by these cautionary statements. ********* Company Overview Summary We are a late-stage biopharmaceutical company pursuing therapies with the potential to extend and enrich the lives of patients living with hematologic ma

Unless the context indicates otherwise, the terms we, us and our refer to Geron Corporation, a Delaware corporation, and its subsidiary on a consolidated basis. This Exhibit 99.1 includes trademarks, service marks and trade names owned by us or other companies. All trademarks, service marks and trade names included in this Exhibit 99.1 are the property of their respective owners.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Exhibit 99.1 contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. These statements relate to future events or to our future operating or financial performance and involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements. Forward-looking statements may include, but are not limited to, statements about:

-the therapeutic potential of imetelstat and its expected uses and benefits;

-our plans to submit a New Drug Application, or NDA, and a marketing authorization application, or MAA, for imetelstat in Low or Intermediate-1 risk myelodysplastic syndromes, or lower risk MDS, and the anticipated timing thereof;

-the progress, timing, magnitude, scope and costs of clinical development, manufacturing and commercialization of imetelstat, including the number of indications which are or may in the future be pursued, subject to clearances and approvals by the U.S. Food and Drug Administration, or FDA, and other regulatory authorities;

-the continued enrollment in, and the continued conduct and completion of, IMpactMF, our Phase 3 clinical trial in relapsed/refractory myelofibrosis, or MF, IMproveMF, our Phase 1 combination clinical trial in frontline Intermediate-2 or High Risk MF, and IMpress, an investigator-led Phase 2 clinical trial in Intermediate-2 or High-Risk myelodysplastic syndromes and acute myeloid leukemia;

-the achievement and timing of clinical trial events related to IMpactMF, IMproveMF and IMpress, including the completion of patient enrollment and anticipated timing of data availability;

-other potential planned future clinical development plans for imetelstat;

-our plans to market and sell imetelstat, upon regulatory approval or clearance, in the U.S. and in Europe, whether alone or with new collaborative partners, and the anticipated timing thereof;

-our ability to obtain and maintain potential new collaborative arrangements to assist us in the development and potential commercialization of imetelstat, especially outside the U.S.;

-the availability of coverage and adequate third-party reimbursement for imetelstat, if any;

-our ability to consistently and reproducibly manufacture imetelstat;

-our ability to meaningfully reduce manufacturing costs of imetelstat;

-the impacts of the ongoing COVID-19 global pandemic, macroeconomic conditions, such as rising inflation rates, uncertain credit and global financial markets and supply chain disruptions, and geopolitical events, such as the conflict between Russia and Ukraine and related sanctions, on the foregoing;

-our ability to establish and maintain agreements with third-party service providers to support the development of imetelstat;

-the size and timing of expenditures and whether there are unanticipated expenditures;

-our ability to manage the anticipated growth of our business, including our ability to recruit and retain key personnel to support the development and potential future commercialization of imetelstat;

-our estimates and expectations regarding the sufficiency of our cash resources, our cash resource conservation efforts;

-our estimates regarding the extent of our ability to progress our imetelstat program with our existing capital resources;

-our ability to protect our intellectual property and the duration of any such protection, and operate our business without infringing upon the intellectual property rights of others;

-the implementation of our corporate strategy;

-our future financial and operating performance;

-our anticipated use of our existing capital resources; and

-our plans, objectives, expectations and intentions and any other statements that are not historical fact.

In some cases, you can identify forward-looking statements by terms such as may, plan, intend, will, should, could, would, expects, plans, anticipates, believes, estimates, projects, predicts, potential and similar expressions intended to identify forward-looking statements. These statements reflect our current views with respect to future events, are based on assumptions and are subject to risks and uncertainties. Given these risks and uncertainties, you should not place undue reliance on these forward-looking statements. We discuss many of these risks, uncertainties and other factors in greater detail under the heading Risk Factors below. Also, these forward-looking statements represent our estimates and assumptions only as of the date of this Exhibit 99.1. Unless required by law, we undertake no obligation to update or revise any forward-looking statements to reflect new information or future events or developments. Thus, you should not assume that our silence over time means that actual events are bearing out as expressed or implied in such forward-looking statements. We qualify all of the forward-looking statements in this Exhibit 99.1 by these cautionary statements.

