancer experienced more frequent low-grade AEs during treatment, and this warrants attention to support their symptom burden. Study dose management should be considered for recurrent grade 2 AEs, particularly during continuous therapy.

Reversion and non-reversion mechanisms of resistance to PARP inhibitor or platinum chemotherapy in BRCA1/2-mutant metastatic breast cancer

BACKGROUND

Little is known about mechanisms of resistance to poly(adenosine diphosphate-ribose) polymerase inhibitors (PARPi) and platinum chemotherapy in patients with metastatic breast cancer and BRCA1/2 mutations. Further investigation of resistance in clinical cohorts may point to strategies to prevent or overcome treatment failure.

PATIENTS AND METHODS

We obtained tumor biopsies from metastatic breast cancer patients with BRCA1/2 deficiency before and after acquired resistance to PARPi or platinum chemotherapy. Whole exome sequencing was carried out on each tumor, germline DNA, and circulating tumor DNA. Tumors underwent RNA sequencing, and immunohistochemical staining for RAD51 foci on tumor sections was carried out for functional assessment of intact homologous recombination (HR).

RESULTS

Pre- and post-resistance tumor samples were sequenced from eight patients (four with BRCA1 and four with BRCA2 mutation; four treated with PARPi and four with platinum). Following disease progression on DNA-damaging therapy, four patients (50%) acquired at least one somatic reversion alteration likely to result in functional BRCA1/2 protein detected by tumor or circulating tumor DNA sequencing. Two patients with germline BRCA1 deficiency acquired genomic alterations anticipated to restore HR through increased DNA end resection: loss of TP53BP1 in one patient and amplification of MRE11A in another. RAD51 foci were acquired post-resistance in all patients with genomic reversion, consistent with reconstitution of HR. All patients whose tumors demonstrated RAD51 foci post-resistance were intrinsically resistant to subsequent lines of DNA-damaging therapy.

CONCLUSIONS

Genomic reversion in BRCA1/2 was the most commonly observed mechanism of resistance, occurring in four of eight patients. Novel sequence alterations leading to increased DNA end resection were seen in two patients, and may be targetable for therapeutic benefit. The presence of RAD51 foci by immunohistochemistry was consistent with BRCA1/2 protein functional status from genomic data and predicted response to later DNA-damaging therapy, supporting RAD51 focus formation as a clinically useful biomarker.