0001709401 false 0001709401 2021-03-15 2021-03-15 iso4217:USD xbrli:shares iso4217:USD xbrli:shares

 

 

 

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

 

 

 

FORM 8-K

 

 

 

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

 

Date of Report (Date of earliest event reported): March 15, 2021

 

 

 

RUBIUS THERAPEUTICS, INC.

(Exact name of registrant as specified in its charter)

 

 

 

Delaware   001-38586   46-2688109
(State or other jurisdiction
of Incorporation)  
  (Commission
File Number)
  (IRS Employer
Identification Number)  

 

399 Binney Street, Suite 300
Cambridge, MA
  02139
(Address of registrant’s principal executive office)  (Zip code)

 

(617) 679-9600

(Registrant’s telephone number, including area code)

 

N/A

(Former name or former address, if changed since last report)

 

 

 

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

 

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 203.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

 

 

 

Securities registered pursuant to Section 12(b) of the Act:

 

Title of each class Trading symbol(s) Name of each exchange on which registered
Common Stock, par value $0.001 per share RUBY The Nasdaq Global Select Market

 

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

 

Emerging growth company x

 

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

 

 

 

 

 

Item 8.01.  Other Events.

 

On March 15, 2021, Rubius Therapeutics, Inc. (the “Company”) announced initial clinical, pharmacodynamic and tumor trafficking data from its ongoing Phase 1/2 clinical trial of RTX-240 in patients with advanced solid tumors. The Company also shared tumor trafficking data from one patient with relapsed/refractory acute myeloid leukemia (AML) in the second Phase 1 arm of the study. The Company believes these data provide initial proof-of-concept of the RED PLATFORM® by providing evidence that red blood cells can be engineered to mimic the human immune system and stimulate adaptive and innate immunity to generate clinical responses in cancer patients with refractory disease.

 

Initial Efficacy Data

 

Five (5) dose cohorts were completed in the solid tumor trial at the time of the data cutoff on February 28, 2021 (n=16), with 16 patients evaluable for safety (primary outcome measure) and 15 patients evaluable for efficacy (secondary outcome measure) based on RECIST v1.1.

 

The study is continuing to enroll patients and despite the fact that dose optimization is still ongoing, RTX-240 generated:

 

·A confirmed partial response (PR) with a 54% reduction in the target lesions at the 1e8 dose administered every 4 weeks in a patient with metastatic anal cancer whose disease had progressed on anti-PD-L1 therapy. Treatment of this patient was ongoing 8 months following the first dose at data cutoff;
·An unconfirmed PR with complete resolution of the target hepatic lesion and resolution of 14/15 hepatic lesions at the 1e10 dose administered every 4 weeks in a patient with metastatic uveal melanoma whose disease had progressed on anti-PD-1 therapy; Treatment of this patient was ongoing 4 months following the first dose at data cutoff; and
·Stable disease (SD) was observed in 6 patients, including 4 individual patients with stable disease for at least 12 weeks:
oNon-small cell lung cancer (disease stabilization for 12 weeks with treatment ongoing as of the data cutoff);
oSoft tissue sarcoma (disease stabilization for 4 months);
oPancreatic cancer (disease stabilization for 3 months); and
oProstate cancer (disease stabilization for 4 months).

 

Initial Safety Data

 

The most common treatment-related Grade 1/2 adverse events were fatigue (n=4), chills, nausea, decreased appetite and arthralgias all reported in 3 patients each. There were no treatment-related Grade 3/4 adverse events, no dose-limiting toxicities and a single Grade 1 event of liver toxicity.

 

Ten (10) immune-related adverse events (irAE) were observed among 5 patients with no reported treatment-related Grade 3/4 irAEs. Grade 2 treatment-related irAEs included pneumonitis (n=1), adrenal insufficiency (n=1) and hypothyroidism (n=1).

 

 

 

 

Pharmacodynamic Data

 

In addition to evaluating safety and preliminary efficacy data, the trial is evaluating the pharmacodynamic effects of RTX-240:

 

·RTX-240 stimulated innate and adaptive immunity as demonstrated by the activation and/or expansion of NK or memory CD8+ T cells in all patients, with 9/16 patients showing activation and expansion in both cell types. There was an overall trend towards a dose response in absolute NK cell numbers (expansion);
·Detailed NK cell analysis showed an increased percentage of CD16+CD56dim (mature NK cells) and CD56bright (immature NK cells) across dose levels
oThese cell subtypes are associated with cytotoxicity and cytokine production respectively; and
·RTX-240 induced expression of key NK cell activation receptors, including NKp30 and the ratio of cells expressing the activation receptor NKG2D versus the inhibitory receptor NKG2A.
oThis specific signature of NK cell receptor expression may allow selection of specific tumor types with predicted sensitivity to RTX-240.

 

Tumor Infiltration Data

 

Immune cell trafficking into the tumor microenvironment (TME) was assessed by tumor biopsies from participating patients with solid tumors (optional; n=4) and AML (standard of care; n=1).

 

·Trafficking of T and NK cells into the TME was observed in 3/5 patients (1.6 to 10-fold increases), including one patient each with metastatic mesothelioma, metastatic soft tissue sarcoma and refractory AML. Tumor infiltration was not observed in patients with ovarian cancer (n=1) and heavily pretreated melanoma (n=1);
·There was increased expression of PD-L1 observed in 3/4 patients with solid tumors, suggesting an improved immune-permissive TME; and
·In one patient with AML, trafficking of T and NK cells into the bone marrow was associated with increases in the cellularity of the marrow.

 

 

 

 

A copy of the press release issued in connection with the announcement is being furnished as Exhibit 99.1 to this Current Report on Form 8-K. A copy of the Company’s presentation to be shared with investors and others from time to time in connection with today’s announcement is filed as Exhibit 99.2 to this Current Report on Form 8-K and is incorporated by reference herein.

