Expanded Access Program of Graspa for Treatment of Patients with Acute Lymphoblastic Leukemia Unable to Receive Other Form of L-Asparaginase - a Status Update (NCT02197650) (2015)

Abstract Background L-asparaginase (L-ASP) is a key drug in the treatment of acute lymphoblastic leukemia (ALL). However the toxicity profile, especially hypersensitivities up to acute allergic reactions is a major drawback. GRASPA (eryaspase (proposed INN) or E-Coli L-Asparaginase encapsulated into red blood cells) is a new product under development with the aim of improving the tolerance of this enzyme. Asparagine is actively transported through the membrane of red blood cells (RBC) where it is hydrolyzed by the encapsulated L-ASP, the erythrocytes acting as "bioreactors". The RBC membrane shields against the anti-L-ASP antibody then avoiding binding to encapsulated L-ASP. Recently, a Phase III pivotal study of GRASPA in combination with COOPRALL chemotherapy protocols in patients with relapsed ALL demonstrated highly significant safety profile and clinical activity compared to control. However, there is an unmet medical need for patients who cannot receive current formulations of L-ASP. An expanded access program has recently been initiated in France to provide access for treatment with GRASPA in patients who are unable to receive other forms of L-ASP. Methods: This is a non randomized multicenter open label study, currently initiated in France. The primary objective of the EAP is to evaluate the tolerability of GRASPA. Patients under 55y of age presenting with de novo, relapsed or refractory ALL who are at risk to receive any other available L-ASP formulation are enrolled into this program. Patients with known allergic reactions to E.Coli L-ASP are also eligible. GRASPA is administrated every 2 to 3 weeks at a dose equivalent to 150 IU/kg of L-ASP during all chemotherapy courses intended to contain an asparaginase. Chemotherapy protocols are given according to the Investigator's choice. Patients are assessed regularly for safety and tolerability. The primary endpoint is tolerability; Key secondary endpoints include asparaginase activity, asparagine depletion, and clinical remission rates. An independent Safety Monitoring Board (DSMB) is set up, which will assess toxicities on yearly basis. Results As of time of June 2015, 13 patients were enrolled into the program. The first DSMB meeting reviewed the outcome of the first 7 patients enrolled into the program. Of the 7 pts (range 3 - 49 years), 5 males and 2 females were enrolled. Four pts presented with refractory disease and 3 with relapse, with all patients had evidence of allergies to 2 prior asparaginases (double allergies). There were 2 pts presenting with limiting toxicities, in the form of myelosupression, and streptococcal infection. There was no modification to the protocol recommended by the first DSMB An updated safety and clinical activity information on all patients will be provided. Conclusion: The EAP provides a potential treatment alternative for ALL patients, who are unable, or at risk of developing hypersensitivity reactions to prior asparaginases. The initial results from this program suggests that GRASPA is well tolerated, and may have a potential benefit in patients with double allergies. The program will be expanded to other European countries Disclosures Bertrand: ERYTECH Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees. Dombret:Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Recher:Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Chugai: Research Funding; Amgen: Research Funding; Sunesis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Salako:ERYTECH Pharma: Employment. Godfrin:ERYTECH Pharma: Employment. El Hariry:ERYTECH Pharma: Employment.