Phase I study of peposertib and avelumab with or without palliative radiotherapy in patients with advanced solid tumors

INTRODUCTION

We report results from a phase I, three-part, dose-escalation study of peposertib, a DNA-dependent protein kinase inhibitor, in combination with avelumab, an immune checkpoint inhibitor, with or without radiotherapy in patients with advanced solid tumors.

MATERIALS AND METHODS

Peposertib 100-400 mg twice daily (b.i.d.) or 100-250 mg once daily (q.d.) was administered in combination with avelumab 800 mg every 2 weeks in Part A or avelumab plus radiotherapy (3 Gy/fraction × 10 days) in Part B. Part FE assessed the effect of food on the pharmacokinetics of peposertib plus avelumab. The primary endpoint in Parts A and B was dose-limiting toxicity (DLT). Secondary endpoints were safety, best overall response per RECIST version 1.1, and pharmacokinetics. The recommended phase II dose (RP2D) and maximum tolerated dose (MTD) were determined in Parts A and B.

RESULTS

In Part A, peposertib doses administered were 100 mg (n = 4), 200 mg (n = 11), 250 mg (n = 4), 300 mg (n = 6), and 400 mg (n = 4) b.i.d. Of DLT-evaluable patients, one each had DLT at the 250-mg and 300-mg dose levels and three had DLT at the 400-mg b.i.d. dose level. In Part B, peposertib doses administered were 100 mg (n = 3), 150 mg (n = 3), 200 mg (n = 4), and 250 mg (n = 9) q.d.; no DLT was reported in evaluable patients. Peposertib 200 mg b.i.d. plus avelumab and peposertib 250 mg q.d. plus avelumab and radiotherapy were declared as the RP2D/MTD. No objective responses were observed in Part A or B; one patient had a partial response in Part FE. Peposertib exposure was generally dose proportional.

CONCLUSIONS

Peposertib doses up to 200 mg b.i.d. in combination with avelumab and up to 250 mg q.d. in combination with avelumab and radiotherapy were tolerable in patients with advanced solid tumors; however, antitumor activity was limited.

CLINICALTRIALS

GOV IDENTIFIER

NCT03724890.

A single-arm, multicenter, phase II trial of osimertinib in patients with epidermal growth factor receptor exon 18 G719X, exon 20 S768I, or exon 21 L861Q mutations

BACKGROUND

For patients with stage IV non-small-cell lung cancer with epidermal growth factor receptor (EGFR) exon 19 deletions and exon 21 L858R mutations, osimertinib is the standard of care. Investigating the activity and safety of osimertinib in patients with EGFR exon 18 G719X, exon 20 S768I, or exon 21 L861Q mutations is of clinical interest.

PATIENTS AND METHODS

Patients with stage IV non-small-cell lung cancer with confirmed EGFR exon 18 G719X, exon 20 S768I, or exon 21 L861Q mutations were eligible. Patients were required to have measurable disease, an Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate organ function. Patients were required to be EGFR tyrosine kinase inhibitor-naive. The primary objective was objective response rate, and secondary objectives were progression-free survival, safety, and overall survival. The study used a two-stage design with a plan to enroll 17 patients in the first stage, and the study was terminated after the first stage due to slow accrual.

RESULTS

Between May 2018 and March 2020, 17 patients were enrolled and received study therapy. The median age of patients was 70 years (interquartile range 62-76), the majority were female (n = 11), had a performance status of 1 (n = 10), and five patients had brain metastases at baseline. The objective response rate was 47% [95% confidence interval (CI) 23% to 72%], and the radiographic responses observed were partial response (n = 8), stable disease (n = 8), and progressive disease (n = 1). The median progression-free survival was 10.5 months (95% CI 5.0-15.2 months), and the median OS was 13.8 months (95% CI 7.3-29.2 months). The median duration on treatment was 6.1 months (range 3.6-11.9 months), and the most common adverse events (regardless of attribution) were diarrhea, fatigue, anorexia, weight loss, and dyspnea.

CONCLUSIONS

This trial suggests osimertinib has activity in patients with these uncommon EGFR mutations.

Durvalumab (durva) after chemoradiotherapy (CRT) in unresectable, stage III, EGFR mutation-positive (EGFRm) NSCLC: A post hoc subgroup analysis from PACIFIC

8541

Background: Standard of care for patients (pts) with unresectable (UR) stage III NSCLC is the ‘PACIFIC regimen’, based on data from the phase 3 placebo (pbo)-controlled trial where consolidation durva following CRT improved overall survival (OS; hazard ratio [HR], 0.68 [95% CI, 0.53, 0.87]) and progression-free survival (PFS; HR, 0.52 [95% CI 0.42, 0.65]), in an all-comer population. However, the benefit of immunotherapy (IO) in pts with EGFRm stage III NSCLC is unclear. We report a post hoc exploratory efficacy and safety analysis from 35 pts with EGFRm NSCLC from the PACIFIC trial (NCT02125461). Methods: Pts with stage III UR-NSCLC, WHO performance status (PS) 0/1 and no progression after ≥2 cycles platinum-based concurrent CRT were randomized 2:1 (1–42 days post CRT) to receive durva (10mg/kg IV q2w for up to 1 year) or pbo, stratified by age, sex, and smoking history; enrollment was not restricted by oncogenic driver gene mutation status or PD-L1 expression. Primary endpoints: PFS (BICR; RECIST v1.1) and OS; key secondary endpoints: objective response rate (ORR) and safety. Treatment effects for the EGFRm subgroup were estimated using an unstratified Cox proportional hazard model; medians were estimated using the Kaplan–Meier method. Statistical analyses were exploratory. Data cut-off (DCO) for the EGFRm subgroup efficacy analysis was 11 January 2021. Results: Of 713 pts randomized, 35 had EGFRm NSCLC based on local testing (durva n = 24, pbo n = 11). In the EGFRm subgroup, more pts in the pbo vs durva arm were male (73% vs 54%), had stage IIIA disease (64% vs 46%), PS 0 (64% vs 54%) and received pre-CRT induction chemotherapy (36% vs 8%). More pts in the durva arm were Asian (63% vs 55%) and had PD-L1 on < 25% tumor cells (67% vs 36%); median age was consistent across arms. At DCO, median duration of follow-up for survival was 42.7 months (range, 3.7–74.3 months) for all randomized pts in the subgroup. Median PFS was 11.2 months (95% CI 7.3, 20.7) with durva vs 10.9 months (95% CI 1.9, not evaluable [NE]) with pbo; HR 0.91 (95% CI 0.39, 2.13). Median OS was 46.8 months (95% CI 29.9, NE) with durva vs 43.0 months (95% CI 14.9, NE) with pbo; HR 1.02 (95% CI 0.39, 2.63). ORR was 26.1% (95% CI, 10.2, 48.4) and 18.2% (95% CI 2.3, 51.8) with durva and pbo, respectively. The safety profile for durva was consistent with the overall population. In the durva and pbo subgroup arms, radiation pneumonitis was reported in 42% vs 36% of pts, and pneumonitis was reported in 17% vs 18% of pts (1 grade 3, pbo arm), respectively. Conclusions: In this post hoc exploratory analysis of 35 pts, PFS and OS outcomes with durva were similar to pbo in the EGFRm population, with wide CIs. The benefit of IO in this population remains unclear. The ongoing LAURA study (NCT03521154) is investigating the efficacy and safety of maintenance osimertinib in pts with locally advanced EGFRm stage III UR-NSCLC with no progression after CRT. Clinical trial information: NCT02125461.

Outcomes with durvalumab after chemoradiotherapy in stage IIIA-N2 non-small-cell lung cancer: an exploratory analysis from the PACIFIC trial

Background

The phase III PACIFIC trial (NCT02125461) established consolidation durvalumab as standard of care for patients with unresectable, stage III non-small-cell lung cancer (NSCLC) and no disease progression following chemoradiotherapy (CRT). In some cases, patients with stage IIIA-N2 NSCLC are considered operable, but the relative benefit of surgery is unclear. We report a post hoc, exploratory analysis of clinical outcomes in the PACIFIC trial, in patients with or without stage IIIA-N2 NSCLC.

Materials and methods

Patients with unresectable, stage III NSCLC and no disease progression after ≥2 cycles of platinum-based, concurrent CRT were randomized 2 : 1 to receive durvalumab (10 mg/kg intravenously; once every 2 weeks for up to 12 months) or placebo, 1-42 days after CRT. The primary endpoints were progression-free survival (PFS; assessed by blinded independent central review according to RECIST version 1.1) and overall survival (OS). Treatment effects within subgroups were estimated by hazard ratios (HRs) from unstratified Cox proportional hazards models.

