Are Companies Scrapping COVID Therapies for Monkeypox?

Over the weekend, the World Health Organization declared the monkeypox outbreak, so far documented in more than 70 countries, a “public health emergency of international concern [PHEIC].”

Here are the initiatives some biopharma companies are taking to contain monkeypox.

Tonix Moves from COVID-19 to Monkeypox

One of the companies leading the charge against monkeypox is New Jersey-based Tonix Pharmaceuticals, which owns TNX-801, one of the leading vaccine candidates for the prevention of monkeypox.

Tonix saw its shares rise by as much as 25% on Monday, following the WHO’s PHEIC declaration, and is up some 45% as of Tuesday morning.

Based on synthesized horsepox, TNX-801 is a live virus vaccine that potentially causes fewer toxic side effects than other vaccinia-based shots for monkeypox. Molecular analysis also points to additional viral genes in TNX-801 that could help boost immune protection against monkeypox.

In June, at the fourth symposium of the Canadian Society for Virology, Tonix touted TNX-801’s promising performance. All eight animal models inoculated with the vaccine candidate were fully protected against an intra-tracheal monkeypox challenge. TNX-801 shots were also well tolerated in animal studies. One week prior, the United States Patent and Trademark Office approved the company’s patent application covering the vaccine candidate.

Aside from TNX-801, Tonix has also leveraged its horsepox virus-based vaccine platform against the COVID-19 pandemic. This approach has yielded two candidates for the company, TNX-1840 and TNX-1850, which were designed to induce immune protection against the Omicron variant and its BA.2 subvariant, respectively. Also under Tonix’s belt is TNX-3500 (sangivamycin), an antiviral agent against COVID-19, which the company licensed from OyaGen in April 2021.

Demand Soars for SIGA’s Smallpox Drug

Another beneficiary of the WHO’s PHEIC announcement is SIGA Technologies, whose shares jumped as much as 27% Monday.

The reason for the industry’s avid interest in the New York-based, commercial-stage company is TPOXX (tecovirimat), SIGA’s small molecule drug against smallpox infection. Meant to be taken orally, TPOXX disrupts the maturation of the variola virus, the agent responsible for smallpox. TPOXX is the first FDA-approved drug for smallpox.

Though specifically indicated for smallpox in adults and children who weigh at least 13 kg, TPOXX’s mechanism of action can also interrupt the viral cycle of other poxviruses such as monkeypox. Last month, SIGA announced that it had received around $13 million in procurement orders for TPOXX. Of this sum, $11 million were from two overseas markets that were buying the drug for the first time as part of their countries’ responses to the monkeypox outbreak.

Earlier in July, the United Kingdom approved TPOXX for the treatment of monkeypox. The US FDA has yet to give the drug its regulatory nod for monkeypox.

TEMBEXA Delivers for Chimerix, Emergent BioSolutions

Joining Tonix and SIGA are Chimerix and Emergent BioSolutions, which entered into an acquisition agreement in May over TEMBEXA (brincidofovir), an FDA-approved antiviral agent against smallpox.

Under the terms of the deal, Chimerix is handing over TEMBEXA for $225 million upfront and up to $100 million in milestone payments. The Durham, NC-based company remains eligible for a 20% royalty on gross sales in the U.S. and a 15% royalty on profit overseas.

Since the acquisition was announced, TEMBEXA has raked in money for Chimerix. In June, a third party outside of North America placed a $9.3 million order for the drug. The following day, the Public Health Agency of Canada awarded the company a $25.3-million contract to procure TEMBEXA. Chimerix expects to fulfill both orders as these are set to complete before the closing date of its deal with Emergent.

Monkeypox’s PHEIC designation bumped Chimerix’s shares by as much as 24%, and Emergent’s by as much as 7.4%.