Despite experiencing delays and setbacks in the approval process this year, a number of South Korean biopharmaceutical companies will make another attempt to bring their new drugs to the US market in 2019.

Investors had been pinning hopes that SK Biopharmaceutical’s solriamfetol, an investigational drug to treat narcolepsy, would be approved by the US Food and Drug Administration by the year’s end. 

The US FDA was scheduled to make a decision on Dec. 20. However, the regulator recently decided to extend the review period for solriamfetol’s new drug application to March next year, citing the need for a major amendment to the NDA, according to SK’s licensing partner Jazz Pharmaceuticals. 

“We appreciate the opportunity to work with the FDA to complete the review process as soon as possible,” Jed Black, senior vice president of sleep and CNS Medicine at Jazz Pharmaceuticals, said in a statement.

Solriamfetol is an investigational drug designed to treat excessive sleepiness in adult patients with narcolepsy, a debilitating neurological disorder characterized by excessive sleepiness, or obstructive sleep apnea, characterized by pauses in breathing during sleep.

The drug compound was originally discovered by SK Biopharmaceuticals, the new drug development unit of Korea’s energy-to-telecom conglomerate SK Group.

Solriamfetol currently has orphan drug designation in the US for narcolepsy. If solriamfetol is commercialized in the US, SK Biopharmaceuticals is expected to reap substantial royalties from the drug’s sales in the US, the company said.

SK licensed out solriamfetol to Aerial Biopharma in 2011, which resold its rights on solriamfetol to Jazz Pharmaceuticals in 2014. Now, Jazz Pharmaceuticals holds the worldwide development and marketing rights for the narcolepsy drug, with the exception of 12 markets in Asia, where SK Biopharm retains its rights.

Likewise to SK, Korea’s GC Pharma also faced a setback in September, when the US FDA delayed the approval of the firm’s immunodeficiency drug IVIG-SN, demanding additional data related to the drug’s manufacturing procedures.

The company had initially expected the US FDA to grant final approval for IVIG-SN, short for human normal immunoglobulin G for intravenous administration by September this year.

It was the second time that the US drug regulator pushed back GC Pharma’s biologics license application for IVIG-SN. Now refiling for the third time, the Korean drugmaker will once again seek FDA approval for the immunodeficiency drug next year.

Exclusively developed by GC Pharma, IVIG-SN is a plasma-derived protein drug that treats primary immunodeficiency disorders that weaken or rid the immune system’s ability to fight infectious diseases.

The drug, already being sold in more than 30 countries in Asia, South America and the Middle East, is one of the Korean drugmaker’s top-selling plasma-based biologic treatments.

With IVIG-SN, GC Pharma plans to target the US immunodeficiency disease treatment market, which makes up around half of the global market for this drug segment, estimated at around $10 billion.

Meanwhile, Daewoong Pharmaceutical is on track to obtaining the US regulator’s approval of its Type A botulinum toxin drug Nabota, set to become the first BTX alternative to hit the US market.

Daewoong, along with its US partner Evolus, submitted a biologics license application for Nabota to the US FDA in May 2017, with aims to secure approval by the year’s end.

However, the drug was initially turned down by the US regulator over deficiencies related to the chemistry, manufacturing and control processes. But Evolus resubmitted its biologics license application for the drug candidate in August. The new target approval date is March 2019, as the FDA typically takes around six months to make a conclusive approval decision on a new drug submission.

Other US-bound drugs from Korean companies include Rolontis (eflapegrastim), a treatment for the management of chemotherapy-induced neutropenia, which was developed by Hanmi Pharmaceutical and in-licensed by US-based Spectrum Pharmaceuticals in 2012. Phase 3 clinical trials for the drug have been concluded as of now.

Poziotinib, a cancer therapy developed by Hanmi and in-licensed by Spectrum Pharmaceutical, recently experienced a devaluation, as it failed to obtain breakthrough therapy designation by the US FDA. But the drug’s development will continue as scheduled, according to Spectrum.

In the biosimilars field, Samsung Bioepis’ SB3 -- a biosimilar referencing Herceptin (trastuzumab) -- is also drawing closer to US market entry. Though a FDA decision was delayed this November, the approval process is expected to continue next year.

Meanwhile, the Korean biopharmaceutical industry achieved a number of major milestones before this year’s close, led by major approvals and licensing deals from Yuhan and Celltrion.

In November, Yuhan announced that it had licensed out its new clinical-stage lung cancer drug to Janssen Biotech in a deal potentially valued at up to $1.25 billion. In December, Celltrion obtained FDA approval for two additional biosimilars, each referencing Herceptin and Rituxan (rituximab).

By Sohn Ji-young (jys@heraldcorp.com)