Molecular Templates' Presentations at the 2022 ASCO Annual Meeting Demonstrate Advancement in PD-L1 and HER2 Programs


Presentations on the MT-6402 (PD-L1) and MT-5111(HER2) Phase I dose escalation programs demonstrate unique biology, continued tolerability, and dose-dependent pharmacodynamic effects

AUSTIN, Texas, June 06, 2022 (GLOBE NEWSWIRE) — Molecular Templates, Inc., (Nasdaq: MTEM, “Molecular Templates” or “MTEM”) a clinical-stage biopharmaceutical company focused on the discovery and development of proprietary targeted biologic therapeutics, engineered toxin bodies (ETBs), today announces highlights from the two poster presentations on its clinical programs that were presented on June 5th at the 2022 American Society of Clinical Oncology (ASCO) annual meeting, taking place June 3 through June 7, 2022 at the McCormick Place Convention Center in Chicago, IL. Copies of the posters presented at ASCO can be found in the “Investors” section of Molecular Templates’ corporate website under Presentations.

“ETBs offer novel biology with the potential to drive unique clinical outcomes, even against well-explored targets,” said Eric Poma, Ph.D., CEO and CSO of Molecular Templates. “We are seeing differentiated pharmacodynamic effects and signs of clinical benefit in patients in our on-going Phase I study with MT-6402, our PD-L1 targeting agent, from both that agent’s direct cell-kill effects and its antigen seeding ability. For MT-5111, our HER2-targeting agent, we have achieved exposures in dose-escalation with which have generated pharmacodynamic effects that may be associated with clinical benefit.”

Poster Title: First-in-human, dose escalation and expansion study of MT-6402, a novel engineered toxin body (ETB) targeting PD-L1, in patients with PD-L1 expressing relapsed/refractory advanced solid tumors: Interim Data

Authors: Eugene Ahn, MD; Brian Van Tine, MD; John D. Powderly, MD; Herbert L. Duvivier, MD, JD; Drew Rasco, MD; Agnes Rethy, MD; Chris Moore, PhD; Amy Yuet, PhD; Rachael M. Orlandella, PhD; Swati Khanna, PhD; Joseph D. Dekker, PhD; Angela Georgy, PharmD; David R. Spigel, MD

Abstract #: 2521

Poster highlights:

  • Data were presented on 12 patients with PD-L1+ relapsed/refractory disease across two dose cohorts: 16 mcg/kg (n=6) and 24 mcg/kg (n=6). Treatment is on-going in the 32 mcg/kg cohort with no dose-limiting toxicities (DLTs) observed to date in the third cohort.
  • Pharmacodynamic (PD) effects including PD-L1+ dendritic cell and monocyte cell depletion and T cell activation have been observed in the majority of patients. The extent and timing of these PD effects appear dose-related with patients in the 24 mcg/kg cohort generally showing a more rapid and profound PD effect. Patients in both cohorts demonstrated increases in IL-2.
  • One patient in the first cohort with non-small cell lung cancer (NSCLC) (osseous non-measurable disease only) that had progressed after prior checkpoint therapy (PD-1 and CTLA-4) showed qualitative reduction in tumor burden.
  • One DLT was observed in a single patient (24 mcg/kg) who experienced dermatitis that resolved rapidly with systemic steroids. The patient was rechallenged without incident at 24 mcg/kg. No other DLTs have been reported.
  • Based on these findings, monotherapy will continue to be investigated and a combination approach with a PD-1 inhibitor is also being considered for select populations of patients.

