NuCana Announces Promising Clinical Data at ASCO GI on NUC-1031 (Acelarin ) as Front-Line Treatment of Advanced Biliary Tract Cancer NuCana Planning to Initiate a Phase 3 Study of Acelarin in Front-Line Advanced Biliary

NuCana Announces Promising Clinical Data at ASCO GI on NUC-1031 (Acelarin ) as Front-Line Treatment of Advanced Biliary Tract Cancer

to Initiate a Phase 3 Study of Acelarin in Front-Line Advanced Biliary Tract Cancer

Edinburgh, United Kingdom, January 19, 2018 (GLOBE

NEWSWIRE) NuCana plc (NASDAQ: NCNA) announced interim results today from the ABC-08 Study at the 2018 ASCO Gastrointestinal Cancer Symposium (ASCO GI) in San Francisco, CA. This analysis of the Phase 1b

multi-center, open-label study showed that Acelarin, when combined with cisplatin, achieved high response rates and was well-tolerated in front-line advanced biliary tract cancer.

Eight patients with advanced biliary tract cancer received Acelarin (625mg/m2) and cisplatin (25mg/m2) on days one and eight of a three-week cycle. A Complete Radiological Response was achieved in one patient, a Partial Response in three patients, and Stable Disease in one patient, resulting in an

Objective Response Rate of 50% and a Disease Control Rate of 63% on an intent-to-treat basis. Additionally, the one patient with Stable Disease, whose cancer initially

had been considered unsuitable for surgical resection, went on to have surgery to remove the tumor completely. Two of the eight patients received only one cycle or less of therapy due to complications unrelated to either Acelarin or cisplatin, so

the Objective Response Rate in those patients who received adequate treatment was 67%.

Although this is only an interim analysis in a small number

of patients, these data are very encouraging and suggest that the combination of Acelarin and cisplatin could represent a significant advance in the treatment of advanced biliary tract cancer, a devastating disease for which there are no approved

medicines, remarked Professor Juan Valle, Co-Chief Investigator of the ABC-08 Study and Professor and Honorary Consultant in Medical Oncology at the University of

Manchester and The Christie, Manchester, United Kingdom.

Dr. Mair ad McNamara, Co-Chief Investigator

of the ABC-08 Study and Senior Lecturer and Honorary Consultant in Medical Oncology at the University of Manchester and The Christie, added, In addition to the high response rate, it was noteworthy that

this combination achieved a Complete Response and the patient with Stable Disease went on to have surgical resection. Both outcomes are very uncommon in this setting.

Additionally, the combination of Acelarin and cisplatin was well-tolerated with no unexpected adverse events and no dose-limiting toxicities.

Based on the high response rates and favorable safety profile seen in cohort 1, the Trial Management Group determined that Acelarin at 625mg/m2 with cisplatin at 25mg/m2 was the optimal combination. Professor Valle and his co-investigators had

previously established the current standard of care for the front-line treatment of patients with advanced biliary tract cancer in the ABC-02 study that was published in the New England Journal of Medicine in

2010. Professor Valle added, Since ABC-02, there have not been any studies that have demonstrated an improvement in overall survival in the front-line treatment of patients with advanced biliary tract

cancer; there is an urgent need for new therapies for our patients.

A comparison of the data from the ABC-08 and ABC-02 studies is provided in the following table:

Hugh S. Griffith, NuCana s Chief Executive

Officer, said: We are excited by the exceptional results achieved so early in this study. Consistent with our strategy of rapidly advancing our new medicines in multiple cancer types, and based on the results of this study, we plan to initiate

a pivotal study of Acelarin and cisplatin in front-line advanced biliary tract cancer in 2018.

NuCana is a clinical-stage biopharmaceutical company focused on significantly improving treatment

outcomes for cancer patients by applying our ProTide technology to transform some of the most widely prescribed chemotherapy agents, nucleoside analogs, into more effective and safer medicines. While these conventional agents remain part of

the standard of care for the treatment of many solid tumors, their efficacy is limited by cancer cell resistance mechanisms and they are often poorly tolerated. Utilizing our proprietary technology, we are developing new medicines, ProTides,

designed to overcome key cancer resistance mechanisms and generate much higher concentrations of anti-cancer metabolites in cancer cells.

advanced ProTide candidates, Acelarin and NUC-3373, are new chemical entities derived from the nucleoside analogs gemcitabine and 5-fluorouracil, respectively, two widely used chemotherapy agents. Acelarin is currently being evaluated in three clinical studies for patients with ovarian cancer, biliary cancer and pancreatic cancer. NUC-3373 is currently in a Phase 1 study for the potential treatment of a wide range of advanced solid tumors.

For more information, please visit: www.nucana.com.

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