A phase 1b study of the Notch inhibitor crenigacestat (LY3039478) in combination with other anticancer target agents (taladegib, LY3023414, or abemaciclib) in patients with advanced or metastatic solid tumors

Analia Azaro 1,2 • Christophe Massard 3 • William D. Tap 4 • Philippe A. Cassier5 • Jaime Merchan6 • Antoine Italiano7 •
Bailey Anderson8 • Eunice Yuen8 • Danni Yu8 • Gerard Oakley III8 • Karim A. Benhadji9 • Shubham Pant10

Received: 19 November 2020 / Accepted: 2 March 2021
Ⓒ The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2021

Summary
Notch signaling plays an important role in development and tissue homeostasis. Deregulation of Notch signaling has been implicated in multiple malignancies. Crenigacestat (LY3039478), a potent Notch inhibitor, decreases Notch signaling and its downstream biologic effects. I6F-MC-JJCD was a multicenter, nonrandomized, open-label, Phase 1b study with 5 separate, parallel dose-escalations in patients with advanced or metastatic cancer from a variety of solid tumors, followed by a dose- confirmation phase in prespecified tumor types. This manuscript reports on 3 of 5 groups. The primary objective was to determine the recommended Phase 2 dose of crenigacestat in combination with other anticancer agents (taladegib, LY3023414 [dual inhibitor of phosphoinositide 3-kinase; mechanistic target of rapamycin], or abemaciclib). Secondary objec- tives included evaluation of safety, tolerability, efficacy, and pharmacokinetics. Patients (N = 63) received treatment between November 2016 and July 2019. Dose-limiting toxicities occurred in 12 patients, mostly gastrointestinal (diarrhea, nausea, vomiting). The maximum-tolerated dose of crenigacestat was 25 mg in Part B (LY3023414), 50 mg in Part C (abemaciclib), and not established in Part A (taladegib) due to toxicities. Patients had at least 1 adverse event (AE) and 75.0–82.6% were ≥ Grade 3 all-causality AEs. No patient had complete or partial response. Disease control rates were 18.8% (Part B) and 26.1% (Part C). The study was terminated before dose confirmation cohorts were triggered. This study demonstrated that crenigacestat combined with different anticancer agents (taladegib, LY3023414, or abemaciclib) was poorly tolerated, leading to lowered dosing and disappointing clinical activity in patients with advanced or metastatic solid tumors. NCT02784795 and date of registration: May 27, 2016.

Keywords LY3039478 . Crenigacestat . Notch inhibition . Phase 1 . Metastatic cancer . Abemaciclib

* Shubham Pant [email protected]

1 Molecular Therapeutics Research Unit, Department of Medical Oncology, Vall d’Hebron University Hospital, Barcelona, Spain
2 Department of Pharmacology, Universitat Autònoma de Barcelona (UAB), Barcelona, Spain
3 Drug Development Department (DITEP), Inserm Unit U981, Université Paris Saclay, Université Paris-Sud, Gustave Roussy, Villejuif, France
4 Memorial Sloan Kettering Cancer Center, and Weill Cornell Medical College, 1275 York Avenue, New York, NY, USA
5 Department of Medical Oncology, Centre Léon Bérard, Lyon, France

6 Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL, USA

7 Institut Bergonié, Bordeaux Cedex, France

8 Eli Lilly and Company, Indianapolis, IN, USA

9 Eli Lilly and Company, New York, NY, USA

10 Department of Investigational Cancer Therapeutics, Division of Cancer Medicine, University of Texas Medical Center/MD Anderson Cancer Center, Houston, TX 77030, USA

