Comparison of SP263 and 22C3 immunohistochemistry PD-L1 assays for clinical efficacy of adjuvant atezolizumab in non-small cell lung cancer: results from the randomized phase III IMpower010 trial

BACKGROUND

Tumor samples from the phase III IMpower010 study were used to compare two programmed death-ligand 1 (PD-L1) immunohistochemistry assays (VENTANA SP263 and Dako 22C3) for identification of PD-L1 patient subgroups (negative, positive, low, and high expression) and their predictive value for adjuvant atezolizumab compared with best supportive care (BSC) in resectable early-stage non-small cell lung cancer (NSCLC).

METHODS

PD-L1 expression was assessed by the SP263 assay, which measured the percentage of tumor cells with any membranous PD-L1 staining, and the 22C3 assay, which scored the percentage of viable tumor cells showing partial or complete membranous PD-L1 staining.

RESULTS

When examining the concordance at the PD-L1-positive threshold (SP263: tumor cell (TC)≥1%; 22C3: tumor proportion score (TPS)≥1%), the results were concordant between assays for 83% of the samples. Similarly, at the PD-L1-high cut-off (SP263: TC≥50%; 22C3: TPS≥50%), the results were concordant between assays for 92% of samples. The disease-free survival benefit of atezolizumab over BSC was comparable between assays for PD-L1-positive (TC≥1% by SP263: HR, 0.58 (95% CI: 0.40 to 0.85) vs TPS≥1% by 22C3: HR, 0.65 (95% CI: 0.45 to 0.95)) and PD-L1-high (TC≥50% by SP263: HR, 0.27 (95% CI: 0.14 to 0.53) vs TPS≥50% by 22C3: HR, 0.31 (95% CI: 0.16 to 0.60)) subgroups.

CONCLUSIONS

The SP263 and 22C3 assays showed high concordance and a comparable clinical predictive value of atezolizumab at validated PD-L1 thresholds, suggesting that both assays can identify patients with early-stage NSCLC most likely to experience benefit from adjuvant atezolizumab.

TRIAL REGISTRATION NUMBER

NCT02486718.

Overall survival with adjuvant atezolizumab after chemotherapy in resected stage II-IIIA non-small-cell lung cancer (IMpower010): a randomised, multicentre, open-label, phase III trial

BACKGROUND

IMpower010 (NCT02486718) demonstrated significantly improved disease-free survival (DFS) with adjuvant atezolizumab versus best supportive care (BSC) following platinum-based chemotherapy in the programmed death-ligand 1 (PD-L1)-positive and all stage II-IIIA non-small-cell lung cancer (NSCLC) populations, at the DFS interim analysis. Results of the first interim analysis of overall survival (OS) are reported here.

PATIENT AND METHODS

The design, participants, and primary-endpoint DFS outcomes have been reported for this phase III, open-label, 1 : 1 randomised study of atezolizumab (1200 mg q3w; 16 cycles) versus BSC after adjuvant platinum-based chemotherapy (1-4 cycles) in adults with completely resected stage IB (≥4 cm)-IIIA NSCLC (per the Union Internationale Contre le Cancer and American Joint Committee on Cancer staging system, 7th edition). Key secondary endpoints included OS in the stage IB-IIIA intent-to-treat (ITT) population and safety in randomised treated patients. The first pre-specified interim analysis of OS was conducted after 251 deaths in the ITT population. Exploratory analyses included OS by baseline PD-L1 expression level (SP263 assay).

RESULTS

At a median of 45.3 months' follow-up on 18 April 2022, 127 of 507 patients (25%) in the atezolizumab arm and 124 of 498 (24.9%) in the BSC arm had died. The median OS in the ITT population was not estimable; the stratified hazard ratio (HR) was 0.995 [95% confidence interval (CI) 0.78-1.28]. The stratified OS HRs (95% CI) were 0.95 (0.74-1.24) in the stage II-IIIA (n = 882), 0.71 (0.49-1.03) in the stage II-IIIA PD-L1 tumour cell (TC) ≥1% (n = 476), and 0.43 (95% CI 0.24-0.78) in the stage II-IIIA PD-L1 TC ≥50% (n = 229) populations. Atezolizumab-related adverse event incidences remained unchanged since the previous analysis [grade 3/4 in 53 (10.7%) and grade 5 in 4 (0.8%) of 495 patients, respectively].

CONCLUSIONS

Although OS remains immature for the ITT population, these data indicate a positive trend favouring atezolizumab in PD-L1 subgroup analyses, primarily driven by the PD-L1 TC ≥50% stage II-IIIA subgroup. No new safety signals were observed after 13 months' additional follow-up. Together, these findings support the positive benefit-risk profile of adjuvant atezolizumab in this setting.