Results

Of 713 randomized patients, 287 (40%) had stage IIIA-N2 disease. Baseline characteristics were similar between patients with and without stage IIIA-N2 NSCLC. With a median follow-up of 14.5 months (range: 0.2-29.9 months), PFS was improved with durvalumab versus placebo in both patients with [HR = 0.46; 95% confidence interval (CI), 0.33-0.65] and without (HR = 0.62; 95% CI 0.48-0.80) stage IIIA-N2 disease. Similarly, with a median follow-up of 25.2 months (range: 0.2-43.1 months), OS was improved with durvalumab versus placebo in patients with (HR = 0.56; 95% CI 0.39-0.79) or without (HR = 0.78; 95% CI 0.57-1.06) stage IIIA-N2 disease. Durvalumab had a manageable safety profile irrespective of stage IIIA-N2 status.

Conclusions

Consistent with the intent-to-treat population, treatment benefits with durvalumab were confirmed in patients with stage IIIA-N2, unresectable NSCLC. Prospective studies are needed to determine the optimal treatment approach for patients who are deemed operable.

•

The PACIFIC trial established durvalumab after CRT as standard of care for unresectable, stage III NSCLC.

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The optimum multimodal treatment strategy for patients with potentially resectable, stage IIIA-N2 NSCLC is unknown.

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Survival benefit with durvalumab was observed in patients with stage IIIA-N2, unresectable NSCLC in this post hoc analysis.

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Durvalumab after CRT also exhibited a manageable safety profile in this subpopulation from PACIFIC.

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Studies of surgical vs. non-surgical strategies are needed to establish the best approach for potentially operable patients.

Clinical definition of acquired resistance to immunotherapy in patients with metastatic non-small-cell lung cancer

Acquired resistance (AR) to programmed cell death protein 1/programmed death-ligand 1 [PD-(L)1] blockade is frequent in non-small-cell lung cancer (NSCLC), occurring in a majority of initial responders. Patients with AR may have unique properties of persistent antitumor immunity that could be re-harnessed by investigational immunotherapies. The absence of a consistent clinical definition of AR to PD-(L)1 blockade and lack of uniform criteria for ensuing enrollment in clinical trials remains a major barrier to progress; such clinical definitions have advanced biologic and therapeutic discovery. We examine the considerations and potential controversies in developing a patient-level definition of AR in NSCLC treated with PD-(L)1 blockade. Taking into account the specifics of NSCLC biology and corresponding treatment strategies, we propose a practical, clinical definition of AR to PD-(L)1 blockade for use in clinical reports and prospective clinical trials. Patients should meet the following criteria: received treatment that includes PD-(L)1 blockade; experienced objective response on PD-(L)1 blockade (inclusion of a subset of stable disease will require future investigation); have progressive disease occurring within 6 months of last anti-PD-(L)1 antibody treatment or rechallenge with anti-PD-(L)1 antibody in patients not exposed to anti-PD-(L)1 in 6 months.

A micro-organosphere potency assay for adoptive T-cell therapy

e15027

Background: Lung cancer is the leading cause of death worldwide. Metastatic lung cancer patients often relapse or grow refractory to chemotherapy, radiotherapy, and checkpoint inhibitors. Adoptive T cell therapy (ACT) has been garnering more attention due to longitudinal complete responses. Tumor resections from patients harbor tumor-infiltrating lymphocytes (TILs) which can be cultured ex vivo and assessed for tumor reactivity before infusion. This generally follows a patient lymphodepletion regimen which allows the transferred T cells an optimal environment to proliferate and survive in the patient. TIL ACT can produce complete responses – rarely ever observed using traditional onco-therapy – in metastatic melanoma patients. However, while TILs specific to the neo-antigens expressed by tumor cells can be expanded ex vivo, this observed specificity is low in the clinic. Researchers have attempted to solve this by priming ex vivo expanded T cells with antigen-presenting cells previously pulsed with peptides representative of the neo-antigen repertoire of the matched tumor, but have rarely observed complete responses, likely due to current biomarkers for T cell activity poorly predicting anti-tumor cytotoxicity. To date there has been no acceptable potency assay for manufactured TILs, a requirement by the FDA for approval to use them in the clinic. Thus, the need to assess potency of ex vivo engineered T-cells against matched tumor cells is evident. Methods: We have developed a novel diagnostic immune-oncology (IO) pipeline, which uses a membrane-microfluidic platform to culture patient-derived tumor micro-organospheres (MOs) in extracellular matrix droplets. MOs can be rapidly established following patient tumor sample acquisition through biopsies or resection, and preserve the stromal cell populations in the original tumor microenvironment, as characterized by both flow cytometry and single-cell RNA-seq. An automated imaging assay was further established to robustly quantify the amount of immune-induced apoptosis of tumor cells in the MOs by patient-matched TILs, which is highly specific and yields minimal background. Results: We find that this method is not only amenable to high-throughput microscopy, but the larger surface-area-to-volume ratio of micro-organospheres also allows greater TIL infiltration and interaction with tumor cells. The resulting highly-sensitive assay requires far fewer input immune and tumor cells to achieve robust, clinical grade sensitivity response, making it the first clinically feasible assay for testing personalized TIL potency. Conclusions: The MO IO technology is currently being used for assessing clinical efficacy of manufactured TIL products for an upcoming ACT trial for non-small cell lung cancer patients. This technology also provides a companion to TIL ACT, CAR T therapy, and other immunotherapies, for which the ability to predict clinical potency is generally lacking.

Five-year survival outcomes with durvalumab after chemoradiotherapy in unresectable stage III NSCLC: An update from the PACIFIC trial

8511

Background: In the placebo-controlled Phase III PACIFIC trial of patients with unresectable Stage III NSCLC whose disease had not progressed after platinum-based concurrent chemoradiotherapy (cCRT), durvalumab improved overall survival (OS) (stratified hazard ratio [HR] 0.68; 95% confidence interval [CI] 0.53–0.87; p=0.0025; data cutoff [DCO] Mar 22, 2018) and progression-free survival (PFS) (stratified HR 0.52, 95% CI 0.42–0.65; p<0.0001; DCO Feb 13, 2017) based on the DCOs used for the primary analyses, and the degree of benefit remained consistent in subsequent updates. Durvalumab was associated with a manageable safety profile, and did not detrimentally affect patient-reported outcomes, compared with placebo. These findings established consolidation durvalumab after CRT (the ‘PACIFIC regimen’) as the standard of care in this setting. We report updated, exploratory analyses of OS and PFS, assessed approximately 5 years after the last patient was randomized. Methods: Patients with WHO PS 0/1 (and any tumor PD-L1 status) whose disease did not progress after cCRT (≥2 overlapping cycles) were randomized (2:1) 1–42 days following cCRT (total prescription radiotherapy dose typically 60–66 Gy in 30–33 fractions) to receive 12 months’ durvalumab (10 mg/kg IV every 2 weeks) or placebo, stratified by age (<65 vs ≥65 years), sex, and smoking history (current/former smoker vs never smoked). The primary endpoints were OS and PFS (blinded independent central review; RECIST v1.1) in the intent-to-treat (ITT) population. HRs and 95% CIs were estimated using stratified log-rank tests in the ITT population. Medians and OS/PFS rates at 60 months were estimated with the Kaplan–Meier method. Results: Overall, 709/713 randomized patients received treatment in either the durvalumab (n/N=473/476) or placebo (n/N=236/237) arms. The last patient had completed study treatment in May 2017. As of Jan 11, 2021 (median follow-up duration of 34.2 months in all patients; range, 0.2–74.7 months), updated OS (stratified HR 0.72, 95% CI 0.59–0.89; median 47.5 vs 29.1 months) and PFS (stratified HR 0.55, 95% CI 0.45–0.68; median 16.9 vs 5.6 months) remained consistent with the results from the primary analyses. The 60-month OS rates were 42.9% and 33.4% with durvalumab and placebo, respectively, and 60-month PFS rates were 33.1% and 19.0%, respectively. Updated treatment effect estimates for patient subgroups will be presented. Conclusions: These updated survival analyses, based on 5-year data from PACIFIC, demonstrate robust and sustained OS plus durable PFS benefit with the PACIFIC regimen. An estimated 42.9% of patients randomized to durvalumab remain alive at 5 years and approximately a third remain both alive and free of disease progression. Clinical trial information: NCT02125461.

