Cullinan Oncology Provides Corporate Update and Reports First Quarter 2022 Financial Results Announced U.S. co-development and co-commercialization agreement for CLN-081 with Taiho Pharmaceutical; updated CLN-081 data ac

Cullinan Oncology Provides Corporate Update and

Reports First Quarter 2022 Financial Results

Announced U.S. co-development and co-commercialization agreement for CLN-081 with Taiho Pharmaceutical; updated CLN-081 data accepted for oral presentation at the American Society for Clinical Oncology (ASCO) meeting in June

CLN-049 and CLN-619 Phase I dosing continues with initial clinical data on

track for mid-2023; CLN-081 and CLN-978 IND submissions on track for 1H 2023

Cash of $685 million1, including upfront payment for the Taiho collaboration, provides expected

runway through 2026.

Cambridge, MA, May 16, 2022 Cullinan Oncology, Inc. (Nasdaq: CGEM), a biopharmaceutical company

focused on developing a diversified pipeline of targeted therapies for patients with cancer, today reported on recent and upcoming business highlights and announced its financial results for the first quarter ended March 31, 2022.

We made excellent progress in the first quarter of 2022, substantially advancing our lead asset, CLN-081, and

continuing to progress our diversified pipeline, said Nadim Ahmed, Chief Executive Officer of Cullinan Oncology. Our March clinical and regulatory update for CLN-081 further affirmed its

differentiated profile, and we are looking forward to sharing an additional clinical update in an oral presentation at the upcoming ASCO meeting. We also announced a U.S. co-development and co-commercialization agreement for CLN-081 with Taiho, the original innovators of the molecule, and an ideal partner with whom to advance this asset into later stage

development and commercialization. The proceeds from this transaction will also allow us to accelerate and expand the development of our diverse pipeline as well as discover and obtain promising new oncology therapeutic candidates.

Mr. Ahmed continued, We are also pleased to continue the progression of our pipeline programs. Dosing in the Phase I trials of CLN-619 and CLN-049 was initiated in December 2021 and the studies are continuing on track to deliver initial data readouts by

mid-2023. We are also on track to file INDs for two additional programs, CLN-617 and CLN-978, in the first half of next year.

Importantly, we are in an even stronger financial position to continue advancing our strategically built pipeline of diversified assets, each with the potential to be the first or best in their class. We ended the first quarter of 2022 with

approximately $410 million in cash and investments2, which, when added to proceeds from the Taiho deal, aggregates to $685 million, and extends our cash runway through 2026.

Portfolio Highlights

First Quarter 2022 Financial

About Cullinan Oncology

Cullinan Oncology, Inc.(NASDAQ: CGEM) is a biopharmaceutical company dedicated to creating new standards of care for patients with cancer. We innovate without

borders to find the most promising clinic-ready cancer therapies, whether from our own discovery efforts or through exceptional engagement with our academic and industry partners. Anchored in a deep understanding of immuno-oncology and translational

cancer medicine, we leverage our scientific excellence in small molecules and biologics to create differentiated ideas, identify unique targets, and select the optimal modality to develop transformative therapeutics across cancer indications.

Powered by our novel research model, we push conventional boundaries from candidate selection to cancer therapeutic, applying rigorous early experimentation to fast-track only the most promising assets to the clinic and ultimately commercialization.

As a result, our diversified pipeline is strategically built with assets that activate the immune system or inhibit key oncogenic drivers across a wide range of modalities, each with the potential to be the best or first in their class.

Our people possess deep scientific expertise, seek innovation openly, and exercise creativity and urgency to deliver on our promise to bring new therapeutic

Forward-Looking Statements

This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. These forward-looking

statements include, but are not limited to, express or implied statements regarding Cullinan s beliefs and expectations regarding our preclinical and clinical development plans, clinical trial designs, clinical and therapeutic potential, and

strategy of our product candidates; our ability to evaluate strategic opportunities to accelerate development timelines; the presentation of additional data at upcoming scientific conferences in 2022; our ability to optimize the impact of our

collaborations and license agreements with external parties; our ability to continue our growth; and our expectations regarding our use of capital. The words anticipate, believe, continue, could,

estimate, expect, hope, intend, may, plan, potential, predict, project, target, should, would, and

similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

forward-looking statements in this press release are based on management s current expectations and beliefs of future events and are subject to known and unknown risks and uncertainties that may cause our actual results, performance or

achievements to be materially different from any expressed or implied by the forward-looking statements. These risks include, but are not limited to, the following: uncertainty regarding the timing and results of regulatory submissions; success of

our clinical trials and preclinical studies; risks related to our ability to protect and maintain our intellectual property position; risks related to manufacturing, supply, and distribution of our product candidates; risks related to the impact of COVID-19 affecting countries or regions in which we have operations or do business, including potential negative impacts on our employees, customers, supply chain and production as well as global economies and

financial markets; the risk that any one or more of our product candidates, including those that are co-developed, will not be successfully developed and commercialized; the risk that the results of

preclinical studies or clinical studies will not be predictive of future results in connection with future studies; and success of any collaboration, partnership, license or similar agreements. These and other important risks and uncertainties

discussed in our filings with the Securities and Exchange Commission (SEC), including under the caption Risk Factors in our most recent Annual Report on Form 10-K and subsequent filings with the

SEC, could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any

obligation to do so, even if subsequent events cause our views to change, except to the extent required by law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date of this press

release. Moreover, except as required by law, neither Cullinan nor any other person assumes responsibility for the accuracy and completeness of the forward-looking statements included in this press release. Any forward-looking statement included in

this press release speaks only as of the date on which it was made.

Cullinan Oncology, Inc.

Condensed Consolidated Balance Sheets

(1)The condensed consolidated balance sheet as of the year ended December 31, 2021 is derived from the audited

consolidated financial statements as of that date.

Cullinan Oncology, Inc.

Consolidated Statements of Operations

(in thousands, except shares and per share amounts)