Introduction

Notch signaling is an evolutionarily conserved pathway that plays an important role in development and tissue homeostasis [1–3]. Deregulated Notch signaling due to mutation or over- expression of ligands and/or receptors is implicated in a num- ber of malignancies [4–7]. While Notch has been shown to have both oncogenic and tumor suppressive functions, it seems to be important for survival of cancer cells at advance stages of the disease [8, 9]. Therefore, inhibition of Notch signaling presents a feasible approach to providing therapeutic benefit to cancer patients.
Crosstalk between Notch, hedgehog, Wnt, and other sig- naling pathways have been reported in a variety of cell types [9, 10]. Hedgehog and Notch pathways are often active con- comitantly in breast cancer cells and in medulloblastomas that arise in patched-deficient mice and human soft tissue sarco- mas [11]. Hedgehog signaling leads to transactivation of the Notch target gene, hairy and enhancer of split, in a Notch- independent manner and is considered to be a negative regu- lator of Notch signaling [11]. Preclinical model studies exam- ining crosstalk among Notch, hedgehog, and Wnt pathways as well as other signaling pathways have shown promising re- sults [3]. Crenigacestat has shown significant antitumor activ- ity when combined with taladegib (LY2940680), a hedgehog/ smoothened inhibitor in tumor xenograft models [12]. Combination therapy with Notch and hedgehog inhibitors showed reasonable safety and clinical activity in patients with advanced sarcoma [13].
LY3023414 is an oral dual inhibitor of phosphoinositide 3- kinase (PI3K) and mammalian target of rapamycin (mTOR) pathway, which is activated in >70% of human cancers. The PI3K/mTOR pathway is activated through multiple mecha- nisms including mutations in PI3K and loss of phosphatase and tensin homolog (PTEN) [14]. LY3023414 demonstrated preclinical activity in tumor xenograft models with PTEN loss [15]. Crenigacestat combined with LY3023414 in an ovarian carcinoma xenograft model showed a synergistic inhibition of tumor growth, suggesting that inhibition of Notch and PI3K signaling might provide improved benefit in solid tumors (da- ta on file).
Defects in pathways that regulate cell proliferation in re- sponse to mitogenic signaling and other extracellular stimuli, such as cell density and nutrients are hallmarks of cancer cells [16]. The cyclin-dependent kinase 4/6 (CDK4/6) pathway is a primary mechanism that controls cell cycle progression through the restriction point, which is inactivated in many human tumors [17]. Crenigacestat combined with abemaciclib, a CDK4/6 inhibitor, inhibits tumor growth in human colorectal and human adenocarcinoma of lung xeno- graft models (data on file).
In this Phase 1b study, we assessed the safety of a Notch inhibitor (crenigacestat; LY3039478) in combination with
different therapies (taladegib, LY3023414, or abemaciclib) in order to determine the recommended Phase 2 dose of crenigacestat in combination with these anticancer agents.

Methods

Study design

I6F-MC-JJCD was a multicenter, nonrandomized, open-label, Phase 1b study with 5 separate, parallel dose-escalation co- horts in patients with advanced or metastatic cancer from a variety of solid tumors followed by a dose-confirmation phase in prespecified tumor types (Fig. 1). This manuscript reports on 3 groups investigating crenigacestat combined with taladegib (Part A), LY3023414 (Part B), or abemaciclib (Part C).2.2. Patient eligibility.
Eligible patients included adults (≥18 years) who had his- tological or cytological evidence of cancer, either a solid tu- mor or lymphoma, which was unresectable or metastatic, ad- equate organ function, and Eastern Cooperative Oncology Group (ECOG) performance scale ≤1. In the dose- confirmation phase, all patients were to have had measurable disease (breast cancer or soft tissue sarcoma [Part A], colon cancer or soft tissue sarcoma [Part B], or breast cancer [Part C]), as defined by Response Evaluation Criteria in Solid Tumors (RECIST; version 1.1). Patients were excluded if they had a serious concomitant systemic disorder, symptomatic central nervous system malignancy or metastasis, current acute leukemia, secondary primary malignancy, or current or recent gastrointestinal disease.
This study was performed in accordance with the Declaration of Helsinki and International Council for Harmonization Good Clinical Practice guidelines with regis- tration of ClinicalTrials.gov NCT02784795.

Study treatment and definition of dose intensity

Treatments consisted of crenigacestat (LY3039478) in com- bination with taladegib, LY3023414, or abemaciclib. All medications were supplied by Eli Lilly and Company. Patients received 1 of 3 treatment combinations on alternative days (eg, Tuesday, Thursday, and Saturday) on a 28- day cycle. In the dose-escalation phase (Cycle 1), patients received single oral dose of either taladegib, LY3023414, or abemaciclib, in Parts A, B, and C, respectively, on day 1 of a 3-day lead-in period followed by escalating doses of crenigacestat 3 times per week (TIW) in combination with taladegib (once daily; QD), LY3023414 (twice daily; BID), or abemaciclib (BID). In the dose-confirmation phase (after Cycle 1), patients were to have followed the same dosing schedule and were treated at a dose no greater than the defined maximum-tolerated dose (MTD) from the dose-escalation

Fig. 1 Study design. Abbreviations: BID = twice daily; MTD = maximum-tolerated dose; QD = once daily; TIW = three times per week

phase. Patients remained on study drug until they fulfilled the protocol-defined criteria for treatment discontinuation (physi- cian decision, progressive disease, or withdrawal by patient). The median dose intensity for crenigacestat was defined as the cumulative median dose (mg) given over the median du- ration (weeks). Similarly, the mean dose intensity for crenigacestat was defined as the cumulative mean dose (mg)
given over the mean duration (weeks).

Definition of dose-limiting toxicity

Dose-limiting toxicity (DLT) was defined as an adverse event (AE), which occurred during Cycle 1 that was related to crenigacestat, taladegib, LY3023414, or abemaciclib and ful- filled detailed criteria in supplement Information using the Common Terminology Criteria for Adverse Events (CTCAE) version 4.0.

