Cullinan Pearl Announces Presentation of Preliminary Safety and Efficacy of CLN-081 in EGFR Exon 20 NSCLC Patients at ESMO Virtual Congress 2020

Cullinan Pearl, a Cullinan Oncology company, today announced that an abstract detailing the ongoing Phase 1/2a clinical trial evaluating CLN-081 for the treatment of EGFR exon 20 insertion mutant non-small cell lung cancer (NSCLC) will be presented as a poster presentation at the ESMO Virtual Congress 2020.

Poster Title: Preliminary Safety and Activity of CLN-081 in NSCLC with EGFR Exon 20 Insertion Mutations (Ins20)
Abstract Number: 2133
Poster Number: 1345P
Session Date & Time: From 09:00 Thursday, 17 September 2020 until 20:00 Monday, 21 September 2020.

The poster presentation will summarize the initial Phase 1 experience with CLN-081 up to the data cutoff of September 1, 2020, including data on 22 patients treated at dose levels ranging from 30-150 mg administered orally twice daily. CLN-081 demonstrated acceptable safety, with no dose-limiting toxicities (DLT) and no Grade 3 or greater drug-related adverse events. The most common drug-related adverse events included rash and dry skin, with only one case of Grade 1 drug-related diarrhea being observed.

In this group of heavily pretreated patients with EGFR exon-20 mutant NSCLC (over 80% with 2 or more prior lines of systemic therapy), encouraging preliminary antitumor activity was observed across multiple dose levels, including the initial dose level of 30 mg twice daily. Of the initial 22 patients, 17 were evaluable for objective response at the time of data cutoff, and 5 had not yet reached their initial scan. Of the 17 response evaluable patients, 6 experienced an objective response, including 2 patients with a confirmed partial response, 3 patients with ongoing partial responses not yet reaching a confirmatory scan, and 1 with an unconfirmed partial response. Among the 11 remaining response evaluable patients with a best response of stable disease, the change in target lesions ranged from +3% to -21%. Of these 11 patients, 9 patients remained on treatment with stable disease at the data cutoff.

Commenting on the preliminary data, Jon Wigginton, Cullinan Oncology's Chief Medical Officer (CMO) stated, "We are encouraged with CLN-081's initial safety and efficacy data in this very difficult to treat patient population, with antitumor activity across a broad range of doses tested to date and an acceptable safety profile. Guided by this data, we look forward to defining the recommended phase 2 dose of CLN-081, and initiating discussions with regulators regarding the future clinical development path for the program."

The accepted abstract is now available on the ESMO conference website HERE. The poster can be viewed on the Cullinan Oncology website HERE.

Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Such forward-looking statements include those regarding the potential benefits of CLN-081; Cullinan Pearl's plans regarding future data presentations; and the potential benefit of its strategic plans and focus. The words "anticipate," "expect," "intend," "potential," "milestone," "goal," "will," "on track," "upcoming," and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Such statements are subject to numerous important factors, risks and uncertainties that may cause actual events or results to differ materially from Cullinan's current expectations and beliefs. For example, there can be no guarantee that any product candidate Cullinan Pearl is developing will successfully commence or complete necessary preclinical and clinical development phases, or that development of any of Cullinan Pearl's product candidates will successfully continue. Management's expectations and, therefore, any forward-looking statements in this press release could also be affected by risks and uncertainties relating to a number of other important factors, including: results of clinical trials and preclinical studies, including subsequent analysis of existing data and new data received from ongoing and future studies; the content and timing of decisions made by the U.S. FDA and other regulatory authorities, investigational review boards at clinical trial sites and publication review bodies; Cullinan Pearl's' ability to obtain and maintain requisite regulatory approvals and to enroll patients in its planned clinical trials; unplanned cash requirements and expenditures; competitive factors; Cullinan Pearl's ability to obtain, maintain and enforce patent and other intellectual property protection for any product candidates it is developing; Any forward-looking statements contained in this press release speak only as of the date hereof, and Cullinan Pearl expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

About Cullinan Oncology LLC

Cullinan Oncology was formed to develop a diversified portfolio of highly promising single asset oncology opportunities through both internal and external means and to do so in a unique, cost-efficient model that leverages a central management team and shared services model to drive speed and efficiency. For additional information, please visit www.cullinanoncology.com.