 

The information in Exhibit 99.1 attached hereto is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended or the Exchange Act, except as expressly set forth by specific reference in such filing. 

 

Forward Looking Statements

 

This report contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding the Company’s expectations with respect to the therapeutic potential of its pipeline of Red Cell Therapeutics, including RTX-240, its expectations regarding the timing, enrollment, data from and success of the future cohorts and phases of the clinical trial of RTX-240, including the Phase 1/2 clinical trial of RTX-240, its plans to initiate a RTX-240 Phase 2 expansion cohort, an RTX-240 Phase 1 clinical trial in combination with an anti-PD-1 therapy in advanced solid tumors and file an Investigational New Drug application for RTX-224 over the next twelve months, its expectations regarding the biological effects of RTX-240 on innate and adaptive immunity and the related therapeutic benefits, its expectations regarding the initial preliminary data from RTX-240 and the related therapeutic benefits and validation of its RED PLATFORM and its expectations regarding its strategy, business plans and focus. The words “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “target” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this report are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this report, including, without limitation, those risks and uncertainties related to the development of the Company’s Red Cell Therapeutic product candidates and their therapeutic potential and other risks identified in the Company’s SEC filings, including its Annual Report on Form 10-K for the year ended December 31, 2020, and subsequent filings with the SEC and risks and uncertainties related to the severity and duration of the impact of COVID-19 on our clinical trials, business and operations. We caution you not to place undue reliance on any forward-looking statements, which speak only as of the date they are made. We disclaim any obligation to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements. Any forward-looking statements contained in this report release represent our views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. We explicitly disclaim any obligation to update any forward-looking statements.

 

 

 

 

Item 9.01.  Financial Statements and Exhibits.

 

(d) Exhibits.

 

Exhibit
No.
  Description
99.1   Press Release issued by Rubius Therapeutics, Inc. on March 15, 2021, furnished herewith.
99.2   Presentation of Rubius Therapeutics, Inc., dated March 15, 2021, filed herewith.
104   Cover Page Interactive Data File (embedded within the Inline XBRL document).

 

 

 

 

SIGNATURES

 

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. 

 

Date: March 15, 2021 RUBIUS THERAPEUTICS, INC.  
   
  By:  /s/ Jose Carmona  
    Jose Carmona
    Chief Financial Officer

  

 

 

 

Exhibit 99.1

 

 

Rubius Therapeutics Reports Initial Clinical Data from Ongoing Phase 1/2 Trial of
RTX-240 in Patients with Advanced Solid Tumors, Demonstrating Single-Agent Activity

 

RTX-240 Generated Partial Responses in Metastatic Anal Cancer and Metastatic Uveal
Melanoma Patients; No DLTs or Related Grade 3/4 Adverse Events

 

RTX-240 Promoted Trafficking of NK and T Cells into

Tumor Microenvironment

 

Initial Clinical Data Provide Evidence of Broad Potential of RED PLATFORM® Across
Pipeline of Cancer and Autoimmune Programs

 

Company to Host Conference Call Today at 8:00 a.m. EDT

 

CAMBRIDGE, Mass., March 15, 2021 (GLOBE NEWSWIRE) -- Rubius Therapeutics, Inc. (Nasdaq:RUBY), a clinical-stage biopharmaceutical company that is genetically engineering red blood cells to create an entirely new class of cellular medicines called Red Cell Therapeutics™, today announced initial clinical, pharmacodynamic and tumor trafficking data from its ongoing Phase 1/2 clinical trial of RTX-240 in patients with advanced solid tumors. The Company also shared tumor trafficking data from one patient with relapsed/refractory acute myeloid leukemia (AML) in the second Phase 1 arm of the study. The Company believes these data provide initial proof-of-concept of the RED PLATFORM® by providing evidence that red blood cells can be engineered to mimic the human immune system and stimulate adaptive and innate immunity to generate clinical responses in cancer patients with refractory disease.

 

“These initial data are incredibly exciting and demonstrate that RTX-240 has the potential to generate single-agent activity in patients with solid tumors, including a cold tumor such as metastatic uveal melanoma, where other treatments have failed to induce responses in patients,” said Christina Coughlin, M.D., Ph.D., chief medical officer at Rubius Therapeutics. “The encouraging safety results, including a single event of Grade 1 liver toxicity, and preliminary efficacy data for RTX-240 to date give us the potential to realize the power of immune agonists for the treatment of cancer.”

 

Initial Efficacy Data

 

Five (5) dose cohorts were completed in the solid tumor trial at the time of the data cutoff on February 28, 2021 (n=16), with 16 patients evaluable for safety (primary outcome measure) and 15 patients evaluable for efficacy (secondary outcome measure) based on RECIST v1.1.

 

 

 

 

The study is continuing to enroll patients and despite the fact that dose optimization is still ongoing, RTX-240 generated:

·A confirmed partial response (PR) with a 54% reduction in the target lesions at the 1e8 dose administered every 4 weeks in a patient with metastatic anal cancer whose disease had progressed on anti-PD-L1 therapy. Treatment of this patient was ongoing 8 months following the first dose at data cutoff;
·An unconfirmed PR with complete resolution of the target hepatic lesion and resolution of 14/15 hepatic lesions at the 1e10 dose administered every 4 weeks in a patient with metastatic uveal melanoma whose disease had progressed on anti-PD-1 therapy; Treatment of this patient was ongoing 4 months following the first dose at data cutoff; and
·Stable disease (SD) was observed in 6 patients, including 4 individual patients with stable disease for at least 12 weeks:
o Non-small cell lung cancer (disease stabilization for 12 weeks with treatment ongoing as of the data cutoff);
o Soft tissue sarcoma (disease stabilization for 4 months);
o Pancreatic cancer (disease stabilization for 3 months); and
o Prostate cancer (disease stabilization for 4 months).

