(Yicai Global) March 18 -- Five Chinese companies, including Huahai Pharmaceutical and Fosun Pharmaceutical Group, have been authorized to produce one of the main ingredients of Pfizer's oral Covid-19 drug.

The Medicines Patent Pool has signed agreements with 35 drugmakers around the world, including Shanghai-headquartered Desano Pharmaceuticals and Dongyang-based Apeloa Pharmaceutical, to manufacture a generic version of nirmatrelvir, one of the active pharmaceutical ingredients in Pfizer's Paxlovid, the United Nations-backed public health organization said in a statement yesterday. Meanwhile, Jiuzhou Pharmaceutical is only allowed to imitate the raw materials.

However, the Chinese firms still have work to do before being able to sell the first orally delivered antiviral medicine recommended in the European Union for treating Covid-19. The reason is that Paxlovid contains both nirmatrelvir and ritonavir. The latter is harder to produce.

It is very difficult to examine ritonavir to produce a similar drug as the bioequivalence study takes about four years, said Wu Jinzi, chairman of Ascletis Pharma, which has obtained the permit to make a generic version of ritonavir for the Chinese market.

The expected boost in demand prompted a stock price hike for Ascletis Pharma. The company's Hong Kong-listed shares [HKG: 1672] jumped as much as 31.4 percent to HKD6.15 (80 US cents) intraday.

But the potential nirmatrelvir manufacturers also have other hurdles, such as registrations and facility certification, before rolling out a commercial product on the home turf and abroad.

Still, Shanghai-based Fosun may have an advantage over its rivals. The drug giant has more than 15 years of experience in emerging markets, including some of those of Africa, and it has built a mature sales network, Yicai Global learned.

The news failed to spur major enthusiasm among the five firms' investors. Fosun's Shanghai-listed shares [SHA: 600196] climbed 2.6 percent in value by noon. But those of Huahai, Apeloa, and Jiuzhou slid from 3 to 4 percent.

Editor: Tang Shihua, Emmi Laine, Xiao Yi