Immunomedics, Inc. announced new data for sacituzumab govitecan (IMMU-132) during the Companys Investor R&D Day. IMMU-132 is Immunomedics proprietary solid tumor therapy candidate that is advancing through development in four indications: metastatic triple-negative breast cancer (TNBC), the lead indication and for which the Food and Drug Administration (FDA) has awarded Breakthrough Therapy Designation; urothelial cancer (UC); small-cell lung cancer (SCLC); and non-small-cell lung cancer (NSCLC). Immunomedics expects to submit a Biological License Application (BLA) to the FDA for accelerated approval of IMMU-132 in TNBC patients in mid-2017. New IMMU-132 Results Highlight Progress Toward Potential Accelerated ApprovalMs. Sullivan reported that IMMU-132 has been studied in over 410 diverse cancer patients, with the dose of 10 mg/kg given on days 1 and 8 of repeated 21-day cycles being the established dose regimen. According to Ms. Sullivan, some patients have been treated for more than a year. Immunomedics disclosed results in 85 assessable TNBC patients. These results will be part of the BLA submission for the accelerated approval of IMMU-132. The Company announced last month that it had achieved the goal of enrolling 100 TNBC patients, as requested by FDA for this BLA filing. The Company reported that the objective response rate and median progression-free survival (PFS, intention-to-treat, or ITT, basis) have been maintained with these additional patient results, while the median overall survival (OS also on ITT basis) has been extended to almost 19 months. These patients experienced two complete and 23 partial responses, while an additional threepatients with initial partial responses are awaiting confirmation. Overall, 81% of patients treated with IMMU-132 showed tumor shrinkage from baseline measurements. The clinical benefit rate (complete and partial remissions, and patients with stable disease) at six months or later computed to 44%. The median duration of response for those with objective responses was almost 11 months. It was emphasized that these are interim results, since 20 patients are continuing treatment; a final outcome must await analysis of all patients enrolled. The major toxicity (grade >3) has been neutropenia (39%) in this and most cancer patient cohorts, which has been manageable by dose reduction, dose delays, or giving a hematopoietic cytokine. Diarrhea, which is the major side effect with irinotecan, the parent drug from which SN-38 is derived, has been much less, such as a grade >3 of 13%. Further, with encouraging preclinical results of the combination of IMMU-132 with PARP inhibitors in TNBC models, the company interested in the prospect of this combination in an earlier therapy setting for these patients, Dr. Vahdat added. In addition to TNBC, Immunomedics is making progress with IMMU-132 across the other three advanced indications. In patients with urothelial cancer, especially metastatic urinary bladder cancer, Dr. Scott T. Tagawa, Associate Professor of Medicine and Urology, Weill Cornell Medical College, and Attending Physician, New York-Presbyterian Hospital, New York, reported on 27 assessable patients from more than 40 patients enrolled. The objective response rate was 33%, including one complete and eightpartial remissions. The duration of objective response was a median of 7.5 months, with one patient with a partial response approaching 17 months. The clinical benefit rate at six months or later was 59%, but 10 patients are still under therapy. Overall, 70% of the patients showed tumor shrinkage from baseline with IMMU-132 therapy. The median PFS and OS on an ITT basis were seven and almost 16 months, respectively. The safety profile was similar to the findings in patients with TNBC. Interim results in patients with lung cancers also were presented. Dr. Ronald J. Scheff, Assistant Professor of Clinical Medicine at Weill Cornell Medical College, New York, reported on over 50 patients with metastatic NSCLC being enrolled, showing about one-fifth of evaluable patients had a partial response. Overall, 64% of patients had tumor shrinkage from baseline measurements when given IMMU-132. These patients had a median of three prior therapies. Importantly, patients with either nonsquamous or squamous pathology responded, as well as patients who failed a prior immune checkpoint inhibitor treatment. The clinical benefit rate at four months or later was 43%. The median duration of response was eight months, but two patients remain under therapy and responsive for over 20 months. Median PFS and OS on an ITT basis were five and over nine months, respectively. In patients with metastatic SCLC who had a median of two prior therapies, 16% experienced a confirmed partial response, with an additional nine patients showing tumor shrinkage >20%. Overall, 60% of patients showed tumor shrinkage from baseline. The clinical benefit rate at 4 months or later was 40%. The median duration of partial responses and stable disease was about five months (two patients extending out to 21 months), while the median PFS and OS on an ITT basis were almost four months and seven months, respectively. These results in advanced metastatic NSCLC and SCLC patients are very impressive. Durable responses were seen even in patien ts refractory to multiple prior therapeutic regimens, including immune checkpoint inhibitors, Dr. Scheff said. NSCLC is the most common cause of cancer death in the Western World, with very poor 5-year survival statistics. The demonstration of a median survival of over 9 months after patients had already progressed after a range of oneto sevenprior therapies represents a significant advance.