 

“We believe these data provide clinical validation of our RED PLATFORM® and de-risk our oncology pipeline of Red Cell Therapeutics,” said Pablo J. Cagnoni, M.D., president and chief executive officer. “Given the encouraging initial safety and preliminary efficacy data for RTX-240, we plan to initiate a Phase 2 expansion cohort in the first quarter of 2022, and a new Phase 1 arm of the ongoing RTX-240 clinical trial to evaluate RTX-240 in combination with anti-PD-1 therapy in patients with advanced solid tumors during the second half of 2021.”

 

Initial Safety Data

 

The most common treatment-related Grade 1/2 adverse events were fatigue (n=4), chills, nausea, decreased appetite and arthralgias all reported in 3 patients each. There were no treatment-related Grade 3/4 adverse events, no dose-limiting toxicities and a single Grade 1 event of liver toxicity.

 

Ten (10) immune-related adverse events (irAE) were observed among 5 patients with no reported treatment-related Grade 3/4 irAEs. Grade 2 treatment-related irAEs included pneumonitis (n=1), adrenal insufficiency (n=1) and hypothyroidism (n=1).

 

Pharmacodynamic Data

 

In addition to evaluating safety and preliminary efficacy data, the trial is evaluating the pharmacodynamic effects of RTX-240:

 

 

 

 

·RTX-240 stimulated innate and adaptive immunity as demonstrated by the activation and/or expansion of NK or memory CD8+ T cells in all patients, with 9/16 patients showing activation and expansion in both cell types. There was an overall trend towards a dose response in absolute NK cell numbers (expansion);
·Detailed NK cell analysis showed an increased percentage of CD16+CD56dim (mature NK cells) and CD56bright (immature NK cells) across dose levels
o These cell subtypes are associated with cytotoxicity and cytokine production respectively; and
·RTX-240 induced expression of key NK cell activation receptors, including NKp30 and the ratio of cells expressing the activation receptor NKG2D versus the inhibitory receptor NKG2A.
o This specific signature of NK cell receptor expression may allow selection of specific tumor types with predicted sensitivity to RTX-240.

 

Tumor Infiltration Data

 

Immune cell trafficking into the tumor microenvironment (TME) was assessed by tumor biopsies from participating patients with solid tumors (optional; n=4) and AML (standard of care; n=1).

·Trafficking of T and NK cells into the TME was observed in 3/5 patients (1.6 to 10-fold increases), including one patient each with metastatic mesothelioma, metastatic soft tissue sarcoma and refractory AML. Tumor infiltration was not observed in patients with ovarian cancer (n=1) and heavily pretreated melanoma (n=1);
·There was increased expression of PD-L1 observed in 3/4 patients with solid tumors, suggesting an improved immune-permissive TME; and
·In one patient with AML, trafficking of T and NK cells into the bone marrow was associated with increases in the cellularity of the marrow.

 

Upcoming Anticipated Milestones

 

In order to realize the full potential of RTX-240, the Company’s other oncology programs and the RED PLATFORM, in the next 12 months, Rubius plans to execute several critical milestones:

·Present additional clinical results from the RTX-240 solid tumor Phase 1 clinical trial;
·Select the recommended RTX-240 Phase 2 dose, schedule and specific solid tumor types that will be pursued in the Phase 2 expansion cohort;
·Report initial clinical results for the second Phase 1 arm of the RTX-240 clinical trial in relapsed/refractory AML;

 

 

 

 

·Initiate the Phase 1 clinical trial of RTX-240 in combination with anti-PD-1 therapy in advanced solid tumors in 2H’21;
·Report initial Phase 1 clinical results for RTX-321 for the treatment of HPV 16-positive cancers by 1Q’22; and
·Submit an Investigational New Drug Application for RTX-224 by year-end.

 

Conference Call

 

The Company will host a conference call and webcast at 8:00 a.m. EDT to discuss this update. The audio webcast will be available on the Events and Presentations page within the Investors and Media section of the Rubius Therapeutics website. The update may also be accessed by dialing 1-800-289-0045 (domestic) or 1-615-622-8086 (international) five minutes prior to the start of the call and providing the passcode 1294064. An archived webcast will be accessible for 90 days after the event.

 

About RTX-240

 

RTX-240 is an allogeneic, off-the-shelf cellular therapy product candidate that is designed to simultaneously present hundreds of thousands of copies of the costimulatory molecule 4-1BB ligand (4-1BBL) and IL-15TP (trans-presentation of IL-15 on IL-15Rα) in their native forms. RTX-240 is expected to broadly stimulate the immune system by activating and expanding both NK and memory T cells to generate a potent anti-tumor response.

 

About the RTX-240 Clinical Trial

 

This is a Phase 1/2 open label, multicenter, multidose, first-in-human dose-escalation and expansion study designed to determine the safety and tolerability, pharmacokinetics, maximum tolerated dose and a recommended Phase 2 dose and dosing regimen of RTX-240 in adult patients with relapsed/refractory or locally advanced solid tumors or with relapsed/refractory acute myeloid leukemia. The trial will also assess the pharmacodynamics of RTX-240 measured by changes in T and NK cell number and function relative to baseline and anti-tumor activity. The study will include a monotherapy dose escalation phase followed by an expansion phase in specified tumor types during the Phase 2 portion of the trial. The extent to which the COVID-19 pandemic may impact Rubius’ ability to enroll patients in the trial will depend on future developments.

 

About RTX-321

 

RTX-321 is an allogeneic, off-the-shelf artifical antigen-presenting cell therapy product candidate that is designed to express hundreds of thousands of copies of an HPV peptide antigen bound to major histocompatibility complex class I proteins, the costimulatory molecule 4-1BBL and the cytokine IL-12 on the cell surface to mimic human T cell-APC interactions. In preclinical studies, RTX-321 was shown to have a dual mechanism of action by functioning as an antigen-presenting cell to boost HPV 16 antigen-specific T cell responses and promoting broad immune system stimulation of both innate and adaptive immunity.

