A phase I study of AST1306, a novel irreversible EGFR and HER2 kinase inhibitor, in patients with advanced solid tumors
Journal of Hematology & Oncology
A phase I study of AST1306, a novel irreversible EGFR and HER2 kinase inhibitor, in patients with advanced solid tumors
Jian Zhang 0 1
Junning Cao 0 1
Jin Li 0 1
Zhiyu Chen 0 1
Wei Peng 0 1
Si Sun 0 1
Jiachen Wang 0 1
0 Department of Oncology, Shanghai Medical College, Fudan University , Shanghai , China
1 Department of Medical Oncology, Fudan University Shanghai Cancer Center , Shanghai , China
Background: AST1306 is an orally active irreversible small molecule inhibitor of EGFR (erbB1), HER2 (erbB2) and HER4 (erbB4) signaling. This is a phase I, open-label, dose-escalation study to evaluate the safety and tolerability, pharmacokinetics (PK), and preliminary anti-tumor effects of oral AST1306. In addition the effects of food on PK was tested. Methods: A modified Fibonacci 3 plus 3 dose-escalation design was employed to determine the dose-limiting toxicity (DLT) and recommended phase II dose (RP2D) in patients with advanced solid tumors. The following dose levels were investigated: once daily (QD) at two dose levels (400-and 800 mg), twice daily (BID) in five dose levels (600-, 800-, 1000-, 1200- and 1500 mg), and three times daily (TID) in three dose levels (800-, 1000- and 1200 mg). In the PK and extension study, at least eight patients per dose cohort in three dose levels (maximum tolerated dose [MTD], one or two doses level lower than the MTD) were enrolled to evaluate the PK profiles. Results: Seventy-one patients were enrolled, with breast (n = 22) and lung cancers (n = 14) being the most common primary cancers. The most frequent drug-related adverse events were grade 1 to 3 diarrhea and rash, grade 1 to 2 fatigue. During dose escalation, the key DLT was grade 3 diarrhea observed in 5 patients at 1000 mg BID (n = 1), 1500 mg BID (n = 1), 800 mg TID (n = 1) and 1200 mg TID (n = 2). AST1306 was rapidly absorbed and had moderate to high clearance. PK concentration parameters increased with dose over the range evaluated, with no evidence of accumulation over time. Under fed conditions, the mean Tmax was prolonged, Cmax was increased, and AUC0- was raised. Of the 55 evaluable patients, 7 patients experienced partial responses, including 5 with breast cancer, 1 with lung cancer, and 1 with gastric cancer. The best response with stable disease for 6 months was achieved in 7 patients. Conclusions: Based on the DLT and PK profile, the RP2D was defined as 1000 mg TID with evidence of preliminary anti-tumor activity. Further studies are recommended.
AST1306; ErbB family; Irreversible tyrosine kinase inhibitor; Phase I
The epidermal growth factor (erbB) family of membrane
receptor tyrosine kinases consists of the epidermal growth
factor receptor (EGFR; erbB1) and human epidermal
growth factor receptor (HER) 2 (erbB2), HER3 (erbB3) and
HER4 (erbB4) . The roles of the erbB family members
are well documented in many types of cancer. A number
of small-molecule tyrosine kinase inhibitors (TKIs) (e.g.,
gefitinib, erlotinib, lapatinib) and antibodies (eg,
trastuzumab, cetuximab, panitumumab) targeting the erbB family
have been developed to treat breast, colorectal, lung, gastric
and head and neck squamous cell cancers . Despite the
improvements achieved in patients treated with reversible
inhibitors of EGFR or EGFR and HER2, primary and
acquired resistances to these agents remain a clinical
challenge. This is exemplified by the development of resistance
to EGFR tyrosine kinase inhibitor (TKI), through
emergence of a secondary T790M EGFR mutation in
nonsmall-cell lung carcinoma (NSCLC) , which occurs in
50% of the patients with lung adenocarcinoma .
Irreversible erbB family blocker may be beneficial to the patients
with EGFR-TKI resistant NSCLC and trastuzumab
resistant HER2-positive metastatic breast cancer (MBC) .
AST1306 (Shanghai Allist Pharmaceuticals, China) is an
orally active, highly selective irreversible inhibitor of the
erbB family receptor tyrosine kinases (HER1, HER2, and
HER4) . In preclinical trials, the IC50 values of AST1306
inhibiting EGFR and HER2 were 0.5 and 3 nmol/L,
respectively, which were 5-15-fold more potent than afatinib and
dacomitinib. AST1306 could potently inhibit the EGFR
T790M mutant, exhibiting an IC50 value of 12 2 nmol/L,
which is similar to afatinib (10 nmol/L) and approximately
500-fold more potent than lapatinib [6-10]. In human
tumor xenograft models that expressed or overexpressed
HER family members, AST1306 showed antitumor
activities, especially against those with HER2 overexpression or
EGFR T790M mutant tumors .
The primary aims of this phase I, open-label,
(http://www.chictr.org/cn/identifier:ChiCTRONC-10000893) are to assess the safety and tolerability of
AST1306 by dose-limiting toxicity (DLT) and maximum
tolerated dose (MTD), determine the clinically
recommended dose and schedule, characterize the
pharmacokinetic (PK) profile of the drug following single and
multiple dosing, and investigate the effect of food on the
PK of this oral agent in Chinese patients with advanced
solid tumors. The secondary endpoint was to assess
Materials and methods
Eligible patients were aged 1875 years with histologically
or cytopathologically confirmed advanced solid tumors.
