On September 17, 2020 Deciphera Pharmaceuticals, Inc. (NASDAQ:DCPH), reported the presentation of data from the ovarian cancer cohort in Part 2 of the ongoing Phase 1b/2 study of rebastinib, the Company’s selective TIE2 inhibitor, in combination with paclitaxel and from Part 1 of the Phase 1b/2 study of rebastinib in combination with carboplatin (Press release, Deciphera Pharmaceuticals, SEP 17, 2020, View Source [SID1234565278]). The E-poster presentations, titled "A phase 1b/2 study of rebastinib and paclitaxel in advanced or metastatic platinum-resistant ovarian cancer" and "A phase 1 study of rebastinib and carboplatin in patients with metastatic solid tumors," were featured at the ESMO (Free ESMO Whitepaper) Virtual Congress 2020, being held September 19-21, 2020.

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"Data presented today continue to support the potential of the TIE2 inhibitor rebastinib when combined with paclitaxel or carboplatin across a broad spectrum of solid tumor types," said Matthew L. Sherman, MD, Executive Vice President and Chief Medical Officer of Deciphera. "Earlier this year we presented promising data supporting the combination of rebastinib and paclitaxel in patients with endometrial cancer. We are pleased that the preliminary data with this combination in patients with ovarian cancer has also demonstrated encouraging efficacy, with a 38% objective response rate, confirmed and unconfirmed, and a clinical benefit rate at eight weeks of 88% in the modified intent-to-treat population. In addition, the combination of rebastinib and carboplatin in Part 1 of the ongoing Phase 1b/2 study was generally well tolerated and showed initial clinical activity with the combination in a heterogeneous, heavily pre-treated group of patients with advanced solid tumors."

Phase 1b/2 Study of Rebastinib and Paclitaxel in Advanced or Metastatic Platinum-resistant Ovarian Cancer

The Phase 1b/2 study of rebastinib in combination with paclitaxel is a two-part, open-label, multicenter study assessing the safety, tolerability, anti-tumor activity and pharmacokinetics of rebastinib in patients with advanced or metastatic solid tumors. As previously announced, a recommended Phase 2 dose of rebastinib 50 mg twice-daily (BID) in combination with paclitaxel was selected, based on activity observed in Part 1 of the study, and both the endometrial and ovarian cancer cohorts in Part 2 of the study advanced into Stage 2 of the Simon two-stage design based on demonstrating at least five responses in each cohort in Stage 1.

Data previously presented from the endometrial cancer cohort showed encouraging preliminary anti-tumor activity and favorable tolerability with an objective response rate of 39% (confirmed and unconfirmed) and a clinical benefit rate of 72% at eight weeks in the modified intent-to-treat population of 18 patients.

Data presented at the ESMO (Free ESMO Whitepaper) Virtual Congress 2020 are from a total of 29 patients in the platinum-resistant ovarian cancer expansion cohort in Part 2 of the study who initiated treatment as of June 3, 2020, with follow-up data through July 31, 2020. Ten patients were treated at the starting dose of rebastinib 100 mg BID + weekly paclitaxel 80 mg/m2 (three patients remained at this dose and seven patients reduced to rebastinib 50 mg BID) and 19 patients were treated at a starting dose of rebastinib 50 mg BID + weekly paclitaxel 80 mg/m2. Preliminary efficacy results are from 24 of the 29 patients that met the modified intent-to-treat (mITT) criteria.

Preliminary results from Part 2 included:

Of the 24 patients in the mITT population, there were nine partial responses (3 confirmed, 3 to be confirmed at future follow-up, and 3 unable to be confirmed) and 12 patients with stable disease, for an objective response rate of 38% and a clinical benefit rate, defined as the proportion of patients with best overall response of complete response, partial response, or stable disease per RECIST v1.1, of 88% at eight weeks.
Median treatment duration for the mITT population was 4.2 months.
A CA-125 response, as defined by the Gynecological Cancer Intergroup CA-125 criteria, occurred in 10 of 17 (59%) evaluable patients.
Treatment with rebastinib 50 mg BID in combination with paclitaxel was generally well-tolerated, with treatment-emergent adverse events (TEAEs) consistent with findings from Part 1 of the study and consistent with the first-in-human study of rebastinib, or known to be associated with treatment with paclitaxel.
TEAEs occurring in ≥25% of patients regardless of causality were fatigue (41%), dry mouth (38%), nausea (34%), diarrhea (31%), stomatitis (31%), abdominal pain (28%), and peripheral sensory neuropathy (28%). Eleven patients (38%) had a TEAE of Grade ≥3.
Two patients experienced serious adverse events at least possibly related to rebastinib: muscular weakness/fatigue (starting dose rebastinib 100 mg BID and resolved with drug interruption) and urinary tract infection (starting dose rebastinib 50 mg BID).
Enrollment in Stage 2 of the platinum-resistant ovarian cancer cohort at the rebastinib 50 mg BID dose is near completion and further efficacy and safety evaluation is ongoing.