 

 

 

 

About RTX-224

 

RTX-224 is an allogeneic cellular therapy product candidate that is engineered to express hundreds of thousands of copies of 4-1BBL and IL-12 on the cell surface. In contrast to RTX-240, RTX-224 is designed as a broader T cell- agonist, while also retaining the ability to activate and expand NK cells. It is expected to produce a broad and potent anti-tumor T cell response, an innate immune response and show activity in those tumor types with known sensitivity to T cell killing, including tumor types with high mutational burden, PD-L1 expression and prior activity of checkpoint inhibitors.

 

About Rubius Therapeutics

 

Rubius Therapeutics is a clinical-stage biopharmaceutical company developing a new class of medicines called Red Cell Therapeutics™. The Company’s proprietary RED PLATFORM® was designed to genetically engineer and culture Red Cell Therapeutics™ that are selective, potent and off-the-shelf allogeneic cellular therapies for the potential treatment of several diseases across multiple therapeutic areas. Rubius’ initial focus is to advance RCT™ product candidates for the treatment of cancer and autoimmune diseases by leveraging two distinct therapeutic modalities — potent cell-cell interaction and tolerance induction. Rubius Therapeutics was recently named among the Top Places to Work in Massachusetts by the Boston Globe, and its manufacturing site was recently named 2020 Top 5 Best Places to Work in Rhode Island among medium-sized companies by Providence Business News. For more information, visit www.rubiustx.com, follow us on Twitter or LinkedIn or like us on Facebook.

 

 

 

 

Forward Looking Statements

 

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding our expectations with respect to the therapeutic potential of our pipeline of Red Cell Therapeutics, including RTX-240, our expectations regarding the timing, enrollment, data from and success of the future cohorts and phases of the clinical trial of RTX-240, including the Phase 1/2 clinical trial of RTX-240, our plans to initiate a RTX-240 Phase 2 expansion cohort, an RTX- 240 Phase 1 clinical trial in combination with an anti-PD-1 therapy in advanced solid tumors and file an Investigational New Drug application for RTX-224 over the next twelve months, our expectations regarding the biological effects of RTX-240 on innate and adaptive immunity and the related therapeutic benefits, our expectations regarding the initial preliminary data from RTX-240 and the related therapeutic benefits and validation of our RED PLATFORM and our expectations regarding our strategy, business plans and focus. The words “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “target” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of risks, uncertainties and important factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, those risks and uncertainties related to the development of our Red Cell Therapeutic product candidates and their therapeutic potential and other risks identified in our SEC filings, including our Annual Report on Form 10-K for the year ended December 31, 2020, and subsequent filings with the SEC and risks and uncertainties related to the severity and duration of the impact of COVID-19 on our clinical trials, business and operations. We caution you not to place undue reliance on any forward-looking statements, which speak only as of the date they are made. We disclaim any obligation to publicly update or revise any such statements to reflect any change in expectations or in events, conditions or circumstances on which any such statements may be based, or that may affect the likelihood that actual results will differ from those set forth in the forward-looking statements. Any forward-looking statements contained in this press release represent our views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. We explicitly disclaim any obligation to update any forward-looking statements.

 

Contacts:

 

Investors

Elhan Webb, CFA, Vice President of Investor Relations

elhan.webb@rubiustx.com

 

Media

Marissa Hanify, Director, Corporate Communications

Marissa.hanify@rubiustx.com

 

Dan Budwick, 1AB

+1 (973) 271-6085

dan@1abmedia.com

 

 

 

Exhibit 99.2

REALIZING THE POWER OF RED™ A NEW ERA IN CELLULAR MEDICINEInitial Clinical Results from RTX-240 Phase 1 Clinical TrialMARCH 15, 2021 1

 
 

 

Forward-Looking StatementsThis presentation may contain forward-looking statements. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, our development plans, our clinical results and other future conditions. All statements other than statements of historical facts contained in this presentation, including statements regarding our future financial or business performance, conditions, plans, prospects, trends or strategies and other financial and business matters; our current and prospective product candidates, planned clinical trials and preclinical activities, including timing related to such trials and expected results, research and development costs, current and prospective collaborations; the estimated size of the market for our product candidates, the timing and success of our development and commercialization of our anticipated product candidates; and the availability of alternative therapies for our target market. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. Except as required by applicable law, we do not plan to publicly update or revise any forward-looking statements contained herein, whether as a result of any new information, future events, changed circumstances or otherwise. Although we believe the expectations reflected in such forward- looking statements are reasonable, we can give no assurance that such expectations will prove to be correct. Accordingly, readers are cautioned not to place undue reliance on these forward-looking statements. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements. Certain information contained in this presentation relates to or is based on studies, publications, surveys and other data obtained from third-party sources and our own internal estimates and research. While we believe these third-party sources to be reliable as of the date of this presentation, we have not independently verified, and make no representation as to the adequacy, fairness, accuracy or completeness of, any information obtained from third-party sources. In addition, all of the market data included in this presentation involves a number of assumptions and limitations, and there can be no guarantee as to the accuracy or reliability of such assumptions. Finally, while we believe our own internal research is reliable, such research has not been verified by any independent source. Rubius recommends that investors independently evaluate specific investments and strategies. For further information regarding these risks, uncertainties and other factors, you should read the “Risk Factors” section of our Annual Report on Form 10-K filed for the period ended December 31, 2020 and subsequent filings with the SEC. This presentation may contain tradenames, trademarks or servicemarks of other companies. Rubius does not intend the use or display of other parties’ tradenames, trademarks or servicemarks to imply a relationship with, or endorsement or sponsorship of, these other parties.2

 
 

 

Single-Agent Activity with RTX-240 in Advanced Solid Tumors – Two Responses with Favorable Safety ResultsWe Aim to Realize the Power of Immune Agonists by Enabling a Broad Therapeutic WindowThese Initial Clinical Results Increase the Probability of Success of our Oncology Pipeline3