Phase II randomized trial of first-line pembrolizumab and vorinostat in patients with metastatic NSCLC (mNSCLC)

9567

Background: Histone deacetylase inhibitors may enhance tumor immunogenicity through various mechanisms including induced expression of T cell chemokines. A previous phase I trial demonstrated the combination of pembrolizumab (P) with vorinostat (V) in mNSCLC was well tolerated with signals of activity in ICI-pretreated pts. We initiated a randomized trial in the first-line setting with the primary objective to determine if the combination had superior ORR compared to pembrolizumab monotherapy. Methods: Pts with treatment-naïve mNSCLC and PD-L1 expression ≥ 1% were eligible. Pts were randomized open-label 1:1 to receive P 200 mg IV q3 wk as monotherapy [Arm A] or P 200 mg IV q3 wk plus V 400 mg PO daily [Arm B]. The primary endpoint was overall response rate (ORR). Secondary endpoints included DOR, PFS and OS. Tumor biopsies were collected both pre- and on-treatment (day 15-21) for analysis of CD8+ TIL, scored using a 0-3 scale in tumor beds. Here we report results after a preplanned interim analysis for efficacy, with accrual ongoing to a planned total of 39 patients per arm. Results: Between 7/2017 – 1/2019, 49 pts were enrolled, with 47 pts evaluable for response (24 in Arm A and 23 in Arm B). Median age was 69 (range 47 - 87), 49% female, ECOG PS 0/1 in 11%/89%. PD-L1 TPS was ≥50% in 13/24 (54%) of pts in Arm A, and in 13/23 (57%) of pts in Arm B. The most common TRAEs in Arm A included diarrhea (13%), fatigue (8%), and pruritus (8%). 3 pts in Arm A experienced grade ≥ 3 irAEs (including 1 each of grade 3 hepatitis, pneumonitis, and rash). The most common TRAEs in Arm B included anorexia (43%), fatigue (43%), nausea (35%) and increased creatinine (35%). 1 pt in Arm B experienced grade ≥ 3 irAE (1 grade 3 pneumonitis). Pre-treatment CD8+ TIL were not significantly different between Arm A and Arm B (p = 0.85) with the majority of tumors in both arms having a low TIL score of 1 (65% Arm A and 73.7% Arm B). A significant increase from pre-treatment to on-treatment TIL scores was seen in both Arm A (p = 0.001) and Arm B (p = 0.002). The ORR in Arm B pts with low pre-treatment TIL (score = 1) pts was substantially higher (66.7%) than in Arm A (33.3%), suggesting the combination may be especially beneficial against low TIL tumors. Conclusions: The combination arm had a considerably higher ORR compared to pembrolizumab monotherapy, with a manageable toxicity profile. The combination of pembrolizumab plus vorinostat in mNSCLC warrants further investigation. Clinical trial information: NCT02638090 . [Table: see text]

Interim results from the OPTIMAL trial: A phase II clinical trial of combination nivolumab, ipilimumab, and taxane in patients with untreated metastatic non-small cell lung cancer (NSCLC)

e21683

Background: Combination chemo-immunotherapy is a well-established frontline therapeutic option for treatment naïve NSCLC. Dual immune checkpoint blockade (ICB) with nivolumab (nivo) and ipilimumab (ipi) has demonstrated improved clinical outcomes compared with chemotherapy alone in this setting. Combination dual ICB with low-dose chemotherapy may have advantages of preventing early disease progression and potentiating immunogenic response to treatment. Methods: We are conducting a single arm phase II clinical trial of nivo 360 mg IV Q3 weeks, ipi 1 mg/kg IV Q6 weeks, and weekly paclitaxel 80 mg/m2 IV on d1 and d8 of a 21 day cycle in ECOG 0-1 patients (pts) with treatment naïve NSCLC. Paclitaxel is stopped after a total of 4-6 cycles. The primary endpoint of the trial is progression free survival (PFS) with secondary endpoints of safety and objective response rate (ORR) by independent radiologic review. Interim results are presented from the first 23 evaluable pts, of a planned sample size of 49. Results: 23 pts were enrolled and evaluable with a mean age 63.8 years, 56.5% ECOG 0, 87% current/previous smoking history, and 70% adenocarcinoma. PDL1 score for < 1%, 1-49%, ³ 50% was seen in 9 (39.1%), 4 (17.4%), and 10 (43.5%) pts, respectively. Median time of follow up was 6.5 months (range 1.4–15.0). Partial response was observed in 14 pts, stable disease was seen in 8 pts, and 1 pt progressed during cycle 1, resulting in an ORR of 61%. Grade 3 or higher toxicity at least possibly attributed to study treatment was seen in 47.8% of 23 AE evaluable patients, of which included 4 cases of secondary adrenal insufficiency. Other toxicity rates were as expected for the respective agents. Conclusions: This is the first trial to evaluate weekly paclitaxel with nivo plus ipi in pts with untreated NSCLC. This regimen has demonstrated highly encouraging clinical activity with a manageable toxicity profile. The study is ongoing and updated results will be presented at the annual meeting. Clinical trial information: NCT03573947.

Non-pneumonitis immune-mediated adverse events (imAEs) with durvalumab in patients with unresectable stage III NSCLC (PACIFIC)

9048

Background: The phase 3 PACIFIC trial established durvalumab (durva) after chemoradiotherapy (CRT) as SoC for pts with unresectable stage III NSCLC. We report exploratory analyses to characterize non-pneumonitis (np) imAEs that occurred with durva in PACIFIC. Methods: PACIFIC was a double blind trial of pts without disease progression after platinum-based concurrent CRT (≥2 cycles). Pts were randomized 2:1 to receive durva 10 mg/kg or placebo (pbo) IV q2w for ≤12 months, stratified by age, sex and smoking history. We characterized the time to onset, duration, and management/outcomes of np imAEs and their association with (1) baseline pt/disease factors and (2) AEs (excluding all-cause pneumonitis). Results: Of 709 treated pts, 19% and 11% experienced imAEs and np imAEs of any grade, respectively; proportionally more had np imAEs with durva (71/475; 15%) vs pbo (5/234; 2%). Thyroid disorders (54/475; 11%), rash/dermatitis (9/475; 2%), and diarrhea/colitis (5/475; 1%) were the most common np imAEs with durva; rash/dermatitis had the shortest time to onset (Table). Among durva treated pts with np imAEs, 11% had grade 3/4 np imAEs, 41% had np imAEs that resolved, and none had fatal np imAEs; interventions included endocrine replacement therapy (73%), systemic corticosteroids (34%), high dose corticosteroids (16%), and discontinuation (10%). There were no apparent differences in baseline factors between pts with or without np imAEs. Durva had a broadly manageable safety profile irrespective of the occurrence of np imAEs. However, a higher proportion of durva treated pts with vs without np imAEs experienced all-cause, grade 3/4 events (41% vs 29%); none were fatal (excl. pneumonitis). Conclusions: Np imAEs occurred infrequently in PACIFIC, but were more common with durva vs pbo; thyroid disorders and rash/dermatitis were the most common np imAEs. Of durva treated pts with np imAEs, 11% experienced np imAEs of grade 3/4. Overall, np imAEs were broadly manageable and did not lead to high rates of discontinuation, and no association with baseline factors was seen, suggesting this should not deter use of durva in eligible pts. Clinical trial information: NCT02125461. [Table: see text]

Outcomes with durvalumab by tumour PD-L1 expression in unresectable, stage III non-small-cell lung cancer in the PACIFIC trial

BACKGROUND

In the PACIFIC trial, durvalumab significantly improved progression-free and overall survival (PFS/OS) versus placebo, with manageable safety, in unresectable, stage III non-small-cell lung cancer (NSCLC) patients without progression after chemoradiotherapy (CRT). We report exploratory analyses of outcomes by tumour cell (TC) programmed death-ligand 1 (PD-L1) expression.

PATIENTS AND METHODS

Patients were randomly assigned (2:1) to intravenous durvalumab 10 mg/kg every 2 weeks or placebo ≤12 months, stratified by age, sex, and smoking history, but not PD-L1 status. Where available, pre-CRT samples were tested for PD-L1 expression (immunohistochemistry) and scored at pre-specified (25%) and post hoc (1%) TC cut-offs. Treatment-effect hazard ratios (HRs) were estimated from unstratified Cox proportional hazards models (Kaplan-Meier-estimated medians).

RESULTS

In total, 713 patients were randomly assigned, 709 of whom received at least 1 dose of study treatment durvalumab (n = 473) or placebo (n = 236). Some 451 (63%) were PD-L1-assessable: 35%, 65%, 67%, 33%, and 32% had TC ≥25%, <25%, ≥1%, <1%, and 1%-24%, respectively. As of 31 January 2019, median follow-up was 33.3 months. Durvalumab improved PFS versus placebo (primary-analysis data cut-off, 13 February 2017) across all subgroups [HR, 95% confidence interval (CI); medians]: TC ≥25% (0.41, 0.26-0.65; 17.8 versus 3.7 months), <25% (0.59, 0.43-0.82; 16.9 versus 6.9 months), ≥1% (0.46, 0.33-0.64; 17.8 versus 5.6 months), <1% (0.73, 0.48-1.11; 10.7 versus 5.6 months), 1%-24% [0.49, 0.30-0.80; not reached (NR) versus 9.0 months], and unknown (0.59, 0.42-0.83; 14.0 versus 6.4 months). Durvalumab improved OS across most subgroups (31 January 2019 data cut-off; HR, 95% CI; medians): TC ≥ 25% (0.50, 0.30-0.83; NR versus 21.1 months), <25% (0.89, 0.63-1.25; 39.7 versus 37.4 months), ≥1% (0.59, 0.41-0.83; NR versus 29.6 months), 1%-24% (0.67, 0.41-1.10; 43.3 versus 30.5 months), and unknown (0.60, 0.43-0.84; 44.2 versus 23.5 months), but not <1% (1.14, 0.71-1.84; 33.1 versus 45.6 months). Safety was similar across subgroups.