Association of baseline systemic corticosteroid use with overall survival and time to next treatment in patients receiving immune checkpoint inhibitor therapy in real-world US oncology practice for advanced non-small cell lung cancer, melanoma, or urothelial carcinoma

Immune checkpoint inhibitors (CPIs) have expanded treatment options for patients with solid tumors. Systemic corticosteroids (CSs) have an indispensable role in cancer care, but CS-related immunosuppression may counteract the CPI-driven antitumor immune response. This retrospective study investigated the association between baseline CS use (bCS; ≤14 days before, ≤30 days after CPI initiation) and clinical outcomes in patients with advanced non-small cell lung cancer (aNSCLC), melanoma (aMel), or urothelial carcinoma (aUC). We analyzed data from the Flatiron Health electronic health record-derived de-identified database for adults diagnosed with aNSCLC, aMel, or aUC between January 2011 and June 2017 who received ≥1 CPI monotherapy in any treatment line. Associations of bCS use with overall survival (OS) and time to next treatment (TTNT) were estimated using multivariable Cox proportional hazards models adjusting for demographic and clinical characteristics (i.e., ECOG performance status, site of metastases). In total, 2,213 patients were diagnosed with aNSCLC (n = 862), aMel (n = 742), or aUC (n = 609) and received ≥1 CPI administration. Most patients (67%-95%) received CSs, many during the baseline period (19%-30%). Patients with bCS use had shorter median OS than those with no bCS use for aNSCLC (6.6 vs 10.6 months; P= .00018), aMel (16.4 vs 21.5; P= .095), and aUC (4.1 vs 7.7; P= .0012). bCS use was associated with shorter OS (not significant for aMel) and TTNT in adjusted multivariable analyses, and clinical outcomes were not explained by prior CS use or other measured confounders. These findings suggest a potential association between bCS use and decreased CPI effectiveness, warranting further investigation.

Abstract 5388: Association of baseline systemic corticosteroid use with time to next treatment in patients with advanced melanoma, non-small cell lung cancer or urothelial cancer receiving cancer immunotherapy in US clinical practice

Background: Corticosteroids (CS) are often prescribed with cancer treatment to alleviate symptoms, treat comorbidities and manage treatment-related adverse events. The immunosuppressive properties of CS may decrease the effectiveness of cancer immunotherapy (CIT), and the effect may vary by tumor site. This study explored the association of baseline CS (bCS) use with time to next treatment (TTNT) in CIT-treated patients with advanced melanoma (aMel), advanced non-small cell lung cancer (aNSCLC) or advanced urothelial cancer (aUC).

Methods: The Flatiron Health electronic health record-derived de-identified database was used to select patients diagnosed with aMel, aNSCLC or aUC between January 1, 2011, and June 30, 2017, who received CIT alone in any treatment line and were followed through March 30, 2018. bCS included intramuscular or intravenous administrations or oral orders ≤ 14 days before and ≤ 30 days after the CIT start date. TTNT is a measure of intermediate outcomes, such as cancer progression, in real-world data sources. A TTNT event was defined as initiation of a new line of non-maintenance treatment or death within 60 days of the last CIT treatment during the index line of therapy. Other patients were censored at the latter of either their last CIT administration or last recorded visit. The association of bCS with TTNT was estimated using multivariable Cox proportional hazards models adjusting for key baseline characteristics, including prior CS use.

Results: Most patients were white men aged 66 to 72 years; median follow-up across tumor types was 3.9 to 5.5 months. One-fifth to one-third (19%-30%) of patients received bCS. More than half of patients (58%-61%) received a new treatment line during the study period, the milestone for measuring TTNT. Patients receiving bCS were more likely to have stage IV disease at diagnosis, brain or liver metastases (aNSCLC, aUC) and poorer ECOG performance status (aUC) at baseline. After adjusting for these and other important potential confounders, including prior CS use, bCS use was associated with shorter TTNT compared with no bCS use in multivariable models (aMel HR, 1.28 [95% CI: 1.03, 1.58]; aNSCLC HR, 1.40 [1.16, 1.70]; aUC HR, 1.36 [1.06, 1.82]).

Conclusions: After adjustments for measured confounders, patients receiving bCS had a shorter TTNT than those who did not receive bCS, suggesting a shorter treatment duration that may limit the potential long-term benefits of CIT use. TTNT is commonly used as a proxy for disease progression in real-world data sources; however, treatment changes could be due to reasons other than progression. Further studies are needed to confirm these observations.

Keywords/Indexing: Lung cancer: non-small cell; Melanoma/skin cancers

[A.D. and P.K.D. contributed equally to this work.]

Citation Format: Alexandra Drakaki, Preet K. Dhillon, Heather Wakelee, Stephen Y. Chui, Jinjoo Shim, Matthew Kent, Viraj Degaonkar, Tien Hoang, Virginia McNally, Patricia Luhn, Ralf Gutzmer. Association of baseline systemic corticosteroid use with time to next treatment in patients with advanced melanoma, non-small cell lung cancer or urothelial cancer receiving cancer immunotherapy in US clinical practice [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5388.

Atezolizumab, vemurafenib, and cobimetinib as first-line treatment for unresectable advanced BRAFV600 mutation-positive melanoma (IMspire150): primary analysis of the randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

IMspire150 aimed to evaluate first-line combination treatment with BRAF plus MEK inhibitors and immune checkpoint therapy in BRAF^V600 mutation-positive advanced or metastatic melanoma.