Phase 1b/2 Study of Rebastinib and Carboplatin in Patients with Metastatic Solid Tumors

The ongoing Phase 1b/2 study of rebastinib in combination with carboplatin is a two-part, open-label, multicenter study assessing the safety, tolerability, anti-tumor activity, and pharmacokinetics in patients with advanced or metastatic solid tumors. Data presented at the ESMO (Free ESMO Whitepaper) Virtual Congress 2020 are from 22 patients with advanced or metastatic solid tumors enrolled into Part 1 of the study. Patients were enrolled into one of three dose escalation cohorts of rebastinib in combination with carboplatin administered once every three weeks (Q3W): rebastinib 50 mg BID + carboplatin area under the plasma concentration-time curve (AUC) 5 (n=3), rebastinib 100 mg BID + carboplatin AUC5 (n=14), rebastinib 100 mg BID + carboplatin AUC6 (n=5).

Preliminary results from Part 1 included:

Rebastinib in combination with carboplatin was generally well-tolerated. The majority of TEAEs were Grade 1 and Grade 2. One patient (rebastinib 50 mg BID) experienced a rebastinib-possibly related serious adverse event (Grade 2 retinal vascular disorder).
Based on a higher observed frequency of reversible muscular weakness (Grade 1–2) in preliminary data from the ongoing Part 2 portion of the study phase at rebastinib 100 mg BID, the recommended Phase 2 dose was changed to rebastinib 50 mg BID + carboplatin AUC5 Q3W.
The clinical benefit rate, defined as the proportion of patients with best overall response of complete response, partial response, or stable disease per RECIST v1.1, was 50% at six weeks and 36% at twelve weeks, and the median duration of treatment was 7.8 weeks.
One patient (4.5%) had a partial response (unconfirmed) and 10 patients (46%) had stable disease as best response in this heterogeneous, heavily-treated population where all patients received at least two or more prior anti-cancer regimens and 50% received four or more prior regimens.
At the rebastinib 50 mg BID dose level, the exposure of rebastinib was generally comparable to previously published data.
Mean circulating Ang-2 levels increased after eight days of treatment for all doses, indicating TIE2 inhibition.
The Part 2 portion of the ongoing Phase 1/2 study is currently enrolling and will evaluate the safety and efficacy of rebastinib at the recommended Phase 2 dose in combination with carboplatin in patients with triple-negative breast cancer, recurrent platinum-sensitive ovarian cancer, and mesothelioma.

About Rebastinib

Rebastinib is an investigational, orally administered, potent and selective inhibitor of the TIE2 kinase, the receptor for angiopoietins, an important family of vascular growth factors in the tumor microenvironment that also activate pro-tumoral TIE2 expressing macrophages. In a Phase 1 clinical study, biomarker data have demonstrated rebastinib-induced increases in the TIE2 ligand angiopoietin 2, providing evidence of TIE2 inhibition. Rebastinib is currently being evaluated in a Phase 1b/2 clinical study in combination with paclitaxel (NCT03601897) and in a Phase 1b/2 clinical study in combination with carboplatin (NCT03717415).

On September 17, 2020 Hutchison China MediTech Limited ("Chi-Med") (Nasdaq/AIM: HCM) reported that its New Drug Application ("NDA") for surufatinib for the treatment of patients with advanced pancreatic neuroendocrine tumors ("NET") has been accepted for review by the China National Medical Products Administration ("NMPA") (Press release, Hutchison China MediTech, SEP 17, 2020, https://www.chi-med.com/chi-med-announces-second-nda-acceptance-in-china-for-surufatinib-in-pancreatic-net/ [SID1234565277]).