We are a late-stage biopharmaceutical company pursuing therapies with the potential to extend and enrich the lives of patients living with hematologic malignancies. Our investigational first-in-class telomerase inhibitor, imetelstat, harnesses Nobel Prize winning science in a treatment that may alter the underlying course of these diseases.

Our lead indication for imetelstat is in Low or Intermediate-1 risk myelodysplastic syndromes, or lower risk MDS. In January 2023, we reported positive top-line results from our IMerge Phase 3 clinical trial. The trial met its primary endpoint of 8-week transfusion independence rate and a key secondary endpoint of 24-week transfusion independence rate, demonstrating highly statistically significant (i.e., P<0.001 for both) and clinically meaningful benefits in imetelstat versus placebo. Furthermore, statistically significant and clinically meaningful efficacy results were observed in the trial across key subtypes, including patients who were ringed sideroblast positive, or RS positive, and ringed sideroblast negative, or RS negative; patients with high and very high baseline transfusion burden; and patients classified as Low or Intermediate-1 risk according to the International Prognostic Scoring System, or IPSS.

Based on the positive top-line data from IMerge Phase 3 and the prior IMerge Phase 2, we plan to submit a New Drug Application, or NDA, to the U.S. Food and Drug Administration, or FDA, in the U.S. in mid-2023 and a marketing authorization application, or MAA, in Europe in the second half of 2023 for the use of imetelstat in adult patients with lower risk MDS. If the NDA is accepted for filing and imetelstat is approved for commercialization by the FDA within the timelines we expect, we anticipate commercial launch of imetelstat in lower risk MDS in the U.S. could occur in the first half of 2024. In Europe, we anticipate review of the planned MAA, if validated by the European Medicines Agency, or EMA, could take approximately 14 months and, if approved, we anticipate that the commercial launch of imetelstat in lower risk MDS in Europe could occur by the end of 2024.

We believe that the positive top-line data from IMerge Phase 3 and IMerge Phase 2, as well as our prior Phase 2 clinical trial of imetelstat in patients with Intermediate-2 or High-Risk myelofibrosis who have relapsed after or are refractory to treatment with a janus associate kinase inhibitor, or JAK inhibitor, or relapsed/refractory MF, provide strong evidence that imetelstat targets telomerase to inhibit the uncontrolled proliferation of malignant stem and progenitor cells enabling recovery of bone marrow and normal blood cell production, which suggest potential disease-modifying activity. We believe this potential for disease modification could differentiate imetelstat from currently approved treatments in myeloid hematologic malignancies. Accordingly, in addition to lower risk MDS, we are developing imetelstat for the treatment of several myeloid hematologic malignancies with the following ongoing clinical trials:

-IMpactMF, a Phase 3 clinical trial in relapsed/refractory MF with overall survival, or OS, as the primary endpoint, that currently is enrolling patients. Based on our planning assumptions for enrollment and event (death) rates in the trial, we expect the interim analysis for OS in IMpactMF may occur in 2024, and the final analysis may occur in 2025. Because these analyses are event-driven and it is uncertain whether actual rates for enrollment and events will reflect current planning assumptions, the results may be available at different times than currently expected.

-IMproveMF, a Phase 1 combination clinical trial in frontline Intermediate-2 or High-Risk myelofibrosis, or frontline MF, that currently is enrolling patients and the first patient was dosed in April 2021; and

-IMpress, an investigator-led Phase 2 clinical trial in Intermediate-2 or High-Risk myelodysplastic syndromes, or higher risk MDS, and acute myeloid leukemia, or AML, with the initial clinical site planned to open in the first quarter of 2023.