Safety assessments

Baseline assessments included complete clinical evaluation, clinical laboratory assessments, and electrocardiogram (ECG) measurements. During the study period, safety was assessed by the incidence and severity of AEs using the CTCAE (version 4.0) and Medical Dictionary for Regulatory Activities (version 16.1), and the changes from baseline in laboratory values.

. Pharmacokinetic and bioanalytical methods

Plasma concentrations of crenigacestat, taladegib and its ac- tive metabolite LSN3185556, abemaciclib and its active me- tabolites LSN2839567 and LSN306726, and LY3023414 were analyzed at Q2 Solutions in Ithaca, NY, using a valid liquid chromatography/tandem mass spectrophotometry method. Primary pharmacokinetic (PK) endpoints were de- rived from crenigacestat concentration-time profiles and were analyzed using standard noncompartmental methods of anal- ysis (Phoenix version 8).
Immunohistochemistry assessments

At baseline, patients in the study submitted representative pre- treatment archival diagnostic biopsies as formalin-fixed, paraffin-embedded (FFPE) tissue and immunohistochemistry (IHC) was performed at Eli Lilly and Company (Indianapolis, IN) as previously described [18]. The Notch intracellular do- main (NICD) antigen was detected using the proprietary Notch 1 intracellular domain (N1ICD), Notch 2 intracellular domain (N2ICD), or Notch 3 intracellular domain (N3ICD) antibody developed for Eli Lilly and Company. Results were interpreted and scored by a board-certified pathologist (GJO).

. Efficacy assessments

Tumor assessments were performed using the appropriate criteria (RECIST version 1.1 and/or Choi response criteria) [19]. Progression-free survival was defined as the time from study enrollment (based on the first treatment date) to the first observation of objective progression or death from any cause. Duration of response was defined as the time from the first evidence of a confirmed complete or partial response to ob- jective progression or death from any cause (whichever was earlier).

Statistical analysis

Descriptive statistics were used to summarize the PK param- eters. Log-transformed maximum observed concentration (Cmax) and area under the plasma drug concentration versus time curve (AUC) estimates were assessed using mixed effect models with random patient effect to estimate ratios of geo- metric means and the corresponding 90% confidence inter- vals. Results were summarized using data tabulations, de- scriptive statistics, and graphical presentation. Descriptive analyses of duration of response, overall survival, and progression-free survival were conducted using the Kaplan- Meier methodology.

Results

Patient characteristics and treatment

Between November 2016 and July 2019, all 63 patients enrolled in this study received at least 1 dose of study drug. At data cutoff (02 July 2019), most patients discontinued the study treatment due to progressive disease (65.2–75.0%). One patient in Part C continued receiving treatment with abemaciclib only.
Baseline patient characteristics are summarized in Table 1. Majority of patients were female (54.0%) between the ages of 19 and 77 years. All patients in Part A had undergone at least 1 prior anticancer therapy including 7 patients (87.5%) who underwent prior surgical procedures and 3 patients (37.5%) who underwent prior radiotherapy. Baseline assessments to detect the NICD antigen using IHC indicated that 1 patient (12.5% of 8 patients including 3 patients without testing re- sults) was positive for N1ICD and another patient (12.5% of 8 total) for N3ICD.
All patients in Part B had undergone at least 1 prior anti- cancer therapy including 28 patients (87.5%) who underwent prior surgical procedures and 21 patients (65.6%) who underwent radiotherapy. Baseline assessments to detect the NICD antigen using IHC indicated that 15 patients (46.9% of 32 total including 12 patients without testing results) were positive for N1ICD.
In Part C, 21 patients (91.3%) received prior anticancer therapy, 15 patients (65.2%) received prior radiotherapy, and 19 patients (82.6%) received prior surgical procedures. Baseline assessments to detect the NICD antigen using IHC indicated that 7 patients (30.4% of 23 total including 11 pa- tients without testing results) were positive for N1ICD and 1 of those (4.3% of 23 total) was also positive for N3ICD.

Dose intensities

For crenigacestat in Parts A, B, and C, patients received me- dian (mean) dose intensities of 73.36 (98.40), 76.90 (84.43),
and 81.25 (91.24) mg/week, respectively.

Dose-limiting toxicities and maximum-tolerated dose

Dose-limiting toxicities (≥1) were reported by 12 patients in Cycle 1, including 2 of 8 patients in Part A (25 mg crenigacestat
with 200 mg taladegib), 8 of 32 patients in Part B (25 or 50 mg
crenigacestat with 150 or 200 mg LY3023414), and 2 of 23 patients in Part C (25 or 50 mg crenigacestat with 100 mg abemaciclib) (Table 2). The treatment regimen in Part A was poorly tolerated and was not explored beyond the first dose level of crenigacestat 25 mg TIW with taladegib (200 mg). The MTD of crenigacestat combined with 150 mg LY3023414 (Part B) or with 100 mg abemaciclib (Part C) was determined to be 25 mg TIW and 50 mg TIW, respectively.
Safety and tolerability