Patients had to either be refractory to, or intolerant of
standard treatment known to provide clinical benefit for
their metastatic cancers, or to be unable to afford them. The
other inclusion criteria were as follows: Eastern Cooperative
Oncology Group (ECOG) performance status of 02;
adequate hematology (absolute neutrophil count 1.5 109/L,
platelet count 80 109/L, hemoglobin 9 g/dL); normal
liver function (serum bilirubin 1.5 upper limit of
normal [ULN]; aspartate aminotransferase and alanine
aminotransferase 2.5 ULN, except in patients with liver
metastases) and kidney function (serum creatinine 1.5
ULN); at least one measurable disease according to the
Response Evaluation Criteria in Solid Tumors (RECIST)
1.0; life expectancy of 3 months; and no anticancer
treatment for at least 4 weeks prior to enrollment in the study.
Exclusion criteria included the following: pregnant or
breast feeding patients, any clinically significant
gastrointestinal abnormalities that influence oral administration,
uncontrolled or significant cardiovascular disease, left
ventricular ejection fraction (LVEF) < 40%, metastases to the
central nervous system (symptomatic and/or requiring
treatment), active serious infection, and bleeding diathesis
Study design and treatment
This was the first-in-human phase I dose-escalation study
of AST1306 for patients with advanced solid tumors.
AST1306 was orally administered without food for one
day followed by two days off to evaluate single dose PK
profiles. After that, it was continuously administered for
21 days and two days off to assess multiple dose PK
profiles and safety. Once daily in two dose levels (400 mg QD
and 800 mg QD) was first explored and according to the
PK profile, with shorter t1/2 of 35 hours, twice daily in
five dose levels (600 mg BID, 800 mg BID, 1000 mg BID,
1200 mg BID and 1500 mg BID) were then investigated.
Three times daily in three dose levels (800 mg TID,
1000 mg TID and 1200 mg TID) were explored
subsequently. Treatment was then repeated at the same dose
level in 28-day cycles until unacceptable toxicities, disease
progression or the patients withdrew from the study. PK
extension study was performed to enroll additional
patients up to at least eight patients per dose cohort in three
dose levels (MTD, one or two doses level lower than the
MTD) for further evaluation of PK profiles.
For the food-effect study, an open, two-way crossover
design was adopted to assess the effect of food on the
oral bioavailability of AST1306 at the MTD dose level
(Additional file 1: Figure S1). On day 1, 6 subjects were
fasted and 6 were fed, and all 12 subjects received a
single dose of AST1306. Following a 2-day washout period,
subjects from the fasted group were fed and vice versa.
On fasting days (day 1 or 4), subjects were required to
fast for a minimum of 2 h prior to dosing, and for at
least 1 h post-dosing. On fed days (day 1 or 4), subjects
were fasted overnight and were required to ingest a
standard high-fat breakfast within 30 min prior to
dosing. PK sampling then took place on day 1 and day 4.
The PK sampling time points were pre-dose, 0.5, 1, 1.5,
2, 2.5, 3, 4, 6, 8, 12, and 24 hours after dosing.
This study was conducted in compliance with the ethical
principles derived from the Declaration of Helsinki and
all the International Conference on Harmonization (ICH)
Good Clinical Practice (GCP) guidelines. The protocol, all
the amendments and informed consent documentations
were reviewed and approved by the Institutional Review
Board at Fudan University Shanghai Cancer Center. All
patients provided written, signed informed consent prior
to entry into the trial.
Dose escalation and safety assessment
Safety and tolerability were evaluated and assessed by
investigators throughout the study and up to 14 days after
the final dose of AST1306 according to Common
Terminology Criteria for Adverse Events (CTC-AE) version 4.03.
Laboratory evaluations and electrocardiogram were
conducted at screening; every week of first and second cycles;
every two weeks of third cycle and every four weeks of
subsequent cycles. AEs assessment, vital signs, physical
examinations and echocardiography were performed.
A modified Fibonacci 3 plus 3 dose-escalation design
was employed. Tolerability was evaluated according to the
type and frequency of DLTs observed from
single-daydose administration until day 21 of the first cycle of
continuous dosing. DLTs were defined as follows: grade 3
non-hematologic toxicity (except nausea, vomiting and
diarrhea); grade 3 nausea, vomiting or diarrhea
uncontrollable with standard supportive care; grade 4 neutropenia
or febrile neutropenia; and grade 4 thrombocytopenia or
bleeding requiring a platelet transfusion. If two or more
patients experienced DLTs in three to six patients for each
cohort, dose escalation was terminated and the dose level
below was defined as the MTD.
Dose interruptions were permitted for no more than
14 days for patients experiencing DLTs in the first cycle or
intolerable toxicities in the subsequent cycles, with
treatment resumed at the next lower dose level upon adequate
recovery (grade 1). More than two dose level reductions
were not allowed.
Patients in the PK extension study and food-effect
study were also included to evaluate safety further.
