Pfizer Inc. (NYSE:PFE) announced  that the Phase 3 Rivipansel (GMI-1070): Evaluating Safety, Efficacy and Time to Discharge (RESET) pivotal study did not meet its primary or key secondary efficacy endpoints. The objective of the trial was to evaluate the efficacy and safety of rivipansel in patients aged six and older with sickle cell disease (SCD) who were hospitalized for a vaso-occlusive crisis (VOC) and required treatment with intravenous (IV) opioids. The primary endpoint was time to readiness-for-discharge and the key secondary efficacy endpoints were time-to-discharge, cumulative IV opioid consumption, and time to discontinuation of IV opioids.

“We are disappointed with the results, as we have been working in close partnership with the SCD community to advance rivipansel as a potential treatment option for acute VOC. We plan to share the study data at an upcoming scientific meeting as we want to ensure the learnings from this trial help inform future sickle cell programs that aim to improve care for SCD patients experiencing a VOC,” said Brenda Cooperstone, M.D., Senior Vice President and Chief Development Officer, Rare Disease, Pfizer Global Product Development. “We express our sincere gratitude to everyone who made this study possible, including the study investigators, and in particular, the patients and their families.”

SCD is a debilitating blood disorder, characterized by acute pain crises or VOC. Treatment options for patients seeking medical care for a VOC are currently limited to symptomatic management with analgesics (including opioids and NSAIDs) and hydration, underscoring a significant need for new treatment options.

“We recognize this is a significant setback for the SCD community, who are eagerly awaiting new treatment options, and we share in their disappointment,” said Freda Lewis-Hall, M.D., DFAPA, Chief Patient Officer and Executive Vice President, Pfizer Inc. “Many of us have witnessed first-hand the devastating impact of SCD on patients and their families, but we have also been moved by their incredible strength and bravery, and we will continue to support this courageous community.”

Detailed analyses of the RESET study, including additional data on efficacy and safety endpoints, which are not available at this time, will be submitted for presentation at a future scientific meeting.


RESET (B5201002) was a Phase 3, multicenter, randomized, double-blind, placebo-controlled, parallel-group study that evaluated the efficacy and safety of rivipansel in patients with SCD aged six and older, who were hospitalized for a VOC and required treatment with intravenous opioids. The primary endpoint of the study was time-to-readiness for discharge, defined as the difference between the start time and date of the first infusion of study drug and the time and date of medical staff-assessed readiness-for-discharge.

The RESET trial included 345 patients who were randomized1:1 to receive rivipansel or placebo, administered intravenously every 12 hours to a maximum of 15 doses. All study participants were followed for safety for 35 days after their last dose of study drug.

Eligible patients who completed the RESET trial were able to enter an open-label extension study (B5201003) and receive rivipansel for subsequent VOC episodes over an 18-month period. For additional information about the study, please visit

For additional information about RESET, please visit

Rivipansel is an investigational treatment for VOC in people with SCD and not approved for use. In 2011, GlycoMimetics and Pfizer Inc. entered into a worldwide license agreement for the development and, if approved by applicable regulatory authorities, commercialization of rivipansel. Since completion of the Phase 2 clinical trial, Pfizer has been responsible for clinical development of rivipansel, including the RESET clinical trial.

About Sickle Cell Disease and Vaso-occlusive Crisis

SCD is the most common inherited blood disorder in the United States, impacting approximately 100,000 people.1 Worldwide, approximately 100 million people carry the SCD trait and an estimated five million live with the disease.1 While the majority of people with SCD are of African descent, the disease can affect all ethnic groups, especially those from areas where malaria is or was endemic, such as Africa, the Middle East, India and the Southern Mediterranean.

Acute pain crises or VOC are the most common clinical manifestation of SCD. A VOC occurs when sickled red blood cells irritate the lining of blood vessels and cause an inflammatory response leading to vascular occlusion, tissue ischemia and pain.

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