In Part A, 7 of 8 patients (87.5%) reported ≥1 treatment- emergent adverse event (TEAE), of which 3 patients had Grade ≥ 3 treatment-related adverse events (TRAEs) includ- ing nausea, vomiting, asthenia, increased lipase, and de- creased appetite (1 patient each; Table 3). In Part B, 31 of 32 patients (96.9%) reported ≥1 TEAE, of which 20 patients (62.5%) had Grade ≥ 3 TRAEs. The most common Grade ≥ 3 TRAEs included hypophosphatemia, nausea, diarrhea, hypo- kalemia, fatigue, stomatitis, and decreased appetite. In Part C, all 23 patients (100%) reported ≥1 TEAE, of which 16 patients (69.6%) had Grade ≥ 3 TRAEs. The most common Grade ≥ 3 TRAEs included hypophosphatemia, diarrhea, hypokalemia, vomiting, and fatigue. No patients died due to AEs in this study. Treatment-related serious AEs were reported by 2 pa- tients in Part A, 8 patients in Part B, and 7 patients in Part C, with vomiting, diarrhea, and fatigue being the most common. Six patients (9.5%) withdrew from the study treatment due to AEs of vomiting, hypokalemia, fatigue, or asthenia.

Pharmacokinetics of crenigacestat, taladegib, LY3023414, and abemaciclib

Mean crenigacestat PK parameters are summarized in Table 4. The exposures of crenigacestat were in the range of those previously observed [20], and did not appear to be affected by the coadministration of taladegib, LY3023414, and abemaciclib. The PK of taladegib, LY3023414, and abemaciclib were similar to those reported in the literature [12, 14, 21]. PK exposures of crenigacestat did increase with dose as reported in previous study [20].

Efficacy

Best overall response rates as measured by RECIST are sum- marized in Table 5. No partial or complete responses were observed; no patients had stable disease in Part A, while 6 patients (18.8%) had stable disease in Part B, and 6 patients (26.1%) had stable disease in Part C.

Discussion

This report describes results from a Phase 1b study designed to assess the safety and tolerability of a Notch inhibitor (crenigacestat) combined with different agents in order to de- termine the recommended Phase 2 dose of crenigacestat in combinations with these anticancer agents. All 63 patients enrolled in the study received at least 1 dose of study drug and all but 1 patient was off treatment at data cutoff on 02 July 2019. One patient in Part C was on treatment (abemaciclib only) at the time of data cutoff. In general,

Table 1 Demographics summary

Characteristic Total Part A Total Part B Total Part C
(N=8) (N=32) (N=23)
Age (years) Median 56.5 53.5 55.0
Sex Female 2 (25.0) 18 (56.3) 14 (60.9)
Male 6 (75.0) 14 (43.8) 9 (39.1)
ECOG Performance Status, n (%) ECOG 0 1 (12.5) 12 (37.5) 6 (26.1)
ECOG 1 6 (75) 15 (46.9) 16 (69.6)
ECOG 1 (12.5) 5 (15.6) 1 (4.3)

Cancers/Tumor Types, n (%) (not available/missing) Adenocarcinoma
1 (3.1)
1 (4.3)
Adenoid cystic carcinoma 1 (3.1) 2 (8.7)
Breast cancer 4 (12.5) 8 (34.8)
Cervix cancer 1 (5.6) 1 (7.1)
Colon cancer 6 (18.7) 1 (4.3)
Gastric cancer 1 (4.3)
Lung cancer 1 (4.3)
Pancreatic cancer 3 (37.5) 1 (4.3)
Prostate cancer 1 (12.5) 3 (9.37)
Soft tissue sarcoma 1 (12.5) 2 (6.3) 3 (13.0)
Uterine cancer 1 (5.6)
Other 3 (37.5) 13 (40.6) 4 (17.4)
Prior Anticancer Therapy, n (%) Surgical procedure 7 (87.5) 28 (87.5) 19 (82.6)
Radiotherapy 3 (37.5) 21 (65.6) 15 (65.2)
Systemic therapy 8 (100.0) 32 (100.0) 21 (91.3)
Prior Systemic Treatments, n (%) Bevacizumab 11 (34.4)
(most common) Capecitabine 10 (43.5)
Docetaxel 10 (31.3)
Doxorubicin 11 (47.8)
Fluorouracil 4 (50.0) 11 (47.8)
Folinic acid 3 (37.5) 10 (31.3)
Gemcitabine 5 (62.5) 13 (40.6)
Paclitaxel 10 (43.5)
Notch Status on NICD, n (%)
Notch 1 Negative 4 (50) 5 (15.6) 5 (21.7)
Positive 1 (12.5) 15 (46.9) 7 (30.4)
Not available/missing 3 (37.5) 12 (37.5) 11 (47.8)
Notch 2 Negative 5 (62.5) 19 (59.4) 12 (52.2)
Positive 0 (0) 0 (0) 0 (0)
Not available/missing 3 (37.5) 13 (40.6) 11 (47.8)
Notch 3 Negative 4 (50) 19 (59.4) 11 (47.8)
Positive 1 (12.5) 0 (0) 1 (4.3)
Not available/missing 3 (37.5) 13 (40.6) 11 (47.8)
Abbreviations: ECOG = Eastern Cooperative Oncology Group; NICD = Notch intracellular domain
Note: Part A: LY3039478 with taladegib; Part B: LY3039478 with LY3023414; Part C: LY3039478 with abemaciclib