METHODS

IMspire150 was a randomised, double-blind, placebo-controlled phase 3 study done at 112 institutes in 20 countries. Patients with unresectable stage IIIc-IV, BRAF^V600 mutation-positive melanoma were randomly assigned 1:1 to 28-day cycles of atezolizumab, vemurafenib, and cobimetinib (atezolizumab group) or atezolizumab placebo, vemurafenib, and cobimetinib (control group). In cycle 1, all patients received vemurafenib and cobimetinib only; atezolizumab placebo was added from cycle 2 onward. Randomisation was stratified by lactate dehydrogenase concentration and geographical region. Blinding for atezolizumab was achieved by means of an identical intravenous placebo, and blinding for vemurafenib was achieved by means of a placebo tablet. The primary outcome was investigator-assessed progression-free survival. This trial (ClinicalTrials.gov, NCT02908672) is ongoing but no longer recruiting patients.

FINDINGS

Between Jan 13, 2017, and April 26, 2018, 777 patients were screened and 514 were enrolled and randomly assigned to the atezolizumab group (n=256) or control group (n=258). At a median follow-up of 18·9 months (IQR 10·4-23·8), progression-free survival as assessed by the study investigator was significantly prolonged with atezolizumab versus control (15·1 vs 10·6 months; hazard ratio [HR] 0·78; 95% CI 0·63-0·97; p=0·025). Common treatment-related adverse events (>30%) in the atezolizumab and control groups were blood creatinine phosphokinase increased (51·3% vs 44·8%), diarrhoea (42·2% vs 46·6%), rash (40·9%, both groups), arthralgia (39·1% vs 28·1%), pyrexia (38·7% vs 26·0%), alanine aminotransferase increased (33·9% vs 22·8%), and lipase increased (32·2% vs 27·4%); 13% of patients in the atezolizumab group and 16% in the control group stopped all treatment because of adverse events.

INTERPRETATION

The addition of atezolizumab to targeted therapy with vemurafenib and cobimetinib was safe and tolerable and significantly increased progression-free survival in patients with BRAF^V600 mutation-positive advanced melanoma.

FUNDING

F Hoffmann-La Roche and Genentech.

The Feasibility of a Low Sodium Meal Plan for Residents of a Subsidized Senior Housing Facility: The SOTRUE Pilot Study

Objectives

To determine the feasibility of a low sodium meal plan intervention aimed at reducing seated blood pressure (BP) in residents of a government-subsidized congregate, senior living facility.

Methods

The Satter House Trial of Reduced Sodium Meals (SOTRUE) was an individual-level, masked, randomized, controlled pilot study, testing the feasibility of administering a low versus typical sodium meal plan to adult residents of Jack Satter House, a section 202 congregate living facility in Revere, MA, subsidized by the Federal Department of Housing and Urban Development (HUD). Adults over age 60 years received 3 isocaloric meals with two snacks daily over a 14-day period. Both meal plans were equivalent in potassium and macronutrients, but differed in sodium density (<0.95 mg/kcal vs > 2 mg/kcal). The primary outcome was seated systolic BP (SBP) averaged over 2 visits (days 10 and 14) using an Omron HEM-907XL automated cuff. Our objective measure of compliance was morning urine sodium-creatinine ratio.

Results

We randomized 20 participants (95% women, 95% white, and mean age 78 +/− 8 years), beginning in October 7, 2019. Baseline characteristics were evenly distributed between groups. Dietary compliance was high (only 2 discontinued meals) and follow-up was 100% with the last participant ending November 4, 2019. Baseline SBP changed from 121 to 116 mm Hg on the typical sodium meal plan (N = 9; mean difference of −5 mm Hg; 95% CI: −18, 8) and 123 to 112 mm Hg on the low sodium meal plan (N = 11; mean difference of −11 mm Hg; 95% CI: −15.2, −7.7). Compared to the typical sodium meal plan, the low sodium meal plan non-significantly reduced SBP by 5 mm Hg (95% CI: −14, 4) and non-significantly reduced urine sodium-creatinine ratio (%-difference −36.0; 95% CI: −60.3, 3.4). Effects on SBP were greater in the subgroup using hypertension medications at baseline (−13 mm Hg; 95% CI: −26, −0) and changes in SBP from baseline were correlated with changes in urine sodium-creatinine ratio (Pearson's r = 0.31).

Conclusions

This trial represents an innovative, feasible, and practical approach to healthier eating by altering federally-mandated meal plans. A definitive study with a larger sample size is needed to establish the efficacy and safety of this approach in older adults who reside in section 202 housing.

Funding Sources

ISAC, Marcus Institute for Aging Research, Hebrew SeniorLife.

The Feasibility of Using Computrition Software for Nutrition Research

Objectives

Computrition is a food service software utilized by dieticians in clinical settings to create recipes, design menus, and scale the menus to larger quantities, yet it is underutilized in the research setting. The objective was to determine the practicality of administering two meal plans (low sodium vs typical sodium) designed with Computrition in a double-blind, randomized pilot study in older adult residents of a congregate housing facility.