Evaluation of antitumor activity
Antitumor activity was assessed by tumor measurements
according to RECIST 1.0 and performed at 8-week
intervals. The primary efficacy endpoint was progression free
survival (PFS), which was defined as the time from the
first administration until disease progression or death.
Overall survival (OS) and response rate were also assessed.
Clinical benefit rate was measured and defined as the
proportion of patients with complete response, partial
response and stable disease (SD) 6 months.
All PK sampling was performed in the first cycle. Plasma
concentrations of AST1306 single-day dosing were
determined at the following distinct time points: pre-dose,
0.5 h, 1 h, 1.5 h, 2 h, 3 h, 4 h, 6 h, 8 h, 10 h, 12 h, 24 h,
36 h, and 48 h after the single dose administration in the
400 mg QD and 800 mg QD dose cohorts. For the next
five dose cohorts with twice daily (once every 12 hours)
administration, the time points of plasma sample
collection were as follows: pre-dose, 0.5 h, 1 h, 1.5 h, 2 h, 3 h,
4 h, 6 h, 8 h, and 12 h after the first dose administration,
and pre-dose, 1 h, 2 h, 3 h, 4 h, 6 h, 8 h, 12 h, and 24 h
after the second dose administration. Three dose cohorts
with three times daily (once every 8 hours)
administration were further investigated with distinct time points
for plasma collecting (pre-dose, 0.5 h, 1 h, 1.5 h, 2 h,
3 h, 4 h, 6 h, and 8 h after the first dose administration;
1 h, 2 h, 3 h, 4 h, 5 h, 6 h, and 8 h after the second dose
administration; 1 h, 2 h, 3 h, 4 h, 8 h, 12 h, 24 h, and
36 h after the third dose administration). PK parameters
of AST1306 were also determined on days 10, 23
(predose and 2 h after the first dosing), and 24 (steady state,
the same time points as the first-day dosing) of
continuous treatment. The PK sampling schedule for the PK
extension phase was totally the same as that for the dose
PK analysis was conducted using Phoenix WinNonlin
software (version 6.1, Pharsight, Mountainview, CA).
Standard non-compartmental methods were used to
calculate the area under the plasma concentration-time curve
over the time interval from 0 to 24 h (AUC024,ss),
maximum measured concentration of the analyte in plasma
(Cmax), and terminal half-life of the analyte in plasma (t1/2).
Time from dosing to the maximum concentration of the
analyte in plasma (tmax,) was reported as a median value.
The concentration at the trough level was determined
using the concentration at 24 h (C24) on steady state days.
The power model method was used to assess the dose
proportionality. The differences between fed and fasting
conditions were assessed by ANOVA, and 90%
confidence intervals for ratios were given.
From May 2010 to April 2012, a total of 71 patients with
advanced solid tumors were recruited into this study.
Twelve patients were enrolled in the food-effect study at
the MTD dose level. The baseline demographic
characteristics of these patients are provided in Table 1. Patients
had a variety of cancer types, with the most common
Median age, years
ECOG performance status
Abbreviation: No. number, ECOG Eastern Cooperative Oncology Group.
being breast cancer and NSCLC. Patients were heavily
pretreated, and 84.5% of them had received 3 lines of
therapy regimens. All patients were included in safety and PK
evaluation. Four patients who had no measurable lesions,
and 12 patients who experienced DLTs or withdrew their
informed consents before the first time point of tumor
measurement, were not included in tumor response
evaluation. Thus, 55 patients were evaluable for efficacy
assessment. Fifteen of 17 evaluable breast cancer patients
were HER2 positive (Immunohistochemistry+++ and/or
FISH/CISH+), and of these, 7 patients had received
trastuzumab and 4 patients had received lapatinib. Among the
12 evaluable NSCLC patients, 6 patients harbored
activating EGFR mutations, and 8 patients had a treatment
history of reversible EGFR TKIs. The median duration of
time on study for all patients was 3.2 months (range
Assessment of DLT and MTD
In total, five patients developed DLTs during the dose
escalation study, one patient each from the 1000 mg BID,
1500 mg BID, and 800 mg TID cohorts, and two patients
from the 1200 mg TID cohort. There were no DLTs with
QD dosing. All DLTs were grade 3 diarrhea which was
observed from single-day-dose administration until day 21 of
the first cycle of continuous dosing and was not
ameliorated with appropriate intervention. Based on the DLT
events mentioned above and PK results listed below, the
MTD and recommended phase II dose (RP2D) for
AST1306 was defined at 1000 mg TID when administered
in a continuous-dosing schedule. PK extension study was
performed at MTD dose (1000 mg TID, n = 3) and one or
two doses level lower than the MTD (800 mg TID, n = 5;
600 mg TID, n = 9). In addition, one further case of grade
3 diarrhea was observed at 800 mg TID in the PK
extension phase but not considered in dose escalation decision.
Safety and tolerability
All enrolled patients were included in the safety analysis.
Overall, AST1306 was well-tolerated, with mainly grade 1
to 2 AEs, and no observed grade 4 to 5 AEs. Sixty-eight
patients experienced AEs that were considered to be study
drug-related (Table 2). Diarrhea (n = 61, 85.9%), fatigue
(14, 19.7%) and rash (12, 16.9%) were the most common
treatment-related AEs and usually occurred within the
first 2 weeks of treatment. Diarrhea was managed
effectively with loperamide or temporary interruption of
AST1306. Rash was well controlled in most patients with
topical antibiotics (mainly tetracycline) and corticosteroids
or interruption of AST1306.