baseline demographic characteristics were consistent with oth- er Phase 1 studies (ie, advanced, pretreated cancer patients).
The MTD was not determined for the combination of crenigacestat (25 mg) with taladegib (200 mg; Part A) as

it was deemed to be poorly tolerated by the patients (due to TRAE of Grade 4 lipase increased) and therefore, not a feasible option. In Part B, the MTD of crenigacestat combined with LY3023414 (150 mg) was determined to

Table 2 Summary of dose- limiting toxicities in Parts A, B, and C

Part (N)

Dose Patients with DLT Eventa

A
(N=8)
LY3039478 25 mg
with taladegib 200 mg
2 Grade 2 vomiting (n=1)
Grades 4 lipase increased (n=1)

B
(N=32) LY3039478 25 mg 3
with LY3023414 150 mg Grade 4 thrombocytopenia (n=1)
Grade 3 colitis (n=1)
Grade 4 hypophosphatemia (n=1) Grade 3 rash maculopapular (n=1)
LY3039478 50 mg 2 Grade 1 diarrhea (n=1)
with LY3023414 150 mg Grade 2 nausea (n=1)
Grade 2 abdominal pain (n=1)
Grade3 fatigue (n=1)
Grade 2 mucosal inflammation (n=1)
Grade 3 acute kidney injury (n=1)
LY3039478 25 mg 3 Grades 1 and 3 vomiting (n=2)
with LY3023414 200 mg Grade 3 diarrhea (n=1)
Grade 2 nausea (n=1)
Grade 1 abdominal pain upper (n=1)
Grade 2 stomatitis (n=1)
Grade3 fatigue (n=1)
Grade 2 asthenia (n=1)
Grades 2 and 3 decreased appetite (n=2)
Grade 3 hypophosphatemia (n=1)
Grade 2 rash maculopapular (n=1)
Grade 3 pruritus (n=1)
C LY3039478 25 mg 0

(N=23)
with abemaciclib 100 mg
LY3039478 50 mg
with abemaciclib 100 mg

2 Grade 2 vomiting (n=1) Grade 2 diarrhea (n=1) Grade 2 nausea (n=1) Grade 2 oral pain (n=1) Grade2 fatigue (n=1)
Grade 3 mucosal inflammation (n=1)
Grade 3 palmar-plantar erythrodysesthesia syndrome (n=1)
Grade 1 rash (n=1)

Abbreviations: CTCAE Common Terminology Criteria for Adverse Events, DLT dose-limiting toxicities,
N number of patients in population, n number of subjects in the specified category
a Maximum CTCAE toxicity grades presented MedDRA version 21.0; CTCAE version 4.0

be 25 mg TIW, which was considerably lower than the MTD observed for crenigacestat monotherapy, suggest- ing that this combined regimen was not as well tolerated by patients in this study. Whereas, in Part C, the MTD of crenigacestat combined with abemaciclib (100 mg) was 50 mg TIW and was similar to that previously re- ported for crenigacestat monotherapy (50 mg) in which patients received crenigacestat (75 mg TIW) [20]. In that study, the MTD of crenigacestat monotherapy could not be confirmed in the expansion cohort; therefore, the

recommended Phase 2 dose was determined to be 5 mg TIW as that dose level was tolerated better by patients [20]. Results from the current study indicate the MTD of crenigacestat combined with abemaciclib was similar to that for crenigacestat monotherapy, suggesting that this combined regimen was tolerated by patients as well as the monotherapy.
Similar to patients in previously reported studies with crenigacestat monotherapy, gastrointestinal events of diar- rhea, nausea and vomiting, and hypophosphatemia were the