 
 

 

The Promise of Red Cell Therapeutics™: The Future of Cellular TherapyEARLY PROGENITOR CELLSGENETIC ENGINEERING WITH LENTIVIRUSRED PLATFORM®EXPANSION & DIFFERENTIATIONENUCLEATION & MATURATIONRED CELL THERAPEUTICSINGLE HEALTHY O- DONOR100-1000’s OF DOSESFEATURES • Allogeneic, off the-shelf cellular therapy candidates • Only modification is lentivirus to create new product candidate • Scalable, reproducible manufacturing processBENEFITS • Modular platform is designed to mimic immune biology • Biodistribution of RBC’s confined to vasculature, potentially widening therapeutic window • Leverages common CMC, toxicology data packages4

 
 

 

RTX-240 is Designed to Deliver Two Key Agonist Signals to the Immune SystemRTX-240 | (4-1BBL + IL-15TP)BROAD IMMUNE SYSTEM STIMULATIONDESIGNED TO STIMULATE ADAPTIVE AND INNATE IMMUNE CELL AGONIST PATHWAYSNK)POTENTIAL BENEFITS:• Activate existing agonist pathways leading to enhanced potency • Overcome resistance to immunotherapy • Reduce toxicity given biodistribution confined to vasculature and spleen, widening the therapeutic window of agonists5

 
 

 

mRBC-240 Resulted in No Liver Toxicity and Significantly Inhibited Tumor Growth as MonotherapySERUM ALT B16F10 LUNG METASTASES MODEL250200200 15015010050100500 0mRBC-240 showed no liver toxicity in vivo4 Doses, 1x109 cells day 0, 3, 7, 10; Sacrifice day 18mRBC-240 reduced tumor burden and was equivalent to anti-4-1BB mAb in vivo 3 Doses, 1x109 cells day 1, 5, 8, Sacrifice day 14Dugast, et. al., American Association for Cancer Research; Poster #3272, 2019 6

 
 

 

RTX-240 Proposed Mechanism of Action1 ACTIVATION2 EXPANSION3 TRAFFICKING4 TUMOR KILLING1T cellNK cell RTXRBCNK cell3 4T cellHLA-DR in T and NK cells 2 White pulpNKp30, NKG2D:NKG2A ratioTotal CD8+ memory T cells and NK cellsT cell Red pulp RTX NKcellRBCPotential for enhanced efficacy and safety versus agonists antibodies and recombinant cytokines by confining RTX-240 to the vasculature and spleen7

 
 

 

RTX-240 Led to Clinical Benefit in Certain Patients with Pretreated Advanced Solid TumorsPARTIAL RESPONSE CONFIRMEDMETASTATIC ANAL CANCERPARTIAL RESPONSE UNCONFIRMED METASTATIC UVEAL MELANOMASTABLE DISEASE*NON-SMALL CELL LUNG CANCERSTABLE DISEASESOFT TISSUE SARCOMASTABLE DISEASEPANCREATIC CANCERSTABLE DISEASEPROSTATE CANCER• 54% tumor shrinkage of target lesions • Duration of Response >4 months• Treated at 1e8 Q4W • 3L metastatic• Treatment was ongoing at 8 months • Prior anti-PD-L1 (1L) and anti-PD-L1 + ICOS therapy (2L)• 100% tumor shrinkage of target lesion • Resolution of 14/15 hepatic non-target lesions at 16 weeks• Treated at 1e10 Q4W • 2L metastatic• Treatment was ongoing at 4 months • Prior anti-PD-1 + CTLA-4• Disease stabilization at 8 weeks• Treated at 3e10 Q4W • 2L metastatic• Treatment was ongoing at 3 months • Prior anti-PD-L1 + chemo as 1L therapy• Disease stabilization for 4 months• Converted cold tumor to hot with trafficking of NK and T cells and expression of PD-L1• Treated at 1e10 IV/IT • 3L metastatic• ---• Prior lines of therapy with adriamycin + ifosfamide and tazemetostat• Disease stabilization for 3 months• Treated at 1e10 IV • 2L metastatic• ---• Prior therapy with FOLFOXIRI chemotherapy• Disease stabilization for 4 months• Treated at 3e9 Q4W • 4L metastatic• ---• Prior therapy with enzalutamide, abiraterone, docetaxel and tremelimumabInitial clinical data at the time of the cut-off Feb 28, 2021 *Stable disease according to RECIST v.1.1 of at least 12 weeks duration is reported8

 
 

 

CLINICAL TRIAL DESIGN & INITIAL DATA SUMMARY CHRISTINA COUGHLIN, M.D., PH.D., CHIEF MEDICAL OFFICER9

 
 

 

RTX-240 Clinical Development PlanMONOTHERAPY Relapsed/refractory (R/R) or locally advanced solid tumors1e8 (n=2) Q4W IV1e9 (n=3) Q6W IV3e9 (n=3) Q4W IV1e10 (n=4) Q4W iv1e10 (n=3) Q4W iv/it*3e10 Q4W IV (n=1) Open to Enrollment**cFurther explore dose & intervalRTX-240 + PD-1 Relapsed/Refractory Solid Tumors1e10 Q3W IV Open to Enrollment**Phase 1: Dose-Escalation ~3-4 cohorts (leverage monotherapy data)MONOTHERAPY Relapsed/Refractory Acute Myeloid LeukemiaENROLLING: Phase 1 Dose Escalation Phase 2 Expansion* iv/it (intratumoral) dosing is designed with the combination of iv and it in cycle 1 followed by Q4W iv ** Two dose cohorts open in parallel to explore dose (3e10 iv Q4W) and schedule (1e10 iv Q3W)10

 
 

 