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The NDA is supported by data from the successful SANET-p study, a Phase III pivotal study of surufatinib in advanced neuroendocrine tumors – pancreatic patients in China for whom there is no effective therapy. The study was terminated early following positive interim analysis completed in January 2020. The positive results of the study demonstrating improvement in progression free survival ("PFS") will be presented at the 2020 European Society for Medical Oncology Congress ("ESMO") (Abstract Number 1156O). This is the second NDA acceptance for surufatinib. The first NDA for non-pancreatic NET was accepted by the NMPA in November 2019 and was granted priority review status in December 2019.

Chi-Med currently retains all worldwide rights to surufatinib. This drug candidate is under investigation in multiple solid tumors in China and the U.S., both as a monotherapy and in combination with immunotherapies.

In the U.S., the Food and Drug Administration ("FDA") granted Fast Track Designation status to surufatinib for both the non-pancreatic NET and pancreatic NET development programs in April 2020. Chi-Med has initiated preparatory work for the U.S. NDA and intends to utilize a rolling submission, which is expected to start in late 2020. In addition, the Marketing Authorization Application ("MAA") submission in Europe is planned for 2021.

About NET
NETs form in cells that interact with the nervous system or in glands that produce hormones. They can originate in various parts of the body, most often in the gut or the lungs and can be benign or malignant. NET are typically classified as pancreatic NET or non-pancreatic NET. Approved targeted therapies include Sutent and Afinitor for pancreatic NET, or well-differentiated, non-functional gastrointestinal or lung NET.

According to Frost and Sullivan, there were 19,000 newly diagnosed cases of NET in the U.S. in 2018. Importantly, NETs are associated with a relatively long duration of survival compared to other tumors. As a result, there were approximately 141,000 estimated patients living with NET in the U.S. in 2018.

In China, there were approximately 67,600 newly diagnosed NET patients in 2018 and, considering the current incidence to prevalence ratio in China, potentially as many as 300,000 patients living with the disease in the country.

About Surufatinib
Surufatinib is a novel, oral angio-immuno kinase inhibitor that selectively inhibits the tyrosine kinase activity associated with vascular endothelial growth factor receptor (VEGFR) and fibroblast growth factor receptor (FGFR), which both inhibit angiogenesis, and colony stimulating factor-1 receptor (CSF-1R), which regulates tumor-associated macrophages, promoting the body’s immune response against tumor cells. Its unique dual mechanism of action may be very suitable for possible combinations with other immunotherapies, where there may be synergistic anti-tumor effects.

Chi-Med currently retains all rights to surufatinib worldwide.

About Surufatinib Development
NET in the U.S. and Europe: In the U.S., surufatinib was granted Fast Track Designations for development in pancreatic and non-pancreatic (extra-pancreatic) NET in April 2020, and Orphan Drug Designation for pancreatic NET in November 2019. A U.S. FDA NDA submission is being prepared, to be followed by a MAA submission to the EMA in Europe. The basis to support these filings includes the completed SANET-ep and SANET-p studies, along with existing data from surufatinib in U.S. non-pancreatic and pancreatic NET patients (clinicaltrials.gov identifier: NCT02549937).

Non-pancreatic NET in China: In November 2019, a NDA for surufatinib for the treatment of patients with advanced non-pancreatic NET was accepted for review by the NMPA and granted Priority Review status in December 2019. The NDA is supported by data from the successful SANET-ep study, a Phase III study of surufatinib in patients with advanced non-pancreatic NET in China for whom there is no effective therapy. A 198-patient interim analysis was conducted in June 2019, leading the Independent Data Monitoring Committee ("IDMC") to determine that the study met the pre-defined primary endpoint of progression-free survival ("PFS") and should be stopped early. The positive results of this trial were highlighted in an oral presentation at ESMO (Free ESMO Whitepaper) 2019 (clinicaltrials.gov identifier: NCT02588170).

Pancreatic NET in China: In 2016, we initiated the SANET-p study, which is a pivotal Phase III study in patients with low- or intermediate-grade, advanced pancreatic NET in China. Following an interim analysis review conducted in January 2020 by the IDMC that recommended the registrational study be terminated early as the pre-defined primary endpoint of PFS had already been met (clinicaltrials.gov identifier: NCT02589821), leading to a second NDA accepted by the China NMPA. The results of this study will be presented at ESMO (Free ESMO Whitepaper) 2020.