Grade 3 study drug-related AEs occurred in 28 (39.4%)
patients. The most common grade 3 drug-related AE was
diarrhea (23, 32.4%). Other grade 3 drug-related AEs
presented in lower frequencies and consisted of elevated ALT
or AST (3, 4.2%), rash, anemia, hypokalemia and
abdominal pain (1, 1.4% each). Five patients with DLT
recovered from grade 3 diarrhea after dose interruption, dose
reduction and appropriate medications. The main causes
of discontinuation from treatment due to drug-related
AEs were diarrhea (5 patients) and hypokalemia (1
patient). Seven patients (1 at 800 mg BID, 2 at 1000 mg BID,
2 at 1500 mg BID, 1 at 600 mg TID, 1 at 800 mg TID) had
dose reductions and all due to diarrhea, in which 1 patient
at 1000 mg BID experienced 2 dose reductions and the
rest required 1 dose reduction. There was no significant
decline in LVEF.
Serious AEs (SAE) occurred in 8 patients. Three of the 8
patients had SAE reported during the first cycle of
treatment. In these 3 patients, one had grade 3 diarrhea and
-ftood reodm 3 - - - - 0 0 - - - - - - - - - - - 00+
anH syn -12 - - - - 1 1 - - - - - - - - - - - 01+
ixae 3 - - - - - - - - - - - - - - - 0 - 00+
nA -12 - - - - - - - - - - - - - - - 1 - 11+
saed 3 - - - - - - - 0 - - - - - - - - - 10+
iLTA -12 - - - - - - - 1 - - - - - - - - - 02+
irau 3 - - - - - - - - - - - - - - - 0 - 00+
Po -12 - - - - - - - - - - - - - - - 2 - 30+
itng 3 - - - 0 - - - - 0 0 - - - - 1 0 -
oVm -12 - - - 2 - - - - 1 1 - - - - 1 3 -
sh 3 0 0 0 0 - 0 1 0 0 0 - - 0 0 - - 00+ 00+
aR -21 1 1 1 1 - 1 1 1 1 1 - - 1 1 - - 00+ 10+
eu 3 - - - - - - - - - - - 0 - - - 0 - 00+
iFa -12 - - - - - - - - - - - 3 - - - 2 - 01+
aeh 3 - - - - 0 0 0 1 4 5 0 0 2 3 2 2 31+ 42+
iaD -12 - - - - 1 1 1 1 1 1 2 2 4 4 4 5 53+ 54+
se1uoC llA rseuoC s1euoC llA rsseuoC se1uoC llA rsseuoC se1uoC llA rsseuoC se1uoC llA rsseuoC s1euoC llA rsseuoC rse1uoC llA rsseuoC se1uoC llA rsseuoC s1euoC llA rseuoC
()1400ng=m )(3008ng=m )(3006ng=m )(3008ng=m )(61000ng=m ()30012ng=m )(60051ng=m )(*90006ng+=m )(*58008ng+=m
DQ IBD ITD
dehydration (1500 mg BID cohort), which was thought to
be due to AST1306; one patient developed a lung
infection and the last patient had increased pleural effusions
and shortness of breath and both were considered to be
unrelated to AST1306. The other five patients experienced
SAEs after the first cycle. One of these patients was
diagnosed with grade 3 AST1306-related diarrhea. The rest of
the SAEs included 1 case of hyperbilirubinemia and 3
deaths within 14 days after the final dose of AST1306 due
to disease progression.
Additional patients were enrolled up to at least eight
patients per dose cohort in three dose levels (600 mg TID,
800 mg TID and 1000 mg TID) in the PK extension
study and food-effect study to evaluate PK profiles.
Collected plasma samples were analyzed by dose cohort.
The PK analysis population (n = 61) and the geometric
mean PK parameters of AST1306 for single-day dosing
and multiple dosing are summarized in Additional file 2:
For single dose evaluation, Cmax was achieved in 1.83 to
3.67 hours after oral administration. The plasma levels of
AST1306 increased with increasing doses and varied
considerably between patients. Cmax and AUC024 h showed a
dose-dependent increase. The terminal half-life of
AST1306 ranged between 3.48 to 5.56 hours on day 1.
For multiple-dose evaluation, Cmax and AUC024 h
showed a dose-dependent increase at dose levels of 400 mg
QD to 1000 mg TID. Whereas, Cmax and AUC024 h
increased by a smaller amount at the 1200 mg TID dose
level, and showed moderate-to-high inter-individual
variability. The gMean terminal half-life ranged from 3.33 to
7.57 h on days 2324. Multiple-dose exposure was no
more than 3-fold greater than single-dose exposure across
the entire dose range, as assessed by the mean
accumulation ratio (R, AUCss on study day 2324 to AUC0-24h on
study day 1; Additional file 2: Table S1). These results
suggested that there was no major accumulation of AST1306
after repeated daily administration to patients.
