Abstract P1-10-05: ICEC0942, a new oral selective inhibitor of the cell cycle and transcriptional regulator CDK7 for the treatment of estrogen receptor positive and negative breast cancer

CDK7 is remarkable as a key regulator of both cell cycle progression and gene expression. CDK7 promotes cell cycle progression by phosphorylating cell cycle CDKs in the T-loop, thus stimulating their activities. Additionally, phosphorylation of RNA polymerase II (PolII) by CDK7 is required for transcription initiation. Deregulation of cell cycle and transcription processes is common to most cancer types, so CDK7 inhibitors offer considerable promise as cancer therapeutics.

We previously reported the identification of the first selective CDK7 inhibitor, BS-181, and demonstrated its ability to inhibit breast cancer cell growth in vitro and in vivo (Ali et al 2009 Cancer Res). Screening of more than one thousand analogues has allowed development of a clinical candidate CDK7 inhibitor, named ICEC0942. ICEC0942 selectively inhibits CDK7 with an IC50 of 40nM. In vitro analyses reveal that ICEC0942 inhibits hormone receptor positive and triple-negative breast cancer cell lines, with GI50 values ranging between 0.2-0.3 μM. Growth inhibition is accompanied by inhibition of CDK7 targets, including CDK1, CDK2 and PolII phosphorylation. In xenograft studies using several cancer cell lines, the drug shows substantial anti-tumor effects, with a notable lack of toxicity at efficacious doses. In the combination setting with tamoxifen, ICEC0942 completely blocks growth of ER-positive tumor xenografts, indicative of potential for co-treatment with hormonal agents.

Extensive ADMET and PK/PD studies confirm the suitability of ICEC0942 as a cancer drug and have shown that ICEC0942 is orally bioavailable. Moreover, xenograft tumor studies have allowed definition of surrogate biomarkers of tumor response.

Taken together, our findings confirm CDK7 as an important drug target for ER-positive and -negative breast cancer and identify ICEC0942 as a prototype drug with utility as a single agent or in the combination setting. Our findings also point to the potential value of CDK7 inhibition by ICEC0942 in other cancer types that have characteristics of transcription factor addiction and/or cell cycle deregulation.

Development of ICEC0942 was made possible through funding by EPSRC, Cancer Research UK and Cancer Research Technologies.

Citation Format: Ali S, Patel H, Periyasamy M, Sava G, Bondke A, Slafer BW, Kroll SHB, Barbazanges M, Starkey R, Ottaviani S, Harrod A, Aboagye EO, Buluwela L, Fuchter MJ, Barrett AGM, Coombes RC. ICEC0942, a new oral selective inhibitor of the cell cycle and transcriptional regulator CDK7 for the treatment of estrogen receptor positive and negative 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 P1-10-05.

Patient phenotypes in fibromyalgia comorbid with systemic sclerosis or rheumatoid arthritis: influence of diagnostic and screening tests. Screening with the FiRST questionnaire, diagnosis with the ACR 1990 and revised ACR 2010 criteria

OBJECTIVES

Fibromyalgia (FM) may occur with rheumatoid arthritis (RA) and systemic sclerosis (SSc), and debate remains about its diagnosis. We aimed to use three FM tools (a screening tool (FiRST), diagnostic criteria (ACR 1990 and revised 2010), to compare FM prevalence between RA and SSc patients, to describe the phenotypes of patients with comorbid FM, and to analyze links between FM and secondary Sjögren's syndrome (SS).

METHODS

Consecutive adult patients with confirmed RA or SSc from four university hospitals were tested with the three FM tools.

RESULTS

FiRST detected FM in 22.6% of the 172 RA patients, with confirmation in 22.1% (ACR1990) and 19.1% (ACR2010). ACR1990FM+ RA patients had more diffuse pain, whereas ACR2010FM+ RA patients had higher BMI and pain intensity, more diffuse pain, active disease, disability, and associated SS. FiRST detected FM in 27.8% of the 122 SSc patients, with confirmation in 30.3% (ACR1990) and 23.7% (ACR2010). ACR1990FM+ SSc patients had greater disability and pain intensity, and more diffuse pain, whereas ACR2010FM+ SSc patients had higher BMI, pain intensity, more disability and diffuse pain, and associated SS. Correlations between FM diagnostic and screening tool results were modest in both conditions. Secondary SS was associated with comorbid FM.

CONCLUSIONS

The prevalence of FM is high in SSc and RA, whatever the FM diagnostic tool used. Secondary SS is associated with FM in both RA and SSc. The revised ACR 2010 FM criteria and FiRST screening tool reveal specific phenotypes potentially useful for improving disease management.

Tocilizumab for refractory organising pneumonia associated with Sjögren's disease

Lung involvement in primary Sjögren syndrome occurs in approximately 10-20% of patients. Tocilizumab, an anti-interleukin-6 receptor antibody, has demonstrated efficacy and safety in small series of systemic sclerosis, and systemic lupus erythematosus, but its effect on interstitial lung manifestations of connective tissue diseases is not well known. We report the use of tocilizumab in a refractory organising pneumonia associated with Sjögren's disease. Our observation suggests that tocilizumab could be an alternative therapeutic in refractory organising pneumonia.