Biliary tract cancer in China: In March 2019, we initiated a Phase IIb/III study comparing surufatinib with capecitabine in patients with advanced biliary tract cancer whose disease progressed on first-line chemotherapy. The primary endpoint is overall survival (OS) (clinicaltrials.gov identifier NCT03873532).

Immunotherapy combinations: We have entered into collaboration agreements to evaluate the safety, tolerability and efficacy of surufatinib in combination with anti-PD-1 monoclonal antibodies, including with tislelizumab (BGB-A317, developed by BeiGene, Ltd.), Tuoyi (toripalimab, developed by Shanghai Junshi Biosciences Co., Ltd.) and Tyvyt (sintilimab, developed by Innovent Biologics, Inc.), which are approved in China.

On September 17, 2020 Checkpoint Therapeutics, Inc. ("Checkpoint") (NASDAQ: CKPT), a clinical-stage immunotherapy and targeted oncology company, reported updated interim results from the ongoing global, open-label, multicohort, Phase 1 clinical trial of its anti-PD-L1 antibody, cosibelimab, in patients with advanced cancers, including the registration-enabling cohort of patients with metastatic cutaneous squamous cell carcinoma ("mCSCC") (Press release, Checkpoint Therapeutics, SEP 17, 2020, View Source [SID1234565276]). Cosibelimab demonstrated a 51.4% objective response rate ("ORR") and 13.5% complete response rate, which is nearly double the complete response rate observed at the time of previous analysis. This trial, upon successfully meeting the pre-defined endpoints, is intended to support marketing approval application submissions for cosibelimab worldwide. The interim results were presented in an e-poster at the European Society for Medical Oncology ("ESMO") Virtual Congress 2020.

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"These exciting new interim results demonstrate the potential best-in-class efficacy and safety profile of cosibelimab. Importantly, the observed ORR and complete response rate in approximately half of the planned pivotal cohort of patients continue to trend higher than the response rates that supported the regulatory approvals of the two currently available anti-PD-1s in mCSCC, which we believe is attributable to cosibelimab’s two-fold mechanism of action of engaging both T-cells and natural killers cells to augment its efficacy. These interim results also continue to demonstrate the potential favorable safety profile of cosibelimab versus available anti-PD-1 therapies, with lower observed rates of severe adverse events," said James F. Oliviero, President and Chief Executive Officer of Checkpoint.

"With U.S. patients paying up to 20% of the cost of a drug as coinsurance, many insured patients are responsible for out-of-pocket costs of up to $2,000 per infusion for anti-PD-1 therapy," continued Mr. Oliviero. "Upon approval of cosibelimab, our planned market-disruptive pricing strategy should substantially lower these burdensome out-of-pocket costs, while also enabling more patients to have access to a potentially life-saving immunotherapy cancer treatment that they might not otherwise be able to afford."

"The interim data presented at ESMO (Free ESMO Whitepaper) is highly encouraging and further confirms the safety and efficacy results seen previously in mCSCC patients treated with cosibelimab," said Professor Philip Clingan, Medical Oncologist at Southern Medical Day Care Centre in Australia and co-principal investigator of the trial. "Cosibelimab’s well-tolerated safety profile and early achievement of complete responses seen to date have provided a real benefit to our patients. We look forward to the full cohort results next year and advancing this important treatment option forward."

Summary of Data Presented at ESMO (Free ESMO Whitepaper):

The mCSCC cohort of the ongoing trial is evaluating cosibelimab in patients with cutaneous squamous cell carcinoma with nodal and/or distant metastatic disease, with a target enrollment of approximately 75 patients and a primary endpoint of ORR as assessed by independent central review using Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Patients receive cosibelimab administered as a fixed dose of 800 mg every two weeks or 1200 mg every three weeks until confirmed and worsening disease progression or clinical deterioration, followed by post-treatment follow-up.

As of the interim analysis, 37 mCSCC patients were enrolled and evaluable for efficacy by investigator assessment with at least one post-baseline tumor assessment or discontinued treatment prior. Key efficacy results were as follows:

•51.4% ORR (95% CI: 34.4, 68.1) per RECIST 1.1.