CONCLUSIONS

PFS benefit with durvalumab was observed across all subgroups, and OS benefit across all but TC <1%, for which limitations and wide HR CI preclude robust conclusions.

Nivolumab versus docetaxel in previously treated advanced non-small-cell lung cancer (CheckMate 017 and CheckMate 057): 3-year update and outcomes in patients with liver metastases

Background

Long-term data with immune checkpoint inhibitors in non-small-cell lung cancer (NSCLC) are limited. Two phase III trials demonstrated improved overall survival (OS) and a favorable safety profile with the anti-programmed death-1 antibody nivolumab versus docetaxel in patients with previously treated advanced squamous (CheckMate 017) and nonsquamous (CheckMate 057) NSCLC. We report results from ≥3 years' follow-up, including subgroup analyses of patients with liver metastases, who historically have poorer prognosis among patients with NSCLC.

Patients and methods

Patients were randomized 1 : 1 to nivolumab (3 mg/kg every 2 weeks) or docetaxel (75 mg/m2 every 3 weeks) until progression or discontinuation. The primary end point of each study was OS. Patients with baseline liver metastases were pooled across studies by treatment for subgroup analyses.

Results

After 40.3 months' minimum follow-up in CheckMate 017 and 057, nivolumab continued to show an OS benefit versus docetaxel: estimated 3-year OS rates were 17% [95% confidence interval (CI), 14% to 21%] versus 8% (95% CI, 6% to 11%) in the pooled population with squamous or nonsquamous NSCLC. Nivolumab was generally well tolerated, with no new safety concerns identified. Of 854 randomized patients across both studies, 193 had baseline liver metastases. Nivolumab resulted in improved OS compared with docetaxel in patients with liver metastases (hazard ratio, 0.68; 95% CI, 0.50-0.91), consistent with findings from the overall pooled study population (hazard ratio, 0.70; 95% CI, 0.61-0.81). Rates of treatment-related hepatic adverse events (primarily grade 1-2 liver enzyme elevations) were slightly higher in nivolumab-treated patients with liver metastases (10%) than in the overall pooled population (6%).

Conclusions

After 3 years' minimum follow-up, nivolumab continued to demonstrate an OS benefit versus docetaxel in patients with advanced NSCLC. Similarly, nivolumab demonstrated an OS benefit versus docetaxel in patients with liver metastases, and remained well tolerated.

Clinical trial registration

CheckMate 017: NCT01642004; CheckMate 057: NCT01673867.

Phase 1, open-label, dose-escalation study of M3814 + avelumab ± radiotherapy (RT) in patients (pts) with advanced solid tumors

TPS3169

Background: DNA-dependent protein kinase (DNA-PK) regulates a key DNA damage response (DDR) pathway for double-strand break (DSB) repair. DNA-PK inhibition augments DNA DSB damage generated by many antitumor therapies, including RT. DNA damage and repair impact the interaction of tumors with the immune system; combining immune checkpoint inhibitors (CPIs) with RT + DDR-targeted agents may modulate the tumor immune microenvironment, enhancing responsiveness to CPIs. M3814 (small molecule selective DNA-PK inhibitor) has demonstrated monotherapy activity in several tumor cell lines, and M3814 + RT combined with avelumab (programmed death ligand 1 mAb) significantly delayed tumor growth vs either agent alone + RT in MC38 syngrafts. This study will evaluate the clinical utility of M3814 combined with avelumab ± RT in pts with advanced solid tumors. Methods: NCT03724890 is a 2-part first-in-man study in adult pts with advanced or metastatic solid tumors. Part A is enrolling pts with measurable/evaluable solid tumors (RECIST v1.1); Part B will enrol pts with primary or metastatic tumor(s) in the lung which is/are amenable to be irradiated. In Part A, M3814 will be given orally twice daily. In Part B, M3814 + TRT will be given once daily, 5 days/wk for 2 wk. In both parts, pts will receive avelumab iv once every 2 wk from Day 1 until disease progression/unacceptable toxicity. Part B will initiate once the Safety Monitoring Committee declares the first dose level of Part A to have acceptable safety/tolerability. Primary objectives are to define the recommended Phase 2 dose (RP2D) of M3814 when combined with avelumab (Part A) and with avelumab + TRT (Part B) via dose-limiting toxicities (DLTs) occurring during the first 3/4 (Part A/B) wk of treatment. Secondary objectives include safety/tolerability, pharmacokinetics, immunogenicity, preliminary antitumor activity (BOR, PFS, OS). Sample size for each part depends on the number of DLTs/dose levels for M3814; dose escalation will be based on a Bayesian logistic regression model with overdose control. Part A aims to include 6–24 pts (≤4 dose levels), Part B 6–18 pts (≤3 dose levels). Recruitment began in Dec 2018. Clinical trial information: NCT03724890.

First subsequent treatment after discontinuation of durvalumab in unresectable, stage III NSCLC patients from PACIFIC

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Background: In the phase 3 PACIFIC trial of unresectable, stage III NSCLC patients (pts) without progression after concurrent chemoradiotherapy (cCRT), durvalumab (durva) significantly improved PFS and OS with similar safety compared to placebo (pbo). We performed exploratory analyses to characterize first subsequent treatment (Tx) after discontinuation of durva. Methods: Pts with WHO PS 0/1 and any tumor PD-L1 status were randomized (2:1) 1–42 days after ≥2 cycles of platinum-based cCRT to durva 10 mg/kg IV or pbo Q2W up to 12 months, stratified by age, sex and smoking history. Pts were classified by the use or not of first subsequent Tx and category of first systemic Tx (platinum doublet CT [PDCT], single-agent CT [SCT], immunotherapy [IT] or targeted therapy [TT]). Results: As of Mar 22, 2018, 216/476 (45.4%) and 153/237 (64.6%) in the durva and pbo arms, respectively, had a RECIST-based PFS event per BICR (5.7% and 8.4% due to death). 195 (41.0%) and 128 (54.0%) received first subsequent Tx, most of which were systemic Tx (158 [33.2%] and 109 [46.0%]): PDCT (16.4% and 19.0%), SCT (8.6% and 8.4%), IT (4.2% and 13.5%) or TT (3.8% and 5.1%); 7.8% and 8.0% received RT only. Time to first subsequent therapy or death (TFST) was longer with durva vs pbo (HR 0.58; 95% CI 0.47–0.72; median 21.0 vs 10.4 months). Baseline characteristics of pts with or without first subsequent Tx were similar, and similar across durva or pbo arms. Among pts with systemic Tx, baseline characteristics (including pre-cCRT PD-L1 status) were generally similar, except pts on TT, more of whom were EGFR+ (70.0% vs 0–6.6% of other systemic Tx groups) with commonly associated phenotypes (more females, Asians, non-smokers and non-squamous pts). Best overall response to first systemic Tx will be presented. Conclusions: Due to longer PFS and fewer progression events with durva vs pbo, fewer pts on durva required subsequent Tx and, per TFST, much later. With the exception of IT, use of each subsequent Tx was similar between the durva and pbo arms with PDCT the most common. Baseline characteristics were similar for pts with or without first subsequent Tx and pts who received first systemic Tx, except for pts who received TT, as expected due to their molecular profile.

