Rallybio's Mission of Developing Transformative Medicines Heads Into the Clinic

Rallybio CEO Martin Mackay/Courtesy of Rallybio

Since Rallybio launched in 2018, the Connecticut-based company has been laser-focused on the development of "transformative therapeutics" for patients suffering from rare and ultra-rare diseases. 

The leadership team, formed from former executives of Alexion Pharmaceuticals, all have experience working with the development of innovative therapeutics for rare diseases. With an extensive background in the field, the leadership team, which includes Martin Mackay, Stephen Uden and Jeffrey Fryer, is entering 2022 with a steady sense of purpose around the mission of delivering those transformative therapeutics.

"There are more medicines that we have left in us that can make a difference to society and humanity," Mackay, the company's chief executive officer, told BioSpace on the eve of the company's presentation at the J.P. Morgan Healthcare Conference.

And that desire to develop new medications for these diseases not only led to the formation of the company but also to the name, Rallybio. Uden, the company's chief operating officer, kept telling his colleagues that they must "rally the troops" around the need to develop these new therapies, which led to the company's naming. 

Since its launch four years ago, the company has quickly secured significant funding, including a $145 million Series B financing round in 2020. That was followed by a $92.7 million initial public offering last year. 

In addition to its financing, which has provided the company with enough capital to finance its operations through the end of 2023, Rallybio also forged a joint venture with U.K.-based Exscientia, an artificial intelligence-driven drug discovery company, in order to accelerate the discovery and development of small molecule drug therapeutics for rare diseases. That partnership is primarily focused on the development of candidates targeting ENPP1 for the treatment of hypophosphatasia. 

Now, Rallybio is hoping to see proof of concept this year in its investigational treatment for the prevention of fetal and neonatal alloimmune thrombocytopenia (FNAIT). The disease is a potentially life-threatening rare condition that can cause uncontrolled bleeding in fetuses and newborns. Rallybio's lead program is RLYB212, a novel human monoclonal anti-HPA-1a antibody.

The company is enrolling patients in a Phase I study of RLYB212. The study is designed to assess the safety and pharmacokinetics of single and repeat subcutaneous doses of RLYB212 in HPA-1a negative healthy volunteers. Additionally, Rallybio intends to initiate a Phase Ib proof-of-concept study within the second quarter of this year. That study is designed to demonstrate RLYB212's ability to eliminate transfused HPA-1a positive platelets from the circulation of HPA-1a negative healthy male volunteers. Potential data could be generated by the end of the third quarter of this year. There is currently no approved therapy for the prevention or treatment of FNAIT.

In addition to its FNAIT program, Rallybio is pushing forward with the development of RLYB116, a novel, potentially long-acting, subcutaneously administered inhibitor of complement factor 5, or C5  for treatment of patients with paroxysmal nocturnal hemoglobinuria (PNH) and generalized Myasthenia Gravis (gMG). The company plans to assess RLYB116 in a first-in-human Phase I study. The study, expected to begin in the first quarter of 2022, will examine single-dose safety, pharmacokinetics and pharmacodynamic data. Data from this Phase 1 study are expected in the second half of 2022.

Beyond the company's current assets, Rallybio is actively scouring the globe for potential assets that can be studied for the treatment of rare diseases. Mackay said the company has key business development partners in Europe and Asia continuously monitoring ongoing research conducted in academic institutions. The company has already had success gaining access to little-known assets through this method. In its early days, Rallybio licensed RLYB211, another FNAIT-aimed dug candidate from Norway's Prophylix AS. RLYB211 is a plasma-derived hyperimmune globulin. 

"We had to go to the Arctic Circle to find that one," quipped Mackay, who previously served as global head of research and development at Alexion. Prophylix AS is located in Tromsø, a city in northern Norway. "We have to be open-minded to look anywhere and everywhere. The FNAIT program came from someplace that no one was working. We realized we could apply their experience and development expertise to transform patients' lives. We look forward to further expanding our portfolio with new assets and partners that have the potential to deliver dramatically improved outcomes for patients."

Part of this plan includes leveraging the power of artificial intelligence to help them sift through the data in order to find something that's the right fit for the company's goals. 

When selecting an asset, Mackay said the company asks itself several questions, including how devastating the disease can be to patients and their families, if the biology of the disease is understood and if they believe they can make a transformative difference. 

"We have a romantic notion of the science, of discovering medicines and taking them the whole way through from development to regulatory approval. We want to build a sustainable company. We're not looking for a short-term gain or to spin out assets," Mackay said.