Methods

This pilot study included 19 females and 1 male aged ≥65y residing at Jack Satter House, Revere, MA. Participants were randomized to low sodium or typical sodium meals (<0.95 or >2 mg/kcal), designed with Computrition. A base 7-day meal plan (with breakfast, lunch, dinner, and two snacks) was generated. Recipes entered in Computrition were modified to reach three calorie levels (1750, 2000, 2250 kcal/d) and two sodium densities, while keeping potassium levels constant at ∼3500 mg/d. Finally, Computrition labels were generated to execute meals while maintaining blinding. To determine efficacy of these meal plans, compliance was evaluated by comparing change in urinary sodium (mmol/L) over 2-weeks between low sodium vs. typical sodium groups. These comparisons were also assessed in sub-groups by calorie intake (≤1750 kcal/d, n = 12 and ≥2000 kcal/d, n = 8).

Results

Mean age was 77 ± 6y and calorie intake was 1849 kcal (low sodium group, n = 11) and 80 ± 9y and 1785 kcal (typical sodium group, n = 9). Over 2-weeks, urinary sodium decreased by −30.6 mmol/L in the low sodium diet, compared to 2.4 mmol/L in the typical sodium diet (P = 0.003). In those consuming ≤ 1750 kcal/d on the low sodium diet, urinary sodium decreased non-significantly by −18.3 mmol/L, compared to −2.3 mmol/L in the typical sodium diet (P = 0.16). In those consuming ≥2000 kcal/d on the low sodium diet, urinary sodium decreased non-significantly by −22.0 mmol/L, compared to no change in the typical sodium diet (P = 0.26).

Conclusions

In this study, two sodium meal plans designed using Computrition altered urinary sodium over 2 weeks. Similar trends in reduction were seen in the sub-groups by calorie intake, although results were not significant due to small sample sizes. Future work should evaluate testing and standardization of this software for a multi-site nutrition intervention study.

Funding Sources

ISAC, Marcus Institute, Hebrew SeniorLife.

Patient-reported outcomes (PROs) from the phase III IMspire150 trial of atezolizumab (A) + cobimetinib (C) + vemurafenib (V) in patients (pts) with BRAFV600+melanoma

10073

Background: In IMspire150, A+C+V significantly improved investigator-assessed progression-free survival vs placebo (Pbo)+C+V in previously untreated pts with unresectable stage IIIc/IV BRAFV600+melanoma. PRO data from this trial are now reported. Methods: 514pts were randomized 1:1 to 28-day cycles of A+C+V or Pbo+C+V. Pts received C+V in cycle 1; A or Pbo was added on days 1 and 15 from cycle 2 onward. Pts completed the EORTC QLQ-C30 questionnaire on day 1 of cycle 1 (baseline), days 1 and 15 of cycle 2 and cycle 3, day 1 from cycle 4 onward, within 28-d of treatment discontinuation, and ≤6 months post-treatment. Prespecified secondary PRO endpoints were time to confirmed deterioration (TTCD; defined as time from randomization to first ≥10-point decrease from baseline held for 2 consecutive assessments, or 1 assessment followed by death on treatment) in quality of life (QoL) and physical functioning (PF). Prespecified exploratory endpoints were TTCD in role functioning (RF); mean change from baseline and percentage of pts with a clinically meaningful change (≥10 points from baseline) in QoL, PF, and RF. Results: Questionnaire completion rates were > 80% for most of the treatment period. At baseline, mean QoL, PF, and RF scores were moderate to high (Table). At week 6 (cycle 2), following initiation of A, QoL, PF, and RF scores declined, but returned to near-baseline levels at week 10 (cycle 3) and were largely maintained until week 36 (cycle 10), when < 50% of pts contributed data. In this time, ≥56% pts in both arms did not experience a clinically meaningful deterioration in QoL, PF, and RF. TTCD on QoL (hazard ratio [HR] 1.23; 95% CI 0.90-1.67), PF (HR 1.27; 95% CI 0.93-1.74), and RF (HR 1.15; 95% CI 0.86-1.55) favored Pbo, but only one-third of pts overall experienced a confirmed deterioration. Conclusions: PRO data showed that A+C+V did not worsen QoL, PF, and RF in pts with advanced BRAFV600+melanoma, thus supporting its use as a treatment option. Clinical trial information: NCT02908672. [Table: see text]

Time to central nervous system (CNS) metastases (mets) with atezolizumab (A) or placebo (P) combined with cobimetinib (C) + vemurafenib (V) in the phase III IMspire150 study