Imetelstat Regulatory Designations

Imetelstat has been granted Fast Track designations by the FDA for development in two indications: (1) for the treatment of adult patients with transfusion-dependent anemia due to lower risk MDS, who do not have a deletion 5q chromosomal abnormality, also known as non-del(5q), and who are refractory or resistant to treatment with an erythropoiesis stimulating agent, or ESA (i.e., the treatment population in IMerge Phase 3); and (2) for the treatment of adult patients with Intermediate-2 or High-Risk MF whose disease has relapsed after or is refractory to JAK inhibitor treatment (i.e., the treatment population in IMpactMF). The FDA granted orphan drug designation to imetelstat in June 2015 for the treatment of MF and for the treatment of MDS in December 2015, and the EMA granted orphan drug designation in December 2015 to imetelstat for the treatment of MF and in July 2020 for the treatment of MDS. In October 2021, we gained access to the Innovative Licensing and Access Pathway, or ILAP, in the United Kingdom, or U.K., through the receipt of an Innovation Passport for imetelstat to treat lower risk MDS.

Stage-Gated Milestone-Driven Global Commercial Plans for Imetelstat

If imetelstat is approved in lower risk MDS for marketing by regulatory authorities, we plan to commercialize imetelstat ourselves in the U.S. and may seek commercialization partners for territories outside of the U.S. We have therefore developed a commercial pre-launch and potential launch plan that is driven by the achievement of certain regulatory milestones, such as FDA acceptance for filing of our planned NDA, as well as EMA validation of our planned EU MAA submission. We are conducting pre-commercial preparations for the U.S., such as: enhancing and/or establishing company processes and systems to support a potential commercial launch, refining our market research in lower risk MDS, engaging in marketing and commercial access/reimbursement preparatory efforts, as well as executing on long-lead time activities, such as selecting a third-party logistics provider, completing state licensing requirements and hiring personnel to support potential sales, marketing and commercial operations. In light of the positive top-line IMerge Phase 3 results, we continue to evaluate our strategy for the potential launch and commercialization of imetelstat in Europe. Based on our internal estimates of pricing and addressable patient populations in 2030 and if regulatory authorities approve imetelstat for marketing in lower risk MDS and relapsed/refractory MF, we believe the combined potential peak market opportunity in the U.S. and key European markets for imetelstat is approximately $3.0 billion, of which lower risk MDS represents approximately $1.2 billion and relapsed/refractory MF represents approximately $1.8 billion.

IMerge: Ongoing Phase 2/3 Clinical Trial in Lower Risk MDS

IMerge is a two-part Phase 2/3 clinical trial evaluating imetelstat (7.5 mg/kg dose administered as a two-hour intravenous infusion every four weeks) in transfusion dependent lower risk MDS patients who are relapsed after or refractory to prior treatment with an ESA. To be eligible for IMerge, patients are required to be transfusion dependent, defined as requiring at least four units of packed red blood cells, or RBCs, over an eight-week period during the 16 weeks prior to entry into the trial.

IMerge Phase 3 is a double-blind, 2:1 randomized, placebo-controlled clinical trial that, based on discussions with U.S. and European regulatory authorities, was designed to support, if successful, the registration of imetelstat in lower risk MDS. The trial enrolled patients with lower risk transfusion dependent MDS who were relapsed, or refractory to, or ineligible for ESA, had not received prior treatment with either a hypomethylating agent, or HMA, or lenalidomide and were non-del(5q). IMerge Phase 3 is being conducted at 118 medical centers globally in 17 countries in North America, Europe, Middle East and Asia.

The primary efficacy endpoint of IMerge Phase 3 is the rate of red blood cell transfusion independence, or RBC-TI, lasting at least eight weeks, defined as the proportion of patients without any RBC transfusions during any consecutive eight weeks since entry to the trial, or 8-week TI. Key secondary endpoints for IMerge Phase 3 include the rate of RBC-TI lasting at least 24 weeks, or 24-week TI, and the rate of hematologic improvement erythroid, or HI-E, which is a rise in hemoglobin of at least 1.5 g/dL above the pretreatment level for at least eight weeks or a reduction of at least four units of RBC transfusions over eight weeks compared with the prior RBC transfusion burden. Other secondary endpoints include the time to and duration of RBC-TI; the proportion of patients achieving Complete Response, or CR, or Partial Response, or PR, according to the 2006 International Working Group, or IWG, criteria for MDS; the proportion of patients requiring RBC transfusions and the transfusion burden; the proportion of patients requiring the use of myeloid growth factors and the dose; assessments of the change in the patients' quality of life using several validated instruments; as well as an assessment of OS, and time to progression to AML.