Clinical responses and survival in Hispanic patients with non-small cell lung cancer treated with immunotherapy compared with non-Hispanic whites

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Background: The main immunotherapy (IMMUNO) trials that led to the approval of these agents for non-small cell lung cancer (NSCLC) accrued a minimum number of Hispanic (HISP) patients (pts) or, in some studies, no HISP pts at all. Additional data is thus needed to validate outcomes in HISP pts with NSCLC treated with IMMUNO. While it is known that genomic profiles and cancer survivals are different between HISP, Non-Hispanic Whites (NHW), and African-Americans; no study has yet looked at differences in IMMUNO outcomes between these populations. Methods: We present data in 436 NSCLC pts treated with IMMUNO at 5 large institutions (3 in the US, 2 in Latin America). The agents evaluated include: nivolumab, pembrolizumab and atezolizumab. 256 pts were HISP and 180 pts were NHW. Most of the pts were treated with single agent therapy as second line (or beyond) while a small group of pts were treated as first line. The primary endpoints of the study were: response rate (ORR), progression free survival (PFS) and overall survival (OS). Results: Among NHW pts, disease control rate (DCR) was 67% for Adenocarcinomas (Adeno) and 46% for squamous cell carcinomas (SQCC). In HISP pts there were no differences in DCR rates between both histologies: 68% for Adeno and 67% SQCC. There were no statistical significant differences among HISP and NHW pts regarding ORR, PFS, OS, and responses according to PD-L1 status. Conclusions: This is the largest publication and comparison of NSCLC immunotherapy outcomes in HISP vs NHW pts. No significant differences were found in the clinical outcomes between these 2 ethnic groups despite expected genomic differences. Pts with actionable mutations were excluded as they usually do not get IMMUNO as first or second line; an approach that might change after IMPOWER 150. These results are comparable to the ones seen in Checkmate and Keynote studies. As expected, higher response rates were seen in first line therapy and pts with PD-L1 (+) status. Further comparisons will be better addressed by a larger prospective study.[Table: see text]

Blood tumor mutational burden (bTMB) and tumor PD-L1 as predictive biomarkers of survival in MYSTIC: First-line durvalumab (D) ± tremelimumab (T) versus chemotherapy (CT) in metastatic (m) NSCLC

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Background: MYSTIC, an open-label, Ph3 trial of first-line D (anti-PD-L1) ± T (anti-CTLA-4) vs platinum-based CT, showed an improvement in OS with D vs CT in pts with tumor cell PD-L1 expression ≥25% (PD-L1 TC ≥25%; HR 0.76 [97.54% CI 0.56–1.02], p = 0.036). Exploratory analyses showed bTMB was a predictive biomarker for OS with D±T vs CT. We report further exploratory analyses of OS according to PD-L1 and bTMB. Methods: Immunotherapy/CT-naïve pts with mNSCLC were randomized (1:1:1) to D, D+T or CT. bTMB levels (mut/Mb) were evaluated with the GuardantOMNI platform (Guardant Health), and PD-L1 TC expression with the VENTANA PD-L1 (SP263) IHC assay. Results: D improved OS vs CT in pts with PD-L1 TC ≥25% across bTMB levels (PD-L1 TC ≥25%/bTMB≥20 HR 0.79 [95% CI 0.45, 1.39]; PD-L1 TC ≥25%/bTMB < 20 HR 0.64 [95% CI 0.45, 0.90]). In contrast, D+T improved OS vs CT in pts with bTMB≥20 across different PD-L1 TC expression levels (Table; PD-L1 TC ≥25%/bTMB≥20 HR 0.44 [95% CI 0.23, 0.84]; PD-L1 TC < 1%/bTMB≥20 HR 0.42 [95% CI 0.17, 0.97]). Additional cutoffs and outcomes in subgroups defined by both biomarkers will be presented. Conclusions: These exploratory analyses from MYSTIC support PD-L1 TC expression as an appropriate predictive biomarker for OS with D vs CT, while suggesting bTMB as a predictive biomarker for OS with D+T in mNSCLC. These biomarkers appear to be independent and both may be important for mNSCLC treatment decisions. Interpretation of these data may be limited by small sample sizes; further investigations are warranted. Clinical trial information: NCT02453282. [Table: see text]

Phase I/Ib study of pembrolizumab and vorinostat in patients with metastatic NSCLC (mNSCLC): Updated results

9073

Background: Histone deacetylase inhibitors (HDACi) enhance tumor immunogenicity through several mechanisms and may augment response to immune checkpoint inhibitors (ICI). We report updated results from a phase I/Ib trial testing the combination of oral HDACi vorinostat (V) with PD-1 inhibitor pembrolizumab (P) in mNSCLC. Methods: In phase I, pts with ICI-naïve or ICI-pretreated mNSCLC were treated with P (200mg IV q3 wk) + V (200 or 400 mg PO daily). In phase Ib expansion, pts were required to have progressed on prior ICI treatment. Primary endpoints were safety/tolerability; secondary endpoints included RR, PFS, DOR, and OS. Tissue and blood specimens from pre- and on-treatment were collected for correlative analyses to determine tumor gene expression changes, T cell density and levels of myeloid-derived suppressor cells. Results: Between 3/2016 - 12/2018, Phase I: 13 pts were treated (4 at 200mg, and 9 at 400mg V dose); and Phase Ib: 20 pts were treated. Median age: 68 (range 38-82); Females: 11 (33%); ECOG 1: 31 (94%); and never/former/current smokers: 3/22/8 (9%/67%/24%). PD-L1 expression was < 1% in 8/33 (18%), ≥1-49% in 7/33 (21%), ≥ 50% in 9/33 (27%) and unknown in 11/30 (33%). No DLTs or treatment related deaths were observed. The RP2D was P 200mg and V 400mg. Most common any grade AEs was fatigue (11%) and nausea/vomiting (8%). 2 (6%) patients had treatment discontinued due to toxicity. 30 pts are evaluable for response, 6 ICI-naïve and 24 ICI-pretreated. 4 (13%) had PR (2 confirmed), 16 (53%) had SD, and 10 (33%) had PD for a disease control rate of 67%. In the ICI-pretreated Ib cohort, 3 pts (1 confirmed; 2 unconfirmed) had a PR and 10 had SD (8 confirmed). For ICI-pretreated pts, mPFS was 3.2 and mOS was 7.3 months, and 1-year PFS was 17% (4 pts). For ICI-naïve, mPFS was 7.6 months and mOS was 16 months. CD8 T cell presence in tumor stromal regions was associated with benefit to P + V treatment. Conclusions: P + V were well tolerated. The combination demonstrates preliminary anti-tumor activity despite progression on prior ICI treatment and stromal CD8 T cells may be associated with benefit from P + V treatment. A randomized phase II portion of this study, examining P combined with V vs. placebo in immunotherapy naïve pts, is ongoing. Clinical trial information: NCT02638090.

Three-year overall survival update from the PACIFIC trial

8526

Background: In the phase 3 PACIFIC study of patients with unresectable, Stage III NSCLC without progression after chemoradiotherapy (CRT), durvalumab demonstrated significant improvements versus placebo in the primary endpoints of progression-free survival (HR, 0.52; 95% CI, 0.42–65; P < 0.0001) and overall survival (OS; HR, 0.68; 95% CI, 0.53–0.87; P = 0.00251). Safety was similar and durvalumab had no detrimental effect on patient-reported outcomes. Here, we report 3-year OS rates for all patients randomized in the PACIFIC study. Methods: Patients with WHO PS 0/1 (any tumor PD-L1 status) who received ≥2 cycles of platinum-based CRT were randomized (2:1), 1–42 days following CRT, to receive durvalumab 10 mg/kg intravenously every 2 weeks or placebo, up to 12 months, and stratified by age, sex, and smoking history. OS was analyzed using a stratified log-rank test in the ITT population. Medians and OS rates at 12, 24 and 36 months were estimated by Kaplan-Meier method. Results: In total, 713 patients were randomized of whom 709 received treatment (durvalumab, n = 473; placebo, n = 236). The last patient had completed the protocol-defined 12 months of study treatment in May 2017. As of January 31, 2019 (data cutoff), 48.2% of patients had died (44.1% and 56.5% in the durvalumab and placebo groups, respectively). The median duration of follow-up was 33.3 months (range, 0.2–51.3). Updated OS remained consistent with that previously reported (stratified HR 0.69, 95% CI, 0.55–0.86), with the median not reached (NR; 95% CI, 38.4 months–NR) with durvalumab versus 29.1 months (95% CI, 22.1–35.1) with placebo. The 12-, 24- and 36-month OS rates with durvalumab and placebo were 83.1% versus 74.6%, 66.3% versus 55.3%, and 57.0% versus 43.5%, respectively. After discontinuation, 43.3% and 57.8% in the durvalumab and placebo groups, respectively, received subsequent anticancer therapy (9.7% and 26.6% subsequently received immunotherapy). OS subgroup results will be presented. Conclusions: Updated OS data from PACIFIC, including 3-year survival rates, underscore the long-term clinical benefit with durvalumab following CRT and further establish the PACIFIC regimen as the standard of care in this population. Clinical trial information: NCT02125461.