10023

Background: The phase 3 IMspire150 study (NCT02908672) demonstrated improved progression-free survival with first-line combination treatment with A+C+V vs P+C+V in patients (pts) with previously untreated BRAFV600 mutation–positive advanced melanoma. Here we report incidence and time to development of CNS mets with A+C+V vs P+C+V in the IMspire150 study. Methods: Eligible pts were randomized 1:1 to receive A+C+V or P+C+V. A or P were given on day 1 and 15 of each 28-day cycle after an initial cycle of C+V. Incidence and time to development of CNS mets were evaluated in pts with no history of CNS mets at baseline confirmed by magnetic resonance imaging/computed tomography (MRI/CT). On study MRI/CT assessments were performed as clinically indicated. Time-to-event outcomes were estimated using the Kaplan-Meier method and competing risks analysis. Sensitivity analyses were conducted using landmark analysis at time of initiation of A or P. Results: 514 pts were randomized to receive A+C+V (n = 256) or P+C+V (n = 258); 244 and 247 pts, respectively, had no history of CNS mets at baseline. After a median follow-up of 18.9 months, CNS mets had developed in 52/244 pts (21%) in the A+C+V arm and 62/247 pts (25%) in the P+C+V arm. In both arms, pts with CNS mets were more likely to have other known unfavorable prognostic factors: elevated LDH, presence of liver mets, and/or higher tumor burden. Cumulative incidence of CNS mets as first site of progressive disease with A+C+V vs P+C+V was 8% vs 9%, 16% vs 19%, 20% vs 24%, and 23% vs 26% at 6, 12, 18, and 24 months, respectively (hazard ratio [HR] 0.87; 95% CI 0.60-1.26). Estimated CNS mets-free survival rates for A+C+V vs P+C+V were 91% vs 90%, 81% vs 75%, 74% vs 66%, and 69% vs 62% at 6, 12, 18, and 24 months, respectively, with a trend for improved CNS mets-free survival with A+C+V (HR 0.79; 95% CI 0.55-1.14). Results of landmark analyses for CNS mets-free survival and cumulative incidence of CNS mets were similar to those in the overall analysis. Conclusions: The addition of anti–programmed death-ligand 1 to C+V is associated with numerically lower rates of interval development of CNS mets, consistent with the overall benefit observed for A+C+V in the study. This finding requires further follow-up to fully assess the magnitude of benefit of A+C+V on CNS mets-free survival. Clinical trial information: NCT02908672.

Tumor-Infiltrating Lymphocytes in Patients Receiving Trastuzumab/Pertuzumab-Based Chemotherapy: A TRYPHAENA Substudy

Background

There is an urgent requirement to identify biomarkers to tailor treatment in human epidermal growth factor receptor 2 (HER2)-amplified early breast cancer treated with trastuzumab/pertuzumab-based chemotherapy.

Methods

Among the 225 patients randomly assigned to trastuzumab/pertuzumab concurrently or sequentially with an anthracycline-containing regimen or concurrently with an anthracycline-free regimen in the Tryphaena trial, we determined the percentage of tumor-infiltrating lymphocytes (TILs) at baseline in 213 patients, of which 126 demonstrated a pathological complete response (pCR; ypT0/is ypN0), with 28 demonstrating event-free survival (EFS) events. We investigated associations between baseline TIL percentage and either pCR or EFS after adjusting for clinicopathological characteristics using logistic and Cox regression models, respectively. To understand TIL biology, we evaluated associations between baseline TILs and baseline tumor gene expression data (800 gene set by NanoString) in a subset of 173 patients. All statistical tests were two-sided.

Results

Among the patients with measurable TILs at baseline, the median level was 14.1% (interquartile range = 7.1%-32.4%). After adjusting for clinicopathological characteristics, baseline percentage TIL was not associated with pCR (adjusted odds ratio [aOR] for every 10-percentage unit increase in TILs = 1.12, 95% confidence interval [CI] = 0.95 to 1.31, P = .17). At a median follow-up of 4.7 years, for every increase in baseline TILs of 10%, there was a 25% reduction in the hazard for an EFS event (aOR = 0.75, 95% CI = 0.56 to 1.00, P = .05) after adjusting for baseline clinicopathological characteristics and pCR. Additionally, genes associated with epithelial-mesenchymal transition, angiogenesis, and T-cell inhibition such as SNAIL1, ZEB1, NOTCH3, and B7-H3 were statistically significantly inversely correlated with percentage TIL.

Conclusions

Baseline TIL percentage provides independent prognostic information in patients treated with trastuzumab/pertuzumab-based neoadjuvant chemotherapy. However, further validation is required.

Abstract OT2-01-02: COLET: A multistage, phase 2 study evaluating the safety and efficacy of a doublet regimen of cobimetinib (C) in combination with paclitaxel (P) or triplet regimens of C in combination with atezolizumab (atezo) plus either P or nab-paclitaxel (nab-P) in metastatic triple-negative breast cancer (TNBC)

