Inhibrx takes a second shot at an IPO — this time bumping the goal to $100M-plus
La Jolla, CA-based Inhibrx couldn’t get their $75 million IPO over the goal line last year. But with the fervor for new biotech filings seemingly growing on Wall Street, they plan to see how a $100 million play will work out now.
This time around, Inhibrx touts four Phase I drugs in the pipeline developed on its single domain antibody (sdAb) platform, three of which are geared toward various cancers. The fourth drug, INBRX-101, targets Alpha-1 Antitrypsin Deficiency (AATD).
“Our sdAb platform allows us to pursue validated targets with clinical promise, but where other antibody and biologic based approaches have failed. Highly modular, our sdAbs can be combined with precise valencies and multiple specificities, creating therapeutic candidates designed to be capable of enhanced cell signaling, conditional activation or combined synergistic functions,” the latest SEC filing states.
Jefferies Group, Evercore ISI and Credit Suisse are the joint bookrunners on this year’s deal. In 2019, the biotech sold a convertible promissory note totaling $40 million to Viking Global Investors. This April, it raked in another $15 million in notes to Viking and other undisclosed investors. The notes will eventually settle into shares of the company’s common stock.
Most of the company’s revenue trickles in from grants, equity and debt financings, and license and milestone revenue, according to the filing. By June 30, the company had run through $107.2 million. As the result of a license deal the company struck with Celgene years before the Bristol Myers Squibb buyout, Inhibrx could stand to receive up to $934 million, plus royalties that range from the “high single-digits” to the “low teens.”
Currently, Inhibrx’s most advanced drug in the pipeline is INBRX-109, a tetravalent candidate. The drug agonizes DR5, which Inhibrx says led to cancer cell death in preclinical studies. The company believes INBRX-109 could trigger cell death in a variety of cancers, including colorectal adenocarcinoma, gastric adenocarcinoma, pancreatic adenocarcinoma, mesothelioma and certain sarcomas.
The first part of a Phase I trial and dose escalation conducted in 2018 and 2019 respectively showed that the drug was “well-tolerated, with no significant toxicities observed at doses up to and including the maximum administered dose of 30 mg/kg,” according to the company’s website.
The company is in the middle of Phase I Part 2, and currently has 75 patients enrolled with colorectal and gastric adenocarcinomas, malignant pleural mesothelioma, and chondrosarcoma. Initial data from the chondrosarcoma and malignant pleural mesothelioma patients should be ready by the end of the year.
Inhibrx’s second drug in the pipeline, INBRX-106, is an OX40 hexavalent agonist. The first part of a Phase I trial was conducted in December, with data to come this year.
“We believe INBRX-106, a hexavalent therapeutic candidate with the ability to bind six OX40 molecules per molecule of drug, has the potential to achieve improved receptor clustering and downstream signaling. In preclinical studies, we have observed that INBRX-106 mediated T-cell co-stimulation and also reduced the suppressive activity of regulatory T-cells, with superior activity to bivalent comparators,” the SEC filing states.
The third of Inhibrx’s oncology drugs, INBRX-105, could be used to treat those with PD-L1 expressing tumors. The drug agonizes 4-1BB, but only in the presence of PD-L1. Initial dose escalation data is coming in 2021, the company says.
INBRX-101 is a recombinant human AAT-Fc fusion protein candidate for the treatment of AATD. The Phase I dose escalation trial was put on hold due to the Covid-19 pandemic, but should testing resume, Inhibrx could announce initial data in the second half of 2021.