Positive Top-Line Results from IMerge Phase 3

In January 2023, we reported positive top-line results from IMerge Phase 3. A total of 178 patients were enrolled in IMerge Phase 3, with patients randomized on a 2:1 basis to imetelstat (n=118) or placebo (n=60), and represents the intent-to-treat population in the trial. The population for the analysis of safety data is based on 177 patients (imetelstat, n=118, placebo, n=59) because one patient in the placebo arm was enrolled, but did not receive any treatment. The trial met its primary endpoint of 8-week TI rate and key secondary endpoint of 24-week TI rate, among others, demonstrating statistically significant and clinically meaningful results with imetelstat versus placebo with no new safety signals and safety results consistent with prior imetelstat clinical trials. Key patient participation information is as follows:

Key baseline demographics and disease characteristics of patients in IMerge Phase 3, summarized below, demonstrate the broad range of lower risk MDS subtypes, and patients with high disease burden, enrolled in the trial:

* There were an insufficient number of patients (imetelstat: 7/118; placebo: 4/60) who were previously treated with luspatercept enrolled in IMerge Phase 3 to draw conclusions about the effect of imetelstat treatment in such patients. Of these patients, no imetelstat-treated patients and one placebo patient achieved 8-week TI.

** Pretreatment hemoglobin is defined as the average of all hemoglobin values in the eight weeks prior to the first dose date, excluding values that were within 14 days after transfusion (thus considered to be influenced by transfusion).

After a median follow-up time of 18 months for all patients in the trial, the following chart is the status of patients as of October 13, 2022, the clinical cut-off date for top-line results.

* On imetelstat treatment arm, patient death: neutropenic sepsis not related to drug after ~two-year treatment duration

On placebo treatment arm, patient deaths: (1) COVID-19 and (1) heart valve issue

Efficacy results for the primary 8-week TI endpoint and 24-week TI secondary endpoint summarized below illustrate the depth and durability of transfusion independence demonstrated with high statistical significance for imetelstat versus placebo in IMerge Phase 3.

* Cochran Mantel Haenszel test stratified for prior RBC transfusion burden ( 6 units or >6 units of RBCs/8 weeks) and baseline IPSS risk score (Low or Intermediate-1)

Highly statistically significant (p<0.001; hazard ratio 0.23) durable transfusion independence was achieved with median TI duration approaching one year (95% CI (weeks): 26.9, 83.9) for imetelstat and approximately 13 weeks for placebo (95% CI (weeks): 8.0, 24.9), using Kaplan Meier estimates, as shown in the following graph. Approximately 83% of patients achieving 8-week TI had a single continuous TI period. For imetelstat patients achieving 24-week TI, the median TI duration was 80.0 weeks (95% CI (weeks): 51.6, not estimable (NE)). In addition, approximately 70% of imetelstat patients who achieved 8-week TI continued to achieve 24-week TI.

In addition, there was an increasing magnitude of benefit for imetelstat versus placebo with longer time intervals, as shown in the graph below.

Highly statistically significant (p<0.001) increase in hemoglobin levels over time for imetelstat patients as shown in the graph below. For patients achieving 8-week TI, median increases in hemoglobin were 3.6 g/dL for imetelstat and 0.8 g/dL for placebo. The peak hemoglobin reached for these patients was 11.3 g/dL for imetelstat and 8.9 g/dL for placebo.

Corresponding to the increases in hemoglobin, a statistically significant decrease in the number of RBC units transfused was achieved for imetelstat treated patients versus placebo, as shown in the graph below.