Table 3 Summary of treatment-related adverse events by maximum CTCAE Grade

Part A (N=8) Part B (N=32) Part C (N=23)
n (%) n (%) n (%)
Preferred terms Any Grade Grade 3/4/5 Preferred terms Any Grade Grade 3/4/5 Preferred terms Any Grade Grade 3/4/5
Any TRAE 7 (87.5) 3 (37.5) Any TRAE 29 (90.6) 20 (62.5) Any TRAE 21 (91.3) 16 (69.6)
Nausea 6 (75.0) 1 (12.5) Nausea 23 (71.9) 3 (9.4) Diarrhea 18 (78.3) 4 (17.4)
Vomiting 3 (37.5) 1 (12.5) Diarrhea 17 (53.1) 3 (9.4) Nausea 14 (60.9) 1 (4.3)
Asthenia 2 (25.0) 1 (12.5) Vomiting 17 (53.1) 2 (6.3) Vomiting 13 (56.5) 3 (13.0)
Decreased appetite 2 (25.0) 1 (12.5) Hypophosphatemia 16 (50.0) 14 (43.8) Hypophosphatemia 12 (52.2) 8 (34.8)
Diarrhea 2 (25.0) 0 (0.0) Hypokalemia 9 (28.1) 5 (15.6) Decreased appetite 8 (34.8) 0 (0.0)
Dysgeusia 2 (25.0) 0 (0.0) Stomatitis 9 (28.1) 3 (9.4) Blood creatinine 6 (26.1) 0 (0.0)

Lipase increased
1 (12.5)
1 (12.5)
Fatigue
8 (25.0)
4 (12.5) increased Fatigue
6 (26.1)
3 (13.0)
Abdominal pain 1 (12.5) 0 (0.0) Decreased appetite 7 (21.9) 3 (9.4) Rash 6 (26.1) 0 (0.0)
Abdominal pain upper 1 (12.5) 0 (0.0) ALT increased 6 (18.8) 0 (0.0) Alopecia 5 (21.7) 0 (0.0)
Fatigue 1 (12.5) 0 (0.0) AST increased 5 (15.6) 0 (0.0) Anemia 5 (21.7) 1 (4.3)
Weight increased 1 (12.5) 0 (0.0) Rash maculopapular 5 (15.6) 1 (3.1) Asthenia 6 (26.1) 2 (8.7)
Hypokalemia 1 (12.5) 0 (0.0) Abdominal pain upper 4 (12.5) 0 (0.0) Dry mouth 5 (21.7) 0 (0.0)
Hypomagnesemia 1 (12.5) 0 (0.0) Mucosal inflammation 4 (12.5) 0 (0.0) Dry skin 5 (21.7) 0 (0.0)
Hypophosphatemia 1 (12.5) 0 (0.0) Weight decreased 4 (12.5) 0 (0.0) Hypokalemia 5 (21.7) 4 (17.4)
Muscle spasms 1 (12.5) 0 (0.0) Dysgeusia 3 (9.4) 0 (0.0)
Alopecia 1 (12.5) 0 (0.0)
Dry skin 1 (12.5) 0 (0.0)
Hair color changes 1 (12.5) 0 (0.0)
Palmar-plantar 1 (12.5) 0 (0.0)
erythrodysesthesia syndrome
Rash maculopapular 1 (12.5) 0 (0.0)
Abbreviations: ALT = alanine aminotransferase; AST = aspartate aminotransferase; CTCAE = Common Terminology Criteria for Adverse Events; N = number of patients in safety population; n = number of patients in the specified category; TRAE = treatment-related adverse event
Note: Part A: LY3039478 with taladegib; Part B: LY3039478 with LY3023414; Part C: LY3039478 with abemaciclib

most common TEAEs reported during the study [18, 20]. However, compared to the previously reported AE profiles for crenigacestat monotherapy, patients in this study experi- enced a larger number of Grade ≥ 3 TRAEs when given crenigacestat combined with taladegib, LY3023414, or abemaciclib, including toxicities for nausea, diarrhea, and vomiting [18, 20]. Treatment-related serious AEs were report- ed by approximately 27.0% of the patients. No patients died due to AEs in this study.
Exposures of crenigacestat, based on AUCs and Cmax, ap- peared to increase in a dose-proportional manner and were in the range of those previously reported [20]. The exposures of taladegib and its metabolite in Part A, LY3023414 in Part B, and abemaciclib and its metabolites in Part C did not appear to be affected by the coadministration of crenigacestat. PK ex- posures increased with doses may explain the increased tox- icities at higher doses. In Part C severe toxicities were linked to doses.
The patient population was heterogeneous and majority of patients had received prior systemic treatments. Antitumor activity was limited and disease control rates for Part B (crenigacestat with LY3023414) and Part C (crenigacestat with abemaciclib) were only 18.8% and 26.1%, respectively There were very few patients that presented expression of NICD at baseline, which may possibly explain the limited antitumor activity. Monotherapy of crenigacestat and other Notch inhibitors showed limited activity in clinical studies in patients with solid tumors [22–24]. Crenigacestat monotherapy in pa- tients with advanced or metastatic adenoid cystic carcino- ma showed higher disease control rates (>70%) than ob- served in this study [18]. Combination therapies were ex- pected to present improved activity over monotherapy; however, the combination therapies tested in this study did not show antitumor activity. No further clinical devel- opment is planned for crenigacestat.