Nivolumab monotherapy in metastatic urothelial carcinoma: Longer-term efficacy and safety results from the CheckMate 032 study

414

Background: Nivolumab has shown efficacy and acceptable safety in 2 open-label, multicenter studies (CheckMate 032 and 275) and is approved for patients (pts) with metastatic urothelial carcinoma (mUC) after ≥1 platinum-based therapy. Here we report longer-term efficacy and safety results for pts with mUC in the phase 1/2 CheckMate 032 study who received nivolumab monotherapy based on > 2 years of follow-up. Methods: Pts with mUC, regardless of programmed death-1 ligand 1 (PD-L1) expression status, received nivolumab 3 mg/kg intravenously every 2 weeks until progression or discontinuation. Tumor PD-L1 membrane expression was assessed with Dako PD-L1 immunohistochemical staining. Primary endpoint: objective response rate (ORR; RECIST 1.1); other endpoints: safety, progression-free survival (PFS), overall survival (OS), and duration of response. Results: Of 78 treated pts (median age 65.5 years; range, 31-85), 52 (66.7%) had received ≥2 prior therapies. At a minimum follow-up of 24 months, 11 pts (14.1%) remain on treatment. Treatment discontinuation was mainly due to disease progression (52 pts [66.7%]). Tumor PD-L1 expression was evaluable in 68 pts (87.2%); 26 (38.2%) pts had ≥1% and 42 (61.8%) had < 1% expression. The table shows overall efficacy. Updated ORR was 25.6%, with 1 additional complete response (CR) achieved for a CR rate of 8%. Median duration of response was not reached. ORR, 1- and 2-year PFS and OS rates were similar between the PD-L1 < 1% and > 1% subsets. Grade 3 or 4 treatment-related adverse events (TRAEs) occurred in 22 pts (28.2%); most frequent were ↑lipase (6.4%), ↑amylase (5.1%), and maculopapular rash (3.8%). One pt had a grade 5 TRAE (pneumonitis). Conclusions: Nivolumab showed clinically meaningful, durable efficacy with promising long-term survival regardless of PD-L1 expression, and no new toxicity signals with longer-term follow-up in previously treated pts with mUC. Clinical trial information: NCT01928394. [Table: see text]

Updated overall survival and safety profile of durvalumab monotherapy in advanced NSCLC

169

Background: Single-agent durvalumab is being evaluated in patients with advanced squamous and non-squamous NSCLC in an ongoing Phase 1/2 study (NCT01693562). Here we present updated survival and safety data in NSCLC patients. Methods: Treatment-naïve (1L) and previously treated (2L or 3L+) stage IIIB/IV NSCLC patients received durvalumab 10 mg/kg Q2W for up to 12 months. Patients were stratified by tumor PD-L1 expression (Ventana PD-L1 [SP263] Assay [PD-L1 high: ≥25% of tumor cells with membrane staining]), treatment line, and histology. Results: As of 05 September 2017, 304 NSCLC patients received durvalumab monotherapy. Median duration of follow-up was 35.6 (0.3–50.9) months. Investigator-assessed ORR ranged between 23.2% and 30.0% among PD-L1 high patients, and between 3.6% and 8.3% among PD-L1 low/negative patients. Median PFS and median OS were longer in PD-L1 high vs PD-L1 low/negative patients (Table). Any-grade treatment-related AEs (TRAEs) were reported in 57.2% of pts (including fatigue, 17.4%, decreased appetite, 9.2%, diarrhea, 8.9%); in 10.2% of pts these were Grade 3 or 4. TRAEs resulting in treatment discontinuation were reported in 17 patients (5.6%); 1 patient had a Grade 5 TRAE (pneumonia). Conclusions: In this ongoing phase 1 study, OS and safety profile appear encouraging in treatment-naïve and previously treated NSCLC patients, particularly among PD-L1 high patients. Further investigation regarding PD-L1 expression for selection of patients who most likely benefit from durvalumab is needed. Clinical trial information: NCT01693562. [Table: see text]

Increasing physician recognition and management of immune-mediated adverse events (imAEs): Results of a structured learning platform

211

Background: Immunotherapies have significantly improved cancer outcomes across multiple tumor types, while concurrently introducing new and unique toxicities, requiring timely recognition and intervention. To advance physician knowledge of imAEs, an educational online platform was developed for use by AstraZeneca clinical trial investigators (PIs). Herein, we report the impact of this educational strategy on PIs’ knowledge and confidence in recognizing and managing imAEs. Methods: The web-based learning platform included 8 structured and interactive modules (mode of action, colitis, pneumonitis, rash, hepatitis, endocrinopathy, neurotoxicity and nephritis), each containing 3 lessons reviewing background, pathophysiology and diagnosis of individual imAEs, management strategies and expert videos. Pre- and post-training questions to test knowledge (n = 5) and confidence (n = 2) were offered. The platform launched in May 2016 and remains active. PIs participating in durvalumab and/or tremelimumab clinical trials are eligible for participation. Results: As of Jan 19 2017, 2372 PIs have been invited to participate, 356 accessed the platform, and 294 completed ≥1 lesson (57% mode of action, 62% colitis, 42% pneumonitis, 20% rash, 24% hepatitis, 18% endocrinopathy, 19% neurotoxicity, 15% nephritis). Although an overall high proportion of correctly answered questions was identified at the pre-training stage (73% of 2935 total questions, n = 169 PIs), accuracy increased by a mean of 11% (range -3‒27%) at the post-training stage (84%). In each module, there was ≥1 question (range 1‒3) for which correct answers increased by ≥15% post- vs pre-training. Overall, after learning, confidence levels in recognition and management of imAEs increased by 28% (57 to 85%, p < 0.05; n = 35‒102 PIs) and 28% (51 to 79%, p < 0.05; n = 28‒101 PIs), respectively. Conclusions: The number of PIs completing ≥1 lesson indicates a desire for imAE training. This educational initiative enhanced knowledge, and among PIs with suboptimal confidence pre-training, 1 in 2 reported increased confidence in imAE recognition and management, which may improve patient care and maximize treatment potential.

Anti-PD1 treatment to induce M1 polarization of tumor infiltrating macrophages in a 3D ex vivo system of lung cancer patients

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Background: Nivolumab and pembrolizumab treatment targeting the PD1/PD-L1 axis has demonstrated increased survival benefit in subpopulations of patients with advanced non-small cell lung cancer (NSCLC). The impact of these therapeutics on tumor immune microenvironment is not fully understood. Classical M1 macrophages are critical components involved in the inflammatory response and antitumor immunity. In this study, we evaluated the effect of PD1/PD-L1 blockade on M1 polarization of tumor-associated macrophages (TAMs) and activation of cytotoxic T-cells in a 3D ex vivo system of NSCLC. Methods: Fresh tumor tissues obtained from consented patients with NSCLC at the time of surgical resection were utilized in a 3D ex vivo tumor miscrosphere assay. 3D tumor microspheres were treated with nivolumab or pembrolizumab at 10 mg/ml for 36 hours within an intact tumor microenvironment. Flow cytometry analysis was performed to evaluate treatment-mediated TAM polarization, activation of T-cells and changes in CD4 and CD8 subpopulations. A multiplex human cytokine assay was used to simultaneously analyze the differential secretion of cytokines. Additionally, a NanoString platform containing probes to quantitate 770 immune function genes was used to determine potential positive or negative associations between expression of immune function genes and TIL activation by ex vivo treatment. Results: Both nivolumab and pembrolizumab treatment increased population of M1 macrophages (CD68+, CD80+, CD163-) and simultaneous release of MIP1b, IFN-ɣ, TNF-a, and GM-CSF cytokines as well as expression of genes related to the M1 phenotype that was accompanied by activation of CD8 cells assessed by Ki67 and CD107a expression and increased expression of genes involved in the IFNg pathway. Conclusions: Our studies showed that anti PD1/PD-L1 treatment leads to M1 macrophage polarization and T-cell activation in subgroups of NSCLC patients emphasizing the importance of comprehensive analysis of tumor immune microenvironment for a better understanding of the mechanism of action of immuno-oncology drugs that may help developing rationale combination treatments in NSCLC.

Phase II trial of AZD1775 in combination with carboplatin and paclitaxel in stage IV squamous cell lung cancer (sqNSCLC): Preliminary results

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Background: WEE1, a dual serine/threonine and tyrosine kinase involved in regulation of the G2/M cell cycle checkpoint, is an essential component for proper DNA damage response. In combination with platinum agents, the inhibition of WEE1 is expected to lead to unstable DNA replication structures, inability to repair DNA damage, loss of G2/M arrest and ultimately mitotic catastrophe. In NSCLC cell lines, we previously demonstrated that cisplatin exhibited enhanced effects in combination with AZD1775 (a WEE1 inhibitor). This trial tests AZD1775 combined with a platinum doublet in patients with sqNSCLC. Methods: In this single-arm phase II trial, patients with stage IV sqNSCLC receive intravenous (IV) carboplatin AUC 5, IV paclitaxel 175 mg/m2, and oral AZD1775 225 mg twice/day for 2.5 days every 21 days for 4-6 cycles followed by maintenance AZD1775 at the same doses. Antiemetics prior to each dose of AZD1775 are mandatory. The primary endpoint is response rate per RECIST v1.1, with overall and progression-free survival as secondary endpoints. Archival tissue specimens are collected for correlative analyses of p53, PAXIP1, and WEE1. Results: Interim analysis of the 15 patients [3/15 (20%) female] enrolled through 11/2016 show 14/15 (93%) were ECOG 1, and 1/9/5 (7%/60%/33%) were never/former/current smokers. The most frequent adverse events of any grade were diarrhea (53%), nausea (40%), and vomiting (33%). The 2 most common grade 3-4 adverse events were neutropenia (13%) and fatigue (20%). No patients required treatment discontinuation due to toxicity. Of the 10 patients evaluable for response, 3 (30%) had confirmed partial responses (PR), 1 (10%) had unconfirmed PR, 5 (50%) had stable disease (SD), and 1 (10%) had progressive disease for a disease control rate of 90%. In those with SD, tumors regressed by -15%, -22%, -23%, -26% and -28% at first scan. Conclusions: AZD1775 combined with carboplatin and paclitaxel is tolerable and demonstrates promising activity in advanced sqNSCLC patients. Nausea and vomiting are manageable with antiemetics. The study continues to enroll. Correlative biomarker analyses of the tissue are planned. More mature data will be presented. Clinical trial information: NCT02513563.

