262P - Pragmatic clinical trial assessing response to neoadjuvant taxotere and trastuzumab in Nigerian women with HER2-positive breast cancer (ARETTA): First report from the Nigerian breast cancer study group

Background

There is unacceptably low level of oncology clinical trials in Nigeria, the country with the highest burden of breast cancer in Africa. This has been attributed to poor research infrastructure and trained personnel. This study was designed to assess the feasibility of establishing a robust platform for multi-institutional biomarker driven oncology clinical trials to improve quality of cancer care in Nigeria.

Methods

One-stage phase II single arm design in women with HER2-positive breast cancer with clinical stages IIA to IIIC ( AJCC 2009 ). All patients received 4 cycles of docetaxel + Herceptin SC. Breast ultrasound (USS) was done at diagnosis and after every 2 cycles of neoadjuvant phase. Those with complete clinical response by USS after 4 cycles had surgery. Those with partial response or stable disease (operable) switched to FEC for additional 3 cycles before surgery. All responders received 18 cycles of Herceptin SC. Adjuvant treatment included hormonal therapy as indicated. Radiation therapy was administered as per institutional practice.

Results

Study was initiated in April 2020 at onset of the pandemic and completed accrual in August 2022. Forty-seven of 53 enrolled patients (pts) were evaluable; 4 pts withdrew consent and 2 refused surgery. The median age was 50yrs (range 25-71 yrs.); Fifty-five percent were premenopausal. Majority were clinical stage III (60%), 58% ER- and 60% PR-. Twenty-five of 47 (53.2%) evaluable pts had pathological complete response (pCR) [including 6 pts (12.8%) after 4 cycles of docetaxel + Herceptin SC]. Treatment was well tolerated with Grade 3 toxicities of myelosuppression 6 (12.8%), diarrhea 1 (2.1%) and hepatic toxicity 2 (4.2%). The maximum reductions in LVEF were 20% and 26% in 2 pts respectively but without cardiac symptoms.

Conclusions

The study met its primary endpoint with pCR rate of 53% and manageable toxicity. To our knowledge, this is the first investigator initiated multi-institutional biomarker driven oncology clinical trial ever conducted in sub-Sahara Africa, paving the way for future pragmatic patient-centric biomarker informed clinical trials in populations of African Ancestry.

Clinical trial identification

NCT03879577.

Editorial acknowledgement

Legal entity responsible for the study

Funmi Olopade, University of Chicago, Chicago, IL, USA.

Funding

University of Chicago.

Disclosure

All authors have declared no conflicts of interest.