Table 4 Mean PK parameters following single and multiple oral

Parameter Geometric Mean (%CV)

crenigacestat (LY3039478) doses
administered TIW in patients with intensive PK sampling in study Part A Part B Part C
JJCD Day 22 Day 22 Day 22 Day 22 Day 22
25 mg 25 mg 50 mg 25 mg 50 mg
Nc 2/1 6/6 1/1 4/4 4/4
Tmaxa 1.12–2.00d 2.00 2.00 1.52 1.96
(h)
Cmax
28.2-312d (1.00–4.00)
531
760 (1.00–2.05)
404 (1.00–3.92)
1060
(ng/mL) (40) (41) (44)
AUC(0-∞) or AUC(0–48) (ng•h/mL) 295 2660 4250 1820 5080
(31) (44) (12)
CL/F 84.7 9.40 11.8 13.7 9.84
(L/h) (31) (44) (12)
Vz/F 648 51.7 49.4 73.8 47.2
(L) (28) (52) (8)
t1/2b 5.30 3.81 2.91 3.73 3.33
(h) (3.38–4.37) (3.47–4.14) (3.09–3.57)
Part A: LY3039478 with taladegib; Part B: LY3039478 with LY3023414; Part C: LY3039478 with abemaciclib
Abbreviations: %CV percent coefficient of variation, AUC(0-∞) area under the plasma drug concentration versus time curve from time 0 to infinity, AUC(0–48) area under the plasma drug concentration versus time curve from time 0 to 48 h, AUCtlast area under the plasma drug concentration versus time curve from time 0 to last measurable concentration, CL/F apparent clearance, Cmax maximum observed concentration, N number of patients, PK pharmacokinetic, t½ elimination half-life, TIW 3 times per week, Tmax time to Cmax, Vz/F volume of distribution
a Median (range)
b Geometric mean (range)
c Two N values reported. First N value is for Cmax and Tmax, while the second N value is for remaining parameters that are dependent on terminal phase of pharmacokinetic(s) profile. Parameters dependent on terminal phase only reported when 24-h time point result is available and when ([AUC(0-∞) − AUCtlast]/AUC[0-∞])*100 ≤ 15%
d Range reported when n =2

Table 5 Summary of best overall response by investigator assessment RECIST 1.1

Part A
N=8, n (%)

Part B
N=32, n (%)

Part C
N=23, n (%)

Best overall response Complete response
0
0
0
Partial response 0 0 0
Stable disease 0 6 (18.8) 6 (26.1)
Progressive disease 5 (62.5) 13 (40.6) 8 (34.8)
Non evaluable 3 (37.5) 13 (40.6) 9 (39.1)
Overall response rate (complete + partial response) 0 0 0
Disease control rate (complete + partial 0 6 (18.8) 6 (26.1)
response + stable disease)
Part A: LY3039478 with taladegib; Part B: LY3039478 with LY3023414; Part C: LY3039478 with abemaciclib
Best overall response of complete response required confirmation by subsequent complete response at least 28 days later. Best overall response of partial response required confirmation by subsequent partial response or complete response at least 28 days later
Abbreviations: N number of patients in population, n number of patients in the specified category,
RECIST Response Evaluation Criteria in Solid Tumors

Conclusions

In summary, this study demonstrated that the Notch inhibitor, crenigacestat, combined with different anticancer agents (taladegib, LY3023414, or abemaciclib) was poorly tolerated, which led to lowered dosing and disappointing clinical activ- ity in patients with advanced or metastatic solid tumors. The PK of taladegib, LY3023414, and abemaciclib did not appear to be affected by the coadministration of crenigacestat.

Supplementary Information The online version contains supplementary material available at https://doi.org/10.1007/s10637-021-01094-6.

Acknowledgments Medical writing support was provided by Debra Hidayetoglu, on behalf of Covance, Inc.

Authors’ contributions All authors meet the International Committee of Medical Journal Editors criteria for authorship for this manuscript, take responsibility for the integrity of the work, and have given final approval of the version of the manuscript to be published.
A Azaro: Data analysis and interpretation and manuscript editing and review. C Massard: Data analysis and interpretation and manuscript re- view. WD Tap: Data acquisition, data analysis and interpretation, and manuscript editing and review. PA Cassier: Data analysis and interpreta- tion and manuscript review. J Merchan: Data acquisition, data analysis and interpretation, and manuscript review. A Italiano: Data acquisition, data analysis and interpretation, and manuscript editing and review. B Anderson: Quality control of data and algorithms, data analysis and in- terpretation, and manuscript editing and review. E Yuen: Study design, data analysis and interpretation, and manuscript review. D Yu: Quality control of data and algorithms, data analysis and interpretation, statistical analysis, and manuscript review. G Oakley III: Data acquisition, data analysis and interpretation, and manuscript editing and review. KA Benhadji: Study concepts, study design, data analysis and interpretation, and manuscript editing and review. S Pant: Data analysis and interpreta- tion and manuscript review.