-13.5% of patients achieved a complete response (all confirmed) and 37.8% of patients achieved a partial response (2 pending confirmation at the next scan).

•Median duration of response has not yet been reached, with 84.2% of responses ongoing, with the longest response duration at 24 months (ongoing) at the time of analysis.

•Responses were durable, with 91.7% of eligible responses having a duration of over 6 months.

Tumor response assessments by investigator assessment are summarized in the table below.

Tumor Response by RECIST 1.1 mCSCC (n=37)
Best overall response, n (%)
Complete response 5 (13.5)
Partial response1 14 (37.8)
Stable disease 4 (10.8)
Progressive disease 10 (27.0)
Not evaluated/done2 4 (10.8)
Objective response rate, % (95% CI) 51.4 (34.4, 68.1)
Response ongoing, n (%) 16 (84.2)
Median duration of response, months (min, max) Not reached (0.3, 24.0)
Patients with duration of response ≥ 6 months, n (%)3 11 (91.7)
Median observed time to response, months (range) 1.8 (1.6, 7.7)
Objective response rate = best overall response of complete response or partial response divided by the number of evaluable patients. 1Two partial responses pending confirmation at next scan. 2Represents patients who discontinued study without a post-baseline tumor assessment. 3Proportion excludes 7 patients with ongoing response duration <6 months at time of data analysis.

At the time of analysis, 114 patients with advanced cancers had been treated with cosibelimab and were evaluable for safety. Cosibelimab appeared to be safe and well-tolerated with a potentially favorable safety profile as compared to currently available anti-PD-1 therapies. The most common treatment-related adverse events ("TRAEs") included fatigue (n=17, 14.9%) and rash (n=16, 14.0%), with only 3 patients (2.6%) discontinuing treatment due to a TRAE. Grade ≥3 TRAEs occurred in only 6 patients (5.3%), most commonly anemia and fatigue (each n=2, 1.8%, grade 3 only).

The trial continues to enroll patients, and full top-line results are expected in mid-2021.

A copy of the e-poster presentation is available on the Publications page of the Pipeline section of Checkpoint’s website, www.checkpointtx.com.

Additional information on the meeting can be found on the ESMO (Free ESMO Whitepaper) website, www.esmo.org.

About Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma ("CSCC") is the second most common human cancer in the United States, with an estimated annual incidence of 700,000 cases. While most cases are localized tumors amenable to curative resection, approximately 8% of patients will experience a local recurrence, 5% of patients will develop nodal metastases, and an estimated 2% of patients will die from their disease. Ten-year survival rates are less than 20% for patients with regional lymph-node involvement. For those patients who develop distant metastases, the median survival time is estimated to be less than two years. In addition to being a life-threatening disease, CSCC causes significant functional morbidities and cosmetic deformities based on tumors commonly arising in the head and neck region and invading blood vessels, nerves and vital organs such as the eye or ear.

About Cosibelimab

Cosibelimab (formerly referred to as CK-301) is a potential best-in-class, high affinity, fully-human monoclonal antibody of IgG1 subtype that directly binds to programmed death ligand-1 (PD-L1) and blocks the PD-L1 interaction with the programmed death receptor-1 (PD-1) and B7.1 receptors. Cosibelimab’s primary mechanism of action is based on the inhibition of the interaction between PD-L1 and its receptors PD-1 and B7.1, which removes the suppressive effects of PD-L1 on anti-tumor CD8+ T-cells to restore the cytotoxic T cell response. Cosibelimab is potentially differentiated from the currently marketed PD-1 and PD-L1 antibodies through sustained >99% target tumor occupancy to reactivate an antitumor immune response and the additional benefit of a functional Fc domain capable of inducing antibody-dependent cell-mediated cytotoxicity ("ADCC") for potential enhanced efficacy in certain tumor types.