Nivolumab (nivo) ± ipilimumab (ipi) in advanced small-cell lung cancer (SCLC): First report of a randomized expansion cohort from CheckMate 032

8503

Background: Patients (pts) with advanced SCLC after first-line platinum-based chemotherapy (PLT-CT) have a poor prognosis and limited treatment options. CheckMate 032 is a phase I/II trial evaluating multiple regimens of nivo ± ipi in solid tumors, including advanced SCLC. Tolerability and efficacy of nivo ± ipi were demonstrated in early results from the initial treatment arms (Antonia, Lancet Oncol 2016), prompting long-term follow-up and the addition of a randomized expansion cohort to further evaluate nivo ± ipi in advanced SCLC. Methods: In the initial treatment arms, pts with advanced SCLC and disease progression after prior PLT-CT were assigned to nivo (3 mg/kg Q2W; n = 98) or nivo 1 + ipi 3 (1 mg/kg and 3 mg/kg Q3W x 4, then nivo 3 Q2W; n = 61); safety/efficacy was assessed with a follow-up of ~18 mo. In the subsequent SCLC expansion cohort, pts were randomized 3:2 to nivo vs nivo 1 + ipi 3 and stratified by number of prior therapies. The primary endpoint was objective response rate (ORR). Results: Updated efficacy/safety results from the initial (non-randomized) nivo and nivo 1 + ipi 3 arms are summarized in the table. Responses were durable and occurred regardless of PD-L1 expression or PLT-sensitivity; safety was consistent with prior nivo ± ipi studies. In the expansion cohort, 247 pts were randomized to nivo or nivo 1 + ipi 3. The presentation will contain the first report of efficacy/safety results and subgroup analyses from this randomized expansion cohort. Conclusions: Durable responses are observed with nivo and nivo + ipi in pts with previously treated SCLC. The expansion cohort represents the first randomized evaluation of combined immune checkpoint blockade in SCLC. Clinical trial information: NCT01928394. [Table: see text]

Safety and clinical activity of durvalumab monotherapy in patients with hepatocellular carcinoma (HCC)

4071

Background: Durvalumab, an anti-PD-L1 mAb, has shown early and durable clinical activity with manageable safety in an ongoing Phase 1/2, multicenter, open-label study in pts with advanced solid tumors. Interim analyses from the HCC cohort in the dose-expansion part of this study are reported here. Methods: Patients with HCC (Child-Pugh class A) received durvalumab 10 mg/kg i.v. q2w for 12 months or until confirmed progressive disease, whichever occurred first. The primary objective was to evaluate the safety profile; secondary objective was to assess the antitumor activity (investigator-assessed RECIST v1.1). Clinical activity was evaluated for the total HCC population and by viral status. Results: As of Oct 24 2016, 40 HCC pts with median 23.9 (range 2.4–34.7) weeks follow-up received durvalumab. 93% had prior sorafenib. Treatment-related AEs occurred in 80.0% of pts, most commonly fatigue (27.5%), pruritus (25.0%) and elevated aspartate aminotransferase (AST) (22.5%). Grade 3–4 treatment-related AEs were reported in 20.0% of pts, most commonly elevated AST (7.5%) and elevated alanine aminotransferase (5.0%). 7 (17.5%) pts completed the initial 12-month treatment and 7 (17.5%) pts discontinued treatment because of an AE (none related to treatment). There were no deaths due to treatment-related AEs. Clinical activity is presented in the table. 4 pts achieved a PR; 2 were ongoing at data cut-off. Conclusions: Durvalumab had an acceptable safety profile and showed promising antitumor activity and OS in pts with HCC, particularly HCV+ pts. Clinical trial information: NCT01693562. [Table: see text]

Effect of bavituximab in combination with nivolumab on tumor immune response in a 3D ex vivo system of lung cancer patients

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Background: Bavituximab is a chimeric monoclonal antibody that targets the membrane phospholipid phosphatidylserine (PS) exposed on endothelial cells and cancer cells in solid tumors. Our previous studies showed that bavituximab enhances the activation of CD8+ TILs that correlates with increased cytokine production by lymphoid and myeloid cells in lung cancer with low PD-L1 expression suggesting that the interruption of the PD-1/PD-L1 axis by nivolumab may enhance the bavituximab effect in tumors. Methods: Fresh tumor tissues obtained from consented patients with NSCLC at the time of surgical resection were utilized in a 3D ex vivo tumor miscrosphere assay, where 3D tumor microspheres were treated with bavituximab or nivolumab alone or in combination at 10 mg/ml for 36 hours. At the end of the treatment, a multiplex human cytokine assay was used to simultaneously analyze the differential secretion of cytokines, including human IFNg, in culture media as a surrogate of TIL activation. In addition, a gene expression analysis using a NanoString platform containing probes to quantitate 770 immune function genes. Results: Preliminary results indicate the combination treatment with bavituximab and nivolumab led to increased expression of genes involved in M1 polarization of tumor associated macrophages in a subpopulation of lung tumors that closely correlated with release of cytokines such as MIP1b (CCL4) which is a chemoattractant for natural killer cells, monocytes and a variety of other cells involved in tumor immune response. Conclusions: This lung patient derived ex-vivo approach indicates that bavituximab in combination with nivolumab may enhance immune response. This response likely involves M1 polarization of tumor associated macrophages and suggests potential clinical implications in the treatment of lung cancer.

Safety and clinical activity of first-line durvalumab in advanced NSCLC: Updated results from a Phase 1/2 study

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Background: Single-agent durvalumab demonstrated manageable safety and encouraging clinical activity in advanced squamous and non-squamous NSCLC in preliminary analyses from the Phase 1/2 1108 study (NCT01693562). Here we present updated safety data and clinical activity in NSCLC pts with no prior treatment for advanced disease. Methods: In this Phase 1/2 dose-escalation and expansion study, pts with Stage IIIB/IV NSCLC, ECOG PS 0–1, and availability of a fresh tumor biopsy and/or archival tumor tissue for PD-L1 testing received durvalumab 10 mg/kg every 2 weeks for up to 12 months, with retreatment permitted for those progressing after 12 months of therapy. Tumor PD-L1 expression was assessed using the Ventana PD-L1 (SP263) Assay (PD-L1 high: ≥25% of tumor cells with membrane staining). Results: As of 24 October 2016, 59 pts (63% ECOG PS 1, 49% squamous) received first-line durvalumab. Median duration of follow-up was 17.3 (1.0–36.8) mos. Safety profile was consistent with the overall (N = 304, ≥0 prior lines of therapy) NSCLC cohort. All-grade treatment-related adverse events (AEs) were reported in 56%; the most common were fatigue (15%), diarrhea (13%), and decreased appetite (10%). 7% had a treatment-related AE leading to discontinuation of durvalumab, including diarrhea in 2 pts. Grade ≥3 treatment-related AEs (all n = 1) occurred in 10%; 1 pt died due to drug-related pneumonia. 49 pts had high PD-L1 expression and 9 pts had low/negative PD-L1 expression; data are not summarized for the latter group due to the small number of pts. For the PD-L1 high subpopulation, confirmed ORR (investigator-assessed RECIST v1.1) was 28.6% (95% CI 16.6–43.3) and disease control rate (stable disease ≥24 weeks) was 42.9% (95% CI 28.8–57.8); median PFS was 4.0 months (95% CI 2.3–9.1), median OS was 21.0 months (95% CI 14.5–not estimable), and 12-month OS rate was 72% (95% CI 56–83). Response rates were similar and durable regardless of histology. Conclusions: Consistent with prior data, durvalumab had a tolerable safety profile in advanced treatment-naïve NSCLC. Clinical activity was seen in PD-L1 high pts, with encouraging OS. Clinical trial information: NCT01693562.

