Merrimack
Apr 8, 2014

Merrimack Announces Preliminary Data From Pilot Diagnostic Imaging Study of MM-398

Interim Data Set Presented at AACR Demonstrates Feasibility of Using Ferumoxytol as a Tumor Imaging Agent Imaging Hypothesis Derived From Merrimack's Systems Biology Approach

CAMBRIDGE, Mass., April 8, 2014 (GLOBE NEWSWIRE) -- Merrimack Pharmaceuticals, Inc. (Nasdaq:MACK) today announced Phase 1 results from a clinical pilot study demonstrating that ferumoxytol*, an iron oxide nanoparticle, was well tolerated when used as a tumor contrast agent prior to MM-398 treatment. Data from the first cohort of patients in this study, which was completed in conjunction with the Virginia G. Piper Cancer Center and Imaging Endpoints, were presented at the American Association of Cancer Research Annual Meeting, April 5-9, 2014, in San Diego, California.

"This application of ferumoxytol magnetic resonance imaging has the potential to become a minimally invasive predictive biomarker for liposomal therapies. We hope that the continuation and expansion of this approach will allow us to identify patients most likely to benefit from MM-398 treatment," said Jonathan Fitzgerald, Ph.D., Senior Director of Discovery at Merrimack. "Though our initial data are from a small sample of a diverse patient population, we are encouraged to see that almost all of the tumor lesions that shrank after MM-398 treatment were associated with higher levels of ferumoxytol, as seen on the MRI."

Ferumoxytol's propensity for uptake by tumor associated macrophages and similar distribution patterns to MM-398 in preclinical models led to the clinical feasibility study. The ability to image and analyze the levels of ferumoxytol in tumors may be correlated to estimating the MM-398 tumor concentration.

These data are also supported by Merrimack's proprietary Systems Biology approach, as computational modeling of ferumoxytol MRI was used to calculate parameters describing its behavior in tumor tissue. This modeling platform, coupled with the imaging approach with ferumoxytol MRI, may be useful as a predictive biomarker of nanotherapeutics such as MM-398. Primary objectives of this study are to evaluate the feasibility of ferumoxytol to identify tumor-associated macrophages, which may positively correlate with MM-398 activity, and to measure tumor levels of irinotecan and SN-38. The ongoing study has shown that there were no safety-related interactions between ferumoxytol and MM-398 in this preliminary patient population.

Methodology and Results

Pilot study in patients with advanced solid tumors to evaluate feasibility of ferumoxytol (FMX) as tumor imaging agent prior to MM-398, a nanoliposomal irinotecan (nal-IRI) (Poster #CT224)

About MM-398

MM-398 is a nanoliposomal formulation of irinotecan (nal-IRI). MM-398 is being evaluated in several clinical trials including a Phase 3 study in metastatic pancreatic cancer, a Phase 2 study in patients with metastatic colorectal cancer and a Phase 1 clinical pilot study. MM-398 is not approved for any indication by the U.S. Food and Drug Administration or any other regulatory agency.  Under a 2011 agreement with PharmaEngine, Inc. (Taipei, Taiwan), Merrimack consolidated the worldwide development and commercialization rights to MM-398, with the exception of commercialization rights in Taiwan, which are held by PharmaEngine, Inc.

About Merrimack

Merrimack is a biopharmaceutical company discovering, developing and preparing to commercialize innovative medicines paired with companion diagnostics for the treatment of cancer. Merrimack applies its systems biology-based approach to biomedical research throughout the research and development process. Merrimack currently has six oncology therapeutics in clinical development. For more information, please visit Merrimack's website at www.merrimackpharma.com.

Forward-Looking Statements

To the extent that statements contained in this press release are not descriptions of historical facts, they are forward-looking statements reflecting the current beliefs and expectations of management made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements include any statements about Merrimack's strategy, future operations, future financial position and future expectations and plans and prospects for Merrimack, and any other statements containing the words "anticipate," "believe," "estimate," "expect," "intend," "may," "plan," "predict," "project," "target," "potential," "will," "would," "could," "should," "continue," "hope" and similar expressions. In this press release, Merrimack's forward-looking statements include statements about the potential effectiveness and tolerability of MM-398, the potential to develop ferumoxytol as a predictive diagnostic and the potential to identify patients most likely to benefit from MM-398. Such forward-looking statements involve substantial risks and uncertainties that could cause Merrimack's clinical development programs, future results, performance or achievements to differ significantly from those expressed or implied by the forward-looking statements. Such risks and uncertainties include, among others, availability of data from ongoing clinical trials, expectations for regulatory approvals, development progress of Merrimack's companion diagnostics and other matters that could affect the availability or commercial potential of Merrimack's drug candidates or companion diagnostics. Merrimack undertakes no obligation to update or revise any forward-looking statements. Forward-looking statements should not be relied upon as representing Merrimack's views as of any date subsequent to the date hereof. For a further description of the risks and uncertainties that could cause actual results to differ from those expressed in these forward-looking statements, as well as risks relating to Merrimack's business in general, see the "Risk Factors" section of Merrimack's Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 4, 2014 and other reports Merrimack files with the SEC.

*Ferumoxytol, commercially available as Feraheme® (AMAG Pharmaceuticals),is an iron-oxide, super-paramagnetic nanoparticle, known to be taken up by macrophages and for exhibiting magnetic resonance imaging properties. The U.S. Food and Drug Administration has approved ferumoxytol for intravenous use as an iron replacement product for the treatment of iron deficiency anemia in adult patients with chronic kidney disease (CKD). The use of ferumoxytol in the pilot study mentioned above is for clinical investigational studies only.

CONTACT: Investor Contact:

         Geoffrey Grande, CFA

         Merrimack

         617-441-7602

         ggrande@merrimackpharma.com



         Media Contacts:

         Debbie Tseng

         Merrimack

         617-441-7659

         dtseng@merrimackpharma.com



         Heather Gitlitz

         Spectrum

         202-955-6222

         hgitlitz@spectrumscience.com

Merrimack logo

Source: Merrimack Pharmaceuticals

 

 

News Provided by Acquire Media