Furthermore, as shown in the table below, statistically significant 8-week RBC-TI was observed with imetelstat versus placebo across lower risk MDS subtypes (p<0.05) and similar 8-week RBC-TI was observed for imetelstat within each subtype category in comparison to the overall population.

* Cochran Mantel Haenszel test stratified for prior RBC transfusion burden ( 6 units or >6 units of RBCs/8 weeks) and baseline IPSS risk score (Low or Intermediate-1)

Specifically for the RS+ and RS- subtypes, statistically significant improvement in both 8-week and 24-week TI was achieved with imetelstat versus placebo, as shown in the table below.

* Kaplan-Meier estimates of duration of RBC TI; 8-week/24-week TI Responder Analysis Set; P-value for TI rate is based on Cochran Mantel Haenszel test stratified for prior RBC transfusion burden ( 6 units or >6 units of RBCs/8 weeks) and baseline IPSS risk score (Low or Intermediate-1); P-value for duration of TI is based on stratified log-rank test.

The IMerge Phase 3 protocol specified use of the International Working Group, or IWG, 2006 criteria to measure HI-E and was not statistically significant (p=0.112) for imetelstat versus placebo. The current IWG 2018 HI-E criteria places greater emphasis on durability by measuring response for 16 weeks, rather than 8 weeks. Under these new 2018 IWG criteria, a highly statistically significant (p<0.001) HI-E rate was achieved for imetelstat versus placebo. See the table below for HI-E response under both 2018 and 2006 IWG criteria.

* Cochran Mantel Haenszel test stratified for prior RBC transfusion burden ( 6 units or >6 units of RBCs/8 weeks) and baseline IPSS risk score (Low or Intermediate-1)

Clinical and molecular evidence supporting the potential for disease modification with imetelstat includes a one-year median TI duration for imetelstat 8-week TI responders, a median rise of 3.6 g/dL in hemoglobin levels in those same patients and >50% variant allele frequency decreases in SF3B1, TET2, DNMT3A and ASXL1 mutations, as shown in the graph below.

The safety results in IMerge Phase 3 were consistent with prior clinical trials of imetelstat in hematologic malignancies, and no new safety signals were identified. The most frequent non-hematologic toxicities occurring in 10% of patients on either imetelstat or placebo arms are listed in the table below. Grade 3 elevations in liver function tests, or LFTs, on imetelstat were short in duration (median < 2 weeks) and more than 80% resolved to Grade 2 or lower within 4 weeks, with no cases of liver test elevations consistent with Hy's Law or Drug Induced Liver Injury.

* Includes COVID-19, asymptomatic COVID-19, COVID-19 pneumonia

* n=117 for ALT imetelstat patients

The most frequent hematologic toxicities are listed in the table below.

Clinical consequences from cytopenias were similar between imetelstat and placebo groups as shown in the table below.

* No Grade 3 bleeding events in the setting of Grade 3/4 thrombocytopenia; on imetelstat: two patients with Grade 4 gastrointestinal bleeding, unrelated and resolved and one Grade 3 hematuria, unrelated and resolved

+ On imetelstat: three patients with Grade 3/4 infections in setting of Grade 3/4 neutropenia; all three were sepsis and resolved with only one considered related

** Occurred at day 33, lasted 8 days; assessed by investigator as possibly related to imetelstat; patient subsequently achieved TI >40 weeks and remains on treatment at data cut-off

Furthermore, as shown in the table below, the median duration of cytopenias was shorter for imetelstat versus placebo and the resolution to Grade 2 or lower was higher for imetelstat versus placebo.

+ 18% of imetelstat treated patients received a median of 1 platelet transfusions; 35% of imetelstat treated patients received growth factor support

* Analysis performed for patients who experienced Grade 3/4 cytopenias. Resolution determined by return to Grade 2 or lower

Planned Next Steps to Advance Imetelstat in Lower Risk MDS Toward Potential Commercialization

We plan to present additional data from IMerge Phase 3 at medical meetings later this year, including data relating to potential correlation of decreases in mutation burden and abnormal cytogenetic clones with clinical responses, patient reported outcomes, hTERT and telomerase activity biomarker data and continued follow-up of durability of transfusion independence. These data, which are not yet available to Geron, will not be available to you prior to investing in this offering.