Updated safety and clinical activity of durvalumab monotherapy in previously treated patients with stage IIIB/IV NSCLC

9085

Background: Preliminary analyses of an ongoing Phase 1/2 study of single-agent durvalumab showed antitumor activity and a tolerable safety profile in advanced NSCLC, with higher ORR and longer OS in pts with high vs. low/negative PD-L1 tumor expression. Here we present updated safety analyses (primary endpoint) for all NSCLC pts and clinical activity based on investigator-assessed RECIST v1.1 in pts who had received prior treatment for advanced NSCLC. Methods: Durvalumab (10 mg/kg q2w) was given until unacceptable toxicity or disease progression, or for up to 12 mos; retreatment was permitted upon disease progression after completion of 12 mos of treatment. PD-L1 expression was assessed using the Ventana PD-L1 (SP263) Assay (PD-L1 high = ≥25% and PD-L1 low/negative = <25% of tumor cells with membrane staining). Results: As of 24 Oct 2016, 245 pts with previously treated NSCLC (53% squamous) received durvalumab and were followed for a median of 29.2 (range 0.3–40.5) mos; 142 pts (58%) had treatment-related adverse events (AEs), most frequent: fatigue (18%), decreased appetite (9%), and nausea, rash, and diarrhea (each 8%). 25 pts (10%) had treatment-related Grade 3/4 AEs, most frequent: fatigue and hyponatremia (each 2%); there were no treatment-related deaths. 4% had treatment-related serious AEs including colitis and pneumonitis (each 2%). In the overall population, 12 mo OS rate was 47% (95% CI 40–53) and 18 mo OS rate was 38% (95% CI 31–45). Antitumor activity and survival by PD-L1 status are shown in the table. Conclusions: Consistent with earlier reports, durvalumab had a manageable safety profile in Stage IIIB/IV NSCLC, with encouraging clinical activity as 2L+ therapy. Higher tumor PD-L1 expression enriched clinical benefit of response rate and survival endpoints. Clinical trial information: NCT01693562. [Table: see text]

Nivolumab (N) plus ipilimumab (I) as first-line (1L) treatment for advanced (adv) NSCLC: 2-yr OS and long-term outcomes from CheckMate 012

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Background: The fully human anti–PD-1 antibody N offers long-term OS benefit in patients (pts) with previously treated adv NSCLC. Adding I (anti–CTLA-4 antibody) to N has been shown to improve clinical activity vs either agent alone in multiple tumor types. We present long-term data for 1L N+I treatment of pts with adv NSCLC from CheckMate 012. Methods: In two cohorts in this phase 1 study, pts with recurrent stage IIIb/IV, chemotherapy-naive NSCLC and ECOG PS 0–1 received N 3 mg/kg Q2W combined with I 1 mg/kg Q12W (n=38) or Q6W (n=39) until disease progression, unacceptable toxicity, or consent withdrawal. The primary endpoint was safety and tolerability. Secondary endpoints included investigator-assessed ORR (RECIST v1.1) and PFS. Exploratory endpoints included OS and efficacy by tumor PD-L1 expression. Results: In the N+I Q12W and N+I Q6W cohorts, respectively, 42% and 31% of pts experienced grade 3–4 treatment-related (TR) AEs; 18% in each cohort discontinued due to any-grade TRAEs. The most frequently reported any-grade TRAEs were pruritus (26%) and diarrhea (21%) with N+I Q12W, and fatigue (26%) and diarrhea (23%) with N+I Q6W. There were no TR deaths. N+I showed promising efficacy (table). While efficacy was enhanced with increasing PD-L1 expression, activity was noted in pts with <1% PD-L1 (table). Of 6 complete responses (CRs), 3 were in pts with <1% PD-L1. Conclusions: 1L therapy with N+I demonstrates a manageable safety profile and promising, durable efficacy (including pathological CRs) in adv NSCLC; efficacy was enhanced in pts with ≥1% PD-L1 tumor expression. Longer follow-up data, including 2-yr OS and characteristics of long-term survivors, will be presented. Clinical trial information: NCT01454102. [Table: see text]

Comparison of incidence and average cost per toxicity in patients treated with nivolumab and pembrolizumab

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Background: PD-1 inhibitors such as nivolumab and pembrolizumab have demonstrated efficacy in numerous metastatic cancers. However, these drugs are also some of the most expensive and can have severe adverse side effects. However, most available data comes from clinical trials rather than patients treated in clinical practice as standard-of-care. This study reports the incidence of severe toxicities in a number of cancer types and estimates the per patient cost of managing these toxicities. Methods: All patients treated with nivolumab or pembrolizumab between January 1, 2014 through April 30, 2016 were identified at Moffitt Cancer Center (nivolumab N=74, pembrolizumab N=134). Toxicities occurring during or within 2 months of stopping treatment were identified and graded using the CTCAE 4.0 criteria. A cost of care analysis was performed comparing patients with Grade 3-5 toxicities to patients with Grade 0-2 toxicities. Results: The most common severe toxicities were anemia, dyspnea, dermatitis, hepatitis, and renal failure (Table 1). The average cost of care for patients experiencing Grade 3-5 toxicities was $640 and $4,784 higher than those without toxicity in nivolumab and pembrolizumab, respectively. Conclusions: Primary cost drivers differed between the two drugs with outpatient visits and additional pharmacy costs driving nivolumab cost while inpatient stays and radiation therapy drove costs with pembrolizumab. The large difference between the toxicity cost of each group could be due to the heterogeneity of cancer types treated with nivolumab versus primarily melanoma in the case of pembrolizumab or the smaller sample size of nivolumab patients. [Table: see text]

Incidence and average cost per toxicity in patients treated with nivolumab

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Background: Recently approved PD-1 inhibitors such as nivolumab have demonstrated clear efficacy in metastatic melanoma and other cancers, but also come at a high cost and with the potential for severe side effects. However, most of the data available comes from clinical trials rather than patients treated in clinical practice as standard-of-care. This study reports the incidence of severe toxicities in a number of cancer types and estimates the per patient cost of managing these toxicities. Methods: Patients with metastatic melanoma, non-small cell lung cancer, renal cell carcinoma, and Hodgkin’s lymphoma treated with nivolumab between January 1, 2014 through April 30, 2016 were identified at Moffitt Cancer Center (N=74). Toxicities occurring during treatment or within 2 months of stopping treatment were identified by a chart review and each toxicity graded using the CTCAE 4.0 criteria. A cost of care analysis was performed to estimate the cost of serious toxicities (Grade 3-5) compared to a control group who experienced no or minor adverse events (Grade 0-2). Billing data was used to estimate the mean cost of care for each group. Costs were subcategorized by service line, e.g., pharmacy costs, radiology, laboratory services. Results: The most common severe toxicities were anemia, dyspnea, renal failure, colitis, fatigue, and pneumonitis (Table 1). The average cost of care for patients experiencing grade 3-5 toxicities was $2,036 higher than those without toxicity. Conclusions: The incidence of toxicity in our population was similar to that reported in clinical trials. Costs were higher for patients with toxicities, driven by additional outpatient care (19% higher cost per patient) as well as additional pharmacy costs (22% higher per patient). Though small in comparison to the cost of nivolumab, over $6,000 per dose, these costs should not be dismissed, particularly when performing cost effectiveness and value research. [Table: see text]

Differential association of STK11 and TP53 with KRAS mutation-associated gene expression, proliferation and immune surveillance in lung adenocarcinoma

While mutations in the KRAS oncogene are amongst the most prevalent in human cancer, there are few successful treatments to target these tumors. It is also likely that heterogeneity in KRAS-mutant tumor biology significantly contributes to the response to therapy. We hypothesized that presence of commonly co-occurring mutations in STK11 and TP53 tumor suppressors may represent a significant source of heterogeneity in KRAS-mutant tumors. To address this, we utilized a large cohort of resected tumors from 442 lung adenocarcinoma patients with data including annotation of prevalent driver mutations (KRAS, EGFR) and tumor suppressor mutations (STK11 and TP53), microarray-based gene expression and clinical covariates including overall survival (OS). Specifically, we determined impact of STK11 and TP53 mutations on a new KRAS mutation-associated gene expression signature as well as previously defined signatures of tumor cell proliferation and immune surveillance responses. Interestingly, STK11, but not TP53 mutations, were associated with highly elevated expression of KRAS mutation-associated genes. Mutations in TP53 and STK11 also impacted tumor biology regardless of KRAS status, with TP53 strongly associated with enhanced proliferation and STK11 with suppression of immune surveillance. These findings illustrate the remarkably distinct ways through which tumor suppressor mutations may contribute to heterogeneity in KRAS-mutant tumor biology. In addition, these studies point to novel associations between gene mutations and immune surveillance that could impact the response to immunotherapy.