Principal/Sr. Principal Biologist - Mobility and Aging

At Lilly, the work is demanding because patients are waiting. We unite caring with discovery to help make life better for people around the world, knowing that every decision, every detail, and every day matters. Headquartered in Indianapolis, Indiana, our over 50,000 employees around the globe take on complex challenges to discover and deliver life-changing medicines, strengthen how health is understood and managed, and support the communities we serve. This is hard, urgent, selfless work—but it’s work worth doing. If you’re driven by purpose and ready to bring your best to work that truly matters for patients, we invite you to join us. Principal/Sr. Principal Biologist, Mobility and Healthy Aging Location: Indianapolis, IN About Lilly At Lilly, we unite caring with discovery to make life better for people worldwide. As a global healthcare leader headquartered in Indianapolis, Indiana, we are committed to advancing innovation in areas of high unmet medical need. With a growing focus on mobility and healthy aging, we are building a portfolio of transformative therapies to improve outcomes for patients everywhere and help arrest age-related functional decline of musculoskeletal health across the population. Position Summary The Principal/Sr. Principal Biologist will be a key member of Lilly’s Mobility and Healthy Aging discovery team, conducting and leading in vivo studies that evaluate novel targets and therapeutic candidates in preclinical models of age-related musculoskeletal decline, with a primary emphasis on bone. The successful candidate will generate rigorous, decision-enabling data on bone density, strength, and microarchitecture to support target validation and program advancement, and will perform in vitro studies in bone cell systems to build mechanistic understanding and help complement in vivo efforts. This role also offers the opportunity to help expand the team’s preclinical capabilities into muscle function and joint health. Key Responsibilities In Vivo Studies

• Design, execute, and analyze in vivo studies in rodent models relevant to mobility and healthy aging (e.g., ovariectomy-induced bone loss, aged animals, and other models of age-related or disuse-associated skeletal decline) to evaluate novel targets and candidate therapeutics
• Apply rigorous experimental design, including appropriate controls, power analysis and group sizing, randomization, and blinding, to ensure reproducible, decision-quality data
• Perform in-life procedures, including dosing by multiple routes, blood and tissue collection, and terminal harvest
• Prepare, submit, and maintain IACUC protocols and amendments, including scientific justification for models and animal numbers, description of procedures, anesthesia and analgesia plans, and humane endpoints
• Serve as a scientific point of contact for the IACUC, veterinary staff, and animal facility personnel
• Collaborate with colleagues in PK/PD, pharmacology, and translational science to support dose selection, study design, and interpretation of exposure–response relationships

Bone Imaging and Biomechanics

• Acquire and analyze microCT data to quantify trabecular (e.g., BV/TV, trabecular number, thickness, and separation) and cortical (e.g., cortical thickness, area, and porosity) bone parameters at relevant skeletal sites
• Perform biomechanical testing (e.g., three-point bending of long bones, vertebral compression) and derive structural properties such as ultimate load, stiffness, and energy to failure to assess bone strength
• Contribute to histological and histomorphometric analyses of bone remodeling, including dynamic (fluorochrome-labeling) and static measures of bone formation and resorption, as needed

In Vitro and Mechanistic Studies

• Conduct cell-based assays in relevant bone cell systems to support target validation and mechanism of action, including osteoblast differentiation and mineralization (e.g., primary osteoblasts or bone marrow stromal cells; alkaline phosphatase activity and Alizarin Red staining)
• Assess osteoclast formation and function (e.g., bone marrow–derived macrophage or RAW 264.7 cultures; TRAP staining and resorption pit assays) and evaluate osteocyte-like cell models and co-culture systems to study osteocyte-derived signals and cell–cell crosstalk
• Evaluate target engagement and pathway modulation (e.g., Wnt/β-catenin and RANKL/OPG signaling) using qPCR, ELISAs, reporter assays, and other standard molecular and biochemical methods
• Measure circulating bone turnover biomarkers (e.g., P1NP, CTX-I, osteocalcin) to connect in vitro mechanism with in vivo pharmacodynamic response
• Develop, optimize, and qualify new assays with appropriate controls, documentation, and reproducibility

