Abstract P5-20-07: A phase Ib dose-finding study of subcutaneous pertuzumab in combination with subcutaneous trastuzumab in healthy male volunteers and female patients with early breast cancer

Background:

A fixed-dose combination (FDC) of subcutaneous (SC) pertuzumab (F. Hoffmann-La Roche Ltd, Basel, Switzerland) + SC trastuzumab (F. Hoffmann-La Roche Ltd) is being developed to reduce the treatment burden on patients while improving treatment facility efficiency. This phase Ib dose-finding study (NCT02738970) aimed to identify the SC pertuzumab dose that is comparable to the intravenous (IV) dose, based on serum trough concentrations (Ctrough) and area under the concentration–time curve (AUC) when administered with or without SC trastuzumab.

Methods:

This two-part study consisted of SC pertuzumab dose determination in healthy male volunteers (HMVs) (Part 1) and a subsequent SC pertuzumab dose confirmation in patients with early breast cancer (EBC) (Part 2). Part 1 of the study was comprised of 48 HMVs who received various SC pertuzumab doses (400–1200 mg) or the standard IV dose (420 mg), administered alone or co-mixed with SC trastuzumab 600 mg. Non-compartmental and statistical methods were used to test the pharmacokinetic (PK) interaction between SC pertuzumab and SC trastuzumab when administered with recombinant human hyaluronidase, a permeation enhancer. Two population PK (popPK) models were built to estimate PK parameters and PK variability. Model 1 used IV/SC PK data from Part 1 of the current study only. Model 2 used Part 1 SC PK data and PK parameters from the published IV pertuzumab popPK model (Garg A, et al. Cancer Chemother Pharmacol 2014; 74: 819–829). Each popPK model was used to simulate 400 phase III clinical trials. Per simulated trial, the geometric mean ratio (GMR) of Cycle 8 Ctrough at steady state and AUC at steady state for SC/IV were calculated. The percentage of trials with the 5th percentile confidence interval of the GMR above 0.8 was tabulated.

Results:

In Part 1 of the study, there was no impact on pertuzumab or trastuzumab PK from co-mixing SC trastuzumab with SC pertuzumab. The absolute bioavailability of SC pertuzumab in HMVs was approximately 70–80%, with a median time to reach maximum concentrations of 4–5 days. Clinical trial simulations indicated that an SC pertuzumab dose of 600 mg will achieve the target Ctrough and AUC SC/IV GMRs > 99% of the time. Results were consistent between the models. Safety data supported the selection of an SC pertuzumab maintenance dose of 600 mg. The 600 mg SC pertuzumab dose determined in HMVs was confirmed in Part 2 of the study in patients with EBC.

Conclusions:

These data support the development of an SC pertuzumab + SC trastuzumab FDC product.

Citation Format: Kirschbrown WP, Wynne C, Kagedal M, Wada R, Li H, Nijem I, Badovinac Crnjevic T, Heeson S, Eng-Wong J, Garg A. A phase Ib dose-finding study of subcutaneous pertuzumab in combination with subcutaneous trastuzumab in healthy male volunteers and female patients with early breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-20-07.

Effect of docetaxel duration on clinical outcomes: exploratory analysis of CLEOPATRA, a phase III randomized controlled trial

Background

Combination pertuzumab, trastuzumab, and docetaxel (D) is considered standard first-line treatment of human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. This post hoc, exploratory analysis of CLEOPATRA study data evaluated the clinical effects of D treatment duration within this regimen. The clinical benefits of pertuzumab and trastuzumab by different durations of D treatment were also evaluated.

Patients and methods

Patients with HER2-positive metastatic breast cancer received trastuzumab and D plus pertuzumab or placebo. Clinical outcomes were analyzed by the number of D cycles that patients received (<6D, 6D, or >6D). Progression-free survival (PFS) and overall survival (OS) for each treatment arm within each D cycle group were estimated using the Kaplan-Meier approach. Time-dependent, multivariate Cox regression was applied to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for HER2-targeted therapy and D cycle groups.