We believe the depth, breadth and durability of transfusion independence reported from IMerge Phase 3 to date, as well as from IMerge Phase 2, provide strong support for our planned regulatory submissions in the U.S. and in the EU for the use of imetelstat in patients with lower risk MDS. We therefore plan to submit an NDA in the U.S. in mid-2023 and an MAA in Europe in the second half of 2023 for the use of imetelstat in adult patients with lower risk MDS. With Fast Track designation for imetelstat from the FDA for the treatment of adult patients with transfusion-dependent anemia due to lower risk MDS, non-del(5q), and who are refractory or resistant to treatment with an ESA (i.e., the treatment population in IMerge Phase 3), the FDA granted our request for rolling submission of the NDA. If the NDA is accepted for filing and approved within the timelines we expect, we anticipate that the commercial launch of imetelstat in lower risk MDS could occur in the U.S. in the first half of 2024. In Europe, we anticipate review of the planned MAA, if validated by the EMA could take approximately 14 months and, if approved, we anticipate that the commercial launch of imetelstat in lower risk MDS in Europe could occur by the end of 2024.

IMpactMF: Ongoing Phase 3 Clinical Trial in Relapsed/Refractory MF

IMpactMF, our Phase 3 clinical trial in relapsed/refractory MF, is an open label, 2:1 randomized, controlled clinical trial designed to evaluate imetelstat (9.4 mg/kg administered by intravenous infusion over two hours every three weeks) in approximately 320 patients. Patients relapsed after or refractory to a JAK inhibitor are defined as having an inadequate spleen response or symptom response after treatment with a JAK inhibitor for at least six months, including an optimal dose of a JAK inhibitor for at least two months. The best available therapy, or BAT, control arm of IMpactMF excludes the use of JAK inhibitors. With respect to the trial design for IMpactMF, the FDA urged us to consider adding a third dosing arm to assess a lower dose and/or a more frequent dosing schedule that might improve the planned trial's chance of success by identifying a less toxic regimen and/or more effective spleen response, one of the trial's secondary endpoints. Based on data from IMbark, we believe that testing a lower dose regimen would likely result in a lower median OS, which is the trial's primary endpoint, in the imetelstat treatment arm. We believe existing data also suggest that lowering the dose would not result in a clinically meaningful reduction in toxicity. For these reasons, we therefore determined not to add a third dosing arm to the trial design, and the FDA did not object to our proposed imetelstat dose and schedule of 9.4 mg/kg every three weeks.

The primary efficacy endpoint for IMpactMF is OS. Key secondary endpoints include symptom response; spleen response; progression free survival; complete remission, partial remission or clinical improvement, as defined by the International Working Group for Myeloproliferative Neoplasms Research and Treatment criteria; duration of response; safety; pharmacokinetics; and patient reported outcomes. Currently, we have selected 165 of the planned 180 sites to participate in IMpactMF across North America, South America, Europe, Australia and Asia.

IMpactMF is designed with >85% power to detect a 40% reduction in the risk of death (hazard ratio=0.60; one-sided alpha=0.025). The final analysis for OS is planned to be conducted after more than 50% of the patients planned to be enrolled in the trial have died (referred to as an event). An interim analysis of OS, in which the alpha spend is expected to be approximately 0.01, is planned to be conducted after approximately 70% of the total projected number of events (deaths) for the final analysis have occurred.

