SELLAS Life Sciences Group, Inc. Shareholder Update Call

Sciences Group, Inc.

Life Sciences Group, Inc. - Shareholder Update Call, June 3, 2021

C O R P O R A T E P A R T I

Allison Soss, Investor Relations

Dr. Angelos Stergiou, Founder,

President & Chief Executive Officer

C O N F E R E N C E C A L L

P A R T I C I P A N T S

Jason McCarthy, Maxim Group

Jim Malloy (phon), Alliance Global Partners

P R E S E N T A T I O N

Greetings and welcome to the SELLAS Life Sciences

Group Shareholder Update Call.

As a reminder, this conference is being recorded.

I would now like to turn the conference over to

your host, Ms. Allison Soss, Investor Relations for SELLAS Life Sciences Group. Thank you. You may begin.

Thank you, Melissa. Good morning, everyone, and

welcome to the SELLAS' Shareholder Update call.

Before we begin, I would like to remind you

that SELLAS will be making statements on today's call relating to the future expectations regarding the further development of and regulatory

plans for GPS, its plans for NPS, the Company's financials, its discussions with potential partners and its corporate strategy. These

statements constitute forward-looking statements for purposes of the Safe Harbor provisions under the Private Securities Litigation Reform

Act of 1995 and, by their nature, involve estimates, projections, goals, forecasts and assumptions and are subject to risks and uncertainties,

which include, without limitation, risks and uncertainties associated with the COVID-19 pandemic and its impact on the Company's clinical

plans, risks and uncertainties associated with the immunotherapy product development and clinical success thereof, the uncertainties of

regulatory approval, and other risks and uncertainties affecting SELLAS and its development programs that could cause actual results or

outcomes to differ materially from those expressed in the forward-looking statements.

These forward-looking statements speak only as

of the date of this conference call and should not be relied upon as predictions for future events. While SELLAS may elect to update these

forward-looking statements at some point in the future, the Company disclaims any obligation to do so, even if the Company's views change.

Additional information about the material factors and assumptions forming the basis of the forward-looking statements and risk factors

can be found under the caption, "Risk Factors," and SELLAS' annual report on Form 10-K filed on March 23, 2021 and

in its other SEC filings.

has made considerable efforts to provide an accurate transcription. There may be material errors, omissions, or inaccuracies in the reporting

of the substance of the conference call. This transcript is being made available for information purposes only.

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Life Sciences Group, Inc. - Shareholder Update Call, June 3, 2021

With that, I would like to turn the call

over to Angelos Stergiou, President and Chief Executive Officer of SELLAS. Angelos?

Dr. Angelos Stergiou

Thanks, Allison, and thank you, everyone, for

joining us today on our shareholder update call.

First, I would like to thank each and every

one of you, our shareholders, for your support and trust bestowed upon our Management team and our Company. I'm particularly grateful

and pleased to report that despite COVID-19 we remain clear in our mission and vision to develop and deliver complex and innovative treatments

for patients battling cancer. We're a small team but an experienced team that is dedicated and committed to seeing our lead clinical candidate,

galinpepimut-S, or GPS, through development so that it may one day make a difference in patients' lives.

I will provide some background for today's call

and will mainly focus on updates as they relate to clinical development, business development, commercial strategy and our financial position.

Of interest, we triggered an additional $1 million

milestone payment from our 3D Medicines licensing agreement just last week, which we expect to receive this month. As we have previously

stated, we expect to provide further clinical data in two studies, specifically in GPS combination with checkpoint inhibitors in ovarian

cancer and mesothelioma this month.

As you may be aware, in December 2018, we

entered into a clinical collaboration and supply agreement with Merck & Co. As it relates to the ovarian cancer GPS, pembrolizumab

study, we'll provide a further clinical data update, as I just mentioned, this month on this study once we have reviewed and assessed

data with our partner, Merck.

Before diving into the update, I'd like to

provide a brief introduction to SELLAS. A meet-and-greet, if you will.

The name SELLAS is derived from an ancient Greek

word that means truth and wisdom. Through clinical research and development, we believe we can gain the insight and wisdom necessary to

successfully navigate the drug approval process. Our core mission is to prolong patients' lives.

I've been working in the biotechnology sector

for two decades now and have personally been actively involved in the immunotherapy and cancer vaccine space for the past 15 years. Prior

to founding SELLAS Life Sciences about 10 years ago, I helped develop, among others, one of the first cancer vaccines for lymphoma.

SELLAS is comprised of a highly experienced Management

team with strong oncology backgrounds. We are also fortunate to have a Board of Directors comprised of highly seasoned pharma, biotech,

science and finance professionals who support and guide our Company.

Lastly, our Scientific Advisory Board consists

of truly eminent pioneers in the fields of cancer immunotherapy, chaired by Dr. Jeffrey Weber, a renowned specialist in immunotherapy.

We licensed GPS in 2014 from one of the world's

most renowned oncology centers and world-class laboratories at Memorial Sloan Kettering Cancer Center, specifically David Scheinberg's

lab in New York. Dr. Scheinberg is one of our Board Members.

has made considerable efforts to provide an accurate transcription. There may be material errors, omissions, or inaccuracies in the reporting

of the substance of the conference call. This transcript is being made available for information purposes only.

1-888-562-0262 1-604-929-1352 www.viavid.com

Life Sciences Group, Inc. - Shareholder Update Call, June 3, 2021

GPS is a novel therapeutic cancer vaccine that

targets the Wilms tumor, or WT1 antigen, the number one ranked cancer antigen by the National Cancer Institute, which is present and overexpressed

in about 20 tumor types, including hematological malignancies and solid tumors. GPS is a mixture of engineered and artificially mutated

peptides, i.e., the heteroclitic technology concept, and addresses 25 WT1 optimally selected epitopes. GPS has been shown in clinical

trials to elicit CD4, CD8 immune responses across the majority of HLA types.

We believe that GPS has the potential to target

and destroy recurring tumor and residual cancer cells and to provide treatment for multiple indications to help cancer patients stay in

remission and live longer, with tolerable side effects. It is our belief that when a patient is treated with GPS the immune system is

basically given a picture of what the WT1 expressing malignant cancer cells look like and when they reappear the cytotoxic CD8 and CD4

helper and memory cells can be activated to fight off the cancerous cells which translates to survival benefit.

When we licensed in GPS and to prepare for commercialization,

we reformulated the drug product from a liquid solution into a lyophilized powder product, resulting in a more efficient manufacturing

process. A lyophilized product is also more desirable than a liquid from a supply chain perspective. We introduced technical nuances in

the formulation and manufacturing, the result of which allows doctors to mix the vial of the lyophilized GPS product with saline and introduce

it via subcutaneous injection for an easy and quick administration.

We are encouraged by the data seen to date in

the studies for GPS and we're very excited about the prospects for the GPS programs, both as a monotherapy and in combination with PD-1

inhibitors. Our current development program is focused on our registrational Phase 3 REGAL study of GPS as monotherapy in acute myeloid

leukemia, or AML, patients in second complete remission, as well as two earlier stage studies of GPS in combination with PD-1 inhibitors.

As for AML, the annual incidence rate of AML,

a debilitating disease, is around 80,000 patients in the U.S., EU, Japan and China. We estimate that approximately 15% of all new patients

with an AML diagnosis eventually are eligible for study entry per annum, and this also represents a total addressable market in this AML

In our previous Phase 2 study, in the same patient