Initial RTX-240 Solid Tumor Clinical Data Summary and AML UpdatePHASE 1 Solid Tumor Overview and Initial Clinical DataPHASE 1 AML OverviewOverview: • • • • Efficacy • Safety: • Pharmacodynamic (PD) effects: • Dose response: • •• 5 patients treated across 2 dose levels • Reported trafficking data from 1 patient • Enrollment ongoingInitial clinical data at the time of the cut-off Feb 28, 202111

 
 

 

......·.·.·.·.·..•.•..• . i·.(·.;(•..R...ubiusTherapeutics •••••••••PATIENT CASE STUDIES12

 
 

 

Confirmed Partial Response in Anal Cancer with 54% Reduction in Target LesionsCASE HISTORY1 2 3Baseline June 20204 5C3D1 Aug 2020 (2 months) -11% target lesions (SD)C5D1 Oct 2020 (4 months) -34% target lesions (PR)prior to enrollment • Treated with RTX-240 in the 1e8 Q4W iv cohort in metastatic 3L settingC7D1 Dec 2020 (6 months) -51% target lesions (PR)C9D1 Feb 2021 (8 months) -54% target lesions (PR)13

 
 

 

Unconfirmed Partial Response in Metastatic Uveal Melanoma with Complete Resolution of Hepatic Target Lesion at 16 Weeks CASE HISTORY 1 2Hepatic target lesionBaseline Oct 2020 Target Lesion3Cycle 3 Day 1 Dec 2020 (2 months) Target Lesion (SD)1e10 Q4W iv cohort in the 2L settingCycle 5 Day 1 Feb 2021 (4 months) Target Lesion (-100%, PR) 14

 
 

 

RTX-240 Induced Complete Regression of 14 of 15 Lesions in the Liver in Metastatic Uveal Melanoma Patient1 2 3Baseline Oct 2020 Non-Target Lesion (9mm)1 2Cycle 3 Day 1 Dec 2020 (2 months) Non-Target Lesion (9mm)3Cycle 5 Day 1 Feb 2021 (4 months) Non-Target Lesion (7mm)Lower liver images Non-target lesionsBaseline Oct 2020 Non-Target LesionsCycle 3 Day 1 Dec 2020 (2 months) Non-Target LesionsCycle 5 Day 1 Feb 2021 (4 months) Non-Target Lesion15

 
 

 

......·.·.·.·.·..•.•..• . i·.(·.;(•..R...ubiusTherapeutics •••••••••INITIAL SOLID TUMOR CLINICAL DATA16

 
 

 

Patient Baseline CharacteristicsAge (median, range) Gender (Male/Female) Race/Ethnicity Non-Hispanic/Non-Latino Hispanic/Latino Disease setting1 Colorectal/lower GI cancers, n Melanoma, n Other cancers, n Lines of prior therapy in the metastatic setting, median (range) Prior anti-PD-1/PD-L1 Prior ipilimumab + nivolumab Prior chemotherapy Prior radiationPARAMETER N=16 EVALUABLE 55 (23-80) 8/811 54 5 7 3 (1-10) 11 5 12 71 Lower GI cancers include colorectal cancer (n=2), anal cancer (n=1), pancreatic ductal adenocarcinoma (n=1), gastroesophageal cancer (n=1); melanoma includes cutaneous melanoma (n=2), ocular melanoma (n=2), mucosal melanoma (n=1); and other cancers (all n=1), mesothelioma, ovarian, prostate, soft tissue sarcoma, non-small cell lung, testicular germ cell tumor Safety population n=16 Initial data cut off: February 28, 202117

 
 

 

Treatment-Related Adverse Events (AE)* and Immune-Related Adverse Events – No Grade 3/4 Adverse Events (n=16)ADVERSE EVENT PREFERRED TERMFatigue Chills Decreased Appetite Arthralgia (joint pain) Nausea Fever Myalgia (muscle pain) Dysgeusia (altered taste) Hyperhidrosis (excessive sweating)GRADE 1 N (%) 2 (13) 3 (19) 3 (19) 3 (19) 3 (19) 2 (13) 2 (13) 2 (13) 2 (13)GRADE 2 N (%) 2 (13) 0 0 0 0 0 0 0 0GRADE 3 N (%) 0 0 0 0 0 0 0 0 0GRADE 4 N (%) 0 0 0 0 0 0 0 0 0ANY GRADE N (%) 4 (25) 3 (19) 3 (19) 3 (19) 2 (13) 2 (13) 2 (13) 2 (13) 2 (13)Initial Data cut-off: Feb 28, 2021 Safety population: n=16 evaluableObserved Immune-Related Adverse Events (irAE) • Ten irAE of Grade 1/2 were observed among 5 patients, no Grade 3/4 irAEs reported. Observed irAE with a median time to onset of 42 days from the first dose (range, 0-62 days) • Grade 2 irAE include pneumonitis, adrenal insufficiency, and hypothyroidism • Grade 1 irAE include arthralgia (n=3), myalgia (n=2), AST elevation and ALT elevation*TRAE’s observed in two or more patients18

 
 

 

Best Response Observed in Patients with Solid TumorsCLINICAL EFFICACY RESULTS• The best response is recorded from the start of the treatment until disease progression with 14 patients evaluable for best response• Patients are considered evaluable for response with measurable disease at baseline (per RECIST v1.1) and at least one follow-up scan at least 1 dose of RTX-240• Scans are performed at baseline and every 8 weeks* * * * * * * ** * *cPR (ongoing)+20% (PD)-30% (PR)Objective response evaluable population: n=14 Initial data cut-off: Feb 28, 2021uPR (ongoing)*Patients receiving prior PD-1/PD-L1 therapy are indicated with an asterisk(*)

 
 

 

Time to Tumor Response and Time on Therapy• Two partial responses observed at different iv dose levels* • Four patients with SD lasting >12 weeks 1 • Treatment ongoing in 4 patients** • Enrollment continues in new Phase 1 cohortsTime on Treatment (Days)1 Patient discontinued due to clinical disease progression Safety population: n=16 evaluable *One confirmed and one unconfirmed partial response **Initial data cut-off: Feb 28, 2021 20