Preclinical data suggest that upregulation of the MAPK pathway confers resistance to taxane chemotherapy. Mutations and gene amplifications in the MAPK pathway are present in many TNBC tumors and may contribute to taxane resistance. Preliminary data from an initial safety run-in stage of the COLET study (ClinicalTrials.gov ID, NCT02322814; EudraCT number, 2014-002230-32) suggest improvement of clinical outcomes when MEK inhibition is combined with taxane chemotherapy. Additionally, in preclinical models, MEK inhibition was shown to enhance anti–PD-L1 activity. The monoclonal antibody PD-L1 inhibitor atezo has shown promising activity in combination with nab-P in metastatic TNBC. Accordingly, the COLET protocol was amended to include the evaluation of triplet regimens combining atezo with MEK inhibition and taxane chemotherapy[SL1] . COLET is evaluating the safety and efficacy of various combinations of C as first-line treatment for metastatic or locally advanced TNBC. Key eligibility criteria include measurable disease per Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1) and left ventricular ejection fraction &gt; institutional lower limit of normal or &gt;50%. Neoadjuvant or adjuvant therapy is allowed if completed &gt;6 months prior to study entry. COLET has 3 cohorts: I, II, and III. Cohort I has 2 stages: an initial safety run-in stage (n∼12) followed by an expansion stage (n∼90) of 1:1 randomization to C + P or placebo (PBO) + P. Patients received P 80 mg/m2 on days 1, 8, and 15 and C/PBO 60 mg/day on days 3-23 of each 28-day cycle. In the expansion stage of Cohort I, randomization is stratified by prior neoadjuvant/adjuvant taxane therapy and disease-free interval from last chemotherapy dose. Cohorts II and III will evaluate the safety and efficacy of adding atezo to C + P or nab-P, respectively. Each cohort has a safety run-in stage (n∼15) and an expansion stage (additional n∼15); each will receive atezo 840 mg on days 1 and 15 and C 60 mg/day on days 3-23 of every 28-day cycle. Cohort II will receive P 80 mg/m2 and Cohort III will receive intravenous nab-P 100 mg/m2 on days 1, 8, and 15. Patients will receive treatment until disease progression or toxicity. The primary efficacy end point is investigator-assessed progression-free survival (PFS) for the expansion stage (Cohort I), and the primary PFS analysis will be performed when 60 PFS events occur across the 2 arms. This provides 77% power to detect a hazard ratio of 0.5 at a two-sided significance level of 0.05. For Cohorts II and III, the primary efficacy end point is overall response rate per RECIST v1.1; secondary end points include duration of response, PFS, and overall survival. Recruitment into the safety run-in stage of Cohort I is complete. Accrual into the randomization stage of Cohort I and the initial safety run-in stage of Cohorts II and III are ongoing. Patients from sites across North America, Europe, and the Asia-Pacific region will be enrolled.

Citation Format: Miles D, Kim S-B, McNally V, Simmons B, Wongchenko M, Xu N, Brufsky A. COLET: A multistage, phase 2 study evaluating the safety and efficacy of a doublet regimen of cobimetinib (C) in combination with paclitaxel (P) or triplet regimens of C in combination with atezolizumab (atezo) plus either P or nab-paclitaxel (nab-P) in metastatic triple-negative breast cancer (TNBC) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT2-01-02.

Abstract P4-22-22: Cobimetinib (C) combined with paclitaxel (P) as a first-line treatment in patients (pts) with advanced triple-negative breast cancer (COLET study): Updated clinical and biomarker results

Resistance to standard taxane-based chemotherapy is common in triple-negative breast cancer (TNBC). Mutations and gene amplifications in the MAPK pathway that upregulate MAPK signaling are present in many TNBC tumors. Upregulation of the MAPK signaling pathway can result in degradation of the pro-apoptotic protein BIM and upregulation of anti-apoptotic proteins, including BCL-2, BCL-XL, and MCL-1, thus promoting cell survival and desensitizing tumor cells to the pro-apoptotic effects of taxane chemotherapy. Updated data on clinical safety and efficacy are presented along with biomarker data evaluating the effects of treatment on induction of apoptosis.The COLET study (ClinicalTrials.gov ID, NCT02322814; EudraCT number, 2014-002230-32) consisted of a safety run-in (n∼12) followed by a blinded 1:1 randomized expansion stage (n∼90) to C + P or placebo (PBO) + P. The safety stage is complete and the randomized stage is enrolling pts. Two additional cohorts investigating the effect of adding atezolizumab will be recruiting and are out of scope of this submission. Pts in cohort I were treated with P 80 mg/m2 on days 1, 8, and 15 and C/PBO 60 mg/day on days 3–23 of each 28-day cycle until disease progression or unacceptable toxicity. Gene expression and apoptotic index were measured by RNA-Seq and TUNEL staining, respectively, to assess the biologic activity of C + P.Sixteen women (median age, 55.5 years) were enrolled in the safety run-in stage. At data snapshot (April 22, 2016), all 16 pts had received ≥1 dose of study treatment. Median time on treatment was 116 days (range, 7-336) for C and 84 days (range, 0-351) for P. Fifteen (94%) pts had ≥1 adverse event (AE); 5 (31%) pts had grade 1/2 AEs and 10 (63%) pts had grade 3 AEs (Table). No pts experienced grade 4–5 AEs. Among the 16 safety run-in patients, responses to date include partial response (PR; n = 8 [50.0%]), stable disease (SD, n = 4 [25.0%]), and progressive disease (n = 2 [12.5%]), as well as 2 pts with no post-baseline tumor assessment. Six pts maintained a PR at ∼20 weeks and three maintained a PR at ≥40 weeks. To date, matched pre- and on-treatment biopsies were evaluable for 2 pts, 1 with a PR and 1 with SD. In the patient who attained a PR, increased expression of pro-apoptosis genes, including BIM, was observed; but this was not seen in the patient experiencing SD. The PR patient also had an increase in apoptotic index. Updated biomarker data will be reported.This is the first study to evaluate C + P in TNBC. The safety profile of C + P is consistent with that of known safety profiles. Efficacy and safety will be further evaluated in the ongoing randomized stage.