With the same total daily dose, for example 1500 mg
BID vs. 1000 mg TID, the Cavg, AUC0-24h, AUC0-t and
AUC0- of TID administration schedule were higher
than those of QD and BID schedules. In addition, the
fluctuation index (FI) of the TID schedule (137-204%)
was lower than that of the BID (201-274%) or QD
In the food-effect study, with a fed-fasted two-way
crossover design, a total of 12 patients (6 patients each group)
were enrolled to assess the initial effect of food on the oral
bioavailability of AST1306 (Additional file 1: Figure S1).
High-fat food intake before a single oral AST1306 dose of
1000 mg significantly altered and increased drug exposure
(Additional file 3: Table S2). Under fed conditions, mean
Tmax was prolonged (4.25 hours fed; 2.38 hours fasted;
p = 0.012), Cmax was increased (139 ng/mL fed; 70.3 ng/mL
fasted), and AUC0- was raised (814 h*ng/mL fed;
331 h*ng/mL fasted).
Fifty five of the 71 patients were evaluable for efficacy. The
waterfall plot of best responses in 55 evaluable patients
was shown in Figure 1. Of the evaluable patients, 7
patients (5 with breast cancer, 1 with NSCLC, and 1 with
gastric cancer) had confirmed PRs. Five of the 17 evaluable
breast cancer patients achieved a PR and all responders
were HER2 positive; 1 patient had been previously treated
with trastuzumab and lapatinib (Figure 2). Among the 12
evaluable NSCLC patients, 1 patient had PR. This patient
had failed 3 previous lines of chemotherapy, but was of
unknown EGFR mutational status; in addition this patient
had not previously received therapy with EGFR inhibitors.
One PR was observed in a gastric adenocarcinoma patient
who failed 2 lines of chemotherapy and 1 VEGFR2 TKI;
however, the tumor tissue from biopsy was not enough to
assess EGFR and HER2 status.
There were 7 patients who had SD for 6 months.
Among those patients, 3 were breast cancer patients, all
with HER2 positive; others were NSCLC (1),
nasopharyngeal cancer (1), gastric cancer (1), and cervical cancer
(1). The NSCLC patient achieving SD for 6 months
had an EGFR sensitive mutation (exon 19 deletion) and
previously responded to gefitinib. A secondary mutation
of T790M in EGFR exon 20 was confirmed after
progression on 15-month gefitinib treatment with
subsequent lung wedge resection. The EGFR and HER2 status
was not detected for the rest 3 patient (1
nasopharyngeal, 1 gastric, 1 cervical cancer).
As of the last updated data from July 25, 2013, 29
patients were still alive. The median follow-up time was
22.7 months. For 17 breast cancer patients, the median
PFS and OS reached 5.5 (95% CI, 3.27.9) and 17.7 (95%
CI, 16.119.3) months, respectively. For 12 NSCLC
patients, the median PFS was 3.6 months (95% CI, 3.33.9)
months and the median OS has not yet been reached.
We described a phase I trial of AST1306, which is an
irreversible inhibitor of EGFR, HER2, and HER4. This
study indicated that AST1306 was generally safe and
well tolerated on a continuous dose schedule in patients
with advanced solid tumors. Based on two DLTs in the
1200 mg TID cohort, 1000 mg TID was declared as the
MTD for this study. Grade 3 diarrhea was the key DLT
observed in the dose escalation study. Additionally, 3
patients in the PK extension study and 12 patients in
foodeffect study were treated with 1000 mg TID, and no
grade 3 toxicities were found, indicating that 1000 mg
Figure 1 Waterfall plot of best responses, as percentage decrease in tumor size by RECIST, of the target lesions in patients. Fifty-five
patients had measurable disease by RECIST and had at least 1 evaluation. The numbers above or below the bars represent the number of months
the responders and patients with SD lasting 6 months received AST1306. * No EGFR or HER2 status; EGFR exon 19/exon 20 double mutation;
TID was well tolerated. There were no unexpected
toxicities observed in this study and safety profiles were
similar to the agents that target erbB signaling [11-14].
Diarrhea was manageable by appropriate medications
and dose interruption or reduction in this study. Five
(7%) patients had to discontinue therapy because of
Besides diarrhea, grade 12 fatigue and grade 13 rash
were also the most frequently reported AEs, which is
similar to the other three irreversible erbB family blockers
afatinib [15,16], dacomitinib  and neratinib [18,19]. The
incidence of skin rashes caused by AST1306 (16.9% for all
grades) was comparable to neratinib , however, it was
much lower than afatinib [15,16] and dacomitinib .
The rash could be effectively managed using topical
antibiotics and corticosteroids with no need for dose
interruption or reduction.
Although in the dose escalation study, the PK
information of several patients in multiple dose levels had been
collected, it was not enough to fully evaluate the PK
profiles. According to the regulations and guideline of phase I
study in China , PK extension study was performed to
enroll additional patients up to at least eight patients per
dose cohort in three dose levels (MTD, one or two doses
level lower than the MTD). PK analysis suggested a
doseproportional relationship over the dose range tested. All
PK parameters displayed moderate to high variability
within the expected range for orally administered TKIs
(eg, lapatinib , erlotinib , gefitinib , and afatinib
). The terminal elimination half-life of AST1306 was
relatively short and suitable for TID dosing. Compared
with other TKIs (eg, lapatinib ), AST1306 has a lower
bioavailability, which may be due to its poor aqueous
solubility. Food significantly increased the plasma exposure of
AST1306 and reduced its inter-individual variability,
indicating that poor bioavailability could be improved by
dosing with meals to achieve therapeutic concentrations.
