About Us

Manuel Aivado, president and CEO of Stelexis, is an experienced biotechnology executive with more than 20 years of scientific, medical and business leadership.

Before Stelexis, Manuel served as president and CEO of Aileron Therapeutics (now known as Rein Therapeutics). Previously he held positions as chief medical officer of Aileron Therapeutics, vice president of clinical development and pharmacovigilance at Taiho Oncology, Inc and senior medical director in clinical development at GlaxoSmithKline, Inc. Manuel has also served as instructor in medicine at Beth Israel Deaconess Medical Center/Harvard Medical School. Prior to his industry experience, Manuel practiced clinical medicine in Germany for nearly 10 years. During that time, he was awarded the Dr. Mildred Scheel cancer research scholarship award in 2002.

Manuel is a board director at Rein Therapeutics and Iterion Therapeutics and chairman of the board of directors at Dimericon Therapeutics. He is also a member of the Investment Advisory Committee for the Venture Investors Healthcare Fund.

Manuel is a German board-certified physician for internal medicine, hematology and medical oncology. He holds an M.D. and Ph.D. from the Medical School of the University of Dusseldorf in Germany.

Rossitza Alargova has more than 20 years of experience in pharmaceutical development, including deep expertise in advancing novel therapeutics from discovery through commercialization, with a focus on oncology and rare diseases. At Stelexis, she leads all CMC-related activities across the company’s pipeline.

Before joining Stelexis, Rossitza held leadership roles at Infinity Pharmaceuticals, advancing from director to vice president, head of pharmaceutical development and assuming full departmental leadership in 2017. Early in her tenure at Infinity, she led the formulations team through Phase 3 drug product development and NDA preparation for duvelisib (Copiktra®), which was later approved by the FDA for hematological malignancies. Earlier, she was head of formulation development at Blend Therapeutics, where she established in-house drug delivery capabilities and led IND-enabling activities for the company’s first clinical candidates. Prior to that, she worked at Vertex Pharmaceuticals, where, as drug development lead, she contributed to multiple discovery and development projects, including the early development of two cystic fibrosis drugs Lumacaftor and Tezacaftor, which became part of the FDA-approved combination treatments Orkambi® and Symdeko®.

Before starting her industrial career, Rossitza was a research scientist at Japan Agency for Marine-Earth Science and Technology, Japan and completed a year of postdoctoral research at the department of biomolecular and chemical engineering at North Carolina State University.

Rossitza holds a Ph.D. in physical chemistry and an M.S. in environmental science from Sofia University, Bulgaria, as well as an M.S. in chemical engineering from University “’Prof. Dr. Assen Zlatarov,” Bulgaria.

Eric Feldman has more than three decades of immuno-oncology drug development experience in industry and academia, during which he developed a broad spectrum of antibody-based therapeutics, including novel T-cell bispecific engagers for hematological malignancies and solid tumors. Eric has led several clinical trials resulting in FDA approval.

In addition to being the chief medical officer of Stelexis, he is currently also director of the early phase clinical trial program at the Montefiore Einstein Cancer Center.

Prior to Stelexis, Eric was chief medical officer of Ichnos Sciences Inc., a biotechnology company developing biologic treatments in oncology and autoimmune diseases. Previously, he was chief medical officer at GlycoMimetics, where he led the Phase 3 registrational study of uproleselan in acute myeloid leukemia, as well as other early-stage assets. He also served as chief medical officer at Amphivena, focusing on bispecific antibody therapies for blood cancers, and directed the myeloid leukemia antibody-drug conjugate (ADC) program at Seattle Genetics, Inc.

Eric’s extensive academic career includes a recent position as professor of medicine and director of the hematological malignancies service at Weill-Cornell/New York Presbyterian Hospital, as well as faculty positions at New York Medical College and the University of Texas, MD Anderson Cancer Center. He has authored over 150 scientific articles and is a former editor-in-chief of the journal Leukemia Research.

Eric holds an M.D. from New York Medical College and a B.A. from Tulane University.