Results

Overall, 804 patients received <6D (n = 119), 6D (n = 210), or >6D (n = 475) cycles. After adjusting for pertuzumab benefits versus placebo (PFS HR = 0.61, 95% CI 0.51-0.74, P < 0.0001; OS HR = 0.60, 95% CI, 0.49-0.74, P < 0.0001), >6D versus 6D cycles was not associated with statistically significant improvements in PFS (HR = 0.80, 95% CI 0.63-1.01, P = 0.0640) or OS (HR = 0.88, 95% CI 0.69-1.12, P = 0.3073). Consistent improvements in PFS and OS were observed with pertuzumab versus placebo, irrespective of D duration. The HRs for PFS were 0.395, 0.615, and 0.633 for <6D, 6D, and >6D cycles, respectively (P < 0.05 for all D cycle groups). Corresponding HRs for OS were 0.577, 0.700, and 0.612, respectively (P < 0.05 for <6D and >6D).

Conclusions

After accounting for pertuzumab benefits, more than six cycles of D treatment was not associated with significant improvements in either PFS or OS compared with six cycles. The addition of pertuzumab to trastuzumab improved clinical outcomes versus trastuzumab plus placebo, regardless of D treatment duration.

ClinicalTrials.gov identifier

NCT00567190.

Incidence and management of diarrhea in patients with HER2-positive breast cancer treated with pertuzumab

Background

Pertuzumab disrupts heterodimerization between human epidermal growth factor receptor 2 (HER2) and epidermal growth factor receptor (EGFR), HER3, and HER4. Thus, pertuzumab could result in adverse events similar to those observed with EGFR antagonists, such as diarrhea. We report the incidence and severity of diarrhea observed with pertuzumab in the CLEOPATRA, NeoSphere, and TRYPHAENA studies.

Patients and methods

Patients (n = 1443) had metastatic [CLEOPATRA (n = 804)] or early-stage breast cancer [NeoSphere (n = 416) and TRYPHAENA (n = 223)]. The incidence and severity of diarrhea were analyzed by treatment received. The incidence of febrile neutropenia concurrent with diarrhea and the effect of pre-existing gastrointestinal comorbidities were also evaluated. Subgroup analyses were carried out using CLEOPATRA data.

Results

The incidence of all-grade diarrhea across studies was generally greater for pertuzumab-based treatment, ranging from 28% to 72% (grade 1, 21%-54%; grade 2, 8%-37%; grade 3, 0%-12%; grade 4, 0%). Incidence was highest during the first pertuzumab-containing cycle, decreasing with subsequent cycles. Dose delays or discontinuations due to diarrhea were infrequent, ranging from 0% to 8%. Among pertuzumab-treated patients with diarrhea, 47%-67% received pharmacological intervention, most commonly with loperamide. Overlap between diarrhea and febrile neutropenia was uncommon, ranging from 0% to 11%. No relationship was observed between pre-existing gastrointestinal comorbidities and diarrhea. In CLEOPATRA, patients ≥65 years treated with pertuzumab had a higher incidence of grade 3 diarrhea than patients <65 years (19% versus 8%). All-grade diarrhea occurred at greater frequency among pertuzumab-treated Asian versus white patients with metastatic breast cancer (74% versus 63%); the corresponding rates in the control arm were 53% and 45%, respectively.

Conclusions

In both the metastatic and early-stage breast cancer settings, diarrhea was common but manageable for all pertuzumab-containing regimens. Diarrheal episodes were mainly low grade and occurred most often during the first treatment cycle. Diarrheal-related drug delays or discontinuations were uncommon.

ClinicalTrials.gov identifiers

NCT00567190 (CLEOPATRA), NCT00545688 (NeoSphere), NCT00976989 (TRYPHAENA).

Abstract P4-14-27: Effect of docetaxel duration on clinical outcomes: Results from the phase III trial CLEOPATRA

Introduction:

In the CLEOPATRA study, pertuzumab (P) plus trastuzumab (T) and docetaxel (D) significantly improved median progression-free survival (PFS) and overall survival (OS) compared with placebo (Pla) plus T and D in pts with HER2-positive metastatic breast cancer. Study treatment was given every 3 weeks until disease progression (PD) or unacceptable toxicity. D starting dose was 75 mg/m2 and could be escalated or reduced per protocol. A minimum of 6 cycles of D was recommended. If D was discontinued, patients could continue P+T or Pla+T. To evaluate the potential association between D duration and clinical outcomes, we conducted post hoc exploratory analyses of the CLEOPATRA study.

