Sonnet BioTherapeutics: Oncology-Focused Biotech with Proprietary FHAB Platform

Sonnet BioTherapeutics Holdings is a clinical-stage biotechnology company with a proprietary platform for biologic medicines. Its lead program, SON-1010, is in development for solid tumors and ovarian cancer, and is being evaluated in a Phase 1/2a study. The company is also developing SON-1210, an IL12-FHAB-IL15 for solid tumors, and SON-080, a low dose of rhIL-6 for chemotherapy-induced peripheral neuropathy and diabetic peripheral neuropathy.

Sonnet BioTherapeutics Holdings, Inc. (NASDAQ: SONN) experienced a significant drop in its stock price on July 3, 2025, with a 19.04% decline in pre-market trading [1]. The company's stock has been on a downward trajectory, falling more than 60% from its 52-week high of $10.02 to around $4 [2].

The primary factors contributing to the stock drop include the announcement of a $2.0 million private placement of zero-interest convertible notes and the passing of the company's founder and CEO, Pankaj Mohan, Ph.D. [1]. The private placement, aimed at raising capital, may have raised concerns among investors about the company's financial health and future prospects. Additionally, the loss of a key leader can often lead to investor anxiety, as it raises questions about the company's strategic direction and operational stability.

Despite these challenges, Sonnet has continued to make progress in its clinical trials and research. The company recently announced positive results from a safety review of SON-1010 in combination with trabectedin for certain sarcomas, demonstrating the potential of its therapeutic candidates. Furthermore, Sonnet's proprietary antibody drug conjugate (ADC) platform remains available for drug discovery partnerships, highlighting the company's ongoing commitment to innovation.

The lead drug candidate, SON-1010, is being explored as a potential treatment for advanced solid tumors and certain types of sarcomas. In a phase I trial, SON-1010 demonstrated minimal toxicity at the highest dose and showed clinical benefit in some patients [2]. The company is also evaluating SON-1010 in combination with other drugs for various types of cancer, including ovarian cancer.

Sonnet's pipeline includes SON-1210, a proprietary bispecific version of human Interleukins 12 (IL-12) and 15 (IL-15), and SON-080, a low-dose recombinant human IL-6 (rhIL-6) for chemotherapy-induced peripheral neuropathy (CIPN) and diabetic peripheral neuropathy (DPN) [2]. These drugs are being developed using the company's Fully Human Albumin Binding (FHAB) platform.

Sonnet's cash position as of March 31, 2025, was $2.1 million, which is expected to be sufficient to fund its projected operations into July 2025. However, the company closed a private placement with certain accredited investors on June 30, 2025, issuing convertible notes totaling $2.0 million in principal value [2].

In summary, Sonnet BioTherapeutics Holdings faces a challenging period following the stock drop and the loss of its CEO. However, the company continues to make progress in its clinical trials and research, with several promising drug candidates in its pipeline.

References:
[1] https://www.ainvest.com/news/sonnet-biotherapeutics-plunges-19-04-ceo-passing-private-placement-2507/
[2] https://www.rttnews.com/3550878/can-sonnet-biotherapeutics-make-a-comeback.aspx