What: Shares of Immunomedics (NASDAQ:IMMU), a small-cap antibody-based therapeutics company developing treatments for cancer and autoimmune diseases, briefly rose by as much as 21% today on heavy volume. The stock's rapid rise was triggered by a positive clinical update for the company's lead antibody-drug conjugate (ADC), sacituzumab govitecan, in a midstage study for relapsed or refractory metastatic lung cancer. 

Per the press release, an interim analysis based on 57 patients, that included 28 non-small-cell lung cancer (NSCLC) and 29 small-cell lung cancer (SCLC) patients, suggested that the drug was exhibiting a noteworthy therapeutic signal in a heavily pre-treated group of patients.

Digging into the details, Immunomedics said that about a third of both NSCLC and SCLC patients receiving doses less than or equal to 12 mg/kg exhibited objective responses. The small groups of NSCLC and SCLC patients receiving the 10 mg/kg dose were also showing an interesting trend in terms of median progression-free (PFS) survival as well. The company plans on adding more patients to this dosage cohort going forward to further assess PFS and overall survival. 

So what: Immunomedics' shares took a beating earlier this year after its licensing partner UCB announced that epratuzumab failed to meet its primary endpoint in a late-stage study for lupus. This failure put the onus squarely on 90Y-Clivatuzumab tetraxetan, as a potential treatment for pancreatic cancer, to create value to shareholders in the near-term. With sacituzumab govitecan now showing some compelling midstage results in the metastatic lung cancer arena, Immunomedics' pipeline once again has a couple of interesting clinical candidates that could drive shares higher in the short to intermediate future.

Now what: Immunomedics is plotting a broad development program for sacituzumab govitecan across a host of indications such as NSCLC and SCLC, as well as triple-negative breast, esophageal, urothelial, and colorectal cancers, according to the company. Unfortunately, the drugmaker exited the second quarter of 2015 with only $99.6 million in cash, cash equivalents, and marketable securities, meaning that a major expansion in its clinical activities will probably require a sizable secondary offering. As such, you may want to stick to the sidelines with this speculative biotech until its long-term financing needs are secure.