Data and Scientific Communication

• Maintain accurate records, analyze and interpret data, and present results to the team and cross-functional partners
• Contribute to the development of new methods, models, and capabilities that strengthen the Mobility and Healthy Aging discovery platform
• Support collaborations with CROs and academic partners as needed

Basic Qualifications

• Bachelor’s degree in biology, physiology, or a related field, with a minimum of 3 years of relevant laboratory experience AND/OR Masters degree biology, physiology, or a related field,
• Qualified applicants must be authorized to work in the United States on a full-time basis. Lilly will not provide support for or sponsor work authorization or visas for this role, including but not limited to F-1 CPT, F-1 OPT, F-1 STEM OPT,J-1, H-1B, TN, O-1, E-3, H-1B1, or L-1.
• PhD level is overqualified for this position

Additional Preferences

• Experience in drug discovery or pharmaceutical/biotech research
• Master’s degree in same areas with 3 years of relevant lab experience
• Foundational laboratory skills, including aseptic technique, cell culture, qPCR, and ELISAs
• Minimum 2 years experience in bone biology
• Experience with in vivo rodent models, animal handling, dosing, necropsy, and husbandry
• Experience with preclinical models of osteoporosis, bone loss, and aging
• Experience preparing IACUC protocols and amendments and working directly with IACUC and veterinary staff
• Experience with microCT-based preclinical imaging and analysis
• Experience with bone biomechanical testing systems
• Experience with in vitro bone cell systems, including osteoblast, osteoclast, and osteocyte assays
• Familiarity with bone histology or histomorphometry
• Experience assessing muscle function in preclinical models
• Familiarity with preclinical models of age-related muscle loss and weakness, with measures of muscle mass and body composition
• Experience with preclinical models of joint disease and degeneration
• Familiarity with functional assessments of mobility and joint health in rodents
• Strong organizational, communication, and collaboration skills, with the ability to work independently and as part of a cross-functional team
• Passion for advancing innovative therapies that address unmet needs in mobility and healthy aging

Lilly is dedicated to helping individuals with disabilities to actively engage in the workforce, ensuring equal opportunities when vying for positions. If you require accommodation to submit a resume for a position at Lilly, please complete the accommodation request form ( for further assistance. Please note this is for individuals to request an accommodation as part of the application process and any other correspondence will not receive a response. Lilly is proud to be an EEO Employer and does not discriminate on the basis of age, race, color, religion, gender identity, sex, gender expression, sexual orientation, genetic information, ancestry, national origin, protected veteran status, disability, or any other legally protected status. Our employee resource groups (ERGs) offer strong support networks for their members and are open to all employees. Our current groups include: Africa, Middle East, Central Asia (AMECA), Black Employees at Lilly (View email address on joinrs.com), Chinese Culture Network (CCN), EnAble, Evolve, Lilly Indian Network (LIN), Organization of Latinx at Lilly (OLA), Pride (LGBTQ+ Allies), Veterans Leadership Network (VLN) and Women’s Initiative for Leading at Lilly (WILL). Actual compensation will depend on a candidate’s education, experience, skills, and geographic location. The anticipated wage for this position is $66,000 - $171,600 Full-time equivalent employees also will be eligible for a company bonus (depending, in part, on company and individual performance). In addition, Lilly offers a comprehensive benefit program to eligible employees, including eligibility to participate in a company-sponsored 401(k); pension; vacation benefits; eligibility for medical, dental, vision and prescription drug benefits; flexible benefits (e.g., healthcare and/or dependent day care flexible spending accounts); life insurance and death benefits; certain time off and leave of absence benefits; and well-being benefits (e.g., employee assistance program, fitness benefits, and employee clubs and activities).Lilly reserves the right to amend, modify, or terminate its compensation and benefit programs in its sole discretion and Lilly’s compensation practices and guidelines will apply regarding the details of any promotion or transfer of Lilly employees. #WeAreLilly