Bio Patrika interviews Dr. Joshi on her thoughts about “Orthogonal tools for analytical biosimilarity assessment of biotherapeutics”

Dr. Srishti Joshi’s interview with Bio Patrika hosting “Vigyan Patrika”, a series of author interviews. Dr. Joshi completed her PhD in Molecular Biology and Biochemistry from Massey University, NZ in 2015. After a brief Post Doc experience at the Systems Biology lab at Korea University, she joined DBT-COE-CBT (IIT-Delhi) in 2017 an Institute Post Doctoral Fellow in the lab of Prof. Anurag Rathore at the Centre of Excellence, Biopharmaceutical Technology (DBT-COE-CBT), Indian Institute of Technology, Delhi. She has been learning and exploring the domain of Analytics in Biotherapeutics, since. She published papers titled “An application of Nano Differential Scanning Fluorimetry for Higher Order Structure assessment between mAb originator and biosimilars: Trastuzumab and Rituximab as case studies” and “Monitoring size and oligomeric-state distribution of therapeutic mAbs by NMR and DLS: Trastuzumab as a case study” as first author in Journal of Pharmaceutical and Biomedical Analysis (2020).

How would you explain your papers’ key results to the non-scientific community?

With commercial utilization of rDNA technology and progress in biomanufacturing, the pharmaceutical paradigm has extended to include protein-based medication. These molecules can easily be about 100 to 1000 times larger than small molecule pharmaceuticals. Size is a critical quality attribute for biotherapeutics as the presence of size heterogeneity in the form of aggregates is usually linked with increased immunogenic response. Even when present as a minor impurity, aggregates can vary in their size range and often require multiple complementary or orthogonal tools for detection and characterization. Our recent paper “Monitoring size and oligomeric-state distribution of therapeutic mAbs by NMR and DLS: Trastuzumab as a case study” (Figure 1) published in “Journal of Pharmaceutical and Biomedical Analysis” explores the use of Nuclear Magnetic Resonance as a tool for monitoring size-based heterogeneities and compares it with the more traditional chromatography and light scattering based techniques. We demonstrate the orthogonality of NMR to conventional methods and discuss the utility and limitation of NMR based size monitoring for with respect to biosimilarity assessment of copy biologics (aka biosimilars). When we talk about critical quality attributes, stability of a product is also an important attribute to consider. One of the indicators of stability is the melting temperature of a protein therapeutic which tells us about the structural sensitivity of the protein with respect to change in temperature. In another study we (Dr. Chinmoyee Maharana in shared 1st authorship) published recently “An application of Nano Differential Scanning Fluorimetry for Higher Order Structure assessment between mAb originator and biosimilars: Trastuzumab and Rituximab as case studies” (Figure 1), also published in JPBA, we establish the utility of NanoDSF as a tool for rapid assessment of mAb stability, especially with respect to biosimilar development and comparability assessment. Orthogonality of NanoDSF to conventionally used Circular Dichroism has also been shown in this study.

Figure 1. Graphic representation of analytical comparability assessment workflow for biosimilar products. For attributes relating to Higher Order Structure such as size (size impurities can vary significantly in size) and melting temperature, orthogonal tools are often used. Our studies show the utilization of NMR as an orthogonal tool to DLS and NanoDSF as an orthogonal tool to CD for size and transition temperature estimation of monoclonal antibody based biologics, respectively.

What are the possible consequences of these findings for your research area?

Both NMR and NanoDSF are a relatively new addition to the analytical tool box in the biotherapeutics domain. Therefore careful assessment of its utility and defining the periphery of its application with respect to quality attribute assessment is important. Our study adds to the developing knowledge data bank that is currently growing for NMR and NanoDSF application in biotherapeutics. For biosimilar manufacturers and regulators, these studies serves as an example of biosimilarity assessment for size estimation using NMR and stability assessment using NanoDSF

“[…] these studies serves as an example of biosimilarity assessment for size estimation using NMR and stability assessment using NanoDSF.”

What was the exciting moment (eureka moment) during your research?

Although results from both the studies were rewarding, the NMR study was relatively more challenging. Assessment of large molecules >35 kDa has always been a challenge in NMR. Moreover, doing so at natural abundance (without isotopic labelling of the molecule) presents further challenges of its own. For us, to execute our methodology despite the above-mentioned challenges made this whole study a “Eureka” study. Looking at our first well-resolved mAb-NMR spectra shared by my co-author and collaborator Mr. Lakshya Khatri was definitely an exciting moment.

What do you hope to do next?

Analytical characterization on biotherapeutics is a relatively large domain applying multiple analytical tools covered under its ambit. I have had the privilege of access to and exploring the application of these sophisticated techniques for characterization of critical quality attributes at the DBT-Centre for Excellence, Biotherapeutic Technology. I hope to continue this exploration and am currently looking forward to learning and playing with 2-dimensional liquid chromatography systems to understand their place in biotherapeutic characterization. With respect to NMR, we have also been exploring the application of 2D-NMR for biosimilarity assessment of monoclonal antibody based biosimilars (Prof. Anurag Rathore-IITD and Prof. Ashutosh Kumar- IITB as PI) with Mr. Lakshya Khatri (IIT-B) and I am looking forward to successfully publishing the same.

Where do you seek scientific inspiration?

I have been lucky to have exemplary mentors throughout my life that have inspired me to continually better myself. I draw my scientific inspiration from my PhD guide, Late Prof. Michael McManus who played a big role in my scientific upbringing and always encouraged me to question, think and continually push my boundaries of understanding. I often revisit his teaching to align my thought process whenever circumstances get overwhelming. In the last 4 years, I have been under the tutelage of Prof. Anurag Rathore and he has been instrumental in shaping my thought process in alignment with the requirements of the biopharmaceutical field. He has also taught me that although learning for the sake of learning allows one to better self, focussing on application of one’s learning has the potential for greater good of the mankind.

How do you intend to help Indian science improve?

I consider myself very young in the field and still in the learning phase. However, efficient public communication of research along with teaching has always been of personal interest to me. My efforts are always driven towards motivating people within my environment to adopt a learner’s mind and a scientific temperament. In due course, I hope this contributes towards improvement of “Science in India”.

Reference

Srishti Joshi, Chinmoyee Maharana and Anurag S. Rathore. An application of Nano Differential Scanning Fluorimetry for Higher Order Structure assessment between mAb originator and biosimilars: Trastuzumab and Rituximab as case studies (2020). Journal of Pharmaceutical and Biomedical Analysis; 186, 113270.

Srishti Joshi, Lakshya Raj Khatri, Ashutosh Kumar and Anurag S. Rathore. Monitoring size and oligomeric-state distribution of therapeutic mAbs by NMR and DLS: Trastuzumab as a case study (2020). Journal of Pharmaceutical and Biomedical Analysis; 113841.

Email: srishtijoshi@gmail.com

Rear more about Prof. Anurag Rathore lab: http://biotechcmz.com/

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