Most common (any grade ≥20%) AEsTreatment-emergent AEs, n (%)C + P (safety run-in stage), N = 16 All gradesGrade 3Diarrhea10 (63)1 (6)Rash8 (50)0Nausea7 (44)0Alopecia5 (31)0Blood CPK level increase5 (31)1 (6)Stomatitis4 (25)2 (13)Asthenia4 (25)1 (6)Constipation4 (25)0Dyspnea4 (25)0Edema peripheral4 (25)0Pyrexia4 (25)0Vomiting4 (25)0AEs, adverse events; C, cobimetinib; CPK, creatinine phosphokinase; P, paclitaxel.

Citation Format: Brufsky A, Kim S-B, Velu T, García-Saenz JA, Tan-Chiu E, Sohn JH, Dirix L, Borms MV, Liu M-C, Moezi MM, Kozloff MF, Sparano JA, Xu N, Wongchenko M, Simmons B, McNally V, Miles D. Cobimetinib (C) combined with paclitaxel (P) as a first-line treatment in patients (pts) with advanced triple-negative breast cancer (COLET study): Updated clinical and biomarker results [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-22-22.

Pharmacokinetic and exposure-response analyses of pertuzumab in combination with trastuzumab and docetaxel during neoadjuvant treatment of HER2+ early breast cancer

Purpose

The NeoSphere trial evaluated pertuzumab in the neoadjuvant setting [early breast cancer (EBC)] with pathological complete response (pCR) as the primary efficacy end point. This analysis of pertuzumab aimed to (1) compare its pharmacokinetics (PK) in patients with EBC versus advanced cancers, (2) to further evaluate PK drug–drug interactions (DDIs) when given in combination with trastuzumab, and (3) to assess the relationship between exposure and efficacy to assess the clinical dosing regimen in the EBC patients.

Methods

Pertuzumab serum concentration data from 180 patients in NeoSphere were compared to historical observations and potential DDI was assessed, by applying simulation techniques using a population PK model. The impact of pertuzumab exposure on pCR rate was evaluated using a logit response model (n = 88).

Results

The observed PK matched the population PK model simulations, confirming that the PK in neoadjuvant EBC appear to be in agreement with the historical observations. No evidence of a DDI effect of trastuzumab or docetaxel on pertuzumab was observed supporting the doses when given in combination. In NeoSphere >90% of EBC patients achieved the non-clinical target serum concentration. There was no association between the pertuzumab serum concentration and pCR within the range observed in this study (20–100 μg/mL) supporting no dose adjustments needed for patients with lower exposure.

Conclusions

This analysis further supports the lack of DDI between the two therapeutic proteins and the appropriateness of the approved fixed non-body-weight-adjusted pertuzumab dose in the treatment of neoadjuvant EBC with pertuzumab in combination with trastuzumab and docetaxel.

Electronic supplementary material

The online version of this article (doi:10.1007/s00280-016-3218-0) contains supplementary material, which is available to authorized users.

Abstract P4-14-14: Incidence and management of diarrhea in patients with HER2-positive breast cancer treated with pertuzumab

BACKGROUND:

Pertuzumab (P) in combination with trastuzumab (T) and docetaxel (D) is the approved first line SOC in patients with HER2 positive metastatic breast cancer and is approved neoadjuvantly in patients with HER2 positive stage Ib-IIIc breast cancer. Because of its role in heterodimerization with EGFR, P may cause adverse events associated with EGFR antagonists. Diarrhea is the most commonly reported AE due to P. Increased usage of P has generated clinical questions regarding the incidence and management of diarrhea. Here we report safety analyses of diarrhea from three P containing studies.

METHODS: The safety population evaluated in this exploratory analysis included 804 patients from CLEOPATRA, 416 patients from NeoSphere, and 223 from TRYPHAENA. Diarrhea incidence, severity (NCI-CTCAE v3.0), and management in P containing arms were analyzed.

RESULTS: The incidence and management of diarrhea in MBC (Table 1), EBC (Table 2):

CLEOPATRA P+T+D n=408Pla+T+D n=396Incidence of Events n (%)All Grades279 (68)193 (49)≥ Grade 338 (9)20 (5)Median time to 1st event (days) all grades / Interquartile Range (IQR)8 (4,44)23 (6,82)Discontinuation of any study drug8 (0.2)2 (0.6)Treatment n (%)Antidiarrheal treatment164 (40)77 (19)

 NeoSphere X4 followed by adjuvant FECx3TRYPHAENANeoadjuvant tx followed by T up to 1 yearT+D n=107P+T+D n=107P+T n=108P+D n=94FEC+P+T x3→P+T+D x3 n=72FEC x3 →P+T+D x3 n=75TCH+P x6 n=76Incidence of Events n (%) (neoadjuvant + adjuvant exposure)All Grades41 (38)55 (51)46 (43)53 (56)46 (64)47 (63)55 (72)≥ Grade 34 (4)7 (7)3 (3)5 (5)3 (4)4 (5)9 (12)Median time to 1st event (days) all grades / Interquartile Range (IQR)7 (4,24)8 (3,26)19 (4,117)6 (3,21)9 (4,30)69 (64,82)6 (3,21)Discontinuation of any study drug0000000Treatment n (%)Antidiarrheal treatment13 (12)23 (22)20 (19)28 (30)23 (32)22 (29)31 (41)pertuzumab(P)+trastuzumab(T)+docetaxel(D) FEC= 5FU, epirubicin, cyclophosphamide TCH= docetaxel,(T)carboplatin(C), trastuzumab(H)