 
 

 

....•.·•·•·•·······. ·•·· i{(Rub ius The rap eutics •••••••••••••••INITIAL PHARMACODYNAMIC DATA21

 
 

 

RTX-240 Induced the Activation and Expansion of Both NK Cells and Memory CD8+ T CellsNK CELL FUNCTIONMEMORY CD8+ T CELL FUNCTIONNKG2DHLA-DRNKG2AHLA-EDying tumor cell (attacked by the NK cell)HLA-DRMHC Class IDying tumor cell (attacked by the T cell)NKp30 B7H6T cell receptor (TCR)• NK cell activity is determined by the balance of inhibitory and activating signals that are received from receptor/ligand interactions• Cytotoxic CD8+ T cell activity is triggered by the recognition of the MHC Class I peptide antigen complex T cell receptorNKp30: B7H6 Activating receptor/ ligandNKG2A: HLA-E Inhibitory receptor/ ligandMHC Class I:peptide complexed with the TCR T cell recognition signal22

 
 

 

RTX-240 Stimulated Adaptive and Innate Immunity, Supporting Proof of Mechanism• Demonstrated activation and/or expansion of NK or memory CD8+ T cells or both in all patients with solid tumors (n=16) ▪ Resulted in partial responses in 2 patients• Induced two key NK cell subsets associated with cytotoxicity and cytokine production ▪ CD16+CD56dim (mature NK, killer phenotype) and CD56bright (immature NK, cytokine secretion) ▪ Increased percentage of both NK cell subsets• Induced a specific signature of NK cell receptor expression, including ▪ Expansion of NKp30+ NK cells (activation) and increased ratio of the receptors NKG2D (activation) / NKG2A (inhibitory) ▪ Signature may allow selection of specific tumor types with predicted sensitivity to RTX-24023

 
 

 

RTX-240 Induced Activation and Expansion of NK and T Cell Populations (n=16)NK CELL ACTIVATION AND EXPANSION MEMORY CD8 T CELL ACTIVATION AND EXPANSIONLow dose = 1e8-3e9 cells/dose (n=8); High dose = 1e10-3e10 cells/dose (n=8)RTX-240 activated and expanded NK and T cells across RTX-240 dose levelsInitial data cut-off: Feb 28, 2021 24

 
 

 

RTX-240 Induced Expansion and Activation Receptor Expression in Key NK Cell Subsets (n=8)KEY NK SUBSETS INDUCED BY RTX-240ACTIVATION AND INHIBITORY RECEPTORS INDUCED BY RTX-240High dose = 1e10-3e10 cells/dose (n=8)RTX-240 expanded differentiated (CD56dim) and immature NK cells (CD56bright) in lymphocyte populationInitial data cut-off: Feb 28, 2021 25

 
 

 

TUMOR INFILTRATION DATA: SOLID TUMORS AND AML26

 
 

 

Tumor Trafficking from Periphery into the Tumor Microenvironment• Trafficking of both T and NK cells was observed in 3/5 patients (1.6 to 10-fold increases) ▪ Shown in patients with metastatic mesothelioma (n=1), metastatic soft tissue sarcoma (n=1) and refractory AML (n=1) ▪ Tumor infiltration was not observed in patients with ovarian cancer (n=1) and heavily pre-treated melanoma (n=1)• Increased expression of PD-L1 and/or increased ratio of M1/M2 macrophages observed in 3/4 patients with solid tumors ▪ Suggests improved immune-permissive TME, which may enhance innate and adaptive tumor-associated immune cell responses• Trafficking of activated NK and T cells into the bone marrow was associated with increases in the cellularity of the marrow in the AML patient ▪ Increased activated effector cells (granzyme B+ NK and T cells) were observed at the first two doses of RTX-24027

 
 

 

CASE 1: Metastatic Mesothelioma with NK and T cell Trafficking 10-Fold Increase in Percentage of NK Cells in Refractory DiseaseGmzB+ T cell trafficking NK cell traffickingArchival diagnostic biopsy On-treatment biopsy Day 34 (2 iv doses) On-treatment biopsy Day 34 (2 iv doses)GmzBCD3 (T cells) CD8 (T cell)CD56 (NK cell)Baseline, %On-treatment, % (fold change)• 10-fold increase in % of NK cells • More than 4-fold increase in CD8+ T cells • Improved immune-permissive environment via increase in PD-L1 expressionInitial data cut-off: Feb 28, 2021% NK (CD56) of all cells % All T (CD3) of all cells % Cytotoxic T (CD8) of all cells PD-L1+ cells0.4 4 2 294.5 (10-fold) 16 (4-fold) 8.8 (>4-fold) 51 (1.8-fold) 28

 
 

 

Case 2: Acute Myeloid Leukemia (AML) Biopsy Images Increased Cellularity in Bone Marrow with activated NK and T Cell TraffickingBaseline Pre-treatmentOn-treatment Cycle 2 Day 8 (2 doses, Day 36) On-treatment (Cycle 2, after 2 doses, Day 36)On-treatment (Cycle 3, after 3 doses, Day 64)GmzBCD3 (T cells) CD8 (T cell)CD56 (NK cell) NucleiBaseline, %Cycle 2 Day 8 % (fold change)Cycle 3 Day 8 % (fold change)• 8-fold increase in % of NK cells of all marrow cells • Substantial increases in Granzyme B+ NK and CD8+ T cells at both on-treatment timepoints indicating trafficking of activated mature effector cells% CD8+ T cells of all T cells %GmzB+ of all CD8+ T cells % NK of all cells %GmzB+ of all NK cells Cellularity34% 0.06%1%0 1x47% (1.4-fold) 0.53% (~9-fold)4% (4-fold)0.16% 1.9x32% 1.67% (~28-fold)8% (8-fold)0.64% 2.3x