Alan List brings to Stelexis an extensive track record in hematology and oncology drug development. Previously, he served as chief medical officer of Precision BioSciences, a clinical-stage oncology and gene editing-focused biotechnology company.

Prior to joining Precision BioSciences, Alan served as CEO of the Moffitt Cancer Center and physician/scientist in the Malignant Hematology Department, focused on translational studies in myelodysplastic syndromes (MDS) and other myeloid malignancies. Before joining the Moffitt Cancer Center in 2003, he served as associate center director for translational science at the Arizona Cancer Center.

Alan is internationally recognized for his many contributions in the development of more effective treatments for MDS and acute myeloid leukemia (AML). His work led to the development of lenalidomide (Revlimid®), which went on to receive FDA-approval for the treatment of patients with deletion 5q MDS. His laboratory identified a previously unrecognized form of programmed cell death termed pyroptosis directed by activation of the NLRP3 inflammasome, which underlies the pathobiology of MDS.

Alan holds an M.D. from the University of Pennsylvania College of Medicine, followed by a residency in internal medicine at the Good Samaritan Medical Center, and fellowships in both medical oncology and in hematology at Vanderbilt University Medical Center.

Darrell Nix has more than 30 years of drug development experience spanning multiple clinical indications, including oncology, CNS, inflammation, cardiovascular, pain management, metabolic disease, rare complement disorders and supportive care.

Previously, Darrell was vice president and global head of early drug development at Certara. Before that, he was the president and founder of a drug development consulting firm, DDC, acting vice president of development for Aquilus Pharmaceuticals and chief scientific officer of Recardio Inc. Earlier in his career, Darrell was the senior director of development of Gloucester Pharmaceuticals, which culminated in the successful global registration of ISTODAX® prior to being acquired by Celgene. Darrell led drug development at  Alantos Pharmaceuticals and was part of the M&A team that led to the company’s acquisition by Amgen in 2007. Prior to Alantos, Darrell was senior director, preclinical development and clinical pharmacology at Millennium Pharmaceuticals, where he supported the development and commercialization of the first in class boronic acid proteasome inhibitor VELCADE®, as well as CAMPATH® and INTEGRILIN®.

Darrell was a distinguished member of the U.S. Army’s Medical Corp, assigned to the U.S. FDA in the division of clinical pharmacology at the USUHS in Bethesda, where he served for 8 years as reviewer and worked with biopharmaceutical companies on many drug products.

Darrell holds a B.S. in analytical chemistry and completed his graduate studies in clinical pharmacology at the Uniformed Services University of the Health Sciences (F. Edward Hebert School of Medicine) in Bethesda, MD.

Marie Payton has more than 30 years of drug development experience. At Stelexis, Marie is responsible for setting the strategic direction for clinical development operations and ensuring execution of the company’s clinical programs.

Before joining Stelexis, Marie was an independent clinical development consultant where she collaborated closely with the Stelexis team. Previously, she was vice president, clinical operations at LogicBio, which was acquired by Alexion, AstraZeneca Rare Disease. Before that, she held various positions in clinical development operations at companies such as Aileron Therapeutics, Millennium Pharmaceuticals and Serono.

Marie holds a B.S. in physics from the University of Massachusetts, Amherst and an MBA from Babson College.

Rachael Perry has nearly 20 years of financial, operational and leadership experience. At Stelexis, she plays a key role in driving strategic financial planning and operational excellence.

Prior to joining Stelexis, Rachael held senior finance roles at FORME and Aileron Therapeutics (now Rein Therapeutics), where she was responsible for financial strategy, planning, accounting, reporting and operational management. She has supported multiple corporate transactions, including Aileron’s merger with Lung Therapeutics in 2023. Earlier in her career, Rachael held finance leadership roles across several public and private companies. She began her career in assurance at PwC in Boston.

Rachael holds a B.S. in accounting from Assumption College and an M.Ed. from the University of Massachusetts. She has been a Certified Public Accountant in Massachusetts for more than 15 years.