However, the differences in eating habits between patients
and within a patient from one day to the next do exist.
Under these circumstances, we suggest that the potential
risks of toxicity or loss of efficacy (secondary to loss of
appetite) currently preclude the routine use of food to
reliably and consistently improve AST1306 bioavailability for
chronic therapeutic use. AST1306 is recommended to
take without food in the subsequent phase II study.
AST1306 showed promising anti-cancer activity in
heavily pretreated advanced solid tumor patients; seven
(12.7%) patients demonstrated a confirmed PR and seven
(12.7%) patients demonstrated SD 6 months. Twenty
nine percent (5 of 17) of breast cancer patients achieved
PR: all responders were HER2 positive, 1 of those had
previous trastuzumab and lapatinib exposure. SD 6 months
was observed in 3 breast cancer patients. As an
irreversible HER2 inhibitor, consistent with its preclinical data,
Figure 2 A 67-year old female patient diagnosed with MBC who had experienced treatment failure after 2 chemotheraphy and 2 hormonal
regimens, but did not receive trastuzumab. She had confirmed PR at the 1500 mg BID dose level of AST1306, but withdrew from the study
after 9 months due to continuous grade 2 diarrhea. A) CT imaging of the metastatic lesion prior to starting therapy, and B) shows the response
to AST1306 two cycles after starting therapy. C and D shows continued response three and ten cycles after starting therapy.
AST1306 not only had benefit to HER2 inhibitor naive
breast cancer patients, but also showed potential benefit
to HER2 inhibitor pretreated patients.
Partial response was reported in one NSCLC patient
with unknown EGFR status. One NSCLC patient with
SD lasting 6 months, and who had a mutation in EGFR
had progressed after 15-month gefitinib treatment; he
then subsequently developed a T790M mutation which
was defined prior to entry to this study. The emergence
of a T790M missense mutation is commonly associated
with acquired resistance to first-generation EGFR
inhibitors in NSCLC , and is detected in a subpopulation
of cells in some tumors even before treatment with an
EGFR inhibitor . The ability of AST1306 to inhibit
the growth of cells exhibiting the T790M mutant EGFR
indicates that this agent also deserves further evaluation
in NSCLC patients that are nave and resistant to EGFR
inhibitor. Interestingly, a PR was observed in a gastric
adenocarcinoma patient with unknown EGFR and HER2
status. EGFR and HER2 are overexpressed in 15-45% of
patients with gastric or gastro-esophageal junction cancer,
thereby making them potential targets . Although two
phase III trials (LOGiC  and TyTAN ) for
lapatinib, which is an EGFR and HER2 kinase inhibitor, failed
to reach the primary endpoint, lapatinib did show modest
single-agent activity in advanced/metastatic gastric cancer
patients with a response rate of 9% .
According to the preliminary efficacy of AST1306, HER2
positive breast cancer and EGFR mutant NSCLC are the
two cancer types recommended to be further studied in
the phase II study. Also, the much lower incidence of skin
rashes than afatinib [15,16] and dacomitinib  makes
AST1306 worthy of being further investigated.
In conclusion, oral AST1306 is well-tolerated when
administered continuously, with promising antitumor
activity in multiple tumor types. The MTD of AST1306
was determined to be 1000 mg TID. This dose is the
recommended dose of AST1306 for subsequent phase II
Additional file 1: Figure S1. Randomization to one of two treatment
sequences each comprising two treatment periods (fasted and fed).
Additional file 2: Table S1. Geometric Mean and CV Pharmacokinetic
Parameters of AST1306 on Days 1 and 23-24 (ss) After Single and Multiple
Additional file 3: Table S2. Pharmacokinetic parameters (range) for
subjects receiving AST1306 1000 mg with and without food.
PK: Pharmacokinetic; DLT: Dose-limiting toxicity; RP2D: Recommended phase
II dose; MTD: Maximum tolerated dose; EGFR: Epidermal growth factor
receptor; TKI: Tyrosine kinase inhibitor; NSCLC: Non-small-cell lung carcinoma;
MBC: Metastatic breast cancer; ECOG: Eastern Cooperative Oncology Group;
RECIST: Response evaluation criteria in solid tumors; LVEF: Left ventricular
ejection fraction; ICH: International Conference on Harmonization; GCP: Good
clinical practice; CTC-AE: Common terminology criteria for adverse events;
PFS: Progression free survival; OS: Overall survival; SD: Stable disease;
SAE: Serious adverse events; FI: Fluctuation index.
The authors declared that they have no competing interests.
Conceived and designed the study: JNC, JL. Performed the study: JZ, JNC, JL,
ZYC, WP, SS, JCW. Analyzed the data: JZ, JNC, YFZ, NQZ, DFZ, XFZ, JZ. Wrote
the paper: JZ, JNC, JL. All authors have read and approved the final
We thank all the patients and investigators. We also thank Shanghai Allist
Pharmaceuticals for providing AST1306 free of charge.