Current Status of IMpactMF

IMpactMF opened for patient screening and enrollment in December 2020. As of December 31, 2022, we had 140 of the 165 selected sites open for patient enrollment, and we are continuing to select additional sites. The first patient was dosed in April 2021. Given the uncertain and unpredictable impact of the COVID-19 pandemic on our clinical trial activities, including the constraints on clinical site personnel resources due to other competing trials in MF at the sites where IMpactMF is planned to be conducted, under current planning assumptions, we expect IMpactMF to be fully enrolled in 2024. Based on our planning assumptions for enrollment and event (death) rates in the trial, we expect the interim analysis for OS in IMpactMF may occur in 2024 and the final analysis may occur in 2025. Because these analyses are event-driven and it is uncertain whether actual rates for enrollment and events will reflect current planning assumptions, the results may be available at different times than currently expected. At the interim analysis, if the pre-specified statistical OS criterion is met, then we expect such data may potentially support the registration of imetelstat in relapsed/refractory MF. Subject to protocol-specified stopping rules for futility, if the pre-specified OS criterion is not met at the interim analysis, the trial will continue to the final analysis, which is expected to occur approximately one year later.

The timing and achievement of either or both of the planned analyses depend on numerous factors, including delays or interruptions related to the effects of the COVID-19 pandemic or geopolitical events. In addition, our ability to enroll, conduct and complete IMpactMF depends on whether we can obtain and maintain the relevant clearances from regulatory authorities and other institutions to enroll, conduct and complete the trial, and our ability to raise additional capital following this offering if and when needed in order to complete the trial.

Improvement in Overall Survival and Potential Disease-Modifying Activity Observed in IMbark Phase 2

The IMbark Phase 2 clinical trial was designed to evaluate two dosing regimens of imetelstat (either 4.7 mg/kg or 9.4 mg/kg administered by intravenous infusion every three weeks) in patients with relapsed/refractory MF. The co-primary efficacy endpoints for IMbark were spleen response rate, defined as the proportion of patients who achieve a reduction of at least 35% in spleen volume as assessed by imaging, and symptom response rate, defined as the proportion of patients who achieve a reduction of at least 50% in Total Symptom Score, at 24 weeks. Key secondary endpoints were OS and safety.

We previously reported efficacy and safety results from the IMbark Phase 2 clinical trial, including median OS of 28.1 months for patients on the high dose arm of the study, which is almost twice the reported median OS of 14 16 months in medical literature. To evaluate this potential benefit, we conducted a post-hoc analysis of OS for patients treated with imetelstat 9.4 mg/kg in IMbark compared to OS calculated from real world data, or RWD, collected at the Moffitt Cancer Center for patients who had discontinued treatment with ruxolitinib, a JAK inhibitor, and who were subsequently treated with BAT. To make a comparison between the IMbark data and RWD, a cohort from the real-world dataset was identified that closely matched the IMbark patients, using guidelines for inclusion and exclusion criteria as defined in the IMbark clinical protocol, such as platelet count and spleen size. Calculations from two propensity score analysis approaches resulted in a median OS of 30.7 months for the imetelstat-treated patients from IMbark, which is more than double the median OS of 12.0 months using RWD for patients treated with BAT. These analyses also showed a 65% 67% lower risk of death for the imetelstat-treated patients vs. BAT-treated patients. We believe these analyses suggest potentially longer OS for imetelstat-treated relapsed/refractory MF patients in IMbark, compared to BAT in closely-matched patients from RWD. However, comparative analyses between RWD and our clinical trial data have several limitations. For instance, the analyses create a balance between treatment groups with respect to commonly available covariates, but do not take into account the unmeasured and unknown covariates that may affect the outcomes of the analyses. Potential biases are introduced by factors which include, for example, the selection of the patients included in the analyses, misclassification in the matching process, the small sample size, and estimates that may not represent the outcomes for the true treated patient population. For these and other reasons, such comparative analyses and any conclusions from such analyses should be considered carefully and with caution, and should not be relied upon as demonstrative or otherwise predictive or indicative of any current or potential future clinical trial results of imetelstat in relapsed/refractory MF, including IMpactMF.

In IMbark, patients also experienced other positive clinical outcomes, including symptom improvement, spleen reduction and bone marrow fibrosis improvement. In June 2020, we reported correlation analyses from