BridgeBio Bags First FDA Nod with Rare Disease Drug Acquired from Alexion

BridgeBio Pharma and its affiliate Origin Biosciences grabbed its first FDA approval on March 1st for Nulibry, thereby becoming the first drug to treat Molybdenum Cofactor Deficiency (MoCD) Type-A, an ultra-rare, life-threatening disease.

“Today’s approval represents a new hope for patients and families affected with MoCD Type A,” said Donald Basel, M.D., Section Chief and Associate Professor of Pediatrics at Children’s Wisconsin. “I am encouraged by the clinical data showing that Nulibry not only lowers the levels of toxic SSC but importantly extends the lives of patients who previously had only a three- to four-year median survival.”

Nulibry (previously ALXN1101) was acquired from Alexion Pharmaceuticals and was developed at Origin Biosciences, a new subsidiary of BridgeBio. In a few years, the company turned the product around and bagged breakthrough designation and a priority review from the FDA.

With today’s approval, the company has also gained a fast pass to review its subsequent drugs. Short for rare pediatric disease, priority review voucher, PRV is a powerful incentive for the companies who are developing treatments for rare diseases. The voucher can be used to shorten review times for another experimental drug to six months from 10 months or can be sold to another company.

Rare Disease

MoCD is a rare condition that is known to affect less than 150 patients worldwide. It is characterized by a deficiency in molybdenum cofactor production owing to a mutation in the molybdenum cofactor synthesis 1 gene (MOCS1). This renders the cofactor dependent enzyme ineffective, leading to the accumulation of sulfite and secondary metabolites in the brain and eventually irreversible brain damage. Patients affected by the condition start showing symptoms of brain damage and seizures right after birth and survive for a median of 4 years.

Nulibry aims to treat this condition by providing an exogenous source of cPMP, which is converted to molybdopterin inside the body. This product helps in restoring the missing cofactor, which in turn gets the system running, bringing back the levels of sulfite to normal.

The FDA approval is based on data from three clinical trials that show Nulibry can reduce the risk of death by 82% compared to the untreated, genotype matched, the historical control group in natural history study. Survival probability for treated patients was 84% compared to 55% for the untreated group. All these effects were possibly the result of a reduction in concentrations of S-sulfocysteine, a toxic substance that leads to neurological damage in MoCD type A patients. While giving a striking efficacy, the drug also showed a tolerable safety profile. The most common adverse events observed were fever, viral infection, pneumonia, vomiting, ear infection, and cough/sneezing.

Boost in Investor Confidence

With a smaller population to treat, the drug is not expected to bring high profits to BridgeBio. Nevertheless, it imparts confidence in its working model that many investors had detested in the past.

BridgeBio uses a “hub and spoke” model wherein each of the pipeline programs is put into a subsidiary, and each of the subsidiaries is connected with the central resource center. Like in this case, Nulibry acquired from Alexion was put under Origin Biosciences, which used all the resources of BridgeBio. This idea allows BridgeBio to move its staff and funding between different assets as needed.

The targets that the company and its subsidiaries work on are decided through thorough research of the scientific literature. They constantly are on the lookout for Mendelian or monogenic diseases. When the company finds an interesting drug and disease for which there is a clear blueprint, it picks it up and works on it. The targets picked up so far are mostly for rare diseases.

BridgeBio is currently working on 21 different programs, including acoramidis, a treatment for transthyretin cardiomyopathy (ATTR-CM), a disease indication being actively pursued by Alnylam. It is also working on some cancer indications such as bile duct cancers and hormonal disorders such as congenital adrenal hyperplasia and autosomal dominant hypocalcemia.

The company managed to raise the biggest private biotech financings in 2019 and made its market debut with the second-largest IPO that same year. With the approval of their first drug, BridgeBio would hope to instill confidence in some of its investors.

Related Article: Game-Changing Antiretroviral Regimen from ViiV Receives FDA Approval

Author

Ruchi Jhonsa