Funding This trial was funded by Eli Lilly and Company.

Data availability Not applicable.

Code availability Not applicable.

Declarations

Ethics approval All procedures performed in studies involving human participants were performed in accordance with the Declaration of Helsinki and International Council for Harmonization Good Clinical Practice guidelines with registration of ClinicalTrials.gov NCT02784795.

Consent to participate Written informed consent was obtained from all individual participants included in the study.

Consent for publication Not applicable.

Conflicts of interest/Competing interests A Azaro, Advisory and Consulting: Amcure GmbH and Orion Corporation. C Massard, Advisory and Consulting: Amgen, Astellas, AstraZeneca, Bayer,
BeiGene, BMS, Celgene, Debiopharm, Genentech, Ipsen, Janssen, Lilly, MedImmune, MSD, Novartis, Pfizer, Roche, Sanofi, and Orion; Principal/Sub-Investigator of Clinical Trials: Abbvie, Aduro, Agios, Amgen, Argen-x, Astex, AstraZeneca, Aveo pharmaceuticals, Bayer, Beigene, Blueprint, BMS, Boehringer Ingelheim, Celgene, Chugai, Clovis, Daiichi Sankyo, Debiopharm, Eisai, Eos, Exelixis, Forma, Gamamabs, Genentech, Gortec, GSK, H3 biomedecine, Incyte, Innate Pharma, Janssen, Kura Oncology, Kyowa, Lilly, Loxo, Lysarc, Lytix Biopharma, Medimmune, Menarini, Merus, MSD, Nanobiotix, Nektar Therapeutics, Novartis, Octimet, Oncoethix, Oncopeptides AB, Orion, Pfizer, Pharmamar, Pierre Fabre, Roche, Sanofi, Servier, Sierra Oncology, Taiho, Takeda, Tesaro, and Xencor, outside of submitted work. WD Tap, Advisory Boards: Eli Lilly and Company, EMD Serono, Eisai, Janssen, Immune design, Daiichi Sankyo, Blueprint, Loxo, Glaxo Smith Kline, Agios Pharmaceuticals, NanoCarrier, Deciphera, and C4 Therapeutics; Consulting: Daiichi Sankyo, FDA ODAXC Meeting Pexidartinib; Scientific Advisory Board: Certis Oncology Solutions (and stock ownership); Co-founder of Atropos Therapeutics (and stock ownership); Patent (pending) on the identifica- tion and development of biomarkers for CDK4 inhibitors in cancer. PA Cassier, received honoraria from Amgen, AstraZeneca, Blueprint Medicines, Novartis, Roche/Genentech, and Merck Serono; Investigator/Sub-Investigator of Clinical Trials: Abbvie, AstraZeneca, Bayer, Blueprint Medicines, Bristol-Myers Squibb, Celgene, Eli Lilly and Company, Glaxo Smith Kline, Innate Pharma, Janssen, Merck Serono, Merck Sharp Dohme, Novartis, Plexxikon, Genentech/Roche, Taiho Pharmaceuticals, and Transgene, outside of submitted work; Travel Accommodations and Expenses: Amgen, Bristol-Myers Squibb, Merck Sharp and Dohme, Netris Pharma, Novartis, and Roche. J Merchan, Advisory and Consulting: Exelixis; Investigator/Sub- Investigator of Clinical Trials: Eli Lilly and Company, Pfizer, Novartis, Genentech, Merck, Peloton Therapeutics, Corvus Pharmaceuticals, Tizona Therapeutics, Vyriad, Sillagen, Replimune, Seattle Genetics, Eisai, Calithera Biosciences, and Rexahn Pharmaceuticals, outside of the submitted work. A Italiano, Advisory: Bayer, Daiichi Sankyo, Merck, Roche, and Springworks; Grants: Bayer, Chugai, Pharmamar, MSD, Roche, and Merck. K Benhardji, Patents: LY3039478 related pat- ents; S Pant, Advisory and Consulting: Tyme, Inc., 4D-Pharma, Xencor, Ipsen; Principal/Sub-Investigator for Clinical Trials: Arcus, Arqule, Bristol-Myers Squibb, Eli Lilly and Company, Five Prime Therapeutics, Glaxo Smith Kline, Holy Stone Healthcare Co., Tyme, Inc., Ipsen, Mirati Therapeutics, Inc., Novartis, Onco Response, Red Hill Biopharma, Ltd., Rgenix, Sanofi-Aventis, Xencor, Astellas, and Janssen, outside of submitted work. B Anderson, E Yuen, D Yu, G Oakley III, and KA Benhadji are current or past employees of Eli Lilly and Company and may hold company stocks. B Anderson is an employee of PRA Health Sciences and K Benhadji is an employee of Taiho Oncology, and may hold company stocks.

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