Poster Title: A phase 1 study of the novel immunotoxin MT-5111 in patients with HER2+ tumors: interim results

Authors: Brian A. Van Tine, MD, PhD; Joleen M. Hubbard, MD; Monica M. Mita, MD; Minal A. Barve, MD; Erika P. Hamilton, MD; Frances Valdes, MD; Daniel Ahn, DO; Joshua Pelham; Admasu Mamuye, MD; Amy Yuet, PhD; Diana Yurewicz, MPH; Yanning Liu, PhD, Taunya Smith, MPH; Andrés Machado Sandri, MD; William J. Edenfield, MD; Aki Morikawa, MD, PhD; Meena Okera, MD; Zev A. Wainberg, MD

Abstract #: 2583

Poster highlights

  • Data were presented on 35 patients with HER2+ relapsed/refractory disease across eight dose cohorts ranging from 0.5 mcg/kg to 13 mcg/kg (N=31) and the breast cancer expansion cohort (N=4): Treatment is on-going with the 17 mcg/kg cohort having been closed and dosing has begun in the 23 mcg/kg cohort.
  • No Grade 4 or 5 treatment emergent adverse events or DLTs have been identified in 35 patients, including 2 patients who were treated for 6 months or longer.
  • Serum concentration of MT-5111 showed predictable and dose-proportional increasing exposure in the last three evaluable dose cohorts.
  • Higher MT-5111 doses (6.75 mcg/kg and above) appear to saturate circulating soluble HER2 (sHER2) receptors with patients’ HER2 levels stabilizing or decreasing at higher doses.

About Molecular Templates

Molecular Templates is a clinical-stage biopharmaceutical company focused on the discovery and development of targeted biologic therapeutics. Our proprietary drug platform technology, known as engineered toxin bodies, or ETBs, leverages the resident biology of a genetically engineered form of Shiga-like Toxin A subunit to create novel therapies with potent and differentiated mechanisms of action for cancer and other serious diseases.

Forward-Looking Statements

This press release contains forward-looking statements for purposes of the Private Securities Litigation Reform Act of 1995 (the “Act”). Molecular Templates disclaims any intent or obligation to update these forward-looking statements and claims the protection of the Act’s Safe Harbor for forward-looking statements. All statements, other than statements of historical facts, included in this press release regarding strategy, future operations, future financial position, future revenue, projected expenses, prospects, plans and objectives of management are forward-looking statements. In addition, when or if used in this press release, the words “potential,” “may,” “could,” “should,” “anticipate,” “believe,” “estimate,” “expect,” “intend,” “plan,” “predict” and similar expressions and their variants, as they relate to Molecular Templates may identify forward-looking statements. Examples of such statements include, but are not limited to, statements regarding the safety or potential efficacy of Molecular Templates’ drug or biologic candidates, including MT-6402 and MT-5111, Molecular Templates’ beliefs regarding the anticipated or potential benefits of Molecular Templates’ next-generation ETBs and ETB platform, including MT-6402 and MT-5111; statements relating to the development and evaluation of MT-5111 and MT-6402; the expected timing of submitting various IND applications and conducting studies and generating data; the expected participation and presentation at upcoming conferences; the expected timing for providing updates on MT-6402 and MT-5111, including any pre-clinical data; and Molecular Templates’ belief that its ETBs offer novel biology with the potential to drive unique clinical outcomes, even against well-explored targets.

Forward-looking statements are not guarantees of future performance and involve risks and uncertainties. Actual events or results may differ materially from those discussed in the forward-looking statements as a result of various factors including, but not limited to, the uncertainties inherent in the preclinical and clinical development process; whether Molecular Templates’ cash resources will be sufficient to fund its continuing operations for the periods and/or trials anticipated; Molecular Templates’ ability to timely enroll patients in its clinical trials; the ability of Molecular Templates’ to protect its intellectual property rights; risks from global pandemics including COVID-19; and legislative, regulatory, political and economic developments, as well as those risks identified under the heading “Risk Factors” in Molecular Templates’ filings with the SEC. There can be no assurance that any of Molecular Templates’ drug or biologic candidates will be successfully developed, manufactured or commercialized, that final results of clinical trials will be supportive of regulatory approvals required to market products, or that any of the forward-looking information provided herein will be proven accurate. Any forward-looking statements contained in this press release speak only as of the date hereof, and Molecular Templates specifically disclaims any obligation to update any forward-looking statement, whether because of new information, future events or otherwise.

Sean McLennan
Interim Chief Financial Officer

Joyce Allaire
LifeSci Advisors, LLC

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