1. Yarden Y , Sliwkowski MX : Untangling the ErbB signalling network . Nat Rev Mol Cell Biol 2001 , 2 : 127 - 137 .
2. Tebbutt N , Pedersen MW , Johns TG : Targeting the ERBB family in cancer: couples therapy . Nat Rev Cancer 2013 , 13 : 663 - 673 .
3. Engelman JA , Janne PA : Mechanisms of acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors in non-small cell lung cancer . Clin Cancer Res 2008 , 14 : 2895 - 2899 .
4. Mok TS , Wu YL , Thongprasert S , Yang CH , Chu DT , Saijo N , Sunpaweravong P , Han B , Margono B , Ichinose Y , Nishiwaki Y , Ohe Y , Yang JJ , Chewaskulyong B , Jiang H , Duffield EL , Watkins CL , Armour AA , Fukuoka M : Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma . N Engl J Med 2009 , 361 : 947 - 957 .
5. Lin NU , Winer EP , Wheatley D , Carey LA , Houston S , Mendelson D , Munster P , Frakes L , Kelly S , Garcia AA , Cleator S , Uttenreuther-Fischer M , Jones H , Wind S , Vinisko R , Hickish T : A phase II study of afatinib (BIBW 2992), an irreversible ErbB family blocker, in patients with HER2-positive metastatic breast cancer progressing after trastuzumab . Breast Cancer Res Treat 2012 , 133 : 1057 - 1065 .
6. Xie H , Lin L , Tong L , Jiang Y , Zheng M , Chen Z , Jiang X , Zhang X , Ren X , Qu W , Yang Y , Wan H , Chen Y , Zuo J , Jiang H , Geng M , Ding J : AST1306, a novel irreversible inhibitor of the epidermal growth factor receptor 1 and 2, exhibits antitumor activity both in vitro and in vivo . PLoS One 2011 , 6 : e21487 .
7. Li D , Ambrogio L , Shimamura T , Kubo S , Takahashi M , Chirieac LR , Padera RF , Shapiro GI , Baum A , Himmelsbach F , Rettig WJ , Meyerson M , Solca F , Greulich H , Wong KK : BIBW2992, an irreversible EGFR/HER2 inhibitor highly effective in preclinical lung cancer models . Oncogene 2008 , 27 : 4702 - 4711 .
8. Kobayashi S , Boggon TJ , Dayaram T , Janne PA , Kocher O , Meyerson M , Johnson BE , Eck MJ , Tenen DG , Halmos B : EGFR mutation and resistance of non-small-cell lung cancer to gefitinib . N Engl J Med 2005 , 352 : 786 - 792 .
9. Pao W , Miller VA , Politi KA , Riely GJ , Somwar R , Zakowski MF , Kris MG , Varmus H : Acquired resistance of lung adenocarcinomas to gefitinib or erlotinib is associated with a second mutation in the EGFR kinase domain . PLoS Med 2005 , 2 : e73 .
10. Balak MN , Gong Y , Riely GJ , Somwar R , Li AR , Zakowski MF , Chiang A , Yang G , Ouerfelli O , Kris MG , Ladanyi M , Miller VA , Pao W : Novel D761Y and common secondary T790M mutations in epidermal growth factor receptor-mutant lung adenocarcinomas with acquired resistance to kinase inhibitors . Clin Cancer Res 2006 , 12 : 6494 - 6501 .
11. Perez-Soler R : Can rash associated with HER1/EGFR inhibition be used as a marker of treatment outcome? Oncology (Williston Park) 2003 , 17 : 23 - 28 .
12. Fukuoka M , Yano S , Giaccone G , Tamura T , Nakagawa K , Douillard JY , Nishiwaki Y , Vansteenkiste J , Kudoh S , Rischin D , Eek R , Horai T , Noda K , Takata I , Smit E , Averbuch S , Macleod A , Feyereislova A , Dong RP , Baselga J: Multi-institutional randomized phase II trial of gefitinib for previously treated patients with advanced non-small-cell lung cancer (The IDEAL 1 Trial) [corrected] . J Clin Oncol 2003 , 21 : 2237 - 2246 .
13. Kris MG , Natale RB , Herbst RS , Lynch TJ , Prager D , Belani CP , Schiller JH , Kelly K , Spiridonidis H , Sandler A , Albain KS , Cella D , Wolf MK , Averbuch SD , Ochs JJ , Kay AC : Efficacy of gefitinib, an inhibitor of the epidermal growth factor receptor tyrosine kinase, in symptomatic patients with non-small cell lung cancer: a randomized trial . JAMA 2003 , 290 : 2149 - 2158 .
14. Tjulandin S , Moiseyenko V , Semiglazov V , Manikhas G , Learoyd M , Saunders A , Stuart M , Keilholz U : Phase I, dose-finding study of AZD8931, an inhibitor of EGFR (erbB1), HER2 (erbB2) and HER3 (erbB3) signaling, in patients with advanced solid tumors . Invest New Drugs 2014 , 32 : 145 - 153 .
15. Marshall J , Hwang J , Eskens FA , Burger H , Malik S , Uttenreuther-Fischer M , Stopfer P , Ould-Kaci M , Cohen RB , Lewis NL : A Phase I, open-label, dose escalation study of afatinib, in a 3-week-on/1-week-off schedule in patients with advanced solid tumors . Invest New Drugs 2013 , 31 : 399 - 408 .