Methods:

As of 11 Feb 2014 data cutoff, the safety population analyzed included 804 pts (396 Pla+T+D; 408 P+T+D) who received at least one dose of any study medication. Exposure and clinical outcomes of study treatment groups are presented by dichotomized subgroup of pts who received &lt;6 cycles of D and those who received more than 6 cycles. Median PFS and OS were estimated using Kaplan-Meier methods. Cox regression analyses were used to estimate hazard ratios (HRs).

Results:

The median number of D cycles received was 8 for both arms. Forty-one % of pts received &lt;6 (14% &lt;6; 27% exactly 6) and 59% received &gt;6 cycles.

Docetaxel Duration and Clinical Outcomes D &lt;6 cycles (n=329, 41%)D &gt;6 cycles (n=475, 59%) Pla+T+D (n=159)aP+T+D (n=170)aPla+T+D (n=237)P+T+D (n=238)Treatment Exposure#D Cycle, median (range)6 (1,6)6 (1,6)10 (7,42)10 (7,52)# Study Treatment Cycle, median (range)7 (1,78)14 (1,90)19 (7,92)28 (7,96)Duration of Study Treatment in month, median (range)6 (1,54)10 (1,63)14 (5,67)19 (5,68)Clinical OutcomesPFS in month, median (range)8.2 (6.2,9.0)12.5 (10.5,20.7)14.5 (12.6,17.2)22.8 (17.7,N/A)95% CIHR=0.59 (0.44,0.79)HR=0.65 (0.50,0.84)OS in month, median (range)29.8 (22.2,39.2)48.9 (36.8,N/A)46.7 (39.4,53.0)N/A (56.4,N/A)95% CIHR=0.67 (0.45,0.90)HR=0.62 (0.47,0.81)N/A=not available aTwo pts in each group had missing D cycle

Treatment Discontinuation Summary D &lt;6 cyclesD &gt;6 cycles Pla+T+D (n=159)P+T+D (n=170)Pla+T+D (n=237)P+T+D (n=238)D discontinuation before stopping anti-HER2 agents (n,%)90 (57)118 (69)180 (76)196 (82)Reason (n,%)    AE/intercurrent illness34 (38)27 (23)60 (33)72 (37)Patient reasonb3 (3)5 (4)5 (3)8 (4)Standard practice36 (40)59 (50)65 (36)41 (21)Adequate therapy12 (13)22 (19)36 (20)59 (30)Other1 (1)1 (1)9 (5)11 (6)Missing4 (4)4 (3)5 (3)5 (3)Discontinuation of all study treatment (T+D+Pla or P), n159170237238Reason (n,%)    AE/intercurrent illness15 (9)22 (13)25 (11)32 (13)Death10 (6)5 (3)4 (2)2 (1)Disease progression111 (70)110 (65)182 (77)154 (65)Patient reasonb17 (11)16 (9)12 (5)14 (6)Other6 (4)16 (9)12 (5)35 (15)Missing0 (0)1 (1)2 (1)1 (1)bIncluded failure to return, refused treatment, withdrawal, protocol violation

Conclusions:

Consistent with the overall study results, addition of P to T+D showed significant improvement in clinical outcomes regardless of whether &lt;6 or &gt;6 cycles of D were received. In the poster, three subgroup (&lt;6, 6 and &gt;6 D cycles) analyses and time-dependent Cox regression analysis to capture the dynamic variations in D exposure will be presented.

Citation Format: Miles D, Fung A, Yoo B, Knott A, Heeson S, Portera C, Swain S. Effect of docetaxel duration on clinical outcomes: Results from the phase III trial CLEOPATRA. [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 P4-14-27.

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.

An intragenic methylated region in the imprinted Igf2 gene augments transcription

DNA methylation is usually associated with transcriptional silencing, but in the imprinted mouse Igf2 gene, the paternally expressed copy is methylated in two discrete differentially methylated regions (DMRs). DMR1 is located upstream of the fetal promoters and has been shown to be a methylation sensitive silencer. Here we examine the role of the intragenic DMR2 by gene targeting. In contrast to DMR1, deletion of DMR2 on the maternal allele did not lead to activation of the silent Igf2 gene. Deletion of a 54 bp methylated core region in DMR2 on the paternal allele, however, reduced Igf2 mRNA levels and was associated with fetal growth retardation. Nuclear run-on assays showed that the core region influenced transcription initiation, and luciferase reporter assays suggested that its methylation increases transcription. These results reveal a novel mechanism of gene expression whereby intragenic methylation can increase levels of transcription.