The overall incidence of diarrhea events is greatest in the first cycle containing P: in CLEOPATRA (P+T+D) 43%, in NeoSphere (P+T+D) 34%, (P+T) 21%, and in TRYPHAENA (FEC+P+T→P+T+D) 40%, (FEC→P+T+D c4) 46%, and (TCH+P) 55%. Of patients experiencing diarrhea, the median number of events (all grades) for patients receiving P+T+D in CLEOPATRA and NeoSphere was 2 and 1 respectively, and 2 for patients receiving TCH+P in TRYPHAENA.

CONCLUSIONS:

Diarrhea was common in all P containing arms but events were mostly low grade and occurred more often with the first cycle. Events and management were similar in the EBC and MBC setting. Approximately half of patients required antidiarrheal treatment. However, rates of study drug discontinuation due to diarrhea were low. Studies of treatment associated diarrhea management are planned.

Citation Format: Swain SM, Schneeweiss A, Gianni L, Stein A, McNally V, Heeson S, Portera C, Yoo B, Cortes JC, Baselga J. Incidence and management of diarrhea in patients with HER2-positive breast cancer treated with pertuzumab. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-14-14.

Evaluating the predictive value of biomarkers for efficacy outcomes in response to pertuzumab- and trastuzumab-based therapy: an exploratory analysis of the TRYPHAENA study

INTRODUCTION

Molecular markers that predict responses to particular therapies are invaluable for optimization of patient treatment. The TRYPHAENA study showed that pertuzumab and trastuzumab with chemotherapy was an efficacious and tolerable combination for patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer in the neoadjuvant setting. We analyzed whether particular biomarkers correlated with the responses observed and therefore may predict outcomes in patients given pertuzumab plus trastuzumab.

METHODS

We describe the analysis of a panel of biomarkers including HER2, human epidermal growth factor receptor 3 (HER3), epidermal growth factor receptor (EGFR), phosphatase and tensin homolog (PTEN), and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) by qRT-PCR, immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), enzyme-linked immunosorbent assay (ELISA), and PCR-based mutational analyses as appropriate. For each marker analyzed, patients were categorized into 'low' (generally below median) or 'high' (generally above median) subgroups at baseline and post-treatment.

RESULTS

Correlation of marker subgroups with the achievement of a pathological complete response (pCR) (ypT0/is) was analyzed. HER2 protein and mRNA expression levels were associated with pCR rate in two of the three study arms and the pooled analyses. Correlations of biomarker status with pCR occurred in one individual arm only and the pooled analyses with EGFR and PTEN; however, interpretation of these results is limited by a strong imbalance in patient numbers between the high and low subgroups and inconsistency between arms. We also found no association between expression levels of TOP2A and pCR rate in either the anthracycline-containing or free arms of TRYPHAENA.

CONCLUSIONS

According to these analyses, and in line with other analyses of pertuzumab and trastuzumab in the neoadjuvant setting, we conclude that HER2 expression remains the only marker suitable for patient selection for this regimen at present.

TRIAL REGISTRATION

The TRYPHAENA study was registered with ClinicalTrials.gov, NCT00976989, on September 14 2009.

A phase Ib, dose-finding study of erlotinib in combination with a fixed dose of pertuzumab in patients with advanced non-small-cell lung cancer

BACKGROUND

Pertuzumab, a dimerization inhibitor of human epidermal growth factor receptor 2 (HER2), has demonstrated pharmacodynamic activity, with stable disease in non-small-cell lung cancer. Combining erlotinib and pertuzumab may enhance antitumor activity. This study aimed to establish the recommended dosing of the erlotinib and pertuzumab combination; assess safety, preliminary efficacy, and pharmacokinetics; and analyze biomarkers.

PATIENTS AND METHODS

Fifteen patients with stage IIIb/IV non-small-cell lung cancer who failed chemotherapy were recruited. The patients received erlotinib (days -8 to -1), then combination therapy (21-day cycles for 6 cycles). Pertuzumab was given intravenous at 840 mg, then 420 mg once every three weeks, with erlotinib given daily (100 or 150 mg).

RESULTS

No dose-limiting toxicities were observed. Adverse events were generally grade 1/2 and manageable. The objective response rate was 20% (3/15 patients; 2 responders had mutant HER1, 1 responder had wild-type HER1), median overall progression-free survival was 9.3 weeks. High HER1, HER2, and HER3 messenger RNA expression correlated with increased progression-free survival. Combination therapy did not affect erlotinib's pharmacokinetics; however, pertuzumab mean exposures (maximum concentration, 231 mg/L; area under the concentration-time curve from 0 to 21 days, 1780 mg*d/L) were slightly higher than in previous studies.

CONCLUSIONS

Combination therapy was well tolerated in patients with good performance status, with encouraging efficacy. A loading dose of pertuzumab 840 mg followed by 420 mg once every three weeks plus daily erlotinib 150 mg appears to be the most appropriate regimen for this combination.