On September 17, 2020 Mersana Therapeutics, Inc. (NASDAQ:MRSN), a clinical-stage biopharmaceutical company focused on discovering and developing a pipeline of antibody-drug conjugates (ADCs) targeting cancers in areas of high unmet medical need, reported updated interim safety, tolerability and efficacy data for the ovarian cancer cohort of the ongoing expansion portion of the Phase 1 study evaluating XMT-1536, its first-in-class ADC candidate targeting NaPi2b, as part of the 2020 European Society of Medical Oncology (ESMO) (Free ESMO Whitepaper) Virtual Congress (Press release, Mersana Therapeutics, SEP 17, 2020, View Source [SID1234565275]). The Company will host a conference call and webcast today at 8:00 a.m. ET, during which investigator Erika Hamilton, MD, Director of the Breast Cancer and Gynecologic Cancer Research Program from the Sarah Cannon Research Institute at Tennessee Oncology, and members of the Mersana executive team will present and discuss these data.

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"These data further support the continued development of XMT-1536, our first-in-class Dolaflexin ADC targeting NaPi2b, which has recently been granted FDA Fast Track Designation. We are eager to advance XMT-1536 into registration-enabling studies based on its observed antitumor activity and favorable safety profile in an ovarian cancer population with a very poor prognosis and limited treatment options," said Anna Protopapas, President and Chief Executive Officer of Mersana Therapeutics. "Additionally, we look forward to presenting more comprehensive and mature results from the ongoing expansion cohort around the end of this year."

This interim analysis focused on the ovarian cancer cohort of the Phase 1 expansion study, including heavily pre-treated patients with platinum-resistant or refractory ovarian cancer, fallopian tube or primary peritoneal cancer who have received up to three lines of prior therapy, and in some cases four lines of prior therapy regardless of platinum status. With a data cutoff of August 18, 2020 these data include 47 patients. These data include additional follow up on the 27 ovarian cancer patients previously presented at the American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) virtual program in May of 2020 as well as 20 new patients who entered the study between May 1, 2020 and August 18, 2020.

Key findings include:

Safety profile consistent with previously reported expansion data and no new safety signals observed
oThe most frequently reported treatment-related adverse events (TRAEs) were generally Grade 1-2 fatigue, nausea, decreased appetite, vomiting and transient AST elevation without associated changes in bilirubin or cases of Hy’s law.
oThere were no reported cases of severe neutropenia, peripheral neuropathy or ocular toxicity.

•Continued, significant anti-tumor activity in platinum-resistant and platinum-refractory ovarian cancer and in ovarian cancer previously treated with bevacizumab, PARP inhibitors, or both
oOf the 29 patients that were evaluable for response, 2/29 (7%) achieved confirmed complete responses (CRs) and 8/29 (28%) achieved confirmed partial responses (PRs) for an objective response rate (ORR) of 34%. Additionally, 13/29 (45%) patients achieved stable disease (SD); the disease control rate (DCR) was 23/29 (79%).
•70% of responses were observed within two cycles and 100% of responses were observed within four cycles. Responses appeared to deepen over time, including responses in patients receiving reduced dose levels.
•The majority of responders had prior treatment with bevacizumab, PARP inhibitors, or both. Both patients with confirmed CRs had prior treatment with bevacizumab and PARP inhibitors.
•Reduction in tumor volume was observed in the majority of patients achieving a best response of stable disease.

•Data continue to support a NaPi2b biomarker-based patient selection strategy based on depth, time on study and quality of response
o50% of patients with higher NaPi2b expression are ongoing in the study while only 33% of patients with lower Napi2b expression are ongoing in study. Median duration of response was not yet reached in the 7 patients with ovarian cancer with higher NaPi2b expression.
oThe Company expects to define the patient selection strategy based on the total data set from patients treated with XMT-1536.
Conference Call Details
Mersana Therapeutics will host a conference call and webcast today at 8:00 a.m. ET to discuss these data. To access the call, please dial 877-303-9226 (domestic) or 409-981-0870 (international) and provide the Conference ID 5731456. A live webcast of the presentation will be available on the Investors & Media section of the Mersana website at www.mersana.com.

On September 17, 2020 Exact Sciences Corp. (Nasdaq: EXAS) reported that company management will participate in the following event and invited investors to participate by webcast (Press release, Exact Sciences, SEP 17, 2020, View Source [SID1234565274]).

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Cowen Liquid Biopsy Summit
Presentation on Thursday, September 24, 2020, at 10:30 a.m. EDT
The webcast can be accessed in the investor relations section of Exact Sciences’ website at www.exactsciences.com.