Clinical Trials


Pain threatened to take away these memories.

They’re gardening together for another spring.

That is what drives us. Experience, Rho.


Passionate about our pursuit to help each person live a pain-free life, analgesia is not only a focus for Rho, it’s a center of excellence. With nearly 50,000 patients treated in over 250 studies and 2,900 sites, our expertise navigating the unique challenges associated with analgesia drug development is not only helpful, it’s crucial. Because of our strong site relationships, reputation for meeting or even exceeding program timelines, expertise implementing decentralized clinical trial solutions, and insider’s understanding of the FDA’s Division of Anesthesiology, Addiction Medicine, and Pain Medicine (DAAP), and analgesia clinical trial patient dropouts, Rho is the analgesia and pain partner to help your analgesia clinical research program reach its goals.

Global Reach

Our global client solutions will ensure you reach your patients, wherever they are. With international capabilities that span 5 continents, we provide full-service capabilities to execute your clinical development programs and trials across the globe.

Rho has been an exceedingly and consistently reliable partner in our three pain centric clinical trials in OA, and a true extension of our team at UNITY.

Associate Director, Clinical Operations, UNITY Biotechnology

On a mission to bring relief to the millions in pain, we look forward to setting your program up for success with our cross-functional collaborative approach. We proudly invite you to experience Rho.


Our Expertise


clinical trials


clinical sites



Indications Expertise

  • Acute
  • Associated Conditions
    • Opioid-induced Constipation
    • Opioid Abuse and Misuse
    • Respiratory Depression
  • Chronic
    • Cancer Pain
    • Musculoskeletal Pain (including Chronic Lower Back Pain)
    • Neuropathic Pain
    • Osteoarthritis Pain
  • Outcomes
    • Brief Pain Inventory (BPI)
    • Clinical Opiate Withdrawal Scale (COWS) and Subjective Opiate Withdrawal Scale (SOWS)
    • Likert Scale Outcomes
    • Numeric Pain Rating Scale (NPRS/NRS)
    • Patient Global Impression of Change (PGIC) day
    • Rescue Medications
    • Responder Analyses
    • Roland-Morris Disability Questionnaire (RMDQ)
    • Sum Pain Intensity Difference (SPID)
    • Visual Analog Scales (VAS)
    • Western Ontario and McMaster Osteoarthritis Index (WOMAC)

Overcoming the Challenges of Analgesia Trials

Analgesia and pain management clinical trials come with inherent and unique challenges. Subjects drop out of trials for reasons including insufficient relief or pain management, treatment side effects, use of rescue medication, and the burden of multiple study assessments and visits. Recent studies in chronic and short-term pain report drop-out rates ranging from 5-40%. Missing data resulting from these subject drop-outs can make it difficult to interpret the trial results and can greatly impact the overall drug development process.

Rho has extensive expertise in the pain management therapeutic area and addressing these challenges during clinical trials from Phase II through Marketing Applications. Here are a few ways we can help you:

Trial Design

Successful outcomes start with a strong trial design. For years, Rho’s experts have designed analgesia-related trials that minimize drop-outs, increase study execution efficiency, and lead to robust data analyses. Our experts will help you:

  • Strategize and identify appropriate endpoints.
  • Advise on when to measure and how to summarize the data. Simplifying assessments and visit frequency will reduce the number of drop-outs.
  • Explore alternative trial designs. Rho is experienced with a variety of designs beyond standard parallel arm protocols; these include flexible dosing/titration to effect, enriched enrollment randomized withdrawal (EERW), cross-over trials, and add-on safety extensions.

Rho provides the capability to harmonize your pain program from Phase II through Marketing Applications. By partnering with Rho you enable the ability to re-use clinical trial plans, create more efficient data collection, generate faster site start-up, require less study team training, maximize potential timeline and budget efficiencies, as well as benefit from lessons learned carried across protocols.

Trial Strategy

Rho’s project teams are well-versed in the successful execution of analgesia clinical trials. We emphasize strategies that facilitate recruitment and maximize retention. Our cross-collaborative team will help you:

  • Identify and select high-enrolling and quality-driven clinical sites with proven track records.
  • Create and implement strategies to increase retention rates by limiting subject burden.
  • Implement robust Investigator and clinical site staff training to ensure understanding and reiterate the importance of subject retention and complete data.
  • Monitor data collection with Marketing Applications in mind – providing the ability to identify potential retention issues early, mitigate data loss, and increase budget and timeline efficiencies.


The Rho team of experts have years of experience providing analyses to the FDA’s Division of Anesthesiology, Addiction Medicine, and Pain Medicine (DAAP). We understand today’s regulatory landscape as well as FDA preferences and expectations related to analgesia data and analyses.

  • Our statisticians are drug development experts who know what the FDA expects when it comes to clinical trial analysis. With expertise preparing for and attending FDA regulatory meetings we are uniquely qualified to guide our sponsors successfully through regulatory requirements.
  • Our experts can help you navigate suggested guidelines on missing data as outlined in the recently FDA-endorsed guidance on missing data from the National Academy of Sciences (NAS), The Prevention and Treatment of Missing Data in Clinical Trials.
  • Rho is familiar with the most up-to-date analysis methods for missing data in analgesia-related trials, including:
    • Multiple Imputation
    • Pattern Mixture Models
    • Jump to Control Imputation
    • Retrieved drop-outs
    • Various sensitivity analyses, including last observation carried forward (LOCF), baseline observation carried forward (BOCF), LOCF/BOCF hybrids, mixed-effect model repeated measures (MMRM), delta adjustment, and others.

Learn how our experts mitigated COVID-19 related risks for a complex pain program, while exceeding aggressive timelines and maintaining trial integrity.  

Read Case Study

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