16. Gordon MS , Mendelson DS , Gross M , Uttenreuther-Fischer M , Ould-Kaci M , Zhao Y , Stopfer P , Agus DB : A Phase I, open-label, dose-escalation study of continuous once-daily oral treatment with afatinib in patients with advanced solid tumors . Invest New Drugs 2013 , 31 : 409 - 416 .
17. Takahashi T , Boku N , Murakami H , Naito T , Tsuya A , Nakamura Y , Ono A , Machida N , Yamazaki K , Watanabe J , Ruiz-Garcia A , Imai K , Ohki E , Yamamoto N : Phase I and pharmacokinetic study of dacomitinib (PF-00299804), an oral irreversible, small molecule inhibitor of human epidermal growth factor receptor-1, 2, and 4 tyrosine kinases, in Japanese patients with advanced solid tumors . Invest New Drugs 2012 , 30 : 2352 - 2363 .
18. Wong KK , Fracasso PM , Bukowski RM , Lynch TJ , Munster PN , Shapiro GI , Janne PA , Eder JP , Naughton MJ , Ellis MJ , Jones SF , Mekhail T , Zacharchuk C , Vermette J , Abbas R , Quinn S , Powell C , Burris HA : A phase I study with neratinib (HKI-272), an irreversible pan ErbB receptor tyrosine kinase inhibitor, in patients with solid tumors . Clin Cancer Res 2009 , 15 : 2552 - 2558 .
19. Ito Y , Suenaga M , Hatake K , Takahashi S , Yokoyama M , Onozawa Y , Yamazaki K , Hironaka S , Hashigami K , Hasegawa H , Takenaka N , Boku N : Safety, efficacy and pharmacokinetics of neratinib (HKI-272) in Japanese patients with advanced solid tumors: a Phase 1 dose-escalation study . Jpn J Clin Oncol 2012 , 42 : 278 - 286 .
20. Guiding principles for the clinical pharmacokinetics of chemical drugs . http://www.sda.gov.cn/WS01/CL1616/83420.html.
21. Burris HR , Hurwitz HI , Dees EC , Dowlati A , Blackwell KL , O'Neil B , Marcom PK , Ellis MJ , Overmoyer B , Jones SF , Harris JL , Smith DA , Koch KM , Stead A , Mangum S , Spector NL : Phase I safety, pharmacokinetics, and clinical activity study of lapatinib (GW572016), a reversible dual inhibitor of epidermal growth factor receptor tyrosine kinases, in heavily pretreated patients with metastatic carcinomas . J Clin Oncol 2005 , 23 : 5305 - 5313 .
22. Hidalgo M , Bloedow D : Pharmacokinetics and pharmacodynamics: maximizing the clinical potential of Erlotinib (Tarceva) . Semin Oncol 2003 , 30 : 25 - 33 .
23. Swaisland HC , Smith RP , Laight A , Kerr DJ , Ranson M , Wilder-Smith CH , Duvauchelle T : Single-dose clinical pharmacokinetic studies of gefitinib . Clin Pharmacokinet 2005 , 44 : 1165 - 1177 .
24. Yap TA , Vidal L , Adam J , Stephens P , Spicer J , Shaw H , Ang J , Temple G , Bell S , Shahidi M , Uttenreuther-Fischer M , Stopfer P , Futreal A , Calvert H , de Bono JS , Plummer R : Phase I trial of the irreversible EGFR and HER2 kinase inhibitor BIBW 2992 in patients with advanced solid tumors . J Clin Oncol 2010 , 28 : 3965 - 3972 .
25. Maheswaran S , Sequist LV , Nagrath S , Ulkus L , Brannigan B , Collura CV , Inserra E , Diederichs S , Iafrate AJ , Bell DW , Digumarthy S , Muzikansky A , Irimia D , Settleman J , Tompkins RG , Lynch TJ , Toner M , Haber DA : Detection of mutations in EGFR in circulating lung-cancer cells . N Engl J Med 2008 , 359 : 366 - 377 .
26. Iqbal S , Goldman B , Fenoglio-Preiser CM , Lenz HJ , Zhang W , Danenberg KD , Shibata SI , Blanke CD : Southwest Oncology Group study S0413: a phase II trial of lapatinib (GW572016) as first-line therapy in patients with advanced or metastatic gastric cancer . Ann Oncol 2011 , 22 : 2610 - 2615 .
27. Hecht JR , Bang YJ , Qin SQ , Chuang HC , Xu JM , Park JO , Jeziorski K , Shparyk Y , Hoff PM , Sobrero AF , Salman P , Li J : Lapatinib in combination with capecitabine plus oxaliplatin (CapeOx) in HER2-positive advanced or metastatic gastric, esophageal, or gastroesophageal adenocarcinoma (AC): The TRIO-013/LOGiC Trial . J Clin Oncol 2013 , 31 : A4001 .
28. Bang YJ : A randomized, open-label, phase III study of lapatinib in combination with weekly paclitaxel versus weekly paclitaxel alone in the second-line treatment of HER2 amplified advanced gastric cancer (AGC) in Asian population: Tytan study . J Clin Oncol 2012 , 30 : 11 .