28

 

 
 

 

......·.·.·.·.·..•.•..• . i·.(·.;(•..R...ubiusTherapeutics •••••••••RTX-240 CLINICAL DEVELOPMENT PLAN30

 
 

 

Using the Biology of the NK and T cell Response to Select Development IndicationsNK CELLS AS RTX-240 TARGETS METHODOLOGYNK cell (activated by RTX-240)NKG2DNKp30NKG2AB7-H6MHC Class IDying tumor cell (attacked by the NK cell)• Key factors leveraged to identify potential indications among solid tumors for RTX-240: ▪ RTX-240 in designed to induce a highly specific pattern of NK cell surface activation receptors with known ligands in tumors ▪ Similar analyses of the T cell mechanism and biology of the RTX-240 responders – Anal cancer – Metastatic uveal melanoma • Profiled the Cancer Genome Atlas (TCGA) using this biology in an effort to predict cancers susceptible to NK and T cell mechanisms ▪ Assessed ligands for key activation and inhibitory receptors induced by RTX-24031

 
 

 

Biology of Target Cells Informs Indication Selection and Correlates with Responses in Anal and Uveal Melanoma Patients• Cancer indications ranked the highest in this analysis include ▪ Upper GI cancers (Gastric/esophageal cancer) ▪ AML ▪ Lower GI cancers (anal, colorectal cancer) ▪ Metastatic uveal melanoma ▪ Renal cell cancer• T cell mechanism and biology of the RTX-240 responders yielded similar rankings of indicationsZ-Score is number of standard deviations from the median calculated row-wise+- Patient samples in TCGA ranked by expression level within disease setting (HIGH to LOW for B7H6, LOW to HIGH for HLA-E)NKp30 LigandNKG2A LigandMore optimal Less optimal 32

 
 

 

Key Takeaways from Initial Data• RTX-240 demonstrated a favorable, emerging safety results across dose levels• Single-agent activity with partial responses per RECIST v1.1 in two patients• Pharmacodynamic effects demonstrated the activation and expansion of the key NK and T cell types• Tumor cell infiltration of activated NK and T cells into the tumor microenvironment in solid tumors and AMLEnrollment Continues and Dose and Schedule Optimization Ongoing33

 
 

 

......·.·.·.·.·..•.•..• . i·.(·.;(•..R...ubiusTherapeutics •••••••••PIPELINE34

 
 

 

Clinical-Stage Company Developing a Broad Wholly Owned PipelinePRODUCT CATEGORYPROGRAMRTX-240PRECLINICALR/R Solid TumorsIND ENABLINGPHASE 1Phase 2 initiation 1Q’22*PHASE 2RTX-240R/R Acute Myeloid LeukemiaInitial clinical results by year-end*CANCERAUTOIMMUNE DISEASESRTX-240RTX-321 aAPC (HPV 16+)RTX-224RTX-aAPCRTX-T1DRTX-240 + PD-1 R/R Solid TumorsR/R HPV-16+ Solid TumorsR/R Solid TumorsCancerType 1 DiabetesPhase 1 trial initiation 2H’21*Initial clinical results by 1Q’22*File IND by year-end*Present additional RTX-240 Phase 1 clinical results for solid tumors and integrated clinical program for RTX-240 by year-end, including expansion cohorts*Anticipated milestones35

 
 

 

......·.·.·.·.·..•.•..• . i·.(·.;(•..R...ubiusTherapeutics •••••••••Q&A AND APPENDIX36

 
 

 

Supporting Rubius Preclinical Publications• RTX-240 ▪ 2020 Society for Immunotherapy of Cancer (SITC) Annual Meeting• RTX-321 ▪ 2020 Federation of Clinical Immunology Societies (FOCIS) Virtual Annual Meeting; ▪ 2020 American Association for Cancer Research (AACR) Tumor Immunology Conference; and ▪ 2020 American Society of Gene & Cell Therapy 23rd Annual Meeting• RTX-224 ▪ 2019 American Association of Cancer Research Annual Meeting37

 
 

 

Red Cell Therapeutics Competitive Comparison Indicates Potential AdvantagesOutpatientSafety profile: No lymphodepletion, hospitalizations Safety profile: Narrow biodistribution Safety profile: No lentiviral genetic material present Safety profile: No severe liver or organ toxicity Broad anti-tumor immune response observed Single-agent activity in solid tumors observed Efficacy in hematologic malignanciesEFFECTOR CELL THERAPY (CAR-T, CAR-NK, TIL)+✓* ✓**AGONISTS AND CYTOKINES+ ✓ ✓✓✓ ✓RED CELL THERAPEUTICS✓ ✓ ✓ ✓ ✓ ✓ ✓ Ongoing***+ We have not conducted head-to-head studies of any Red Cell Therapeutic against these product types. Checkmarks represent the potential opportunity for RTX-240 based on these initial clinical results. *TILs have shown single-agent activity in solid tumors. CAR-T and CAR-NK therapies have not shown single-agent activity to date. **CAR-T and CAR-NK therapies have shown efficacy in hematologic malignancies. TILS have not shown efficacy in hematologic malignancies to date. ***Subject to ongoing and future clinical trials38

 
 

 

Comprehensive and Precise Methodology to Identify Target Cell Trafficking into Tumor Microenvironment (TME) in Paired Biopsies*Tissue analysis area definedNuclei definedStroma (SOX10-)Tumor (SOX10+)12-plex stainsSTEP 1 STEP 2 STEP 3 STEP 4 STEP 5Define areas of analysis in tissue sectionsDefine necrotic (dead) tumor to excludeDefine tumor vs. stroma areasApply marker antibodies to a single tissue sectionDigital expression analysis of 12 markers*Optional biopsies for solid tumor Phase 1 arm. Standard of care biopsies for AML Phase 1 arm.39